January 22, 1886.] 



SCIENCE. 



83 



particular the insect type. This proposition that 

 the arthropod form is best adapted for small 

 animals, and the mammalian form for large 

 ones, is one of the points insisted upon through- 

 out. 



Amongst other differences are the following : 

 The nervous impulses would be conducted to the 

 centre in 1-10 the time, and his reflex movements 

 and reactions would be quicker. A water-rat can 

 see the blaze of a gun and dip under the water 

 before the shot has time to reach it. With regard 

 to warmth, it is shown that the body surface of 

 a small animal gives off more heat proportionately 

 than that of a large one : hence small birds have 

 a thick covering, or, again, the small animals 

 become cold-blooded. 



But we will leave this part of the subject to con- 

 sider what may be called a micro-psychology. Some 

 rather curious conclusions are drawn with regard 

 to the sense of sight. While the same amount of 

 light will affect the retina of the meso- and the 

 micro-man, nevertheless, owing to the difference 

 in convergence of the two eyes ( upon which de- 

 pends the inference of distance), the micro-man 

 will judge things to be smaller and nearer than 

 the meso-man. His horizon would be much 

 more limited, and in seeking an object he 

 would be less apt to find it. 



As to hearing. As micro-animals live in a condi- 

 tion where a constant noise is present, they acquire 

 special organs for making loud noises, such as are 

 found on the legs of some insects ; while, of course, 

 their hearing is less available to them than in the 

 case of larger animals. 



The general principle with regard to the nervous 

 system is this : as the amount of nervous matter 

 necessary to the needs of a small animal is pro- 

 portionately much smaller than in a larger animal, 

 such nervous matter becomes available for other 

 purposes, and thus very fine sensibility to small 

 physical variations, and the development of pecul- 

 iar sense-organs, become possible. Eyes and ears 

 are multiplied, touch-organs of various kinds be- 

 come numerous, and there is more room for 

 variability than in higher animals. 



This theory makes it probable that small animals 

 are endowed with a sensibility for fine discrimina- 

 tions of temperature, barometric pressure, moist- 

 ure, and so forth, which is unknown to us ; and 

 thus we account for the observation that animals 

 take cognizance of the approach of a storm before 

 man does. 



With regard to psychic life, the following state- 

 ments will be of importance : the micro-animal 

 procures its food for a given period with less 

 trouble than a meso-animal, it builds its house in 

 a much shorter time, it foresees natural changes 



much better, and its movements are quicker. 

 The result will be far-reaching forethought by 

 means of house-building and harvesting instincts. 

 Any act desirable for the moment, the meso- 

 animal will be apt to neglect on account of the 

 bother of doing it. A man sees a spot on his 

 writing-desk for years, and never cleans it up ; he 

 decides to learn by heart a table of constants which 

 has to be looked up with trouble each time, but 

 never does it. This dread of labor causes most 

 kinds of neglect. But with the micro-animal the act 

 follows the word ; there is no trouble, and thus 

 much annoyance and danger to health are avoided. 

 In the case of approaching danger, say of a storm, 

 a meso- and a micro-animal will act very differ- 

 ently. The meso-animal recognizes the danger 

 only when it is near, is flurried and frightened, 

 has no time to build a shelter, and must seek a 

 chance one. The micro-animal knows that the 

 danger is not very near, that he has ample time to 

 build a shelter, and need not trust to chance. And 

 thus we see why many of the smaller animals 

 prefer to build a new nest, to protecting or 

 finding an old one, it is so readily done. By 

 arguments which it would be difficult to repro- 

 duce, the conclusion is reached that the train of 

 thought of this micro-animal is related to that of 

 the meso-animal somewhat as a minuet to an 

 opera of Wagner's, or a frieze pattern to a painting 

 by Kaulbach ; also that his conceptions would 

 tend to be mathematical and regular. But in 

 general it may be said that in psychic life the 

 meso-man would have the advantage of the 

 micro-man. 



This very partial account of these speculations 

 will, perhaps, serve to show their general ten- 

 dency. They certainly belong to a class of think- 

 ing which is rather foreign to recent thought, but 

 bring with them a suggestiveness which makes 

 the problem discussed a very interesting one. The 

 most serious objection is that very little attempt is 

 made to show that the theory fits the facts 

 (which might easily have been done) , and more 

 attention is paid to select facts that seem to fit the 

 theory. As particularly worthy of consideration, 

 may be noted the argument that when propor- 

 tionately less of a certain tissue is needed for 

 actual sustenance of the animal, more of it be- 

 comes disposable, and is subject to variation. It 

 would seem possible that some valuable facts 

 might be attained by a careful experimental study 

 of the problems suggested by these theoretical con- 

 siderations ; and while they will not be sufficient, 

 as they have been to our author, to rear upon 

 them a whole physiology, a whole zoology, and a 

 whole psychology, they will do a unique service 

 to science. 



