2 ON GERMINAL TRANSPLANTATION IN VERTEBRATES. 



itance. Heape's evidence was this: The fertilized egg of a rabbit of one 

 variety (for example a long-haired albino) was removed from the oviduct 

 of the mother before it had become attached to the uterine wall. It was 

 then transferred immediately to the oviduct of a rabbit of a different vari- 

 ety (for example a Belgian hare, which is neither white nor long-haired) . 

 In several cases the transferred egg became attached in its new position 

 and passed through all the stages of gestation. Young rabbits produced 

 in this way were both long-haired and albinos like the mother of the eggs, 

 not like the rabbit which bore the young. The foster-mother, indeed, seems 

 not to have influenced the inheritance any more than the corn supplied to 

 cattle determines their breed characters. 



Granting all this, a further question remains to be dealt with. The 

 transferred egg was already full-grown and fertilized. If the transfer had 

 been made at an earlier stage while the egg was still growing, would the 

 results have been the same ? Might not the growing egg have lacked that 

 selective power in assimilation which belongs to the full-grown and fertil- 

 ized egg ? May not the former be subject to modification by the environ- 

 ment, even though the latter is not? 



This is the question involved in a study of germinal transplantation. 

 Guthrie believes that he has found evidence of such modification; we ques- 

 tion the validity of this evidence, on what grounds will presently appear. 

 On the other hand, we present one clear case of the transplantation of an 

 undeveloped ovary, which later liberated eggs in the body of a foster-mother, 

 but in the young so produced no foster-mother influence is detectable. We 

 therefore question still the existence of foster-mother influence. We 

 maintain with Weismann not only that modifications of the body are not 

 handed on to the germ-plasm, but that the character of the body does not 

 in the least influence the character of the contained germ-plasm, provided 

 only the body affords a suitable medium within which the germ-plasm may 

 exist. 



2. REVIEW OF THE LITERATURE ON OVARIAN GRAFTING IN ANIMALS 



OTHER THAN MAN. 



Beginning with the year 1895, a large number of investigators have given 

 attention to ovarian grafting. The results have often been conflicting. They 

 represent the work of physiologists, pathologists, biologists, experimental 

 and clinical surgeons, and lastly of students of heredity. It is impossible 

 here to give space for the discussion of the entire subject. All that is pro- 

 posed is a brief review of its more important aspects. 



As now understood, the term autoplastic grafting means the transfer of 

 tissue within the body of the individual, while homoplastic means the trans- 

 fer of tissue between individuals of the same species. A third term, hetero- 

 plastic grafting, is used to denote a transfer between two individuals of 

 different species or genera. 



It is proposed to review very briefly the work done in each of these fields . 



