PHYSIOPHILOSOPHICAL SYSTEMS. 353 



tendencies, the more heterogeneous are the elementary 

 parts which this life brings into action. The same is true 

 of the single parts of any apparatus. That organization 

 is higher in which the separate parts of an entire system 

 differ more among themselves, and each part has greater 

 individuality, than that in which the whole is more uni- 

 form. I call type the relations of organic elements and 

 organs, as far as their position is concerned. This relation 

 of position is the expression of certain fundamental con- 

 nexions in the tendency of the individual relations of life ; 

 as, for instance, of the receiving and discharging poles of 

 the body. The type is altogether distinct from the de- 

 gree of perfection; so that the same type may include 

 many degrees of perfection, and, vice versa, the same de- 

 gree of perfection may be reached in several types. The 

 degree of perfection, combined with the type, first deter- 

 mines those great animal groups which have been called 

 classes. 1 The confounding of the degree of perfection 

 with the type of organization seems the cause of much 

 mistaken classification; and in the evident distinction 

 between these two relations we have sufficient proof that 

 the different animal forms do not present one uniserial 

 development from the Monad up to Man." 



The types he has recognized are : 



I. The Peripherie Type. The essential contrasts in 

 this type are between the centre and the periphery. 2 The 



1 From this statement it is plain complication of structure as deter- 

 that Baer has a very definite idea of mining the relative rank of the orders, 

 the plan of structure, and that he and the different ways in which, and 

 has reached it by a very different the different means by which, the 

 road from that of Cuvier. It is clear plans are executed, as characteristic 

 also that he understands the distinc- of the classes. 



tion between a plan and its execu- 2 Without translating verbatim 



tion. But his ideas respecting the the descriptions Baer gives of his 



different features of structure are not types, which are greatly abridged 



quite so precise. He does not dis- here, they are reproduced as nearly 



tinguish, for instance, between the as possible in his own words. 



AA 



