52 DARWINISM AND RACE PROGRESS. 



a man who is healthy and living in healthy surround- 

 ings excepting for the microbe that lurks in his well 

 the microbe of leprosy feeds upon those who are 

 debilitated by conditions under which healthy and 

 strong racial development is impossible. It is a 

 depopulator of starved, ill-nourished districts, and the 

 race recruits to its advantage from those more favour- 

 ably placed. 



In the case of syphilis, serious and often permanent 

 tissue change is produced as a result of the action of 

 the microbe, and in this disease, to an absolute 

 certainty, an effect may be produced upon the off- 

 spring. Many suppose that this is due to the trans- 

 mission of the specific microbe itself from the body 

 of one or both of the parents to the developing egg. 

 That such a thing is not impossible is shown in the 

 case of silk-worm disease, in which the spores are 

 to be found within the egg of the silk-worm moth. 

 These spores subsequently develop and attack the 

 tissues of the grub of the next generation. In syphilis 

 the same kind of thing no doubt occurs ; for a syphili- 

 tic child may subsequently infect the mother or nurse 

 during the period of suckling. But there are other 

 cases in this disease which appear hardly to be ex- 

 plained so easily, and we have to assume that the 

 germinal cells are themselves changed in some way 

 during their sojourn in the parental body, for after a 

 certain time the disease is no longer capable of trans- 



