"70 what kind of culture ground would most definitely yield his 

 protozoon the more abundant life, when, behold! he found 

 this "fixed" species possessed of "the ability to turn, appar- 

 ently at will, into actively motile flagellated form" [39]. 

 This was a change in biological nature as violent as when a 

 nigger goes white, or a chicken develops webbed feet. Wherry 

 loved the antics of his amoeba so much that he got enthusiastic 

 — he wrote an eighteen-page article about it, plus a fine set 

 of his own wash drawings. What he wanted most, however, 

 was knowledge of the conditions that had wrought this change 

 from gelatinous droplet to flagellate. Why had other men 

 never seen it? They had grown tired, for one thing, when they 

 had cultivated their amoebae but a little while. Wherry had 

 observed his microorganism "daily, for a year" but still felt 

 it only "a beginning towards an insight into the life history 

 of a single species." Also, they had paid no attention to the 

 kind of food fed their amoebae, either in the general substrate 

 or the bacteria. 



Wherry got these matters under control. As to the bacteria, 

 they seemed to make no difference, but as to the substances 

 furnished in general food supply, this made a lot. The amoebse 

 were being raised on an egg-white fodder, and when so nour- 

 ished never got out of their pudding form; but as soon as a 

 little egg-yolk — shades of the viosterols! — was added, they 

 made themselves into independent, free-swimming forms. 

 Plenty of drinking water and fresh air also helped. Under 

 such circumstances "literally hundreds or thousands of flagel- 

 lates" developed out of their slimy ancestors — to return to 

 their slimy form when again submerged in an environmental 

 diet less rich. 



Wherry's study of Limax was an extension merely, of his 

 Philippine labors — further incursion of the field of "varia- 

 tion" in species as inducible through changes in environment. 

 Besides his amoeba, he had busied himself with another organ- 

 ism — the bacillus of tuberculosis. Two elements in its physical 

 make-up had always appeared as "variants" — some of the 

 bacilli would at times develop within themselves bodies which 

 in other bacteria were designated "spores"; and yet others 

 would lose their "acid-fastness." 



As to the spores, [3 6] two or three of these commonly ap- 



