The Nervous System 145 
is an elongated, almost band-like structure situ- 
ated in the roof of the eye-socket, near its border; 
its long axis lies in an antero-posterior direction. 
It is so closely inclosed by and united with con- 
nective tissue that it is difficult to find. 
The Harderian gland is much larger than the 
lachrymal gland proper and is easily found. It 
lies in the forward part of the eye-socket and is 
of a somewhat three-cornered shape. From its 
outer and forward base it sends a short, delicate 
duct to open between the nictitating membrane 
and the eyeball. 
The lachrymal canal is well developed in the 
Crocodilia. Near the forward angle of the eye, on 
the inner side of the lower lid, are found from 
three to eight tear dots, lying in a row from behind 
forward. Each of these dots opens into a small 
elongated sac. This sac opens downwards and 
forwards into a common canal, which canal, at 
first narrow but soon widening, extends for a 
time parallel to the free border of the eyelid and 
then enters the opening in the hinder side of the 
lachrymal bone. Rathke found none of these 
tear dots on the upper eyelid so concluded that 
the lachrymal fluid could escape only through 
the lower lid. This canal, which might correspond 
to the lachrymal sac of higher forms, is rather 
narrow until it enters the lachrymal bone, then it 
becomes considerably wider and forms a sort of re- 
servoir that Rathke calls the “ saccus naso-lachryma- 
