26 Outline of Genetics 



be spoken of as antilens. Serum obtained from the 

 blood of fowls thus ''sensitized," and therefore contain- 

 ing antilens, was injected into the blood stream of nor- 

 mal white rabbits. No noticeable modification was 

 obtained in any case upon adult rabbits that were so 

 treated. 



When, however, the serum was injected into pregnant 

 mother-rabbits, starthng results were obtained. Some 

 of the resulting progeny had eyes that were clearly defect- 

 ive. Furthermore, the abnormality was readily trans- 

 mitted through the female line for quite a number of 

 generations, without any additional injections being 

 made. The defect did not decrease in degree, but seemed 

 even more pronounced in the later generations. 



At this point a few questions might be asked. Have 

 such eye defects ever been known to occur among 

 untreated white rabbits; is this the sort of thing that 

 might appear ''spontaneously" through mutation, or a 

 recessive character that might have been segregated out 

 through inbreeding, as is true of so many other functional 

 abnormalities? Careful inquiry has revealed the fact 

 that no such eye defects have been reported elsewhere. 



Again, is this the sort of thing that might be expected 

 to result from any sort of mutilation, or is it a specific 

 response to a specific stimulus ? This question is clearly 

 answered by the behavior of the controls. Untreated 

 pregnant mothers, mothers treated with serum from 

 unsensitized fowls, and mothers treated with serum from 

 fowls that had been sensitized to rabbit tissues other 

 than lens never gave any defective progeny. 



An even more critical question is the following: is 

 this another case of transmission rather than true inherit- 



