Sectioning insects with sclerotized cuticle.

Cyclic development and longevity of theileria parva in the tick rhipicephalus appendiculatus.

Abstract: Full details of the technical methods evolved in the study of Theileria parva in the tick Rhipicephalus appendiculatus are described. Stages of T. parva discovered in intestinal contents, gut epithelial cells, and the cells of the salivary glands are fully described. Only the stages of the parasite found in the salivary glands and ducts could definitely be said to be a part of the normal life cycle of T. parva. Multiplication occurred in this site by a process of multiple fission. No sexual stages were discovered. Salivary gland inclusions of T. lawrencei (South African strain) were similar to those of T. parva. The many sources of error that have confused earlier workers are fully discussed. Studies on the longevity of T. parva in its tick vector confirmed the fact that the contained parasites die before the tick. Ticks become noninfective within 34–40 weeks after molting but are capable of feeding up to 15 months. It was found that ticks infected with T. parva could transmit the parasite to cattle 24 hours after being placed on the host.

XIV.—The Muscular and Reproductive Systems of Atomaria ruficornis (Marsham) (Coleoptera, Cryptophagidæ.)*

Abstract: This is a study of the functional morphology of the muscular and reproductive systems of the adult beetle, Atomaria ruficornis (Marsham) made by means of serial sections and dissections. An account is given of the skeleto-muscular system of the head, thorax and abdomen with reference to previous work in this sphere. Wherever possible, the muscles described have been homologized with those of other Coleoptera. In a small number of cases, it has been found necessary to use new names for muscles. The probable mode of action of the mouth-parts and foregut during feeding is described. An account is given of the reproductive organs and genitalia of both male and female beetles; the muscular system of the genitalia in both sexes is described fully, and the functioning of the genitalia is discussed.

The spermatheca in the flour beetle (tribolium castaneum herbst)1

Abstract: The( histology of the spermatheca of the Tenebrionid beetles has been very poorly studied. The structure of the spermatheca of Triboliu?, castaetur, IIHerbst differs greatly from the Coleop teran spermath ece described by previous authors (see Snodgrass, 1935; In mls, 1934). It is characterized by being unrecognizable in gross anatomcial dissection. The descriptive terms used in this paper are those employed by Snodgrass (1935). IATIRIALS AND M!IETHODS Adult females of Triboliinl castanJeum Herbst were fixed in Mukerji's fluid (Miukerji, 1937; Sinha, 1953, in press) and serial sections of the entire body, 8 micra in thickness, were made in transverse and longitudinal planes. The technique employed for sectioning the sclerotized beetles was that of Mukerji with the author's modification. Some dissections of the organ were also made in normal saline solution and later sectioned by the ordi nary, paraffin method. Sets of the serial sections of tlhe insects were stained in Mallory's triple stainl and Delafield's lemlatoxy li1 and Eosin, whereas the sets from the dissected organs were stained only in'the latter. DESCRIPTION The spermatheca of the Tribolium, castaneulr I-Herbst is a blunt, apical, anterior swelling of the vagina:t which is totally unrecog nizable from outside. It is 0.08 nmn. long and 0.1.3 mnm. in diam eter and is located 0.13 m11n. above the juncfion of the fifth and the sixth abdominal sterla (third and fourth visible sterna) in natural position. A study of the serial sections reveals that the organ is a rectangulatr mImus:cular chamber iomposcd- of four long

Frozen sections of arthropods for histological studies and fluorescent antibody investigations.

Abstract: A method for the rapid sectioning of arthropods is described whereby specimens are quick-frozen in gelatin and sectioned in a freezing cabinet at −15 °C. Sections in which the internal anatomical structures were excellently preserved could be prepared regularly from the nymphal and adult ticks, Dermacentor andersoni, Ornithodoros moubata and O. parkeri, and from the cone-nosed bug, Rhodnius prolixus. The usefulness of this frozen section technique was demonstrated or suggested for, (a) histological studies on the relationship of organ systems, (b) localization of parasites and disease agents by means of conventional stains, and (c) fluorescent antibody studies on the development and behavior of disease agents in ticks and other arthropods. By employing conventional stains Trypanosoma rangeli has been localized in the salivary glands of the arthropod host and by fluorescent antibody methods Rickettsia rickettsii was demonstrated successfully in frozen sections prepared from whole ticks.

Reproductive system of the bruchid beetles bruchus quadrimaculatus Fabr., bruchus (callosobruchus) chinensis L., (bruchidae—Coleoptera)

Abstract: The reproductive organs of Bruchus quadrimaculatus Fabr., and B. (Callosobruchus) chinensis L., including histology are described in detail. The role of the different parts of the male and female copulatory apparatus is discussed and the physical composition and function of the secretions of the accessory glands are indicated. The specific differences in the structure of the genitalia of the two species are shown.