ON GENERATION. 399 



exact cognizance and foresight both of the future action and 

 use of every part and organ. So much of the primary action 

 of the egg, which is the generation of the chick, and to accom- 

 plish which both the semen of the cock as agent and fecun- 

 dator, and the chalaza as matter are required. In the second 

 place comes accretion or growth, which is accomplished by nu- 

 trition, whose faculties consist in attraction, retention, concoc- 

 tion, expulsion, and, finally, apposition, agglutination, and assi- 

 milation of food." 



But for my part I neither regard such a distribution of actions 

 as correct, or useful, or convenient in this place. It is incorrect, 

 because those actions which he would make distinct in kind 

 and in time for instance, that parts are first produced similar 

 by the alterative or transformative faculty, to be afterwards 

 fashioned and organized by the formative faculty, and finally 

 made to grow by the auctive faculty are never apparent in the 

 generation of the chick; for the several parts are produced and 

 distinguished and increased simultaneously. For although in the 

 generation of those animals which are formed by metamorpho- 

 sis, where from matter previously existing, and already adequate 

 in quantity and duly prepared, all the parts are made distinct 

 and conformed by transformation, as when a butterfly is formed 

 from a caterpillar, a silkworm from a grub, still in generation 

 by epigenesis the thing is very different, nor do the same pro- 

 cesses go on as in ordinary nutrition, which is effected by the 

 various actions of different parts working together to a com- 

 mon end, the food being here first assumed and retained, then 

 digested, next distributed, and finally agglutinated. Nor is the 

 similar constitution the result of the transformative faculty, void 

 of all foresight, as Fabricius imagined ; but the organic comes 

 from the formative faculty which proceeds with both con- 

 sciousness and foresight. For generation and growth do not 

 proceed without nutrition, nor nutrition or increase without 

 generation ; to nourish being in other terms to substitute for 

 a certain quantity of matter lost as much matter of the same 

 quality, flesh or nerve, in lieu of the matter, flesh or nerve, 

 that has become effete. But what is this but to make or 

 engender flesh or nerve ? In like manner, growth cannot go 

 on without generation, for all natural bodies are increased by 

 the accession of new particles similar to those of which they 



