ALBERT

Notizen: Sinistral ovariectomy in the Japanese quail resulted in some hypertrophy of the rudimentary right gonad in about 80% of the cases. The hypertrophied right gonads were composed of cords of epithelial origin, fat laden cells and a connective tissue stroma containing masses of lymphocytes. Neither cortical tissue nor germ cells were found in any of the gonads. In some cases regeneration of a testis-like tissue was seen on the site of removed left ovary. This, however, did not alter the effects of ovariectomy on rudimentary right gonad, accessory sex organs, plumage or sexual behavior. Neither Wolffian nor Müllerian ducts exhibited hormonal stimulation in poulards showing hypertrophy of right gonad with exception of the latter in two poulards. Early orchiectomy inhibited growth and differentiation of the cloacal gland. This organ revealed no noticeable stimulation in poulards showing hypertrophied right gonads. Castration produced no significant changes in plumage of males. Similarly, sinistral ovariectomy did not effect the first juvenile, but the second juvenile, adult winter and summar plumages changed to the male type. However, the plumage of some of these poulards began to revert to the female character as early as 10 to 12 weeks following ovariectomy. The behavior of capons and poulards revealed no conspicuous difference and neither showed any masculine behavior. The average weight of adult females was 20 to 30 gm above that of adult males whereas that of capons was above normal males and that of poulards below normal females. The average weight of capons was somewhat above that of poulards.

Notizen: The morphology of the gonads and epididymides, and an analysis of selected scale characters of six hybrid males presumed to be the result of the natural mating of the all-female whiptail lizard species Cnemidophorus neomexicanus and the bisxual species C. inornatus are presented. The histological appearance of the gonads and epididymides reveals a seasonal cyclicity with respect to the production and storage of spermatogenic elements. On the basis of the limited sample, it is postulated that some abnormality may be present in gametogenesis of these hybrid males which could be related to their chromosomal number. The data on scale characters support the interpretation that these hybrids are intermediate with respect to the parental species.

Notizen: The thoracic skeleton and musculature of the adult bittacid mecopteron Bittacus strigosus Hagen is described. In its musculature, Bittacus shows only moderate differences from two panorpids (Neopanorpa, Panorpa) that have been studied by Maki ('38) and by Hasken ('39), respectively. Not only are these three genera much alike in their musculature generally, but in all of them, and in Boreus (Boreidae) too, the mesothorax is extremely similar to the metathorax. Functional emphasis (for flight) on either of the two pterothoracic segments has not appeared among neuropteroid insects at the metopteran evolutionary level.Although the “snowfleas” of the genus Boreus possess striking alterations of pterothoracic structure in comparison with other mecopterons (Füller, '54, '55), these are related to their unusual activities and have not, to any great extent, affected the two pterothoracic segments differentially.In terms of thoracic specialization, the overall mecopteran pattern represents a stage somewhat advanced beyond the primitive conditions exemplified by the Megaloptera and certain coleopterous larvae, but one that is in general less highly developed than is charatceristic of such neuropteroid orders as the Siphonaptera, Diptera, Trichoptera, and Lepidoptera.

Notizen: This report presents light microscopic descriptions of normal histology, including innervation, of the lymph glands and jugular bodies, of larval and adult Rana catesbeiana. A brief description of two other adult organs, the propericardial and procoracoid bodies, is also included. The parenchyma was studied by employing the May-Grunwald-Giemsa staining technique for better cytoplasmic differentiation; the Periodic Acid-Schiff technique and hematoxylin and eosin yielded clearer nuclear and cytoplasmic delineations. The intercellular portion of the stroma was studied from sections stained with Masson's trichrome, Weigert's elastic stain, Periodic Acid-Schiff and Wilder's reticulum stain. Demonstration of phagocytes was facilitated by intraperitoneal India ink injections followed by the above staining procedures. Innerrvation was observed in serial sections of silver impregnated whole organs as well as in the other serial sections. These organs are lymphocytopoietic and to a certain extent granulopoietic; they also serve, like the spleen, as graveyards for dead cells and most probably play a role in immunity especially in the synthesis of antibodies as indicated by the presence of plasma cells, macrophages and lymphocytes.

Notizen: A morphological study of the presoma of adult Corynosoma hamanni (Linstow, 1892) was undertaken in an effort to clarify some problems encountered during analysis of a large collection of juveniles of this species assembled from fishes of McMurdo Sound. This study is based on approximately 600 adult specimens recovered from four Weddel seals, Leptonychotes weddelli, collected at McMurdo Sound.Morphologically the proboscis armature is more varied than previously reported and consists of 18 to 23 longitudinal rows each with 11 to 15 hooks of two distinct types. At the apex of the proboscis is an undivided, bi-nucleated apical organ unlike that described for species of Neoechinorhynchus. In the basal third of the proboscis is a thin-walled vesicle which extends into the anterior quarter of the proboscis receptacle. The more posterior of two external folds on the presoma is a cuticular invagination permitting recognition of the neck-trunk border of C. hamanni. Lemnisci originate between the two folds and extend into the trunk cavity between the body wall and extensive neck retractor muscles. Contrary to Linstow's original description, each lemniscus is a single structure.Several limitations in material prevent speculation at this time about the limits of intraspecific variation in C. hamanni.

Notizen: The structure of the cellular cyst which encapsulates the parasitic copepod, Scolecodes huntsmani, in the subendostylar blood vessel of the ascidian, Styela gibbsii, is described from light and electron microscopic studies.The cells comprising the cyst are contributed by the ascidian. The cells are columnar, contain large central reservoirs of glycogen and lipid, and have a conspicuous Golgi apparatus, many small cisternae of smooth endoplasmic reticulum and peripheral mitochondria. The cells are held together by complex basal interdigitations and a short apical zonula occludens. Long cilia emerge in circular clusters from the cell apices and beat in the lumen of the cyst. As atypical of a columnar epithelial layer, the nuclei are staggered in position in the cells and there is no basal lamina. One end of the cyst is blind, but the other end, which may be either anterior or posterior with respect to the longitudinal axis of the host, narrows to a profusely ciliated duct which opens through the wall of the blood vessel to the atrium of the ascidian by a ciliated funnel. The effective beat of the cilia of the duct and the funnel is outward toward the atrium.The first nauplii of the copepod emerge from the incubatory pouch of the adult and pass to the exterior sea water through the cyst funnel and the atrium and atrial siphon of the ascidian. As in other notodelphyid copepods, the life cycle of this incarcerated form also involves free-living naupliar stages followed by two free-living copepodid stages. The provision of an egress for the first nauplii is, therefore, important to the survival of the species.The adult females of Scolecodes, which range in length from 2 to 14.6 mm, are sluggish when removed from the cyst and fail to survive in sea water for more than 24 hours. The males, which have only been obtained when parasitic fifth copepodids molt in culture, are much smaller, averaging 0.8 mm, and are very active. Since one dead male has been found inside the cyst of an adult female and females are often found with attached spermatophores, it is suggested that the funnel of the cyst may also serve as an entrance for the males.Evidence is presented for the formation of the cyst as an accumulation of totipotent lymphocytes around the copepod. Cysts of parasitic developmental stages (third through fifth copepodids) are also described. All of these cysts and those of immature adult females lack funnels to the atrium. The funnel of the cyst of mature females is formed, in part, by modified cells of the wall of the blood vessel, but is induced after the major portion of the cellular cyst has been formed.Cells in the general circulation of the ascidian and those inside the lumen of the cyst are compared. The cells in the lumen of the mature cyst do not arise by diapedesis of blood cells from the subendostylar blood vessel, but by conversion and migration of cells composing the cyst proper. These cells have been found in the guts of the copepods and they may serve as a nutritive source.The ascidian appears not to be harmed by the association, but the copepod gains in many ways.

Notizen: Eggs of the common snapping turtle, Chelydra serpentina serpentina were incubated at 30°C and at 20°C. The incubation period at the higher temperature was about 63 days. At the lower temperature, the period was estimated to be 140 days. Lengths of the embryos at various times of development were recorded. A series of 26 stages is described. The staging is based on timed intervals at a constant temperature, 20°C.

Notizen: The rate of RNA synthesis in synchronously growing HeLa S3 cells was determined as a function of position in the cell generation cycle. Measurements throughout the cycle of both the rate of incorporation of radioactively-labeled uridine and of the total amount of RNA indicate that (1) the rate of RNA synthesis is constant (or increases only slightly) during G1, approximately doubles during the first half of S, and then remains constant during the remainder of S and G2, and (2) cells attain the average G1 rate of RNA synthesis very early in G1, and maintain the average G2 rate until mitosis.If the initiation of DNA synthesis is blocked, the acceleration of RNA synthesis is markedly reduced or eliminated. Further experiments in which DNA synthesis was inhibited at different times in S, or to varying degrees from the beginning of S, suggest that the extent to which RNA synthesis is accelerated depends on the amount of DNA duplicated. These data also indicate that duplication of the first half, and in particular the first few per cent, of the DNA complement results in a disproportionate acceleration of RNA synthesis.The possibility that fluctuations in the sizes of precursor pools may lead to misinterpretation of labeled-uridine incorporation data was examined. Experiments indicate that in this system pool fluctuations do not cause invalid measures of RNA synthesis.It is concluded that RNA synthesis occurs throughout interphase, but undergoes a two-fold increase in rate which is dependent on the duplication of DNA.