Showing papers in "American Midland Naturalist in 1943"
TL;DR: The conductivity bridge derives its bridge source from a self-contained vacuum tube oscillator adjusted to approximately 1,000 cycles as mentioned in this paper, which operates directly from the A.C. power source.
Abstract: The new Conductivity Bridge derives its bridge source. voltage from a self-contained vacuum tube oscilltor adjusted to approximately 1,000 cycles. Voltage for the amplifier and null indicator tubes is provided by a.builtin D.C. power supply which operates directly from the A.C. power source. 9-324 Conductivity Bridge, without Conductivity Cell, for use with 110 volts 5060 cycle A.C. 9-351.Cosi~uCvity Cell, for use with Conductivity Bridge, constant 0.8, $20.00
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TL;DR: The purpose of the present study is to learn which turtles, if any, retard the production of fish, to experiment with methods of control, to establish "a clean bill of health" for deserving species, and to determine other economic relations of these reptiles.
Abstract: This report, based on a combination of field and laboratory studies, is one of a series dealing with pr?dation on fresh-water fishes as related to the practical problems of fish yield (Lagler, 1937). Researches on the physical, chemical, and on the more familiar biological features of fresh-water communities need to be supplemented by studies on the role of pr?dation in their dynamic economy. Although the reduction of populations of predatory and so-called "noxious" animals is a common fish management practice, it often has little scientific basis and is for the most part of unknown effect. It is the purpose of the present study to learn which turtles, if any, retard the production of fish, to experiment with methods of control, to establish "a clean bill of health" for deserving species, and to determine other economic relations of these reptiles.
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TL;DR: In this article, the authors describe the animals, their behavior, and dispersion in all 27 states east of the Mississippi River and provide an abundance of scientific information in combination with anecdotes, field notes, and an underlying reverence for the fragile diversity of animal life.
Abstract: \"The authors have done a superb job of distilling a vast amount of information on the biology of the terrestrial mammals of the eastern United States in a style that will not only satisfy the expert's need for accurate data but will also appeal to students and others interested in natural history.\" -James N. Layne, Archbold Biological Station In their definitive work on eastern mammals, John O. Whitaker, Jr., and W. J. Hamilton, Jr., vividly convey their sheer delight at the variety and abundance of mammalian life. They have brought together a wealth of biological information and applied a biological subspecies concept to the mammals of the eastern United States. Their research extends \"from the high reaches of Mount Katahdin in northern Maine, where water shrews and moose hold company,\" to the unglaciated hills of southern Indiana, where pygmy shrews (each weighing less than a dime) lived undetected until 1981. From there, they reach to \"the cypress swamps of lower Florida, where the spoor of the mountain lion may be seen.\"*Describes the animals, their behavior, and dispersion in all 27 states east of the Mississippi River.*Almost entirely rewritten, this edition provides an abundance of scientific information in combination with anecdotes, field notes, and an underlying reverence for the fragile diversity of animal life. *Illustrations include 110 range maps, 167 black-and-white photographs, and 92 color images.*Covers 121 species, 17 more than in the previous edition. *Uses a biological subspecies concept, showing the results of evolution through differentiation. *Provides keys to orders and genera, anatomical line drawings. *Summarizes information on endangered and threatened species for each of the eastern states. *Lists state mammal books in the literature section.
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TL;DR: Denudation of soil by removal of litter that has been formed as a result of accumulation of fallen leaves and other organic materials is well known to produce significant changes that affect growth of trees.
Abstract: Denudation of soil by removal of litter that has been formed as a result of accumulation of fallen leaves and other organic materials is well known to produce significant changes that affect growth of trees. Not only is much of the organic matter removed and available nitrogen decreased, but soil also tends to become more alkaline (Jenny 1941) and without a humus layer may tend to form superficial crusts (Hilgard 1930). Burning-over releases mineral salts; thus makes a soil surface more alkaline and also opens the way to loss of salts by leaching (Issac & Hopkins 1937). Cultivation tends to decrease nitrogen; it makes particles smaller and soil more compact. The removal of litter and humus decreases water-holding capacity and soil erosion often results. Rains drive air out of soils and, if there is no humus or litter to shelter soil animals, they are exposed to enemies and other dangers (Shelford 1929).
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TL;DR: The present study is an attempt to provide age determination data for bob-whites (Colinus virginianus) one to five months old, similar to that determined by Louis Bureau for the Hungarian partridge and red quail in France.
Abstract: Criteria for separating young of the year from adult gallinaceous birds are comparatively well known and have been treated in an earlier paper (Petrides, 1942), but more exact methods of determining age have yet to be developed for most species. The present study is an attempt to provide age determination data for bob-whites (Colinus virginianus) one to five months old, similar to that determined by Louis Bureau for the Hungarian partridge (Perdix perdix) and red quail (Alectoris rufa) in France. His reports (1911, 1913) contain tables and diagrams of wing feather replacement and growth that purportedly permit the determination of age, within 1 to 3 days, of healthy birds collected during their post-juvenal molt.
TL;DR: Immature specimens of the later stadia, which greatly outnumber mature specimens in most collections, resemble the latter closely in shape, but are easily distinguished by their smaller size, paler color, absence of mature gonopods, and smaller number of post-cephalic somites.
Abstract: Like other polydesmid millipedes, Orthomorpha gracilis is flattened dorsoventrally. The keels or carinae are nearly horizontal and less than one-fourth the width of the body cavity. The 20 post-cephalic somites bear 30 or 31 pairs of legs, depending upon whether the specimen is a male or a female. The gonopods, a pair of highly modified walking appendages present only in adult males, are on the seventh post-cephalic somite between the seventh and eighth pairs of legs. Each gonopod (Fig. 1) is composed of a prominent basal joint and an apical joint with a short cushion-like hirsute base, a stout, slightly curved shaft, and four terminal curved prongs. Male specimens vary between 18.5 and 19.9 mm. in length and 2.0 and 2.2 mm. in width; female specimens vary between 19.4 and 22.2 mm. in length and 2.0 and 2.5 mm. in width. Recently moulted specimens are creamy white, but before they leave the moulting chamber the color may change to light brown. In the oldest specimens the dorsum is a deep chestnut brown or black, the keels are bordered with lemon yellow, the sides are chestnut brown, the sterna and basal joints of the Iegs are pallid, the distal joints of the legs and the apex of the body are light brown, and the antennae and vertex are dark brown. Immature specimens of the later stadia, which greatly outnumber mature specimens in most collections, resemble the latter closely in shape, but are easily distinguished by their smaller size, paler color, absence of mature gonopods, and smaller number of post-cephalic somites. Stadia I and II are shown in figures 2 and 3.
TL;DR: Most insect morphologists now agree that there is a fundamental pattern from which all the insect venations are derived, though there is still a good deal of argument as to the equivalence of particular veins in the different orders.
Abstract: There have been many theories as to how the wings of insects arose, and from what parts of the body they were derived, but with increase of knowledge of the morphology most of them are either wholly abandoned or considered very improbable. Most insect morphologists now agree that the wings are in some way derived by the extension of the lateral edges of the dorsal sclerites of the two segments (mesothorax and metathorax) to which they are attached, and that they served to plane through the air, more or less like a flying squirrel or a flying fish, before true flight was developed. In a similar way the theories as to the pattern of wing veins have evolved with increasing knowledge of the details, until we now have agreement that there is a fundamental pattern from which all the insect venations are derived, though there is still a good deal of argument as to the equivalence of particular veins in the different orders. The remaining points of argument have come to be mainly the following: 1, whether the dragon flies and may-flies can be properly compared to each other, and, whether or not, the relation of their veins to those of other winged insects; 2, whether the difference between convex and concave veins is more or less significant than the patterns of the pupal and nymphal tracheae, and if important, which veins were originally concave; 3, whether the front branch of the vein called media is homologous in all orders of insects, and if not, whether the vein called R4+5 in some orders is the equivalent of the one called "media anterior" in others by some authors; 4, whether the "axillary" or "anal" veins can be directly compared in the different 'groups of orders, or whether they must be considered to be several different selections from an originally amorphous series; and 5, to what extent the veins in the various fossil insects loosely grouped as "Palaeodictyoptera" can be homologized to those of living insects.
TL;DR: During the summer of 1939 the movements of 237 tagged bullfrogs, Rana catesbeiana Shaw, were studied at the Edmund Niles Huyck Preserve, at Rensselaerville, Albany County, New York.
Abstract: During the summer of 1939 the movements of 237 tagged bullfrogs, Rana catesbeiana Shaw, were studied at the Edmund Niles Huyck Preserve, at Rensselaerville, Albany County, New York. These frogs were marked by locking numbered monel metal tags around the dentary bone. The results were reported by Raney (1940). Other studies on the growth of these bullfrogs in nature have been reported by Raney and Ingram (1940 and 1941). Additional returns on 22 individuals recaptured by Ingram in the summer of 1940, and 12 records obtained by Dr. Jean Piatt during 1941 serve as a basis for these notes.
TL;DR: The black-banded skink is the northern form; it is replaced in the southern part of the Great Plains area by the subspecies, Eumeces septentrionalis obtusirostris (Bocourt).
Abstract: An interesting account undoubtedly referring to the black-banded skink appears in Schoolcraft's "Narrative of an Expedition Through the Upper Mississippi to Itasca Lake," published in 1834 (pp. 64-65). He writes that a "small animal of the amphibious kind was here brought to our notice, under the name of Ocant Ekinabic, or legged snake, a species of lizard, striped blue, black, and white, with a disproportionate length of tail. It is thus readily distinguished from ordinary species. Its most striking peculiarity of habit, is its extreme activity and swiftness of motion." This is apparently the first mention of this lizard in the literature. The species was described and named by Spencer F. Baird in 1858, who gives "Minnesota and Nebraska" as the type locality of the species. There is some confusion in this respect, and Taylor (1935, p. 395) concludes that Fort Ripley, Minnesota, should be regarded as the type locality. Our skink is the northern form; it is replaced in the southern part of the Great Plains area by the subspecies, Eumeces septentrionalis obtusirostris (Bocourt). Description
TL;DR: In this paper, plant microfossils of coal measure plants, preserved in coal, offer a clue to the plant communities of the Carboniferous period in the same manner as do pollen grains and spores to the paleoecologist working with Quaternary peat deposits.
Abstract: A knowledge of the fossil flora of successive geological periods provides a basis for determining the relative position of geological strata much in the same manner as does the fossil fauna. Plant microfossils of the coal measure plants, preserved in coal, offer a clue to the plant communities of the Carboniferous period in the same manner as do pollen grains and spores to the paleoecologist working with Quaternary peat deposits. Variations in these plant communities are seen in the change of spore types throughout the coal bearing rocks which have been investigated. These variations may possibly be correlated with different types of coal.
TL;DR: A revision of the taxonomy of this genus is published with adequate information on its speciation, phylogeny, and distribution, and the morphological aspects are limited to those external and internal structures, which are or have been considered of taxonomic importance.
Abstract: The giant West Coast land slugs have a complex genital physiology (Heath, 1916), the details of which are unknown, except that they frequently gnaw off the penis at the close of copulation. The first step in a study of this behavior undertaken by the author was to examine critically a great number or specimens not only to familiarize himself with the genital morphology of the several species in the hypertrophied, atrophied, and immature states, but to attempt to find a structural explanation for this unique practice. Examination of large series of live specimens afforded great advantages which earlier workers unfortunately had not enjoyed; consequently the literature contains not only serious errors regarding the taxonomic status of the group, but also many morphological misinterpretations based on examinations of very limited and often poorly preserved material. For this reason, it was thought advisable to publish first a revision of the taxonomy of this genus with adequate information on its speciation, phylogeny, and distribution. In this paper the morphological aspects are limited to those external and internal structures, which are or have been considered of taxonomic importance. Other structures, including especially the apical genital structures, will be treated in a later paper dealing with the biology and genital physiology of the genus.
TL;DR: During the late winter and spring of 1936 and 1937 the writers made a field study of the anostracan phyllopods occurring in the vicinity of Urbana, Illinois, with special attention toward the distribution, life history, and rate of growth in the ponds.
Abstract: During the late winter and spring of 1936 and 1937 the writers made a field study of the anostracan phyllopods occurring in the vicinity of Urbana, Illinois. Extensive field surveys were conducted and intensive collections made from one pond for experimental purposes. Special attention was directed toward the distribution, life history, and rate of growth in the ponds from the hatching of the eggs into metanauplii until the attainment of sexual maturity of the anostracan fairy shrimp Eubranchius serratus Forbes (1876), a form commonly found in Illinois and also reported from Missouri and Nebraska. Additional observations on the survival and growth of this form were made on individuals taken into the laboratory and maintained there at controlled temperatures. Collections other than near Urbana were made north to Rantoul, west to Monticello, east to Gray's Siding, and south to Savoy and Homer Park.
TL;DR: This paper presents the evidence concerning the mating type of a double animal containing two nuclear complexes each of which determined a different mating type and a summary of which has appeared previously (Powers, 1942).
Abstract: The mating types in Euplotes patella and the genetic mechanism determining them were described almost concurrently with the morphology and cytology of the double animal of this species (see citations to Kimball below). The double animal contains two nuclear complexes, one or Doth of which can be involved in conjugation with single animals of various mating types. Since these two nuclear complexes occur together in the same cytoplasm while retaining their individualities, this question arose: what would be the mating type of a double animal containing two nuclear complexes each of which determined a different mating type? This paper presents the evidence concerning this question, a summary of which has appeared previously (Powers, 1942).
TL;DR: The Edmund Niles Huyck Preserve, which comprises about 500 acres adjoining the village of Rensselaerville, N. Y., is located about twenty-seven miles southwest of Albany on the Helderberg peneplain at an elevation of 1400 to 1700 feet.
Abstract: The Edmund Niles Huyck Preserve, which comprises about 500 acres adjoining the village of Rensselaerville, N. Y., is located about twenty-seven miles southwest of Albany on the Helderberg peneplain at an elevation of 1400 to 1700 feet. The Preserve was established and formally incorporated in 1931 by Mrs. Edmund Niles Huyck as a memorial to her late husband and in recognition of a need for the preservation of natural areas for recreation, education, and study. In addition to the protection of the native plants, animals, and the scenic beauty of the area, the construction of suitable trails, and the operation of a restricted camp ground, the officers of the Preserve felt that something more constructive should be done with the area so that it might become more than just another small sanctuary. At the suggestion of several prominent biologists, a Scientific Advisory Committee consisting of William J. Hamilton, Chairman, the late G. Kingsley Noble, Thomas Ordway, Lewis Eldridge, John R. Greeley, and William Vogt was appointed to consider the possibility of establishing a research biological station. During the summers of 1936 and 1937 Dr. Hamilton made a preliminary biological survey of the area and in 1939 a biological station was established with provisions for a Resident Biologist and several Summer Fellows to devote their full time to problems in field biology.
TL;DR: Besides observations on most of the habitats in which the specimens were collected, there are observations on the feeding, breeding, and behavior of many of them in captivity especially of some of the rarer rattlesnakes.
Abstract: The forty species of reptiles and amphibians contained in this report are represented by 101 specimens collected in Arizona in the Huachuca Mountains, the Chiricahua Mountains, the Douglas-Cochise region, Cochise County, and in the Tucson region in Pima County during sixteen days, from July 8th to 23rd, 1941. Besides observations on most of the habitats in which the specimens were collected, there are observations on the feeding, breeding, and behavior of many of them in captivity especially of some of the rarer rattlesnakes.
TL;DR: Most of the species of freshwater Amphipoda of the eastern United States were obtained at the type localities, or so near as to leave little doubt as to the determinations.
Abstract: Descriptions of most of the older species of freshwater Amphipoda of the eastern United States being inadequate, it was essential that material from the type localities be examined in order to fully understand the species. As such material was not available, the author undertook to make collections at as many of these type localities as could be located. As a result, most of the species were obtained at the type localities, or so near as to leave little doubt as to the determinations. In addition, in the regions traversed, a large number of collections were made which add to our knowledge of the distribution of these species. This paper is a report on these collections, together with some material collected by other persons and examined by the author.
TL;DR: In the course of paleobotanical studies of coal balls from the Des Moines Series in the Pennsylvanian strata of Iowa, numerous elater-bearing spores were discovered, extending the record from the early Mesozoic Era back into the latter part of the Paleozoic era.
Abstract: In the course of paleobotanical studies of coal balls from the Des Moines Series in the Pennsylvanian strata of Iowa, numerous elater-bearing spores were discovered. A review of the literature on spores of this type showed that none are recorded from rocks earlier than the Triassic. The discovery is therefore significant in that it extends the record from the early Mesozoic Era back into the latter part of the Paleozoic Era. In addition, several interesting structural features are also shown by these Paleozoic spores.
TL;DR: The fundamental organic matter produced by a lake is manufactured by the aquatic chlorophyll-bearing organisms from carbon dioxide, water and various other substances dissolved in the water and the manufacuring process is energized by the subsurface solar radiation.
Abstract: The fundamental organic matter produced by a lake is manufactured by the aquatic chlorophyll-bearing organisms from carbon dioxide, water and various other substances dissolved in the water and the manufacuring process is energized by the subsurface solar radiation. It represents the primary anabolic activity on which all aquatic life depends, either directly or indirectly, for its sustenance. Both the large aquatic plants and the microscopic forms of the phytoplankton contribute to the production of this organic material; generally speaking however, the phytoplankton plays a more important role in the manufacuring process than the large aquatics, especially in lakes that are deep enough to become thermally stratified in summer. The latter are usually confined to the shallow water where light and soil conditions are more favorable for their growth. The phytoplankton, on the other hand, is free floating and is distributed throughout the epilimnion due to the wind circulation of that stratum; it is present even in the lower water where conditions are not so favorable for photosynthesis.