George L. Streeter 165 
DESCRIPTION OF PLATES I AND II. 
The reproductions shown on these plates represent different views, in most 
eases lateral, front, and median, of seven selected models showing the mem- 
branous labyrinth and acoustic complex reconstructed from the following 
human embryos: No. 148, 4.3 mm.; No. B17, 6.6 mm.; No. 163, 9 mm.; No. 
109, 11 mm.; No. 175, 13 mm.; No. 22, 20 mm.; No. 86, 30 mm. The colors, 
yellow and red, are used to indicate respectively the cochlear and vestibular 
divisions, and in general nerve fibers can be distinguished from ganglion 
cell masses by their lighter tone. The pictures represent a magnification of 
. 25 diams. 
The following abbreviations are used: 
absorpt. focus =area of wall where absorption is complete. 
amp.— ampulla membranacea. 
crus = crus commune. 
c. 8c. lat. = ductus semicircularis lateralis. 
c. sc. post. = ductus semicircularis posterior. 
c. $C. sup. = ductus semicircularis superior. 
coch. or cochlea = ductus cochlearis. 
duct. endolymph. = ductus endolymphaticus. 
d. reuniens = ductus reuniens Henseni. 
endol. or endolymph. = appendix endolymphaticus. 
rec. utr. = recessus utriculi. 
sacc. = sacculus. 
sac. endol.—=saccus endolymphaticus. 
sinus utr. lat.= sinus utriculi lateralis. 
utric. = utriculus. 
vestib. p. = vestibular pouch. 
