450 



NATURE 



\March 8, 1888 



One of these forms is Heteroinita rostrata, which it will be 

 remembered, in addition to a front flagellum, has also a long 

 fibre, or flagellum-like appendage that gracefully trails as it 

 swims. At certain periods of its life they anchor themselves in 

 countless billions all over the fermenting tissues, and as I have 

 described in the life-history of this form, they coil their anchored 

 fibre, as does a Vorticellan, bringing the body to the level of the 

 point of anchorage, then shoot out the body with lightning-like 

 rapidity, arid bring it down like a hammer on some point of the 

 decomposition. It rests here for a second or two, and repeats 

 the process ; and this is taking place, by what seems almost like 

 rhythmic movement all over the rotting tissue. The results are 

 scarcely visible in the mass ; but if a group of these organisms 

 be watched, attached to a small particle of the fermenting tissue, 

 it will be seen to gradually diminish, and at length to disappear. 



Now, there are at leist two other similar forms, one of which, 

 Heteroniita unci>iata, is similar in action, and the other of 

 which, Dallingeria diysdali, is much more ]5owerful, being 

 possessed of a double anchor, and springing down upon the 

 decadent mass with, relatively, far greater power. 



Now, it is under the action of these last forms, that in a 

 period, varying from one month to two or three, the entire 

 substance of the organic tissues disappears, and the decomposition 

 has been designated by me "exhausted" ; nothing being left in 

 the vessel but slightly noxious, and pale gray water, charged 

 with carbonic acid ; and a fine, buff-cjloured impalpable 

 sediment at the bottom. 



My purpose is not, by this brief notice, to give an exhaustive, 

 OP even a sufficient account, of the progress of fermentive action, 

 by means of saprophytic organisms, on great masses of tissue : 

 my observations have been incidental, but they lead me to the 

 conclusion that the fermentive process is not only not carried 

 through by what are called saprophytic Bacteria, but that a 

 series of fermen'.ive organisms arise, which succeed each other, 

 the earJier ones preparing the pabulum or altering the surround- 

 ing medium, so as to render it highly favourable to a succeeding 

 form. On the other hand, the succeeding form ha? a special 

 adaptation for cari-ying on the fermentive destruction more 

 ■efficiently from the period at which it arises, and thus ultimately 

 of setting free the chemical elements locked up in dead organic 

 compounds. 



That these later organisms are saprophytic, although not 

 Bacterial, there can be no doubt. A set of experiments re- 

 corded by me in the Proceedings of this Society some years 

 since would go far to establish this {Monthly Microscopical 

 Journal, 1876, p. 288). But it may be readily shown, by 

 extremely simple experiments, that these forms will set up 

 fermentive decom )osition rapidly, if introduced in either a 

 desiccated or living condition, or in the spore state, into suitable 

 but sterilized pabulum. 



Thus while we have specific ferments which bring about' 

 definite and specific results ; and while even infusions of nroteid 

 substances may be exhaustively fermented by saprophytic Bec- 

 teria ; the most important of all ferments, that by which Natura's 

 ■dead organic masses are removed, is one which there is evidence 

 to show is brought about by the successive vital activities of a 

 series of adapted organisms, which are for ever at work in 

 •every region of the earth. 



There is one other matter of some interest and moment, on 

 which I would say a few words. To thoroughly instructed 

 biologists, such words will be quite needless ; but, in a Society 

 of this kind, the possibilities that lie in the use of the instrument 

 are associated with the contingency of large error, epecially in 

 the biology of the minuter forms of life, unless a well-grounded 

 biological knowledge form the basis of all specific inference, to 

 say nothing of deduction. 



I am the more encouraged to speak of the difficulty to which 

 I refer, because I have reason to know that it presents itself 

 again and again in the provincial Societies of the country, and is 

 often adhered to with a tenacity worthy of a better cause. I 

 refer to the danger that always exists, that young or occasional 

 observers are exposed to, amidst the complexities of minute 

 animal and vegetable life, of concluding that they have come 

 upon absolute evidences of the transformation of one minute 

 form into another ; that in fact they have demonstrated cases 

 of heterogenesis. 



This difficulty is not diminished by the fact that on the shelves 

 of most Microscopical Societies there is to be found some sort of 

 literature written in support of this strange doctrine. 



You will pardon me for allusion again to the field of inquiry in 



which I hxve spent so many happy hours. It is, as you know, 

 a region of life in which we touch, as it were, the very margin 

 of living things. If Nature were capricious anywhere, we might 

 expect to find her so here. If her methods were in a slovenly 

 or only half determined condition, we might expect to find it 

 here. But it is not so. Know accurately what you are doing, 

 use the precautions absolutely essential, and through years of 

 the closest observation, it will be seen that the vegetative and 

 vital processes generally, of the very simplest and lowliest life- 

 forms, are as much directed and controlled by immutable laws, 

 as the most complex and elevated. 



The life-cycles, accurately known, of monads, repeat them- 

 selves as accurately as those of Rotifers or Planarians. 



And of course, on the very surface of the matter the question 

 presents itself to the biologist why it should not be so. The 

 irrefragable philosophy of modern biology is that the most com- 

 plex forms of living creatures have derived their splendid 

 complexity and adaptations from the slow and majestically 

 progressive variation and survival from the simpler and the 

 simplest forms. If, then, the simplest forms of the present and 

 the past were not governed by accurate and unchanging laws of 

 life, how did the rigid certainties that manifestly and admittedly 

 govern the more complex and the most complex come into play ? 



If our modern philosophy of biology be, as we know it is, 

 true, then it must be very strong evidence indeed that would lead 

 us to conclude that the laws seen to be universal break down and 

 cease accurately to operate, where the objects become microscopic, 

 and our knowledge of them is by no means full, exhaustive, and 

 clear. 



Moreover, looked at in the abstract, it is a little difficult to 

 conceive why there should be more uncertainty about the life- 

 processes of a group of lowly living things, than there should be 

 about the behaviour, in reaction, of a given group of molecules. 



The triumph of modern knowledge is the certainty which 

 nothing can shake, that Nature's laws are immutable. The 

 stability of her processes, the precision of her action, and the 

 universality of her laws, is the basis of all science ; to which 

 biologyformsnoexception. Once establish, by clear and unmistak- 

 able demonstration, the life-history of an orgartism, and truly 

 some change must have come over Nature as a whole, if that 

 life-history be not the same to-morrow as to-day ; and the same 

 to one observer, in the same conditions, as to another. 



No amount of paradox would induce us to believe that the 

 combining proportions of hydrogen and oxygen had altered, in a 

 specified experimenter's hands, in synthetically producing water. 



We believe that the melting-point of platinum and the 

 freezing-point of mercury are the same as they were a hundred 

 years ago, and as they will be a hundred years hence. 



Now, carefully remember that so far as we can see at all, it 

 must be so with life. Life inheres in protoplasm ; but just as 

 you cannot get abstract matter — that is, matter with no properties 

 or m ,des of motion — so you cannot get abstract protoplasm. 

 Every piece of living protoplasm we see has a history : it is the 

 inheritor of countless millions of years. Its properties have 

 been determined by its history. It is the protoplasm of some 

 definite form of life which has inherited its specific history. It 

 can be no more false to that inheritance than an atom of oxygen 

 can be false to its properties. 



All this, of course, within the lines of the great secular 

 processes of the Darwinian laws ; which, by the way, could not 

 operate at all if caprice formed any part of the activities of 

 Nature. 



But let me give a practical instance of how, what appears like 

 fact, may over-ride philosophy, if an incident, or even a group 

 of incidents, per se are to control our judgment. 



Eighteen years ago I was paying much attention to Vorticellse. 

 I was observing with some pertinacity Vorticella coiivallaria ; for 

 one of the calices in a group under observation, was in a strange 

 and semi-encysted state, while the remainder were in full normal 

 activity. 



I watched with great interest and care, and have in my folio 

 still the drawings made at the time. The stalk carrying this 

 individual calyx fell upon the branch of vegetable matter to 

 which the Vorticellan was attached, and the calyx became 

 perfectly globular ; and at length there emerged from it a small 

 form with which, in this condition, I was quite unfamiliar : it was 

 small, tortoise-like in form, and crept over the branch on setae 

 or hair-like pedicels ; but, carefully followed, I found it soon 

 swam, and at length got the long neck-like appendage of ^//-!//i?- 

 leptus anser ! 



