ORIGIN OF LIFE IN THE CELL. 149 



become an independent life is the result. Development is the 

 sequel to generation. 



The reproductive process in itself consists in the formation 

 of certain cells from preceding cells through well-defined 

 procedure. It may be by subdivision, by gemmation, or 

 through the intervening act of generation. When, by sub- 

 division or by gemmation, each act of development appears 

 to diminish the germinal capacity ; when, by generation, the 

 germinal capacity appears to be renewed. By subdivision is 

 meant the method of multiplication of cells, which, for a time, 

 may retain their juxtaposition ; by gemmation, the forma- 

 tion of cells which are to be cast forth, the commencement of 

 a separate existence. The reproductive process includes the 

 repair of injuries and the increase and renewal of parts. 

 Growth may be the sequel to reproduction. 



Life may be said to commence with the cell, for it is only 

 at this stage that we ordinarily recognize individuality. In 

 the higher animal structures, as in the mammalia, we have 

 the whole structure either built of or derived from cells, pre- 

 senting a most varied and complex appearance as viewed in 

 their completed state, but which, when studied with reference 

 to their history and development, are seen to be all derived 

 from this same formative element. Each cell is or has been 

 at some time, within certain limits, an individual and inde- 

 pendent whole, in which the vital processes are or have been 

 repeated ; as in one, so in all. Although presenting this 

 apparent individuality, yet, in the animal structure, these 

 separate units are all combined, each with all, to form the 

 harmonious whole, — the animal life. 



The study of the cell is the foundation from which the 

 science of breeding is to be built up, for natural law is univer- 

 sal and simple and unvarying, acting on all alike, but its 

 actions disguised by environment. That the law may be seen 

 in its primal force, it is necessary that its workings should be 

 sought for amid the simplest conditions and amongst the least 

 complexity of structure. 



THE CELL. 



The cell proper, or the ideal cell, is a homogeneous and 

 extremely simple structure, which may be defined as merely 



