6S INTRODUCTION TO SEXUAL PHYSIOLOGY 



The term " foetus " is usually applied to the embryo after it has 



acquired something of its final shape, that is, at about the third 



month. 



Heart 



Hyoid arch 

 Mandibular arch 

 Maxillary process 

 Eye 



l^^^y Fore limb 



Hind-limb 



Fig. 49.— Human embryo, between thirty-one and thirty-four days old. 

 (After His, from Gra>fs Anatomy.) 



Ear 



Fore limb 



Hind-limb 



Umbilical cord 



YiQ^ 50, — Human embryo about six weeks old. 

 (After His, from O'raf/s Anatoiiiij.) 



