Showing papers in "The Biological Bulletin in 1918"

Appetites and aversions as constituents of instincts.

Abstract: The overt behavior of adult animals occurs largely in rather definite chains and cycles, and it has been held that these are merely chain reflexes. Many years of study of the behavior of animals-studies especially of the blond ring-dove (Turtur risorius) and other pigeons-have convinced me that instinctive behavior does not consist of mere chain reflexes; it involves other factors which it is the purpose of this article to describe. I do not deny that innate chain reflexes constitute a considerable part of the instinctive equipment of doves. Indeed, I think it probable that some of the dove's instincts include an element which is even a tropism as described by Loeb. But with few if any exceptions among the instincts of doves, this reflex action constitufes only a part of each instinct in which it is present. E1ach instinct involves an element of appetite, or aversion, or both. An appetite (or appetence, if this term may be used with purely behavioristic meaning), so far as externally observable, is a state of agitation which continues so long as a certain stimulus, which may be called the appeted stimulus, is absent. When the appeted stimulus is at length received it stimulates a consummatory reaction, after which the appetitive behavior ceases and is succeeced by a state of relative rest. An aversion (example 7, p. Ioo) is a state of agitation which continues so long as a certain stimulus, referred to as the disturbing stimulus, is present; but which ceases, being replaced by a state of relative rest, when that stimulus has ceased to act on the sense-organs. The state of agitation, in either appetite or aversion, is exhibited externally by increased muscular tension; by static and

Spermatogenesis of the pacific coast edible crab, cancer magister dana

Abstract: 1. During the latter part of June and the early part of July the testicular lobes of Cancer magister are in the best shape for the study of spermatogenesis.2. Two spermatogonial divisions can be recognized, and these ultimately form the resting primary spermatocytes.3. Sometimes, larger and more intensely staining cells are found interspersed among the spermatogonia. These are the nutritive cells, and it seems very probable that they have originated from a transformation of some of the spermatogonia. The nuclei of the nutritive cells are irregular in shape and many of them possess amœboid processes. In sections of some of the nutritive cells two or more nuclei are oftentimes found, and this might easily mislead one into concluding that amitosis occurs amongst them.4. The resting primary spermatocyte undergoes a growth period, during which thin leptotene threads are produced through the fragmentation of the chromatin. No continuous spireme is formed as the leptotene threads appear distinct and separate.5. ...

Factors involved in the atrophy of the organs of the larval frog

Abstract: Throughout the two great branches of the organic realm, in stances are presented where persons, organs or tissues or cells themselves undergo retrogressive changes.2 In the plant king dom, we have the familiar elimination of stems, leaves and other parts of the individual, upon the approach of untoward condi tions. In the animal series, we are enabled to identify an anal ogous process in the protozoa where, in Amirba the ephemeral pseudopodia are constantly being absorbed into the protoplasmic mass proper; in the species of Actinophrys, where this process of absorption is delayed permanently or at infrequent intervals; in the genus Trypanosoma, where the undulating membrane be comes absorbed under certain conditions. Similar phenomena are observed in the sponges where Maas's studies have shown that hitherto highly differentiated cells become reduced to a more typical and fundamental cell-form, the ama@bocyte. In the Ccelenterata we find the hydranths of Tubularia (i) and of other species either absorbed or eliminated @rntoto, while in Renilla Wilson has described a degeneration of the polyp. The “? brown bodies― of the Bryozoa represent degenerated individuals. In brachiopods, during the stages of fixation there is present an extensive degeneration of parts resembling in a superficial way the various changes undergone by the larvae of the ascidians. In Sacculina we have, fac@rleprinceps, this property of involution. Even amongst the vertebra ces we find instances of important degenerations of a natural sort, as in the fish Fierasfer where Bykowski and Nusbaum discovered extensive degeneration proc esses when the fish became parasitic.

An experimental study of acclimation to temperature in planaria dorotocephala

Abstract: 1. The susceptibility of Planaria dorotocephala to toxic concentrations of KNC increases with rise and decreases with fall in temperature.2. When animals which have been living at one temperature are subjected to another a gradual change in susceptibility to KNC in the new temperature occurs. In animals brought from a lower to a higher temperature the susceptibility undergoes gradual decrease at the higher temperature, and in animals brought from a higher to a lower temperature the susceptibility undergoes a gradual increase at the lower temperature. These secondary changes in susceptibility are distinguishable after twelve hours' subjection to a new temperature, but extend over days or weeks, apparently gradually approaching a limit. These changes occurring in a temperature higher or lower than that at which the animals have previously been living represent a process of acclimation.3. Estimations of CO2 production by a colorimetric method and by the Tashiro biometer give essentially the same results as t...

The microvivisection method

Abstract: The dissection of living cells has hitherto proved inadequate for a study of the physical properties of protoplasm and of its structural components. This is owing largely to a lack of means for the manipulation of dissecting instruments under a sufficiently high magnification of the microscope. Before and since Barber first devised his mechanical pipetteholder for the isolation of bacteria, various ingenious methods for the dissection of microscopic objects have been described. They all, however, fall short of Barber's method, because, with them, only comparatively low powers can be used, since the dissecting needles must operate between the objective and the tissue to be dissected. On the other hand, by using needles instead of micro-pipettes, Barber's instrument has been converted into an excellent microdissection apparatus. The needles operate in a shallow hanging drop containing the cells to be dissected which are pressed against the undersurface of a coverslip in a moist chamber. There being no obstacle above the coverslip, oil immersion lenses may be used for observation. In an article appearing as long ago as I859, Dr. H. D. Schmidt, of Philadelphia, describes in detail an excellent " microscopic dissector" consisting of a base to be fastened on the stage of a microscope with a number of clamps to hold instruments, each clamp possessing three movements controlled by screws. A lever fastened in one of the clamps holds the tissue in place. Fine scissors, knives or steel needles are fastened in the other clamps. By turning the various screws, the instruments can be brought into place and be operated with remarkable accuracy. Dr. Schmidt worked with the tissue, the instruments and the lower lens of the objective immersed in water or diluted alcohol. The full results of his investigations with this instrument were not published until I869, owing to interruptions due to the Civil

The relation of the embryo to the principal axis of symmetry in the bird's egg

Abstract: I. The Fundamental Relations of the Various Parts of the Bird's Egg ..... 319 II. H istorical R eview 324 A. The Principal Egg Axis 324 B. The A ir Space 324 C. The Shell Pigm ent 333 D . T he C halazae 325 E. Ligamentum Albuminis 328 F. The Long Axis of the Yolk 328 G. The Oviducal and Ovarian Orientation 334 H. The Relation of the Embryo to the Principal Egg Axis: Axis A ngle . ......... 335 III. Axis Angles in the Pigeon's Egg 339 IV . D iscussion 347 A. Variability in Axis Angles 347 B . Inversions 349 C. Variability in the Chalazae 353 V . C onclusions ....... ........ 355 Bibliography . 356

Observations on the structure of protoplasm by aid of microdissection

Abstract: 1. Protoplasm is an emulsion colloid normally in the sol state.2. The density of protoplasm varies from the very liquid state of young Fucus oogonia and embryos and of streaming protoplasm in myxomycetes and pollen tubes, to the quite viscous condition found in mature and resting eggs of marine organisms.3. There is a rapid increase in viscosity of the Fucus egg during the last stages of its ripening, which is, on fertilization, followed by a return to the liquid consistency characteristic of active, growing proptolasm.4. The plasma membrane is a definite morphological structure, constantly and repeatedly capable of repair through the conversion of the fluid protoplasm into a hyaline layer of greater molar concentration. This film of gel is exceedingly elastic, pliable and glutinous.5. The surface layer, like the interior cytoplasm, seems to be capable of alteration with changes in environment.6. The capacity for membrane-formation is one of the last essential properties of the living substance to be lost...

Autotomy of the tail in rodents

Abstract: It is perhaps not generally known that certain species of small rodents detach portions of the tail in a seemingly voluntary manner when they are seized by this member. Among the mouse-like rodents of California such an autotomy of the tail appears to be most typically exhibited by the pocket-mice (Perognathus). It is the general practice of the writers, as probably of most breeders of mice, to pick up their animals by the tail. This appendage constitutes a convenient handle by which a mouse may be lifted, commonly relieving one of the risk of being bitten. But such a procedure is hazardous in the case of Perognathus. By a sudden gyratory movement of the body, the tail is likely to be severed at some point in its length, allowing the animal to make its escape and giving the pursuer something of a handicap in the race. The whole performance is so suggestive of what occurs in many lizards that the question naturally arose in our minds: Can it be possible that autotomy, in the one case, as in the other, is followed by regeneration? This of course was not to be expected in a mammal, but the experiment seemed at least worth trying. In any case, the act and its consequences were thought to be worthy of a brief consideration. The species upon which most of these observations were conducted was a rather large pocket-mouse, Perognathus fallax fallax Merriam, which is very common in the neighborhood of La Jolla. Despite the frequency of autotomy in this species, we soon found that all individuals cannot be depended upon to "perform" when desired. Those, in particular, which have been kept captive for some time seem to lose the tendency. More-

A contribution to the physiology of wing development in aphids

Abstract: Results of the observations and experiments reported above may briefly be summarized as follows:1. Either an apterous or an alate parthenogenetic female may bear young larvae, some of which may finally attain the winged condition, while the others may remain wingless throughout life.2. When newly born aphids were reared on rose twigs planted in tumblers, containing washed and sterilized sand which had previously been saturated with the solution of a certain substance, nearly one hundred per cent. of winged individuals appeared on the twigs, while either none or few winged forms developed on the twigs charged with any one of another set of chemicals. For the sake of making a distinction between these two groups of substances, we may call the former the "wing-developing" substances, and the latter, the "non-wing-developing" substances.3. As far as the tests go, the salts of the alkalis (Na, Cl, K, etc.) and alkaline earths (Ca, Br) with the exception of magnesium, distilled water, urea, alum and others were ...

The cytology of the myxomycetes with special reference to mitochondria

Abstract: The Myxomycetes, or Slime moulds, constitute a most in teresting group of organisms since they are at once so primitive and so specialized and partake of the distinctive properties of both animals and plants. They stand as a sort of link between the two kingdoms. In the plasmodial phase of their existence, for example, they look like gigantic amceba@, crawl from place to place, exhibit typical protoplasmic streaming and actively phagocytize foreign particles. In the reproductive phase, on the other hand, they form brilliantly colored fungous-like masses strongly suggestive of plants. It is not surprising, therefore, that they have attracted so much interest among botanists and zoologists alike. Their general form and nuclear structure has been carefully worked up, but no attempt has been made to ex tend to them the recent work on mitochondria. This is all the more surprising, because the unique properties of these organisms would lead one to suppose that a careful study of mitochondria in them might yield valuable information bearing upon the Myxomycetes themselves, as well as upon the vexed problem of the general functional significance of mitochondria.

Effects of aging upon germ cells and upon early development part ii., changes in moderately aged eggs and sperm

Abstract: Aging eggs show progressive measurable morphologic and physiologic changes. Besides those described in Study II., there are a number particularly evident in later stages of aging eggs, such as agglutination and fusion of eggs, irregular cleavage, separation of the blastomeres and cytolysis.A. 1. The agglutination phenomenon occurred only in physiologically very deteriorated or "aged" eggs, as evidenced in part by the low per cent. of the jelly layer, inability to develop a fertilization membrane, a more viscous condition of the cytoplasm and cortical layer, and by numerous other tests. These are exactly the conditions that have been sought in the experimental agglutination of eggs.2. The onset of agglutination occurred at different ages for the eggs of different females, such variations being due to differences in physiologic condition of the eggs at the time of liberation from the parent. The more deteriorated the eggs at liberation the earlier the agglutination, and vice versa. Agglutination occurred in...

Further studies on the production of functional and rudimentary spermatozoa in rotifers

Abstract: 1. The normal and motile spermatozoa of Brachionus mulleri, Brachionus amphiceros, Hydatina senta and Diaschiza sterea possess large heads in which is located the chromatin material.2. The motile bodies of seven other species of rotifers which were figured and considered as the normal spermatozoa in the former paper were probably only the tails of such normal spermatozoa.3. The degenerate and immotile spermatozoa as seen in Brachionus mulleri and Hydatina senta also possess heads in which there is chromatin material.4. The stiff processes, called rudimentary spermatozoa in the former paper, are now considered to be not the complete rudimentary spermatozoa but only the degenerate tails of these rudimentary spermatozoa.5. The sperm head in the fertilized egg of Hydatina senta is about the same size as the head of the normal spermatozoon of this species.6. The four species of rotifers enumerated above together with the seven other species described in the former paper constitute eleven species of rotifers in...

Sex-determination and biology of a parasitic wasp, hadrobracon brevicornis (wesmael)

Abstract: made to test the cause of color variation except that it has been shown that it does not yield to selection. It seems probable, therefore, that i't is due to some environmental influence. It shows a certain correlation with size, for the dwarfed specimens are usually very dark while the larger individuals are either very light or of intermediate color. There is no apparent correlation of color with sex. In view of the fact that genetic differences with respect to color exist in the honey-bee, I had expected the yellow and the black variations of Hadrobracon to reproduce themselves, but this is not the case. Fig. i, A, shows a light colored male and Fig. I, B, shows a rather dark female. Sexual dimorphism is evident in the longer antenna of the male and in the presence of the ovipositor of the female. Variation occurs in the number of antennal joints and

The effect qf radium radiations on the development of chætopterus

Abstract: 1. Radiation of the unfertilized eggs of Chœtopterus results in injurious effects which do not become manifest until after the extrusion of the polar bodies, following insemination with normal sperm. That two normal mitotic divisions should intervene after radiation and only then that the injury to the chromosomes becomes apparent can be explained by the fact that the two longitudinal divisions preparatory to polar-body formation have been completed. Only when the chromosomes again "grow" in preparation for a new division do abnormal characters manifest themselves.2. If the radiation is brief (20 to 30 min.) the germ nuclei fuse normally but the radiated egg chromatin fails to form normal chromosomes. No spindle fibers develop from these abnormal chromatin masses, and they remain in the cleavage plane during mitosis. If the radiation is longer (35 to 50 min.) the chromosomes, after the extrusion of the polar bodies, develop abnormally and fail to fuse with the sperm nucleus. In both cases the sperm nucleu...

The effect of selection upon the sex-ratio in drosophila ampelophila

Abstract: 1. The sex-ratio in Drosophila ampelophila is 100 females to 95 males.2. The age of the parent has no effect upon the sex-ratio of its offspring.3. The difference which Moenkhaus found between his two strains, and which he attributed to selection, was probably due to the fact that his male strain was a normal one and his female strain was a lethal bearing one.4. The sex-ratio in Drosophila ampelophila is not readily, if at all, modifiable by selection.5. There was probably one sex-linked lethal mutation in the writer's selection stocks.

The toxic action of kcn and its relation to the state of nutrition and age of the cell as shown by paramecium and didinium

Abstract: 1. An attempt was made to discover what factor or factors are responsible for the observed differences among individuals of a pure line of Paramecia and Didinia living in the same culture medium; e.g., hay infusion. What are the differences in a protozoan cell which cause difference in response to apparently identical external conditions at different times?2. Survival time (resistance) of Paramecia and Didinia in solutions of KCN was selected and used as an index because of the generally supposed relation of the toxic action of KCN to the rate of oxidation in cells.3. All the data on survival time of Paramecium and Didinium were obtained by observations on individual cells and not by estimating the average survival time of large numbers of cells as is usual in such experiments. In this way the variation in resistance of the cell at different times during the period between cell divisions was followed accurately and is summarized in curves.4. The cessation of movement of Paramecium is a less variable "end ...

Effects of aging upon germ cells and upon early development part iii. changes in very aged eggs

Abstract: In the previous two studies it was shown that, beginning with maturation, definite progressive morphologic and physiologic changes took place in the egg, both within and without the body, such as (i) an increase in volume of the egg, (2) a loss of sur rounding jelly layer, (@) a retardation in the rate and change in the manner of forming the fertilization membrane, (@) a retarda tion and inhibition in cleavage. These changes served as measur able and corroborative evidences of the physiologic condition or vitality of the eggs of a female at any time, and served to measure the deterioration or loss of vitality with age. There were other symptoms or evidences of physiologic de terioration, especially in late stages of ageing, or overripening, which will be discussed briefly in this paper. These changes include: (i) Agglutination of eggs, (2) fusion of eggs, (3) abnormal cleavage, (4) separation of blastomeres and (@) cytolysis of the eggs. The same technique, the same nomenclature, the same pre cautions and the same three species of sea urchin were used as in Parts I. and II. For details of these I must refer to these studies.

Physiological senescence in hydromedusæ

Abstract: Four species of hydromedusae show evidence of a process of physiological sensecence in the decrease in pulsation-rate and apparent spontaneity and in the decrease in susceptibility to KNC, HCl, KOH and "vital" dyes in various concentrations with advancing development. The criteria of susceptibility are change in rate or cessation of pulsation, loss of contractility, shrinkage of the jelly and disintegration of cellular tissues, and all these criteria agree. The facts justify the conclusion that a decrease in the rate of metabolism, or more specifically of oxidations, is a characteristic feature of this process of senescence.

Bilateral tendencies and habits in the twenty-rayed starfish pycnopodia helienthoides (stimpson)

Abstract: 1. Pycnopodia is highly bilateral when moving about in its natural abode. It uses the same side always as anterior end.2. During righting reactions, this same side almost always takes the initiative and the greatest number of rightings are made in that direction. Repeated rightings do not improve its speed.3. It is hardly ever found on dry land; its movements are swift enough so that it keeps below the tidal mark; it moves swiftest when stimulated from within.4. In this, it seems to be partly governed by its sense to the pressure of minimum depths.5. Three prime causes effect its migratory habits, to wit: (1) sensitivity to light of a certain intensity; (2) search for food; and (3) the breeding impulse. During the breeding season it is neither negative nor positive heliotropic; for it moves up from deeper water to shallower water independently of the directions of the rays of light. After spawning, however, it seems to be positive heliotropic.6. It is omnivorous; it is carnivorous. It feeds mainly on Gast...

Variations in somatic chromosomes

Abstract: The chromosomes of the germ cells have received considerably more attention than have their descendants in the body and our knowledge of the behavior of these chromosomes is based on comparatively few studies of somatic cytology. During the process of karyokinesis in the body tissues the chromosomes may be studied, thus affording a basis for a comparison of their general characteristics and behavior with those of their ancestors or predecessors in the reproductive glands. Such investigations may eventually give an insight to some of the problems of development, including the function or activities of the chromosomes, and may also aid in strengthening the position taken in regard to these bodies by students of gametogensis. Cytologists have demonstrated that in any given species the chromosome number is constant and that in the diploid complexes of the germ and body cells the chromosomes exist in pairs. For a given species the chromosomes are frequently readily recognizable by characteristic structure and behavior. This numerical and morphological constancy has led to the theory of the individuality of chromosomes and is now so well supported by many observations that it may be said to be a part of the creed of modern biology. Indeed our knowledge has reached the point where numerical variations are not considered as prima facia evidence against the theory, but as another manifestation of an imperfectly understood organization. The following report deals with the chromosomes in the so-

Scarlet, an autosomal eye color identical with sex-linked vermilion

Abstract: 1. Scarlet is a new eye color identical in appearance with vermilion but in the third chromosome.2. When scarlet is crossed to vermilion, normal red eyes result, except where sons inherit vermilion from their mother.3. Scarlet gives a crossover percentage of 2.7 with dichaete and 25.4 with hairless.4. Pinkoid is a new second chromosome mutant that appeared contemporaneously with scarlet, and that affects both the color of the eye and the shape of the wings.

Experiments on the determination of the fate of the gray crescent material in the frog egg

Abstract: In the latter part of March of this year I began a series of experiments at Princeton University, having for my aim the determination of the location of the organ-forming substances, if such exist, in the cytoplasm of the frog egg. The work is scarcely more than begun and I should not ordinarily venture to present my results in such an incomplete form, but since I am leaving Princeton to enter army work it seems advisable to give a preliminary account of such results as I have obtained thus far. I hope to be able to do further experiments at a later time and to publish a full account with figures. The method used in these experiments was to inject small amounts of a three-fourths of one per cent. aqueous solution of trypan blue, a colloidal vital (?) stain, into the cells of the early cleavage stages of the egg and into certain regions of the young blastula. Injections were made under a binocular dis secting microscope by means of exceedingly fine pointed glass pipettes in which the large upper end was sealed. By warming the upper end of the pipette part of the air would be driven out and during cooling a quantity of the stain could be sucked in. On rewarming, the stain would be forced out in a steady flow and by inserting the needle into the cell or region that I desired to inject a small amount of the stain would be left in the egg. Since no sections have been made as yet I cannot give any report in regard to the distribution of the stain to the daughter cells in those cases where the presence of the stain or the mechan.