Horváth Géza (szerk.): A Magyar Természettudományi Múzeum évkönyve 8. (Budapest 1910)
Soós, L.: A Helix arbustorum hím csirasejtjének fejlődése
SPJ^ MIOGENESIS OF HELIX ARBUSTORUM. 311 the latter a later phase. At the end of the scattering the polarisation is completely lost and the loops open out again. On Fig. 4., PL YIII., a cell is figured, in which the chromosomes are divided nearly equably through the nucleus. The chromatin forms then a network consisting of threads of different thickness. Together with the scattering of the chromosomes the cytoplasm increases considerably (auxocytes, BOLLES LEE). We can regard the scattering of the chromatins as completed, when it has transformed itself into nearly equal thin threads and forms a reticulum (PI. YIII., Fig. 5.). The nucleus is in this condition very similar to the resting nucleus, as is well seen when comparing PI. YIII., Fig. 5. with Figs. 8., 9. and 11., Pl. VII.; BOLLES LEE really regarded them as resting spermatocytes. The cell in this stage is considerable in size. It is rich in cytoplasm, in which after fixing with FLEMMING'S mixture a large chromatic apparatus is to be seen stained deeply with iron hematoxylin. It consists of several, curved or rodlike bodies having sharp outlines, which lie on the surface of a homogeneous, dark, spherical body, the idiozome of MEVES ; their number varies in a considerably manner. They are the pseudochromosomes of H EIDENHAIN . There is in the cytoplasm also a fine granular material, identical with the mitochondria, stained in the same manner as the pseudochromosomes. The close connection of chromatic apparatus and mitochondria has been shown by ANCEL (2), and particularly by POPOFF (94), who have found that the former developes from the latter by their arranging into rodlike bodies. The chromatin in the following stage begins to mass in some points of the reticulum, particularly at its cross points which can be regarded as the foci of chromosome development. These masses consist of smaller and larger chromomeres which can be clearly distinguished (PI. YIII., Fig. 7.. Pl. IX., Fig. 3.), but in a slightly later stage the outlines of the future chromosomes begin to form, i. e. they begin to transform themselves into definite chromosomes, though they are yet connected by linin threads and chromatin corpuscles lying in the threads. Later the connection becomes looser, and then the chromosomes begin to become defined more sharply (Pl. VIII., Fig. 8., Pl. IX., Fig. 4.), but their chromomeres are also in this stage distinguishable. In other cases the chromomeres first flow together into spherical masses, and then several masses melt together to form a chromosome (Pl. IX., Figs. 1., 2.). The developing chromosomes are very different in shape. They are someti'mes rodlike or arcuated, they consist in some cases apparently of 3—4 spherical parts; the free ends of the elongated chromosomes often
