BLOOD. 



519 



surface, and less affecting the general system than the 

 animal poisons. A numbing or suspension of the 

 sensal energy, rather than a corruption of the system 

 through the medium of the blood, appears to be the 

 effect even of these. When, however, one animal 

 acts upon another, not by specific organs, which have 

 a mechanical effect, but physiologically, it acts on 

 the blood. 



As life is known to us on\y as motion, so the blood 

 of an animal is the indication of life only in so far as 

 it moves or circulates. This motion is faster in some 

 animiils and slower in others ; there are some in 

 which it is hardly perceptible, and there are others in 

 which (as in the case of hybernation, and the more 

 temporary one of fainting) it appears to be merely 

 suspended. But when these suspensions take place, 

 whether for a longer or a shorter period, all the other 

 functions of the animals are suspended also. The 

 first sign of life in the hybernating or the fainting 

 animal is a renewal of the circulation. 



Thus we are warranted in concluding, that the 

 circulation of the blood is the original and charac- 

 teristic function of animal lite. Nor are we left to 

 inference on this point, though inference here comes 

 as near to demonstration as it possibly can come. It 

 is true that, in the perfectly developed animal, all the 

 functions, and all the systems by means of which 

 those functions are performed, are so intimately con- 

 nected, form so much parts of one whole, which can 

 exist only as a whole, that if any one of them is 

 deranged, it deranges all the others. But, when we 

 examine the animal in its rudimental state, and trace 

 its progress towards maturity, we find that the system 

 of the blood is in all cases the first which is developed. 

 When we say " in all cases, " we of course mean all 

 those which observation can reach, for there are 

 some which we have no means of observing, and 

 others which, from the colour of the blood, we are 

 unable satisfactorily to observe. In the case of all 

 animals which have red blood, blood and blood-vessels 

 are the first indications of rudimental life. This is very 

 apparent in the eggs of birds ; and, though there 

 observations are not so easily made, the same is the 

 case in the eggs of fishes. When the rudiment of 

 the chicken is first discoverable, it is as a heart and 

 blood-vessels ; and, as was long ago observed by 

 Haller, these can be distinctly seen before there is a 

 single vestige either of brain or of lungs. This first 

 rudimental stage may be considered as the very lowest 

 state of animal life, the simplest one of organisation 

 in the chicken ; and as there are different degrees ol 

 perfection, or, to speak more accurately, of organic 

 development in animals, according to the different 

 parts which they are to act in nature's economy, it i 

 not only perfectly consistent, but even in strict ac- 

 cordance with what we observe of that economy, tha' 

 there are animals which never get beyond this firs 

 rudimental stage of organisation. But we can trace 

 nothing of the kind in vegetables, whether in their 

 rudimental stages, or when they are most fully de 

 veloped. Therefore we have the character of the 

 animal, as such, stamped at the first development o 

 the germ, and in the simplest of the kingdom : o 

 rather, that character is of itself the development 

 the animal as distinct in kind from every other pro 

 duction of nature. Therefore, we must discard al 

 the attempts which have been made to confound th 

 physiology of plants with that of animals, and all th 

 conclusions which have been verbally drawn iron 



hose attempts, as equally repugnant to rational 

 heory and practical observation, and wholly un- 

 vorthy of any one having the slightest pretensions 

 o philosophy. 



We are in the habit of saying that certain systems 

 r structures of animals, or that certain animals alto- 

 gether, are organised upon particular parts, as that 

 ^ertebrated animals are organised upon the spinal 

 jolumn, that other races are organised upon the ali- 

 mentary canal, and that others again are articulated 

 ipon the crust or the integument. In as far as the 

 iction of the animals is concerned, these references 

 >f particular organisations and marks of organisation 

 o certain structures, as organs or bases, are no doubt 

 rue ; but it is to be understood that the primary and 

 ^rand organisation of every animal is upon the sys- 

 ,em of the blood, as that in all the species is the 

 iniversal elementary matter out of which every ani- 

 mal structure and animal whatever is formed. We 

 viiow not how far absorption at the surface may, in 

 some cases, assist internal assimilation, or even upon 

 mergency render it unnecessary, just as we do not know 

 low far the application of air to the surfacee of the 

 jlood vessels may assist the lungs or gills, or even 

 "t as a substitute for them in respiration ; but we 

 annot imagine a case in which the body of an animal 

 an either grow or be nourished without a circulation 

 of the blood. We have reason to believe, too, that, 

 iii all cases, the circulation of the blood, without 

 which there can he no action of animal life, is carried 

 on by muscular exertion, over which what is called 

 the will of the animal has no controul ; and, by the 

 way, this furnishes an unanswerable argument against 

 the existence of will as usually defined by writers on 

 physiology, whether animal or mental. Those actions 

 of the animal frame which are supposed to result from 

 the exercise of this imaginary power of will, are all 

 immediately muscular, or ultimately resolvable into 

 muscular action of some kind or other ; for even the 

 most doting believer in this self-contradictory notion 

 never went so far as to alledge that he could " will a 

 thought ;" and yet as all human action is the result 

 of thought, even in those cases which are called 

 " thoughtless," there is no need for inventing an 

 original power, which demonstratively has no con- 

 cern with the origin of the business, to bring up that 

 portion of the rear which must follow the unwilled 

 part. As well might he who has the fountain say 

 that he wills the stream, or he who has the tree claim 

 the power of willing the apples. The cause of the 

 outward act, whether in man or in any other animal, 

 is the inward impulse ; and though we may not be in 

 every or in any case able to trace it to its primary 

 origin, no finite being can create the impulse any 

 more than it can create itself. As the animal impulse 

 must be supposed to be always stimulated by some- 

 thing material something which has an entity or 

 separate existence, and not by a relation which is 

 cognisable by mind only, we may naturally suppose 

 that it begins with the development of the vital sys- 

 tem, in the first pulse of the rudimental heart ; but 

 that there is not any external knowledge of it till sens- 

 ation, either general or located to a particular organ 

 for a particular use, connects it with the external 

 world. 



In this, as well as in every other point of view, a 

 knowledge of the blood and vital system of animals, 

 as their grand characteristic, becomes of the highest 

 importance, not only to the proper understanding of 



