Horváth Géza (szerk.): A Magyar Természettudományi Múzeum évkönyve 8. (Budapest 1910)
Soós, L.: A Helix arbustorum hím csirasejtjének fejlődése
SPJ^ MIOGENESIS OF HELIX ARBUSTORUM. 313 found on examination of living cells that their chromatin gradually contracted when they were dying. His figure (10, Pl. I., Fig. 12), as well as those of DAVIS (19. Pl. II.. Figs. 24 -25) really show pathologically changed cells. A careful study of the synaptocytes of //. arbustorum led me to the conclusion that the contraction of their chromatin is not an artifact, but a normal condition. I regard as an evidence of this statement the fact that I have got the same, or nearly the same microscopical figures by all the used fixing agents, the inner figures being quite similar to the peripheral ones. If the contraction of chromatin were due to the shrinking influence of the reagentia, then it would be quite obscure why are not the neighbouring cells shrunken which are at an other stage of development? It is undoubtedly true that the chromatin of. these cells which have a tendency to contract themselves, can be more easely influenced by the reagents, and I myself have sometimes found in my preparations made with P ERÉNYI'S fluid, cells the chromatin of which was contracted into an unformed mass, but such cells were always well distinguishable from the synaptic ones, the latter having separated threads. The chromatin of the synaptocytes first forms itself into thin threads, such a nucleus is called after WINIWARTER (128 N leptotene nucleus (Pl. VII., Fig. 12.). The threads in the next stage transform themselves into thicker ones (Pl. I., Fig. 1 3., pachytene nucleus, WINIWARTER), and they occupy also one side of the nucleus. The transformation of the leptotene spireme into the pachytene one takes place very suddenly which can be concluded from the fact that no transitions are to be found between them. The same observation was made by L ÉRAT (61) in Cyclops strenuus, the leptotene spireme of which transformed itself by leaps into pachytene spireme. During this early growth period the chromosomes assume the form of polar loops, as is well visible on the next figure (Pl. VII., Fig. 14.), directed with their open ends toward a determined point (distal end) of the nucleus, where they are more or less closely attached to the nuclear membrane. Their number is appearently reduced. Together with the formation of the loops the amount of the cytoplasm increases, and the nucleolus also becomes larger which lies then, as a rule, near the open ends of the loops. This was named bouquet by the French authors. Such an arrangement regularly occurs during synapsis in the germ-cells of many animals. DAVIS (19) has given a nearly complete list of them, therefore I can renounce doijg so. Near the open ends of the loops in the cytoplasm lies a particular cell-organ which was discovered by LA V ALETTE ST. GEORGE in 1867.
