ADAPTATION AND INHEEITANCE KAMMEEEK. 437 



yielded spotted young, while the ovaries from a spotted female im- 

 planted on an experimentally changed striped individual yielded 

 spotted, striped, and interrupted striped young. Commonly ex- 

 pressed, we reached the following conclusions: 



1. If one deals with completed race characteristics which have 

 become established in the foreign body, the so-called nurse, then the 

 progeny will correspond to the characters of that individual from 

 which the ovary originated, not to that individual into whose body 

 the ovary has been transplanted. 



2. If one deals with only recently acquired, newly produced, or 

 other characters which have been taken out of their equilibrium, 

 which in the body of the nurse may quantitively diminish or increase, 

 or may be on the point of becoming quantitively changed, then the 

 progen}^ resembles, at least in part of its characters, that individual by 

 which they were carried in the undeveloped state. In this case only 

 there passed from the bodily peculiarities, which w^ere stiU easily 

 changed, being as it were, still new and unaccustomed to their pos- 

 sessor, a sufhciently strong stimulus upon the reproductive elements. 



These results may at some future time prove valuable in harmo- 

 nizing the contradictions which have resulted from the experiments of 

 other investigations in ovarian transplantation. For Guthrie, by 

 exchanging the ovaries of black and white chickens, obtained an 

 influence upon the chicks through the colored feather covering of the 

 nurse. Magnus obtained the same results in black and white rabbits. 

 Heape, on the other hand, in transplanting fertiUzed ova from white 

 Angora rabbits into gray Belgian hares, obtained no such influences; 

 nor did Castle by ovarian transplantation of black guinea pigs into 

 white individuals ; nor PoU, in the same operation upon gray and white 

 mice; nor Morgan in operating upon Ciona intestinalis. 



My experiments in transplanting may serve to straighten out the 

 controversy between the so-called neo-Mendelists and neo-Lamarck- 

 ists. Let us therefore return briefly to our crossing experiments with 

 the midwife toad. Each hybridization is in reahty a transplantation 

 of the germ elements, in a nonoperative natural way. We noted that 

 in a body with entirely different properties, those germ elements which 

 were carried over into it during coition retained then- own pecuharities, 

 often with the greatest persistence; even to such an extent that they 

 always reappeared unchanged in a certain percentage of the offspring. 

 It is possible, indeed probable, that we are now in possession of the 

 explanation of these plienomena, for we are dealing always only w^ith 

 well-fLxed, old, constant pecuharities, which no longer exert a form 

 or color-changing stimulus upon each other or their surroundings. 

 In our midwife toad we are also deahng, not with pecuharities which, 

 in the strict sense, are new, but with reawakened old peculiarities 

 85360°— SM 1912 29 



