68 Forty Years Beagling 



something which the foetus passes to its dam in a 

 previous pregnancy causes a metabolic change in 

 its power of assimilating food, but rather that the 

 something causes a variation in the nature of its 

 cells, which cells, when in a second pregnancy, 

 cause a variation in the type of one or more of her 

 forthcoming offspring. In one of his letters Dr. 

 Mills instances the varying disposition of cells by 

 showing that while some dogs die under distemper, 

 others appear immune to the disease though living 

 with their moribund brothers and sisters. I would 

 in no wise contradict Dr. Mills on this point, at t]^ 

 same time Dr. Mills will be the first to allow that 

 in this case the variation in the cells is a physiolog- 

 ical differentiation in the power of the cells to with- 

 stand a microbic product of a toxic nature, and that 

 immunity is not arrived at by variation in form. 



"Again, if we take a well-known disease which 

 does cause variation and effects in the offspring to 

 that of the parents, we have one at hand in syphilis. 

 In this disease, it is perfectly possible, and not an 

 infrequent occurrence, that while a man is suffi- 

 ciently recovered as to be incapable of infecting his 

 wife while non-pregnant, he can do so through her 

 foetus when she does become pregnant. The result 

 of this is that the foetus, which was the agent of 

 infection, while itself being born blind, deaf, mute, 



