M'Weenet — On a Method of Preparing Schizomycetes. 161 



curious plants whicli live upon the surface of tlie human body are^ 

 to everyone, of sujEficient interest and importance, to entitle them 

 to a place in natural-history collections. 



Coming now to tlie yeasts or Saccharomycetes, when we rejQect 

 that it is to the activity of these minute plants that we owe all our 

 fermented liquors, beer, porter, wine and vinegar, we cannot fail 

 to recognize their vast economic importance. The scientific study 

 to which the various processes that make up the brewing and wine 

 industry have been subjected on the Continent, under the leadership 

 of Pasteur and Hansen, has demonstrated that most of the failures 

 in the course of the manufacture of those articles, due to the 

 appearance of muddiness, of bitterness, of viscidity or other objec- 

 tionable qualities in the wine or beer, are to be attributed to the 

 action of " wild " species of Saccharomycetes. These species have 

 been isolated and studied, and it is no esaggeration to say that 

 the genus Saccharomyces as now constituted is one of the very 

 highest economic importance and general interest, and surely 

 ought not to be omitted from our natural-history collections. As for 

 the fission fungi or Schizomycetes, it may at once be stated that 

 they surpass every other class of living beings in the closeness of 

 their relations to the human species, and in the personal importance 

 to the human individual of the nature of their relations to him. 

 For, as is well known, most, if not every one, of the infectious 

 diseases of which so many men die annually, and of which the 

 epidemic of typhoid at present devastating this city is an excellent 

 example, are directly traceable to the parasitism in the human 

 economy of various species of fission-fungi: a parasitism surpassing 

 in intimacy that which obtains in the case of what are generally 

 known as intestinal worms, and of far more sinister import to the 

 host. In addition to the numerous disease-producing organisms, 

 the class of Schizomycetes comprises numerous species, the function 

 of which is commonly termed putrefactive. By the process of 

 putrefaction we now mean a coexistence of various fermentative 

 activities, usually giving rise to foul-smelling products and ceas- 

 ing only with the complete decomposition of the substratum. The 

 substratum usually consists of the bodies of dead animals and 

 plants or the products of their bodies. The complex organic 

 molecules are taken to pieces, and the elements reduced to simpler 

 (so-called inorganic) compounds, which are once more capable of 



