VOL. II.] PHILOSOPHICAL TRANSACTIONS. 1 79 



together with a very ingenious assignation of the cause of that variety. Where 

 do occur many uncommon observations concerning the difference of milk in 

 ruminating and other animals ; the various degrees of thickness of the uterine 

 liquor in oviparous and viviparous creatures ; the property of the humour, turn- 

 ing into eggs, with a hint of the cause of their being excluded, and not 

 quickened and formed within ; as also, of the cause of moles in the womb, 

 and of many kernelly and fleshy substances in other parts of the body ; where 

 he takes notice of a concretion seen by himself grown to the cone of the heart, 

 of nine ounces weight, in a healthy body, that died of a violent death ; and of 

 the like adhering to the spleen, kidneys, and liver, without any perceived trou- 

 ble to the animal ; yea of some found within the heart itself. 



He adds the number, shape and use of these placentas ; and first observes, 

 that those that are kernel-bearing (glandulifera) animals, or chewing the cud, 

 have many ; and those that are cake-bearing (placentifera) have for the most 

 part one cake for each foetus ; but a woman commonly but one, though she 

 happen to have many embryos. 



He annexes a particular description of the placenta of a woman, as the most 

 considerable, and teaches how it may be most conveniently severed from the 

 vessels to render them conspicuous, which are a numerous offspring of arteries, 

 veins and fibres ; of the last whereof he inquires whether they be the capillaries 

 of the arteries and veins, or nervous. 



The shape of that in a woman is orbicular, about a foot large, and two 

 inches thick ; one of its superficies convex, but uneven, the other concave, 

 and every where sticking close to the chorion. 



The use of the placentas is known to be, to serve for conveying the aliment 

 to the foetus. The difficulty is only about the manner. Here are examined 

 three opinions of Curvey, Everhard and Harvey. The two former do hold, 

 that the foetus is nourished only from the amnion by the mouth ; y^t with this 

 difference, that Curvey will have it fed by the mouth when it is perfect, but 

 whilst it is yet imperfect by filtration only through the pores of the body, and 

 by a kind of juxta-position ; but Everhard, supposing a simultaneous forma- 

 tion of all the instruments of nutrition together at first, and esteeming the 

 mass of blood by reason of its asperity and eagerness unfit for nutrition, and 

 rather apt to prey upon, than feed the parts, maintains that the liquor is sucked 

 out of the amnion by the mouth, concocted in the stomach, and thence passed 

 into the milky vessels, even from the beginning. Meantime they both agree 

 in this, that the embryo doth breathe, but not feed through the umbilical 

 vessels. 



This our author undertakes to disprove ; and having asserted the mildness of 



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