STUDIES ON INSECT SPERMATOGENESIS

Studies on Insect Spermatogenesis. V. On the Formation of the Sperm in Lepidoptera

Quantitative studies on spermatogenesis in buffalo (Bubalus bubalis).

The qualitative behaviour of spermatogenetic cells and Sertoli cells in the buffalo (Bubalus bubalis) was studied by identifying 8 stages of the seminiferous epithelium cycle based on meiotic division and morphology as well as the position of more mature spermatids. To achieve better results, stages 1, 2, 3, 4 and 8 were sub-divided. Six peaks of spermatogonial mitosis suggested six generations...

Studies of Spermatogenesis in the Hepaticae

An ultrastructural study of late-stage androgonial cells of Blasia pusilla, a thallose liverwort, showed the nearly spherical nuclei often lying close or appressed to the cell walls. In some cells the two membranes comprising the nuclear envelope separated, the inner membrane continuing intact as a limiting boundary of the nucleus and the membrane on the outer, cytoplasmic side recurving away f...

Immunological Studies of Insect Metamorphosis

1. The cell-free blood of the Cecropia silkworm produces a maximum of nine bands of antigen-antibody precipitate when reacted in antiserum-agar tests with antisera prepared by injecting Cecropia extracts into rabbits. The blood antigens producing these bands of precipitate have the properties of proteins in that they are non-dialyzable, labile at 75 degrees C., and salted out by 75 per cent sat...

Comparative studies of spermatogenesis in fertile and subfertile men.

Testicular biopsy specimens from 16 fertile and 10 subfertile men with normal male karyotype were studied quantitatively to provide histological and cytogenetic data for a basis of reference in assessing abnormalities of spermatogenesis. Histological studies included estimation of the proportion and activity of germinal epithelium and an assessment of tubular morphology. In cytogenetic preparat...