Spermatogenesis in a Spider (Amaurobius sp.)

Abstract

AT the suggestion of Prof. J. Bronte Gatenby, I recently made some preparations of spider's testis, in order, if possible, to test the accuracy of the observations described by Prof. Ernest Warren in a letter to NATURE of September 12. In my preparations I have found many of the appearances figured by Prof. Warren. Fig. 1, probably corresponding to Prof. Warren's Fig. 3, is an early prophase of the first spermatocyte division; the clumps of chromatin are the first appearance of the chromosomes, and one clump (x), which is larger than the others, is presumably the sex chromosome. Fig. 2 shows a leptotene stage, Fig. 3 syndesis, and Fig. 4 a contraction figure in the diplotene stage. In all these, the sex chromosome can be easily distinguished, and in Fig. 5, which shows the chromosomes arranged on a normal spindle, the sex chromosome is seen lying apart in the cytoplasm. Fig. 6 shows the telophase of this division. The second spermatocyte division also appears to be normal.