12C) BIOGRAPHICAL SKKTCH OF HENRY MILNE-EDWARDS. 



vided with orifices for receiving iiouri^lmient and lor tlirowing- oil' waste 

 matter, also with fixed conditions of life and a definite form. Next, 

 the digestive apparatus is divided into several regions, one designed 

 for the introduction of food, another for its chemical o})erations, and 

 still another for the absorption of nutritive juices. The form of each 

 of these regions is again subdivided, prehensile organs are seen to 

 appear employed for seizing prey, other organs employed in sharing 

 and submitting it to a preliminary mechanical i)reparation. Special 

 glands are observed that manufacture cheiaical agents designed to 

 effect changes in the various kinds of food. In other cases the trans- 

 portation of digested material instead of ])eing effected by contact and 

 by means of diffusion among the tissues, gives place to a new appara- 

 tus which carries them thoughout — this is the vascular system — and 

 by virtue of a growing specialization it develoi)S a double current for 

 distributing the fluids even to the most remote organs, Avhere they give 

 up their nutritive elements, and are brought back to the center to again 

 resume their first ofitice; from this process the vessels and the heart 

 result, which again sei)aTat<' into different ]»arts. each ])erforming a 

 distinct act. 



In this may be observed all the a])plications of the new principle and 

 its infiuence upon the division of organic labor as distributed into 

 multiplied functions, each one performed by a suitable apparatus 

 resulting from the specialized development of one part or another, 

 hencefortli to be set apart for one sole purpose, whilst it becomes 

 insufficient if not absolutely useless for all other purposes. It mustl)e 

 understood in addition to this that this i)aitial function remains neces- 

 sarily co-ordinated witli other fuuctions in the general physiological 

 action of which it ])erforms one part, that is to say, that the complete 

 system while centralizing more and more always as a whole, becomes 

 particularized into special oigans. 



The result of this provision is Avork better done and continually' per- 

 fected, so that as a result of tlie princii)le of the division of labor we 

 have the perfecting of particular organs for a special purpose, along 

 with the elevation of tl)e general animal ty])e and of the part it i)Iays 

 in the order of nature. 



Advancing still further, tlu' ])rinf'iple of the division of labor enables 

 us to reach the heart itself of zoological pliilosophy. From the moment 

 that the organ does not create the function, but is on the contrary 

 modified and adapted by it, from the point of view of classification the 

 form and even the existence of the organ do not assume the arbitrary 

 significance it- was formerly deemed nci essary to attribute to them; it 

 it is no longer permissible to si)eak o^' established and preponderating 

 types. On the conti-ary the zoological siguiticance of one anatomical 

 tyije varies continually in passing from one group of aiiimals to another. 

 It varies even in sinnlar parts of the same animal, according to the 

 diverse fuuctions the <n'gan is called upon to iierform. 



