PAPERS OF GENERAL INTEREST 65 



Corn is sensitive to climatic changes, and can enclnre 

 only slight changes without suffering seriously. But by 

 moving it a short distance northward each year, it is now 

 fully acclimated in regions where it was impossible to 

 raise it forty years ago. Corn goes through the seed 

 stage ; flagellata do not. But each of them by continually 

 exerting the powers they had, acquired powers of resist- 

 ing temperature changes which they did not have before. 

 The presence or absence of a seed stage does not affect 

 the matter except as to the rate at which the acquirement 

 occurs. The acquirement comes as a direct result of 

 exercising the powers in existence. When the matter ex- 

 tends over several generations, the seed stage simply in- 

 serts idle periods during which there is no acquirement. 



The blood reaction of different animals is different. 

 With this in mind, let us consider some phenomena relat- 

 ing to vaccination. If we inoculate a cow with smallpox 

 virus we remove the germ from a place where it was able 

 to live to a new place where it meets a new blood reac- 

 tion. Only occasionally does the germ survive in this 

 new place, but when it does survive we may pass it on 

 from cow to cow without difficulty. If, after passing the 

 germ through ten or more cows in series, we take this 

 virus and inoculate a man, we tind that it is cow}30x and 

 not smallpox. A man so inoculated becomes immune to 

 smallpox. 



Going back to what we have learned about power being 

 developed by exercise and lost by idleness, and applying 

 that information to the facts just given about smallpox 

 and cowpox, we can get some new light on the phenomena 

 relating to vaccination. When smallpox ^T.rus is inocu- 

 lated into a cow it will ''take" only when it comes to 

 some cow more susceptable than others. The germ in 

 fighting for its o^\ii existence in a new blood reaction de- 

 velops its powers of meeting that kind of blood reaction 

 so that when it later is passed on to another cow it finds 

 no difficulty in surviving in a place where before it could 

 not have survived. In passing along from cow to cow 

 these germs continue to develop their powers of meeting 

 the blood reaction of cows. But while thev are doing: 



