ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
177 
results of mutilations would prove that tho germ-cells could bo specifi- 
cally affected by the body. According to Reli, whose paper has a pleasant 
eirenic tone, acquired characters are certainly transmitted, but they pre- 
suppose a definite rudiment, Anlage, or predisposition. It is evident 
that, if thero were not the possibility of their arising, they would not 
arise! A somatogenic adaptation, he says, is not a completely new 
acquisition, it is only the outcrop of latent qualities ; latent, not in 
Weismann’s sense, but in a purely physico-chemical manner, as there is 
in water the latent quality of becoming steam at 100° C. The whole 
question seems to him so simple that he wonders there has been so much 
argument over it. 
j8. Histology. 
Spermatogenesis in Salamandra maculosa.* — Dr. 0. vom Rath 
devotes the first half of his paper to the “ Reduktionsfrage.” As a 
preliminary he points out that, to avoid error, he will make use of 
Hertwig’s terminology. That is to say, the primordial genital cells give 
rise by mitosis to indifferent germ-cells , from which, on sexual differentia- 
tion, primitive sperm- and primitive egg-cells arise. This is the first 
period. In the second there are periods of growth and rest, and the 
sexual cells become sperm-mother-cells or egg -mother-cells. In the third 
period, or that of maturation, the mother-cells divide and give rise to 
daughter- and granddaughter-cells. The sperm-granddaughter-cells 
(spermatids or unripe sperm-cells) undergo a more or less complicated 
metamorphosis and form spermatozoa (spermatosomes or ripe sperm- 
cells) ; the fourth period, which obtains only in spermatogenesis, is the 
period of conversion. By “ Reduktionstheiling ” the author means, 
with Weismann, every division of the nucleus in which the number of 
ids present in the resting nucleus is reduced to a half for the daughter- 
nuclei. 
The author finds that in all cases of spermatogenesis or oogenesis 
investigated by him the quadripartite groups arise before the maturation 
period in the same way ; in the coil-stage two adjoining segments remain 
connected with one another, and are in connection with the two similarly 
connected sister-segments, which have been formed by longitudinal 
cleavage of the chromatin-filament ; this connection may be more or less 
intimate. From each of these four segments there then arise, by con- 
traction, four rod-like or spherical chromosomes. Dr. vom Rath thinks, 
therefore, that it is most natural to regard each quadripartite group as 
consisting of four separate chromosomes. 
Dr. 0. vom Rath discusses in a second paper f the significance of 
amitosis in sexual cells, and its appearance in the genital apparatus of 
Salamandra maculosa. He comes to the conclusion that the amitotic 
phenomena observed in sexual cells support the empirical and theoretical 
results which he has established by observations on amitosis in somatic 
cells. When amitosis occurs in the testis, ovary, or as yet undifferen- 
tiated rudiment of a gonad, it occurs either in temporary investing cells 
or in sexual cells which develope no further and degenerate. The 
statements of those who suppose that amitotic phenomena must always 
* Zeitschr. f. wiss. Zool., lvii. (1893) pp. 97-40 (1 pi.). 
t Tom. cit., pp. 141-85 (2 pis.). 
