592 



DEVELOPMENT 



Fig. 283. 



[CHAP. XLI. 



Human foetus between the twenty-fifth and twenty-eighth days, to shew the relative position of 

 several organs, a. Chorion with tufts developed over the greater part of its surface, b. Amnion ; 

 tween the situation of the two b's the amnion forms a sheath which invests the structures which compose 

 the umbilical chord, c. Position of Allantois with the vessels upon it which ramify in that part of the 

 chorion where the placenta is developed, d. Umbilical vesicle with its narrow pedicle and trunks of 

 omphalo-mcsenteric vessels which spread out upon its surface, e. The point at which it opens into 

 the intestine. /. Corpora Wolfflana. g. Liver, h. Heart, i. Rudiments of anterior ; and k, rudimentary 

 posterior extremities. I. Branchial fissures and visceral arches, m. Cavities of nose and mouth not yet 

 separated, n. Rudimentary eye. o. Rudiments of ear. After Coste. 



