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 "sacciis naso-lachryma- 



