186 Transactions of the Society. 



certain particles of living matter belonging to the blood or to some 

 of the tissues. 



When a portion of a mass of living matter moves away from 

 the rest, the moving portion invariably presents a convex surface, 

 of which the portion in the exact centre is of course in advance of 

 the rest and is the point towards which the movement of adjacent 

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

 moved away from the rest and had dragged witli it neighbouring 

 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 forward and determine the direction which is to be taken by 

 those near. As far as can be seen, multitudes of living particles 

 stream in one direction, the greater number being either carried 

 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 surface of smooth ground, and shoals of fishes in water, 

 is evidently determined and often very quickly changed in obedience 

 to impulses aflecting a very few of the great multitude of indi- 

 viduals of which the whole body is composed. These movements 

 cannot, however, correctly be compared with those of a mass of 

 living matter, inasmuch as there is no reason whatever for sup- 

 posing that, in the latter, one jjarticle has the power of choosing and 

 determining, much less of conveying to its neighbours the results of 

 its decision or choice and the request to follow. 



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

 mena we are considering are comparable with the movements occur- 

 ring among iron filings under the influence of the magnet, or with 

 the Brush discharge of electricity, the movements of the streams 

 of highly attenuated moving matter in vacuum tubes, and other 

 changes in place afi'ecting particles of non-living matter. Surely 

 it must be obvious to any one who thinks over the 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 still main- 

 tained 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 come it will be most difficult 

 to get a hearing for any views not in accord with the materialist 

 tendencies of what is miscalled the science of our time. Thought 

 is to be crushed, and any speculations are to be condemned which 

 do not happen to favour the arbitrary dogmas of the purely physical 

 school. But no doubt these attempts, like preceding ones of the 



