Plexus endoiymphaticus 



Sinus dur. matr. 

 transversus 



Sac. endoly m ph 

 (c 



Fig. 4 Camera lucida drawing showing the endolymphatic plexus and its com- 

 munications in a human fetus 54 mm. long (No. 458, Carnegie Collection). 

 The blood vessels were injected with India ink and the whole rendered transparent 

 with wintergreen oil. A portion of the plexus was removed to show the contained 

 endolymphatic sac, and part of the sac was also removed in order to show the 

 drainage of the plexus. The vessels of the rest of the labyrinth are only filled 

 in far enough to show their communication with the endolymphatic plexus. En- 

 larged about 17 diameters. 



79 



