J 80 PHILOSOPHICAL TRANSACTIONS. [aNNQ I667 . 



at least many parts of the blood, and consequently their fitness for nutrition, he 

 defends the Harveian doctrine of the colliquation of the nourishing juice by the 

 arteries, and its conveyance to the foetus by the veins. 



In the third chapter, the membranes and humours of embryos are considered. 

 The membranes are in some three, in others four, in an egg six. All placenti- 

 ferous animals (if I may assume this word) he affirms to have three membranes, 

 and sows, mares, and women also ; but only two humours. Again, bitches, 

 cats, and conies four membranes, and three humours ; so that the number 

 of the membranes has been hitherto observed always to exceed that of the 

 humours. 



Giving the history of both, he begins from sheep, cows, and other ruminat- 

 ing animals, describing first the chorion, assigning its use, and comparing it 

 with that in deer, sows, mares, women, rabbits, bitches and cats, when with 

 young. Then he proceeds to the description of the allantoides (the membrane 

 immediately encompassing that skin wherein the foetus is wrapped) and thence 

 to that of the amnion, wherein the embryo itself lies swimming in its alimental 

 liquor ; and lastly to that which is observed to be in bitches, cats and rabbits, 

 and contains a very good and nourishing juice ; which how it comes thither, 

 is a difficult inquiry, as well as that other, how the liquor gets into the amnion. 

 To resolve both which our author, having disproved the filtration of the liquor 

 held by Curvey and Everhard out of the chorion into the amnion, and evinced 

 that the liquor in the allantoides, inteijected between those two, is urinous, he 

 concludes, that the alimentary juice passes through the umbilical vessels, by 

 a proper artery, depositing it in those membranes we speak of, and reserving it 

 there for the use of the foetus. 



Concerning the humours he affirms, that all of them in all animals are nu- 

 tritive, except that in the allantoides. He observ^es also, that most ovipar- 

 ous fishes have eggs or spawn, as to sense of one only colour, and but one 

 humour ; yet that the spawn of a skate has a white and a yolk. Birds have 

 mostly three nutritious substances that are visible, viz. a yolk and a double 

 white ; to which upon incubation comes a fourth, colliquated out of the former; 

 the tender embryo feeding upon the two whites, till they being consumed, 

 the yolk of the chick now to be hatched is shut up in the abdomen, and 

 thence by a peculiar duct conveyed into the guts ; and so serves the young bird 

 for breasts it is fed by until the twentieth day. 



In viviparous creatures are found sometimes two, sometimes three humours, 

 and in bitches, cats, and rabbits four ; which perplexes the author as to the 

 giving a reason for it. These humours, he says, he has examined, by con- 

 creting, distilling, and coagulating them ; where he furnishes the reader with 



