No. 637] 



IMMUNE SERA 



mitted from the mother's blood or engendered in that of 

 the young would seem to be of secondary importance. 

 It stands to reason that antibodies originated in an ani- 

 mal's own body will modify germinal factors if corre- 

 sponding antibodies introduced from without can accom- 

 plish this. 



The whole question as to how important such a fact 

 may be in contributing to an understanding of the causes 

 of the germinal changes in organisms in general, which 

 lead to variation and evolution, hinges on the question 

 of whether changes in an animal's tissues will induce the 

 formation of antibodies or kindred active substances in 

 its own body. We have steadily accumulating evidence 

 that such reactions do occur. 



In our own laboratory, for example, after many at- 

 tempts we have succeeded in securing a defective-eyed 

 young rabbit from a mother of normal stock by injecting 

 her repeatedly with pulped rabbit lens before and during 

 pregnancy. Since the young rabbit in question has both 

 eyes badly affected there can be no question that a rabbit 

 can build antibodies against rabbit-tissue which are as 

 effective as those engendered in a foreign species such as 

 the fowl. We have likewise found it relatively easy to 

 secure spermatoxins by directly injecting rabbits, both 

 male and female, with rabbit spermatozoa. Moreover, 

 a given male will develop antibodies against his own. 

 spermatozoa if he is injected intravenously with the 

 latter. 



We are also securing evidence that serologic reactions 

 induced in the fetus through operations on the mother 

 are not mere passive transmissions, but may become 

 actively participated in by the tissues of the fetus. For 

 example, female rabbits sensitized with typhoid vaccine 

 followed by living typhoid germs may transmit to their 

 young and even to their grand descendants the ability to 

 agglutinate t\]ilioi(I Imeilli in serum diluted from 60 to 

 160 times. Fnnii \hv stnndpoint of heredity we have no 

 reason so far for maintaining that this is anything but 



