Page:The Works of William Harvey (part 1 of 2).djvu/499

 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