Page:The Works of William Harvey (part 1 of 2).djvu/498

 for the major part without the egg, though they are begun and also perfectly performed within it. Now these actions, as they flow from three faculties, the generative, the nutritive, and auctive, so do three operations follow them. From generation all the parts of the chick result ; from increase and nutrition, the growth and maintenance of its body. From studying the formation of the chick, we perceive that, under the influence of the generative faculty, the parts of the creature which formerly had no existence are produced : the matter of the egg is changed into the organized body of a chicken. But whilst any part or substance undergoes transmutation into another, it must needs be that its proper essence undergoes change, otherwise would it still remain as it was and unaltered ; it must at the same time receive figure, position, and dimensions apt and convenient to its new nature ; and indeed it is into these two states or circum- stances that procreation of matter resolves itself, viz. trans- formation and conformation. The transformative and the formative faculties would therefore be the cause of these func- tions ; and whilst one of them has produced every individual part of the chick, such as we see it, from the chalaza of the egg, the other has given it figure, articulations, and position, fitting it for its destined uses. The first, the transformative or alterative faculty, is entirely natural, and acts without all con- sciousness ; and taking the hot, the cold, the moist, and the dry, it alters all through the substance of the chalaza, and in altering this substance changes it into the component parts of the chick, that is to say, into flesh, bones, cartilages, ligaments, veins, arteries, nerves, and all the other similar and simple parts of the animal, and these, through the proper and innate heat and spirit of the semen of the cock, out of the substance of the egg, that is to say, its chalaza; by altering and commuting, it engenders, creates, produces the proper substance of the chick, imparting at the same time to every substance its appropriate quality. The other, which is called the formative faculty, and which out of similar forms dissimilar parts, namely, giving them elegance through figure, due dimensions, proper position, and congruous number is much more noble than the former, is possessed of consummate sapience, and acts not na- turally [or instinctively], but with election, and consciousness, and intelligence. For the formative faculty appears to have