10 SCHMIDT ON THE COMPARATIVE PHYSIOLOGY 



oil were readily taken up by aether. I was fortunate enough to 

 isolate the germinal vesicle in Atiodonta ; it completely disap- 

 peared when treated with potash, excepting some drops of fat 

 in the situation of the germinal spot ; the contents of the ger- 

 minal vesicle were coagulated by alcohol or nitric acid. Hence 

 the chorion and vitelline membrane would consist of proteine 

 compounds, the contents of the yolk abounding in fluid fat ; the 

 germinal vesicle, with its transparent contents, consists of albu- 

 minates ; the germinal spot would consist of one or more vesicles 

 of fat*. On incineration, they all left comparatively large quan- 

 tities of ash, consisting principally of phosphate of lime. 



If we add these experiments as a slight contribution to Ascher- 

 son'sf important observations on the formation of membrane 

 around globules of fat in albuminous fluids, and above all to 

 Wagnei''s profound researches in this most difficult branch of 

 the history of reproduction, the view of the latter upon the for- 

 mation and import of the individual parts of the ovum becomes 

 more deeply impressed upon our conviction. 



Cannot then the earliest formation of the ovum-cell, in ac- 

 cordance with the observations which have been made, be 

 explained by known mechanico-chemical laws ? Wherever he- 

 terogeneous bodies come into contact, condensation occurs at 

 the surface of contact ; the fact has been proved in the case of 

 coercible gases and fluids. If now a fluid, in consequence of its 

 chemical constitution, possesses the property of becoming com- 

 paratively solid even by slight condensation, every drop of a 

 heterogeneous fluid which gets into it becomes surrounded on 

 all sides by a condensed mass, i. e. forms the contents of a cell. 

 That the required property is probably possessed by a combina- 

 tion or mixture of albumen M'ith phosphate of lime, I hope sub- 

 sequently to prove; but that fat and albumen are extremely 

 heterogeneous bodies is evident. In the glandular tubules of 

 the ovary this fluid (albumen + phosphate of hme) exists; each 

 globule of fat which reaches it condenses a portion to form the 

 membrane of a cell. By the separation of solid constituents, the 

 remaining albuminous solution must become more dilute, an 

 effort at the restoration of equilibrium, endosmose, must occur, 

 and a portion of fluid must get between the oil-globule and the 



* Most of these reactions have already been given by Wagner {Lehrh, d. 

 Plujsiologie, 1843, S. 40). 



t Muller's Archiv, 1810, S. 14 e( scq. 



