624 The American Naturalist. (July, 
; EMBRYOLOGY. 
On the Significance of Spermatogenesis.’™—Auerbach has 
recently shown that a characteristic of the ovum and of the sperm is 
the fact, that the nucleus of the former takes on a red color, while that 
of the latter takes a blue, when both are treated exactly in the same 
way; to use Auerbach’s expression, the hereditary substance of the 
male is cyanophilous, while that of the female is erythrophilous. I 
have tried this method of differentiating the sexual cells in the follow- 
ing animals: Asterias, Loligo, Unio, Limax, Rana, Bufo, Necturus, 
Diemyctylus, Mouse, Rabbit, Dog, Cat, Tortoise, Fowl, and Man. I 
used three kinds of aniline colors, viz., Cyanine, for the blue staining, 
and Erothrosine and Chromotrop for the red. These anilines do not 
appear in the list of colors used by Auerbach, but they give the char- 
acteristic stains for the sperm and the ovum as described by him. 
In all of the animals mentioned, the nuclear contents of the well 
developed spermatozoon is eminently cyanophilous, that is, it takes 
cyanine in preference to chromotrop or erythrosine, and the nuclear 
contents of the ovarian ovum, particularly the nucleolus, is erythro- 
philous, that is, it takes either erythrosine or chromotrop in preference 
to cyanine. 
It is difficult, however, to tell how much of the contents of the 
nucleus of the ovarian ovum, before a portion of its chromosome has 
been removed in the formation of polar globules, is directly com- 
parable with the nuclear contents of a single spermatozoon, and we 
are therefore in doubt as to how far a color contrast obtained in differ- 
ential staining of the two sexual cells actually indicates the real 
nature of the chromosomes contributed by two parents to the body of 
anembryo. It seems important to bear this point in mind, for, in 
instituting comparisons between the nucleus of the spermatozoon and 
of the ovarian ovum, as representative elements of the maternal and 7 
the paternal organisms, one is left to infer that the protoplasmic con- 
tents of the two are in an analogous stage of development—an infer- 
ence open to objection. If the germinal vesicle of the well-developed 
ovarian ovum is to be compared with any structure in the a 
organism, it ought to be compared with the nucleus of the sperm 
mother cell or the spermatocyte, and not with that of the spermatozoon. 
1This department is edited by Dr. E. A. Andrews, Johns Hopkins University. 
*An abstract of a paper read before the Biological Club, Clark University, Wor- 
cester, Mass., March 10, 1892. 
