March 8, 1888] 



NATURE 



449 



The fermentative saprophyte is as absolutely essential to the 

 setting up of destructive rotting or putrescence in a putrescibie 

 fluid as the torula is to the setting up of alcoholic fermentation 

 in a saccharine fluid. Make the presence of torula; impossible, 

 and you exclude with certainty fermentive action. 



In precisely the same way, provide a proteinaceous solution, 

 capable of the highest putrescence, but absolutely sterilized, and 

 placed in an optically pure, or absolutely calcined air ; and while 

 these conditions are maintained, no matter what length of time 

 may be suficred to elapse, the putrescibie fluid will remain abso- 

 lutely without trace of decay. 



But suffer the slightest infection of the protected and pure air 

 to take place, or, from some putrescent source, inoculate your 

 sterilized fluid with the minutest atom, and shortly turbidity, 

 offen-ive scent, and destructive putrescence ensue. 



As in the alcoholic, lactic, or butyric ferments, the process set 

 up is shown to be dependent upon and concurrent with the vege- 

 tative processes of the demonstrated organisms characterizing 

 these ferments ; so it can be shown with equal clearness and 

 certainty that the entire process of what is knowii as putrescence 

 is equally and as absolutely dependent on the vital processes of a 

 given and discoverable series of organisms. 



Now it is quite customary to treat the fermentive agency in 

 putrefaction as if it were wholly Bacterial, and, indeed, the putre- 

 factive group of Bacteria are now known as Saprophytes, or 

 saprophytic Bacteria, as distinct from morphologically similar, 

 but physiologically dissimilar, forms kniwn as parasitic or patho- 

 genic Bacteria. 



It is indeed usually and justly admitted that B. termo is the 

 exciting cause of fermentive putrefacti in. Cohn has in fact con- 

 tended that it is the distinctive ferment of all putrefactions, and 

 that it is to decomposing proteinaceous solutions what Torula 

 cerevisice is to the fermenting fluids containing sugar. 



In a sense, this is no doubt strictly true : it is impossible to find 

 a decomposing proteinaceous solution, at any stage, without find- 

 ing this form in vast abundance. 



But it is well to remember that in Nature putrefactive ferments 

 must go on to an extent rarely imitated or followed in the labora- 

 tory. As a rule 'the pabulum in which the saprophytic organ- 

 isms are provided and "cultured," is infusions, or extracts of 

 meat carefully filtered, and, if vegetable matter is used, extracts 

 of fruit, treated with equal care, and if needful neutralized, are 

 used in a similar way. To these may be added all the forms of 

 gelatine, employed in films, masses, and so forth. 



But in following the process of destructive fermentation as it 

 takes place in large masses of tissue, animal or vegetable, but 

 far preferably the former, as they lie in water at a constant tem- 

 perature of from 60° to 65° F., it will be seen that the fermen- 

 tive process is the work, not of one organism, nor, judging by 

 the standard of our present knowledge, of one specified class of 

 vegetative forms, but by organisms, which, though related to each 

 other, are in many respects greatly dissimilar, not only morpho- 

 logically, but also embryologicaliy, and even physiologically. 



Moreover, although this is a matter that will want most 

 thorough and efficient inquiry and research to understand pro- 

 perly its conditions, yet it is sufficiently manifest that these 

 organisms succeed each other in a curious and even remark- 

 able manner. Each does a part in the work of fermentive 

 destruction ; each aids in splitting up into lower and lower com- 

 pounds ; the elements of which the masses of degrading tissue are 

 composed ; while apparently, each set in turn, does by vital 

 action, coupled with excretion, (i) take up the substances neces- 

 sary for its own growth and multiplication ; (2) carry on the 

 fermentive process ; and (3) so change the immediate pabulum 

 as to give rise to conditions suitable for its immediate successor. 

 Now the point of special interest is that there is an apparent 

 adaptation in the form, functions, mode of multiplication, and 

 order of succession in these fermentive organisms, deserving of 

 study and fraught with instruction. 



Let it be remembered that the aim of Nature in this fermentive 

 action is not the partial splitting of certain organic compounds, 

 and their reconstruction in simpler conditions, but the ultimate 

 setting free, by saprophytic action, of the elements locked up in 

 great masses of organic tissue : the sending back into Nature of 

 the only material of which future organic structures are to be 

 composed. 



I have said that there can be no question whatever that 

 Bacterium tcriiio is the pioneer of Saprophytes. Exclude B. termo 

 (and therefore with it all its congeners) and you can obtain no 

 putrefaction. But wherever, in ordinary circumstances, a decom. 



posable organic mass, say the body of a fish, or a considerable 

 mass of the flesh of a terrestrial animal, is exposed in water at a 

 temperature of 60° to 65" !•"., B. termo rapidly appears, and 

 increases with a simply astounding rapidity. It clothes the 

 tissues like a skin, and diffuses itself throughout the fluid. 



The exact chemical changes it thus efTects are not at present 

 clearly known ; but the fermentive action is manifestly concurrent 

 with its multiplication. It finds its pabulum in the mass it 

 ferments by its vegetative processes. But it also produces a 

 visible change in the enveloping fluid, and noxious gases con- 

 tinmously are thrown off. 



In the course of a week or more, dependent on the period of 

 the year, there is, n^t inevitably, but as a rule, a rapid accession 

 of spiral forms, such as Spirillum volulatis, S. undula, and 

 similar forms, often accompanied by Bacterium lineola: and 

 the whole interspersed still with inconceivable multitudes of 

 B. termo. 



These invest the rotting tissues like an elastic garment, but 

 are always in a state of movement. These, again, manifestly 

 further the destructive ferment, and bring about a softness and 

 flaccidity in the decomposing tissues, while they without doubt, 

 at the satne titne, have, by their vital activity and possible 

 secretions, affected the condition of the changing organic mass. 

 There can be, so far as my observations go, no certainty as to 

 when, after this, another form of organism will present itself; 

 nor, when it does, which of a limited series it will be. But, in a 

 majority of observed cases, a loosening of the living investment 

 of Bacterial forms takes place, and simultatieously with this, the 

 access of one or two forms of my putrefactive monads. They 

 were amongst the first we worked at ; and have been, by means 

 of recent lenses, amongst the last revised. Mr. S. Kent named 

 them Cercomonas typica, and JlPonas dallingcri respectively. 

 They are both simple oval forms, but the former has a flagellum 

 at both ends of the longer axis of the body, while the latter has. 

 a single flagellum in front. 



The principal difference is in their mode of multiplication by 

 fission. The former is in every way like a Bacterium in its 

 mode of self-division. It divides, acquiring for each half a 

 flagellum in division, and then, in its highest vigour, in about 

 four minu'.es, each half divides again. 



The second form does not divide into two, but into many, and 

 thus, although the whole process is slower, develops with 

 greater rapidity. But both ultimately multiply — that is, com- 

 mence new generations — by the equivalent of a sexual process. 



These would average about four times the size of Bacteriti7ii 

 termo : and when once they gain a place on, and about, the 

 putrefying tissues, their relatively powerful and incessant action, 

 their enormous multitude, and the manner in which they glide 

 over, under, and beside each other, as they invest the ferment- 

 ing mass, is worthy of close study. It has been the life-history 

 of these organisms, and not their relations as ferment--, that 

 has specially occupied my fullest attention ; but it would be in 

 a high degree interesting if we could discover, or determine, 

 what beside the vegetative or organic processes of nutrition 

 are being effected by one, or both, of these organisms on the fast- 

 yielding mass. Still more would it be of interest to discover 

 what, if any, changes were wrought in the pabulum, or fluid 

 generally ; for after some extended observations I have found 

 that it is only after one or other, or both, of these organisms, 

 have performed their part in the destructive ferment, that 

 subsequent and extremely interesting changes arise. 



It is true that in some three or four instances of this sapro- 

 phytic destruction of organic tissues, I have observed that, after the 

 strong Bacterial investment, there has arisen, not the two forms 

 just named, nor either of them ; but one or other of the 

 striking forms now called Tetramitus rostratus, and Polytoma, 

 uvella ; but this has been in relatively few instances. The rule 

 is that Cercomonas typica, or its congener, precedes other forms, 

 that not only succeed them in promoting, and carrying to a still 

 further point the putrescence of the fermenting substance, but 

 appear to be aided in the accomplishment of this by mechanical 

 means. 



By this time the mass of tissue has ceased to cohere. The 

 mass has largely disintegrated, and there appears amongst the 

 countless Bacterial and monad forms, some one, and sometimes 

 even three forms, that whilst they at first swim and gyrate, and 

 glide about the decomposing matter, which is now, much less 

 closely invested by Cercomonas typica, or those organisms that 

 nT'y have acted in its place, they also resort to an entirely new 

 mode of movement. 



