itl the Animal Kingdom. 117 



design ; while the metamorphoses presented in a realization of 

 this design, and the remarks that may be made on develop- 

 ment in general, will apply equally to both ;- it is intended to re- 

 strict the further prosecution of the subject to animals alone. 



The terms " lower" and " higher" animals, will be throughout 

 this paper strenuously avoided, because they are calculated to 

 mislead. Should they occur, it will be as forming part of a quo- 

 tation. Such terms, if used in regard to the organs of relat;< ;i on- 

 ly, arc, to say the least of them, ambiguous; because we do not 

 know what parts of structure may not contribute to constitute 

 these organs. If they be used to describe differences in the de- 

 gree of elaboration only, such application of them presupposes 

 a simply " ascending" or " descending" scale of structure, dif- 

 fering in degree alone, a thing, the existence of which, it is in 

 part the object of this paper to question, and then acknowledge 

 or deny. We therefore disuse them, substituting the expres- 

 sions general and special, simpler and more complex, diffused 

 and concentrated, homogeneous and heterogeneous, less or 

 more elaborate, less or more developed. 



It is important to appreciate exactly, the difference in mean- 

 ing between the terms " individual" and " individuality."" An 

 element, or a set of elements, acquires a separate or distinct 

 existence, i. e. an individuality, and there is thus constituted an 

 individual.* 



The constituent parts of an individual perform certain func- 

 tions, in the sum of which consists its life. These functions 

 are reducible to changes of condition, and of relative position, 

 to dismissal and renewal, of the elements of which the in- 

 dividual is composed ; which changes are not identical in any two 

 individuals. The effect of these continued changes, up to a cer- 

 tain period of life, is a more and more elaborate and special 

 structure, performing more and more diversified and special 

 functions. 



Now, as the elements of an individual cease, in turn, to be 

 constituent parts of the same, the identity of that individual 



" " I exhort you to be particularly on your guard against loose and imle. 

 finite expressions ; they are the bane of all science, and have been remark- 

 ably injurious in the different departments of our own.'' Lateivnce't two Lee- 

 tures; being an Introduction to Comparative Anatomy and Physiology. 

 182C. P. 118. 



