THE MALE-CELL OR SPERMATOZOON. II5 



It is possible to follow out the homology into even further detail ; thus the 

 antithesis seen in polar-globule formation may be fairly collated with similar 

 separations occurring in spermatogenesis. Van Beneden and Julin, in their 

 researches in oogenesis and spermatogenesis in Ascaj-is, have noted the 

 morphological correspondence of the polar globules, as we may call them, of 

 both ovum and sperm. Again we have a recent micro-chemical demonstration 

 of the similar staining reactions of polar globules in ova, and the correspond- 

 ing remnant of the parent cell in spermatogenesis. In the differentiation of 

 the reproductive cells in plants, both higher and lower, similar extrusions 

 are to be observed. Of this Strasburger has given numerous illustrations, 

 crowned by his own demonstration, that the nucleus of the pollen grain, in 

 its germination upon the stigma, separates into a vegetative, relatively 

 unimportant, and a generative or essential nucleus. Even in Protozoa, 

 Biochmann and others have found analogues. A process so general is 

 capable of a unified explanation, more specific than that of simply referring 

 the matter to the mysterious necessities of cellular physiology. Just as in 

 the development of the " worm " Sao/Ua a single cell divides into two, 

 which become the starting-points of male and female organs respectively, 

 so the cell divisions above alluded to express antitheses between more 

 katabolic and more anabolic protoplasmic constituents. 



§ 7. Chetnistry of tJie Sperm. — Comparatively little has been done in 

 regard to the chemistry of the male elements in different animals. The 

 most important observations are those of Miescher, on the milt of salmon. 

 His analysis demonstrated the presence of lecithin, fat, and cholesterin, — 

 also component parts of the ovum. Besides these, after the heads of the 

 spermatozoa have been formed, Miescher detected the abundant presence 

 of a substance which he called prota/nin, which occurs in association with 

 the }iitcleiii already noted as present in the yolk. Albuminoid material, 

 and products of decomposition, such as sarkin and guanin, were demon- 

 strated, according to Hensen, by Picard. 



Miescher emphasised the interesting fact, that while the sperm is being 

 formed in the Rhine salmon, the animal is fasting. As no food whatever 

 is taken, and as the muscularity of the fish is well known to decrease 

 greatly, Miescher directly connected the degeneration of the lateral muscles 

 with the development of the spermatozoa. 



Zacharias has more recently made a micro-chemical comparison 

 of the male and female elements in Characerc, mosses, ferns, phanerogams, 

 and amphibians. Me finds that the male cells are distinguished by their 

 small or absent nucleoli, and by their rich content of nuclein ; while the 

 female elements exhibited a poverty of nuclein, an abundance of albumen, 

 and one or more nucleoli, more or less large in proportion. The male cells 

 have, in relation to their protoplasm, a larger nuclear mass than the female 

 elements. 



It is interesting to notice that two investigators have recently pointed 

 out, that an analysis of two different kinds of pollen showed a great analogy 

 of composition between these male reproductive cells and those of the 

 salmon and ox. 



