114 



SCIENCE 



[N. S. Vol. XXXIV. No. 865 



of the animal in which those cells were con- 

 tained; we hold that it is unnecessary to as- 

 sume such a change, but that the young were 

 like the mother because she was their mother, 

 and that they developed from her own ova, 

 not from those introduced. We have shown 

 elsewhere by a detailed examination of the 

 facts reported by Guthrie that there is noth- 

 ing in them at variance with the known facts 

 of color inheritance in fowls, if it be supposed 

 that in these experiments the mother fur- 

 nished her own ova to produce offspring. But 

 if it be supposed, as Guthrie does, that the 

 ova came from an engrafted ovary, then seri- 

 ous contradictions are encountered as regards 

 the color inheritance. Such contradictions 

 Guthrie may not lightly push aside by dis- 

 claiming any interest in laws of inheritance 

 on the ground that they are of " no concern " 

 to him. He who claims to have modified 

 inheritance should know what normal inherit- 

 ance is, and he can not divert attention from 

 chickens by scornful references to " peas," nor 

 from stubborn facts by thrusts at " theories 

 built largely upon speculation." No theories 

 are involved in this discussion except the one 

 which Guthrie has propounded, that inherit- 

 ance is affected by foster-mother influence. 

 We are concerned merely with facts which 

 may either substantiate or disprove this hy- 

 pothesis. It happens that the subject of color 

 inheritance in fowls has been an object of 

 careful study by several competent observers 

 for a number of years, and we have a large 

 body of data on the normal inheritance of 

 black and white in crosses of fowls. Is it wise 

 in discussing a supposed case of modified 

 color inheritance in fowls to disregard this 

 data as of " no concern " ? Is breeder's evi- 

 dence of " no concern " in a question of modi- 

 fied breeding? 



To sum up in a few words our criticism of 

 Guthrie's " evidence of soma influence," we 

 hold that no satisfactory evidence of such 

 influence has been produced because first, it 

 has not been shown that a hen can be com- 

 pletely castrated, but if this can not be done, 

 we can not be certain that eggs discharged 

 from the ovary were really derived from intro- 



duced tissue and not from a regenerated 

 ovary. Secondly, it has not been shown that 

 in Guthrie's experiments the transplanted tis- 

 sue actually persisted. Without the fulfill- 

 ment of hoth these conditions no transplanta- 

 tion experiment can be considered critical. 



Guthrie calls attention to the fact that in 

 an early announcement of his results he drew 

 only provisional conclusions. This is quite 

 true; they were in their entirety as follows:^ 



1. " The ovaries transplanted in these 

 chickens seemed to function in a normal 

 manner." 



2. " The color characters of the resulting 

 offspring appeared to be influenced by the 

 foster-mother." 



JSTo exception can be taken to these modest 

 conclusions. No claim is made in them of 

 more than a seeming persistence of engrafted 

 tissue and an apparent modification of the 

 color characters of the offspring, which how- 

 ever at the present time we are in a better 

 position to explain. 



If we are to understand that in the present 

 paper Guthrie means merely to reassert these 

 original conclusions, I make no objection to 

 them. 



It did seem, as Guthrie stated, that in his 

 experiments the transplanted ovaries func- 

 tioned, but that is no proof that they did. 

 Our criticism of Guthrie's results is directed 

 merely toward establishing this point. Doubt- 

 less it seemed to the boy who threw the stone 

 into the poultry yard that he had killed 

 the hen, but I doubt whether his father would 

 have accepted that conclusion without some 

 independent investigation. Such an investi- 

 gation of Guthrie's results, Phillips and I 

 have made. 



In a case which we have fully described 

 elsewhere the two criteria of the persistence 

 and functioning of transplanted ovarian tis- 

 sue which have been enumerated are, I be- 

 lieve, adequately met. That Guthrie does not 

 share this view is of little consequence in 

 this connection, but in stating his reasons 

 for dissent Guthrie, doubtless inadvertently, 



'^Journ. Exp. Zool., 5, p. 571. 



