186 DEPARTMENT OF AGRICULTURE. 



REMAKKS. 



Ill a geiicral way it may be stated, that all abnormal appearances 

 observed in the tlnids examined were such as might be attributed to 

 putrefaction. Although much remains to be learned as to the causes 

 and nature of this process, the tendency of modern science is to class it 

 as a species of fermentation, which may be dotined as a particular mode 

 of decomposition of organized bodies, accompanied by the growth of cells 

 of a fungoid character, supposed to be the active agents in the process. 



In fluids undergoing the alcoholic, the acetic, lactic, or butyric acid 

 fermentations, in wine affected with the bitter fermentation, or in a 

 solution of tannic acid changing to gallic acid, we find minute cells, in 

 German called " Hefe," in French " mycoderms," in English " yeast." 

 Although the cells of ordinary yeast and those of the mycoderma vini 

 aceti, or lactis, ditfer in shape and size, it is supposed that these varia- 

 tions are due to the character of the fluids by which they are nourished, 

 and that they are all really derived from the same source, namely, the 

 ordinary moulds. Common brewers' yeast {Cryptococcus cerevisi) is now 

 thought to be not a distinct species of plant, but merely a stage of 

 development of several different genera of fungi, such as penicillium, 

 aspergillus, mucor, and perhaps several others. And the same is proba- 

 bly true of the other mycoderms. 



\^^len organic substances rich in nitrogen decompose, the action is 

 termed putrefaction ; and in all such, when examined with a sufficiently 

 high magnitying power, there will be found little molecules, either single 

 or in chains of from two to six, and minute colorless rods, single or in 

 chains of two or three, straight or spirally twisted, rigid or flexible. All 

 of these may be at rest or in motion ; if the latter, it may be a vibrating, 

 trembling motion, without change of place, or a direct propulsion through 

 the fluid. These minute organisms have been successively considered as 

 aniumls, as algre or water plants, and as fungi. The globular molecules 

 are termed monads, and more recently micrococcus. The rods have 

 received many names, but are usually known as bacteria. The tendencj'^ 

 of investigators of this subject is to consider these monads and bacteria 

 as the mycoderms of the i)utrefactive fermentation, and to suppose that 

 they also are but one form of development of penicillium and other 

 common molds. Mrs. J. Luders asserts that she has seen the bacteria 

 emerge from spores of penicillium ])laced in meat juice, and the pro- 

 duction of yeast by adding putrefying fluids to saccharine solutions 

 has been repeatedly accomplished. 



We have performed some experiments on this subject which may per- 

 hai)s be of interest. 



Our aim was to develop in a saccharine solution an unmistalcable 

 yeast cell with its attendant special form of fernu'utation, from a vibrio 

 or bact(Tinin ('ontained in a putrefying Huid ; and the practical ])rol)lem 

 was to devise some means whereby the putrid fluid might be added to 



