VASCULAR DRAINAGE OF ENDOLYMPHATIC SAC 73 



ENDOLYMPHATIC APPENDAGE DUIIING FIRST TWO MONTHS 



The features with which we are chiefly concerned in the pres- 

 ent paper do not become established until toward the end of the 

 second month (embryos over 30 mm. long). A review, however, 

 will be briefly made of the form and relations of the endolymphatic 

 appendage prior to that time. For a more detailed description 



PLEXUS ANT. 



PLEXUS 

 SAGITTALIS 



SIN. TRANSVERSUS 



V. OPTHAL. 



SIN. CAVERNOSUS 



Fig. 1 Profile reconstruction showino; the topography of the membranous 

 labyrinth and the endolymphatic appendage in a human embryo 24 mm. long 

 (No. 632, Carnegie Collection). The principal head veins are shown in solid 

 black. Enlarged about 4 diameters. 



with illustrations the reader is referred to a paper previously 

 published on the development of the membranous labyrinth 

 (Streeter '06) and to a recent paper on the dural sinuses in which 

 special attention is given to the topography of the labyrinth at 

 its different stages (Streeter '15). 



THi: AMKHICAN JOURNAf. OF .ANATOMY, VOL. 19, NO. 1 



