SCIENCE. 



295 



microscopical work which has engaged much of my at- 

 tention during many years, I would remark that many 

 observations have been made upon the structure and ar- 

 rangement of the most delicate nerve-fibres less than the 

 hunched-thousandth of an inch in diameter, and other 

 tissue-elements of very small insects. With due care, 

 facts are ascertained which could not have been demon- 

 strated with the aid of object-glasses magnifying less than 

 from 2500 to 3000 diameters. Not only is the demonstra- 

 tion of structure and arrangement satisfactory, but in 

 many cases a conception of the action and working of the 

 textures during life has been formed, which would not 

 otherwise have been obtained. The exact relation of 

 certain delicate nerve-fibres to the living matter of the 

 nerve in special organs has been determined, and many 

 elementary facts necessary for the determination of the 

 changes constituting nerve action have been ascertained. 



To my mind, however, the study, with the aid of high 

 powers and various improved means of examination, of 

 the phenomena which occur in living matter during life, 

 transcends in importance at this time all other inquiries 

 in which the Microscope takes a leading part. For these 

 changes characterize every form of living matter at every 

 period of its being, and in every condition of health and 

 disease. In every form of living matter which exists or 

 has ever existed, the great mystery of life and death is en- 

 acted under our very eyes, but we have not yet been able 

 to discover the exact nature of the change, though we can 

 prove most conclusively that it is not merely mechani- 

 cal or chemical, as some pertinaciously insist. No 

 chemist or physicist has been able to explain the 

 changes which do occur, or has succeeded in imitating 

 them out of the livirg body. The most diverse structures 

 and the most widely different chemical compounds are 

 produced by changes occurringin particles of living mat- 

 ter which could not be distinguished from one another, 

 and which are equally devoid of color and structure. 

 Many of the current theories on the nature of vital phe- 

 nomena are in advance of some that were propounded" 

 two thousand years ago ; and yet men occupying high 

 scientific position's are found to defend them, and to repeat 

 again and again statements concerning the relation be- 

 tween the living and non-living, which are at vaiiance, 

 not only with facts familiar to every one, but are contra- 

 dicted by the experience and knowledge every person 

 possesses concerning certain vital phenomena of his own 

 organism 



When a particle of living matter is increasing in size 

 — is growing by taking lifeless matter into its substance, 

 and without itself losing anything, is communicating to 

 certain of the elements of this non-living matter, or to 

 combinations of these, the marvellous powers it possesses 

 — movements take place, it may be in every part of the 

 original ma: s. These movements are, however, always 

 most observable, nost ac ive, and most extensive at 

 some part of the circumference. Occurring now on one 

 side, now on the opposite, it is very improbable that the 

 movements in question are determined by any changes 

 occurring in, or by force belonging to, any non-living 

 matter in the vicinity of the living mass. These remark- 

 able movements are universal in the world of life. They 

 are more accelerated in some kinds of living matter than 

 in others, but they are present in all, and in most are 

 discernible at some time or other during the course of 

 existence. Parts of the living matter continually tend to 

 move away and separate from the rest, not in conse- 

 quence of any attraction between these and surrounding 

 matters outside, nor from any repelling influence exerted 

 by parts of the mass itself upon other parts. There 

 seems to be an active tendency on the part of different 

 portions of a living mass to move away fiom the rest 

 and so to detach themselves, and, having acquired vital 

 power, to become independent, and to increase and then 

 divide. This remarkable tendency on the part of every 

 kind of living matter to divide and subdivide begins to 



operate as soon as the original mass has attained a cer- 

 tain size, and it seems to increase in intensity as the liv- 

 ing matter approaches its proper dimensions. Invariably 

 when a certain size has been retched, which, however, is 

 different for different kinds of living matter, division 

 occurs. The size is always, within certain very moderate 

 limits, fixed and defimte for the living matter of each 

 particular species of living being. Among the lowest 

 forns of existence, however, no definite limit of size has 

 to be attained befcre division can occur. Particles 

 smaller than the smallest particles that can be seen with 

 the aid of the highest magnifying powers freely divide 

 and subdivide, and there is reason to think that under 

 certain conditions the division and infinite multiplication 

 of the animate particles may continue tor a considerable 

 time, none of them attaining their fully developed form 

 or dimensions. In higher foims of life, premature divi- 

 sion of a living mass before it has grown for a proper 

 time and reached a certain size, is very detrimental, and 

 in many cases disastrous ; for it is associated with deg- 

 radation or even complete loss of formative, construc- 

 tive, and developmental power. In seme cases, by the 

 rapid multiplication and division of the paiticles, the well 

 t eing of the whole organism is jeopardized, and death 

 may be occasiored by the changes brought about by 

 great increase and rapid growth and multiplication of 

 certain particles of living matter belonging to the blcod 

 or to some of the tissues. 



When a portion of a mass of living matter moves 

 away from the rest, the moving portion invariably pre- 

 sents a convex surface, of which the portion in the exact 

 centre is of course in advance of the rest and is the 

 point towaids which the movement of adjacent portions 

 tends. It almost seems as if one minute portion had moved 

 away from the rest and had dragged with it neighboring 

 portions, the power of the particles constituting which was 

 not strong enough to act in opposition to it or to resist its 

 influence. These seem to yield and follow the one or 

 few particles in which the movement is strongest, and 

 which seem to act the part of leader. It may be that 

 certain particles here and there, having attained a larger 

 size, or from being more active than the rest, move for- 

 ward and determine the direction which is to be taken 

 by those near. As far as can be seen, multitudes of liv- 

 ing particles stream in one direction, the greater number 

 being either cairied along by the very few or irresistibly 

 drawn onwards by them. The direction taken by flocks 

 of birds and clouds of insects in still air or upon the sur- 

 face of smooth ground, and shoals of fishes in water, is 

 evidently determined and often very quickly chaDged in 

 obedience to impulses affecting a veiy few of the great 

 multitude of individuals of which the whole body is com- 

 posed. These movements cannot, however, correctly be 

 compared with those of a mass of living matter, inasmuch 

 as there is no reason whatever for supposing that, in the 

 latter, one particle has the power of choosing and de- 

 termining, much less of conveying to its neighbors the 

 results of its decision or choice and the request to 

 follow. 



It will, of course, be said by some that the remarkable 

 phenomena we are considering are comparable with the 

 movements occurring amoDg iron filings under the in- 

 fluence of the magnet, or with the Brush discharge of 

 electricity, the movements of the streams of highly at- 

 tenuated moving matter in vacuum tubes, and other 

 changes in place affecting particles of non-living matter. 

 Surely it must be obvious to any one who thinks over the 

 1 facts of the case that no true analogy has been shown to 

 exist between the movements of living particles and 

 those of any form of non-living matter. Nevertheless, 

 the existence of such analogy is st ill maintained by a 

 few, although the fallacy of the arguments upon which 

 it is supposed to rest has been many times pointed out. 



I dare say that for some time to ccme it will be most diffi- 

 cult to get a hearing lor any views not in acccrd with the 



