/ 



VIL 



Im 



>; 





^'^^^e the 



yah 



ftll, 



fee 



e fiavilij 



edl 



•"^ted fro 



m 



into a 



pro. 



caudex down 



^" individual 

 litly produced 

 that this new 

 It ; and that, 

 it us foritsre* 



:mmunlcation 



leaf, and the 

 vXXlX. 2. 2. 

 {lation and 



bud and 

 by takin 

 bud in it5 



S^ 



new 



:en 

 leiv 



D 



as vv 



ell as the 



a 



Iburnuin 



> 



or 



• and 



in 



ication 

 with veg^f^' 



III!' 



jires 

 5 the 



both 

 chicle 



in 



nn 



that 







fthe 



Sect.VII. I. 2. 



REPRODUCTION 



93 



fetus In the womb of viviparous animals in the whole of its nutnnrient 



beino- at firft provided for it, which confifts of the albumen 



of th'^e eco-, which is contained in cells, and is of different degrees of 



hite 



DO 



fiflency 



that which is moft fluid being firft confumed 



h 



the hquor amnu 



creted by adapted glands from 



wanted 



ment of the fetus in utero, is gradually fe- 



the blood of the mother, as it is 



Another difference between the condition of the chick and of the 

 fetus confifts in the manner, by which their blood acquires its necef- 

 fary oxygenation. In the fetus this is done by means of the placental 



'^ ' ; of the 



veflcls. whofe extremities are inferted 



the blood-veffel 



d receive oxygen through their molft membranes from th 



\3terus, ar 

 paffing currents of the 

 Vol. I. Sea. XXXVIII, 

 bation a membrane is fe 



moth 



blood, as defcribed in Zoonom 



Whereas in the egg after a few days 



;n, which includes the albumen, and fpreads 

 the extremities of its fine blood- veflels on the moift membrane, which 



the air at the broad end of th 



Db 



which 



fionally 



renewed, as would appear by its being feen fo eafily to pafs through 

 the fhell, when an egg is covered wkh water in the exhaufted re- 

 ceiver of an air-pump. 



The condition of the embryon bud, when the parent leaf-bud dies, 

 I conceive to be fimilar to that of the chick in the egg, when that Is 



- - 



feparated from its parent 

 of nutriment provided for 



Each of them has at this time a refervol 

 : that of the chick confifts of the albu 



men, or white of the egg above mentioned ; and that of the bud cc 

 fifts of mucilage and fugar, which are depofited in the alburnum 



D 



fap-wood, or in the roots of the pla 



And fecondly, I 



that the extremities of a fine fyftem of veffels belonging to the bud 



may terminate on the moift membrane, which covers the horizontal 



air-veffels defcribed in Sed, III. 2. 6. as thofe on the chorion of the 



chick terminate on the air-bag of the egg, and thus acquire the ne- 



ccffary oxygenation of their vegetable blood. 



This 



