■306 SfhiSiure of Eggs, 



cliarafter in each fpecies. He propofes to give to this' ar- 

 ticu'atiou the name of the os tinguinalis. 



ANIMAL THYSIOLOGT. 



Leveille has given a very curious work on the manner in 

 which young oviparous animals are nouriflied in the egg. 

 He compares it with that in which nutrition is performed iu 

 the fcEtus of mammalia, ahd (hows : 



1. That the foetus of mammalia is nouriflied only by the 

 umbilical cord, and that it receives no nourifliment by the 

 mouth : that the fame thing takes place in the young ovi- 

 parous animal cnclofed in the egg ; and to prove it, he gives 

 the anatomy of the egg, and of the membranes which envelop 

 the foetus. 



2. That the egg, when incubated, confifts of thetye {cica- 

 tr'icula), the yolk, three diftinft albumens, an abforbing ca- 

 nal, five membranes, fanguine and ferous veflels. 



3. That the third albumen is divided into two parts, united 

 by a very thin prolongation : that their pofition is not at the 

 two oppofitc poles of the volk, and that each has for its 

 centre an annular cordon ; in one of them it is membrana- 

 ceous, in the other vafcular. 



4. That there exifts a communication between the albu- 

 minous mafs and the capfule of the yolk, by means of this 

 abforbing conduit. 



5. That the yolk has no fufpcnding ligament, and that it 

 floats at freedom in the interior of the white. 



6. That the volume of the albuminous mafs decreafes in 

 proportion to the time of incubation, while that of the yolk 

 increafes ; which feems to prove that the one abforbs the 

 other. 



7. That the firll albumen having no communication with 

 -the other two, there is reafon to prefume that it is abforbed 



bv the vellels of the facciform membrane. It is this which 

 is ceuicuted to the fliell of the egg, except at the broad end. 



i5. That the yolk, beiides its augmentation of bulk, has 

 very groat fluidity ; and that it is abforbed by the vafcular 

 membrane, which forms its proper tunic. 



9. That it is proved by expcriaice that there are no yellow 



veflels 



