Horváth Géza (szerk.): A Magyar Természettudományi Múzeum évkönyve 8. (Budapest 1910)
Soós, L.: A Helix arbustorum hím csirasejtjének fejlődése
SPJ^ MIOGENESIS OF HELIX ARBUSTORUM. 317 PLAINER (91, 92) Avas the first to endeavour to distinguish the spermatogonia and spermatocytes, but his efforts were not followed by sufficient success. He hold the resting spermatocytes as spermatogonia cf. his Fig. 11., Pl. XXIII. (91)], and could distinguish only one division in the development of the germ-cells, though he — as is seen from one of his papers (92) — observed all the chief stages in the division of the spermatogonia and spermatocytes, and only his seriation is incorrect. He found (93) the normal number of the chromosomes of Helix pomatia to be 24. Z IMMERMANN (131) distinguished in germ-cells two generations. The cells of the first generation — according to him — have a very small amount of cytoplasm, their chromatin forms loops which occupy the side of the nucleus directed toward the liebenkern, while the opposite part of the nucleus remains quite clear. The cells of the second generation are much larger, and have a larger amount of cytoplasm. The chromatin of the resting nucleus forms spherical masses, in which also the constituent parts are to be distinguished. The number of these masses is at most 24. From Z IMMERMANNS statements it can be seen that he knew only one cell generation, i. e. the primary spermatocytes. The generation described by him as the first generation of the germ-cells is identical with the younger generation of the spermatocytes from the period succeeding the synapsis, and his second generation identical with the older spermatocytes. The results of BOLLES LEE'S (10) valuable investigations have already been mentioned when discussing the spermatogonia. I emphasized there that he could not distinguish the spermatogonia and spermatocytes from each other, and he regarded the young spermatocytes as spermatogonia, therefore he described these phases which we have had the opportunity of knowing as those of the primary spermatocytes, as belonging to the division of the spermatogonia. His results agree in this respect with those of Z IMMERMANN. BOLLES LEE regarded as resting spermatocytes the cells figured on our Fig. 5., Pl. VIII. cf. BOLLES LEE (10), Pl. II., Fig. 30]. WE have seen above that such cells are not resting spermatocytes, but auxocytes from the period after the synapsis. The chromatin of these cells — according to BOLLES LEE — transforms itself into 24 spherical or ovoidal chromosomes. ANCEL'S (2) results agree in general with those of BOLLES LEE. He also regarded the young spermatocytes as spermatogonia, but he determined the series of the stages differently from BOLLES LEE. According to ANCEL in the young spermatocytes firs^t appear very fine threads
