20 JOURNAL OF THE [January, 



ness. As soon as vitality is diminished in an organized body 

 their hungry attack begins. 



If they were all of a kind, or even of but a few kinds, we 

 might hope to exterminate, or fully control them. Their habits, 

 appearances, and powers vary so widely that their study is 

 almost hopelessly complex. Even their classification is a mat- 

 ter of dispute and doubt. Some of them are so unlike either 

 plants or animals, that the proposal has been made to give 

 them a sub-kingdom of their own. They have been referred to 

 as fungi and algae, but the lines run so confusedly into each 

 other, that this method of distinction is being abandoned for 

 that of Sachs, which includes the whole debatable ground under 

 the name, Thallophytes. 



The number of known Thallophytes, formerly included under 

 the title, fungi, rises up among the hundreds of thousands. 

 Many of them pass through successive changes in their life his- 

 tory, which at various stages give such diverse characteristics, 

 that the most careful investigators are baffled in attempting to 

 find their place in nature. Two Mycologists, viewing the 

 same genera, species, or even varieties, in different stages, may 

 give them totally different names, as well as descriptions, and 

 put them in families exceedingly remote. It will probably be a. 

 long time before this trouble is obviated. 



Of the forms that infect our medical supplies, no less than 

 thirty different kinds are found in the solutions presented here 

 to-night. It is quite probable that an increase in the number 

 of samples would add materially to the number of kinds that 

 could be discovered. 



Exhibit I., under the first microscope, is a sample of infected 

 dilute Phosphoric Acid (Fig. i). The engraving represents 

 one view of this object. The long, branching, obscurely jointed 

 stems constitute the most conspicuous thing in sight. A closer 

 inspection will reveal numerous minute motile specks, and little 

 rod-like masses squirming and twisting, like the larvae of flies in 

 a piece of spoiled meat. The very minute bodies are living 

 micrococci, and the somewhat larger ones are innominate bac- 

 teria. Some of them are probably Bacterium termo. It is unusual 

 to see these minute plant-forms in their active state. Generally 

 such exhibits are of dead, stained forms. What adds greater 

 interest to these is the fact, that every slide before us to-night is 



