154 



ZOOLOGY FOR MEDICAL STUDENTS 



CHAP. 



alimentar}' canal which passes from crop to anus. The intestine is at 

 its front end somewhat funnel-shaped, then it becomes slightly dilated, 

 bulging outwards as a pair of small rounded caeca (d.g). Behind these 

 it forms a straight narrow tube which finally dilates somewhat to form 



n.c. 



ph .■ 



dff 



inh 



Fig. 73. 



Hirudo. A, Alimentary canal ; B, reproductive organs ; C, enlarged view of female organs 

 spread out in one plane, a.g, Albumen gland ; c, caeca of crop ; d.g, digestive caecum ; e.d, ejaculatory 

 duct ; ep, epididymis ; int, intestine ; j, saws ; nx, nerve-cord ; od, oviduct ; ov, ovary ; ph, pharynx ; 

 f, rectum ; s, posterior sucker ; t, testis ; f, vagina ; v.d, vas deferens r v.e, vas efierens. 



the rectum (r), terminating in the anal opening, situated on the dorsal 

 surface just in front of the posterior sucker. 



The alimentary canal is as usual provided with definite glandular 

 arrangements. Projecting from the wall of the pharynx are numerous 



