226 



ASSIMILATION. 



new case, except in the ordinary way in which the 

 animal is produced. This is but a small matter in 

 respect of positive knowledge, but it is an important 

 one in the prevention of error. 



But when we have followed the progress of assimi- 

 lation through all the steps that have been traced, 

 from the mouth to the discharge of the arterialised 

 blood from the left ventricle into the aorta, for the 

 purpose of being sent all over the body, we have 

 traced the process only to what may be considered 

 as the beginning of its most curious work. Out of 

 that general circulating fluid there have still to be 

 elaborated all the parts of which an animal consists, 

 and all the products of those parts, whether they be 

 turned to use in the system, or discharged out of it. 

 Of the same fluid are formed bones, ligaments, ten- 

 dons, muscles, membranes, skin, hair, feathers, nails, 

 horns, teeth, and all the parts of which an animal 

 with such a circulation as has been described can 

 consist. The blood has even to maintain the vessels, 

 and' furnish the fluids, by means of which it obtains 

 its supply. Those local assimilations constitute the 

 wonder of the matter, in comparison with which all 

 the external actions, habits, and economy of animals, 

 curious as some of them are, sink into comparative 

 insignificance. 



When we contemplate the external actions of ani- 

 mals, we are apt to speak about their reason, and 

 wisdom, and intelligence ; but where is the intelli- 

 gence here ? Even in ourselves, all these operations 

 take place, not only without what we vainly, but by 

 no means correctly, call our will, but without our 

 ing in the least aware of their occurrence. When 

 they are suspended, or in any way go wrong, \ve are 

 indeed admonished of the fact by the uneasy sensa- 

 tions of pain and disease. But when the derange- 

 ment is in those internal and constitutional functions, 

 how little can we tell of what is the matter with us 

 beyond the mere uneasy sensation ? And how often 

 are those who have made the structure and functions 

 of the body the subject of most careful and scientific 

 study nearly as much in the dark as we ? When 

 we find that all these operations are constantly going 

 on, in manners as varied as the species of animated 

 beings, without design, purpose, or knowledge of the 

 creatures, but merely in virtue of that law of the 

 species which has been given to it by its Creator, 

 descending without change through countless genera- 

 tions, what small reason have we to perplex ourselves 

 about the causes of those far more simple external 

 operations which individuals or races perform? If, 

 in the mightier matter, we must admit the operation 

 of Divine wisdom and power, through the fulfilment 

 of the law which Divine goodness has seen meet to 

 institute, with what consistency of philosophy, with 

 what pretensions to even the humblest shade of rea- 

 son can we deny, doubt, or question it in the less? 

 Such conduct cannot be called impious, because im- 

 piety involves the abuse of at least a certain portion 

 of knowledge ; but it is the most gross and utter 

 ignorance ; and as it is but too often ignorance which 

 is vain in its own c.onceit, it is in these cases as 

 hopeless as it is humiliating. 



And yet, wonderful as all these organisations are, 

 working unseen and unknown to the owners, and 

 working with the utmost perfection, the special mar- 

 vel of the whole, that which should humble man in 

 his own eyes, and send him to adore, where adoration 

 is the path of sound wisdom and genuine happiness, 



remains behind. Whence come all those varied 

 organisations, whose functions are so very curious, 

 and performed in so admirable a manner? They, too, 

 are of the same law the same simple but sure man- 

 date, which once given forth at the moment of crea- 

 tion, shall remain and operate immutably till time be 

 no more. " Vtnirh xat ""Eymro? Let the world 

 arise ! And the world arose in all its beauty, and 

 all its inhabitants, in all their forms, functions, and 

 habits, perfect and self-sustained, until He shall 

 command it back into its primaeval nothing. 



And this, too, is effected in the most silent, and 

 apparently the most simple manner. An egg, for 

 instance, which is perhaps the best form in which to 

 contemplate the beginning of life, is found, upon ana- 

 lysis, to consist of very simple materials ; and the egg 

 is walled in by its shell, so that, save the air, through 

 its pores, and the all-pervading influence of heat, it 

 can receive nothing from without no material sub- 

 stance nothing that has weight in the scale can 

 be added to its contents ; and in the progress of its 

 vivification it no doubt gives out matter, a portion 

 of carbon in the state of carbonic acid gas, for it 

 becomes specifically lighter. 



The egg thus contains within its shell both the 

 workman and the materials ; and though, in the 

 usual course of nature, it is hatched by the heat of 

 the parent bird, yet there is no specific virtue in that 

 heat which renders it indispensable for the purpose ; 

 any heat will do, so that it is in the proper degree 

 and maintained with the proper uniformity. If we 

 take in the whole range of oviparous animals, there 

 are far more eggs cast upon the common bounty of 

 nature than there are tended by the animals which 

 produce them ; and those which are so cast fail not 

 a jot more than the others. Countless multitudes of 

 reptiles, fishes, insects, and molluscous animals, com- 

 mit their eggs to the earth or the waters, or fix them 

 upon, or insert them in the bodies of plants or ani- 

 mals ; and these succeed as well as the eggs which 

 are hatched under the most careful bird, or the young 

 of the mammalia, which are brought to maturity 

 in an internal matrix. All these facts, and many 

 analogous ones, which will readily suggest them- 

 selves to the reader, tend to show that, from the 

 very instant that the act of organisation passes upon 

 it, the life which is in the egg is that of a distinct and 

 separate being, endowed with all the powers of assi- 

 milation, by means of which it can evolve itself to 

 maturity, and maintain its existence for the average 

 of that period of life which is the portion of its 

 species. Once begun, the animal organisation does 

 not require, and indeed cannot receive, the aid of any 

 helping hand from without ; but, placed in the proper 

 circumstances, and when not interfered with, the law 

 of nature arranges and adapts these ; it works on for 

 its appointed period, and in its appointed way, free 

 and independent. 



The vital part is, in the recent egg, a very simple 

 matter a little of a jelly-looking substance, barely dis- 

 tinguishable ; yet, by the action of heat, this simple 

 thing elaborates out of the matter contained in its 

 storehouse, those membranes, with their blood-vessels 

 and blood, which are necessary for its own develop- 

 ment. It forms this apparatus gradually as is required, 

 and germ and apparatus then work together, in all 

 the curious operations which take place ere the chick 

 comes out of the egg. Out of the apparently simple 

 contents of that, there are elicited viscera, and bones, 



