THE BIOLOGY OF DAILY LIFE. 117 



flourish remarkably in solutions in which sugar 

 and pepsin replace the Ammonium Tartrate. 

 In this case the nitrogen of their protein com- 

 pounds must be derived from the pepsin ; and it 

 would seem that the mode of nutrition of 

 such Torulge approaches that of animals." 

 Thus we have the newest and highest authority for 

 the statement that the essential identity of the yeast, 

 the blue mould and similar moulds and the leucocyte 

 cannot be disproved. I do not claim it as fully ad- 

 mitted, but that the accepted scientific teachers (apart 

 from J. Yy r allace) are in an agnostic state (i.e., neither 

 affirming nor capable of denying) on the subject. 



The thoughtful reader will compare these facts 

 (which have been completely verified, and which 

 prove the polymorphism of yeast) with the behaviour 

 of the leucocyte in the human body. Outside the 

 body we see the Torula like a plant living on inorganic 

 matter, arid so also inside the drugged body, the 

 leucocyte becomes the organizer of drugs into the 

 fell nutriment of disease. It imparts its own noxious 

 vitality to the poisons, and receives in return from 

 them greater permanency, and a deadlier virulence.* 



* It makes no difference to our argument whether we regard 

 the several fermentative organisms as varieties of one species, 

 or as being of quite distinct species. In the yeast-world, with 

 its threefold and even fourfold mode, and its amazing rate of 

 reproduction, most of the Darwinian agencies which originate 

 new species, (such as natural or artificial selection, appetite- 

 selection, survival of fittest to the environment, &c.) have ample 

 scope for their operation, and that in a few days. We must 

 measure time, as regards development of species, by the succes- 

 sion of generations, or generative phases, in the reproduction of 

 more or less similar individuals, and hence a month or so would 

 fairly correspond to a geologic period, in the differentiation into 

 species of the ordinary flora and fauna. This remark also holds 

 good if it be extended from species to genera. 



