428 ZOOLOGY. 



organization to which the third eyelid, in man a mere rudi- 

 ment, attains in them. Not wanted in man, the organ sinks 

 to its rudimentary ;md scarcely perceptible condition. Of 

 essential service in liinls. it suddenly acquires its seemingly 

 highest development. Yet the organ was always present, 

 rudimentary in one, developed in the other. Let us take 

 another instance. 



" The adult, or grown-up man, has, as you all no doubt 

 know, three bones to each toe, with the exception of the first ; 

 these three bones are connected to each other, and to the 

 metatarsal bone, their supporters, by three joints. In the 

 feet of birds you meet with four or five bones in certain of 

 the toes ; and it might seem to you that the feet of birds 

 were formed on a different numerical plan, at least; but it is 

 not so : for in man, as in birds, each digital bone is formed of 

 two elements, or distinct bones, at first, that is, in the .young 

 of each: as the bird grows up, they remain distinct in man. 

 on the contrary, they unite that is all. The arrangement is 

 not only analogous, but homologous or identical, in the 

 strictest sense of the terms. 



"Again, remember that a thousand similar instances might 

 be given : I merely select a few of the easiest understood. 



" In man there is a little cartilage, scarcely perceptible, 

 connected to one of those bones occupying the nostrils, called 

 turbinated bones. It may or it may not in him serve any 

 purpose; that is a matter of pure indifference. It is a rudi- 

 mentary and a useless organ seemingly. Now, mark the 

 extension and development of this cartilage or organ in the 

 horse still more in the whale ; in the horse, where it most 

 admirably serves to shut off the great cavities of the nostrils 

 from the vestibular cavities in front thus protecting them 

 from foreign bodies : in the whale, acquiring their presumed 

 highest development, these cartilages, now grown to the 

 size of bolsters, return after breathing, into the vast nos- 

 trils of the whale from which they had been momentarily 

 withdrawn, filling them up, sealing them hermetically against 

 the pressure of a thousand fathoms deep of water, which they 

 sustain with ease, when, plunging into the vast abyss of the 

 ocean, the giant of nature seeks to avoid his enemies. 



" Let us now briefly review the progress we have made in 

 this the highest of all analyses : deepest of all theories : most 

 important to man. Man, we have seen, stands not alone, he 

 is one of many ; a part and parcel of the organic world, from 

 all eternity. That organic world is the product of secondary 



