430 



SCIENCE 



[N. S. Vol. XXXII. No. 822 



tirely new and directly opposed to the results 

 attained by all experimental breeders. 



The method of controlling the maternal 

 metabolism is through the injection of leci- 

 thin subcutaneously and intraperitoneally or 

 even by feeding. According to Professor 

 Eusso the ovaries of such artificially nourished 

 rabbits are very much larger than normal 

 ones, and the mechanism of this transfer of 

 the food material (lecithin) from the peri- 

 toneal cavity is traceable through the ger- 

 minal epithelium into the ovary, past the 

 stroma to the stratum granulosum of the 

 Graafian follicles, through this and the cells 

 of the corona radiata and finally into the 

 ovum. He detects two general classes of eggs 

 in the ovary; those with large deutoplasmic 

 content and others having little or no food 

 material. The former class is greatly in- 

 creased by the use of lecithin, and such fe- 

 males as have been thus artificially nourished 

 are said to produce females exclusively or in 

 relatively large numbers. Also the author 

 claims that the young of such mothers repro- 

 duce her characters of pigmentation even 

 though they be recessive and in the presence 

 of dominant characters introduced by breed- 

 ing her with a dominant bearing male. In 

 the last analysis therefore, according to Pro- 

 fessor Eusso, sex and somatic structure are 

 determined by the nutrition of the mother 

 acting through the medium of the ovary upon 

 the eggs. 



It is essential to Professor Eusso's conten- 

 tion to prove that the ovary is really an organ 

 of absorption and that it is capable of being 

 influenced by the soma. To this part of his 

 subject he devotes 68 out of the 105 pages of 

 the paper. He presents the evidence from a 

 study of normal ovaries in rabbits of various 

 ages from two months to maturity and in 

 different degrees of reproductive activity, and 

 adds to this results derived from the study of 

 artificially nourished ovaries. Gonads from 

 starved females were also studied. The char- 

 acter of the germinal epithelium, of the stroma, 

 of the stratum granulosum and liquor folliculi 

 and of the zona pellucida under the various 

 conditions of the experiments is described. 



A detailed consideration of the extra nuclear 

 bodies and their chemical and morphological 

 natures follows. The author's purpose in this 

 second part is indicated in the following 

 passages : 



Auf diesen, fuer die gegenwaertigen Untersucli- 

 ungen fundamental wichtigen Punkt muss ich 

 entsehiedeu beharren, darni wenn auch einige in 

 der Organismus eingefuehrte Stoffe sich als un- 

 wirksam, mitunter auch als schaedlich sich er- 

 wiesen, werden andere dagegen vom Eierstoek 

 aufgesogeu und somit durch ihr Eindringen in 

 denselben im deutoplasmatisehen Material ver- 

 wandelt. . . . Der Zweek dieses zweiten {II.) 

 Teils findet weiter auch darin seinen Grund: den 

 Beweis zu erbringen, dass der Eierstoek der Sau- 

 egetiere, im Gegensatz zur allgemein herrschenden 

 Ansicht, naeh welcher er, weil tief im Soma 

 gelegen, den experimentellen Angriff gegenueber 

 unrerletzlich sei, in seiner inneresten Struktur 

 durch verschiedenartig Mittel modifiziert kann. 



In the final section of the work there is 

 presented the results of a series of breedings 

 between rabbits of different races intended to 

 show that characters in new races, ordinarily 

 recessive, may, under conditions of over nu- 

 trition, be made dominant. The experiments 

 to show the effect of nutrition upon the pro- 

 portions of the sexes, together with a consid- 

 eration of the normal ratios of the sexes in 

 rabbits, are also outlined here. Finally, the 

 technical methods of administering the artifi- 

 cial food products and of preparing the ma- 

 terial for study are given. 



Comment. — It is perhaps a little unfair to 

 judge an investigator's work by such a com- 

 pilation of it as Professor Eusso presents in 

 this publication, but since he has prepared it 

 specifically for the purpose of representing his 

 exact attitude in respect to the subjects of sex 

 determination and Mendelian inheritance it 

 will be necessary to judge his work and opin- 

 ions by this presentation of it. A general 

 consideration of the paper gives one the im- 

 pression that its author has not been thor- 

 oughly critical in his methods, and this feel- 

 ing is intensified as details are studied. The 

 Experimental Part, for instance, contains only 

 about eight pages, largely illustrations, of ex- 

 perimental results, while the Analytical Part 



