VASCULAR DRAINAGE OF ENDOLYMPHATIC SAC 



77 



munications along the endolymphatic appendage. It also an- 

 astomoses with the posterior dural plexus. These blood-vessels 

 and their communications can be recognized in embryos 20 mm. 



Pix. Chor 



Cerebe 



Cartilage 



Utriculus 



dolymph. 



Ty m p a n u m 

 Ductus cochlearis 



Sinus 

 transver-us 



Fig. 3 Sagittal section through the ear region of a human fetus 52 mm. 

 long (No. 448, Carnegie Collection). The blood vessels are injected with India 

 ink and are represented in solid black. The endolymphatic sac is outlined as a 

 clear space and surrounding it can be seen its dense capillary plexus and the 

 manner in which this drains into the transverse sinus. Enlarged about 10 

 diameters. 



long, but subsequent to that they rapidly increase in size and 

 importance, and in embryos 50 mm. long obtain a characteristic 

 appearance which we shall now proceed to describe. 



