392 C. O. WHITMAN. 
bend, runs back along the dorsal side of the penial pouch (p.), 
and enters the pouch near its hind end, passing first through 
the so-called glandule prostatice. 
The stomach, or that portion of the alimentary canal corre- 
sponding to the “stomach” of Hirudo, is a straight tube, 
showing (in alcoholic specimens) no trace of metameric divi- 
sion, and terminating behind in two slender diverticula, the 
length of which was not ascertained. Just behind the junc- 
tion of the diverticula with the main canal, the intestinal 
portion begins to enlarge; and a litle farther back it becomes 
smaller, tapering quite gradually to the very end. The intes- 
tine may be described as a fusiform canal, not differentiated, 
so far as I could see, by superficial examination into regions, 
and showing no evidence of metameric constrictions. 
Segmental Papille. 
Literature.—The segmental papille of the Leech have 
been noticed by a considerable number of naturalists ; but no 
one, so far as I have been able to learn, has suspected that 
they were sense-organs. Hbrard,! who has described and 
figured them, gives us no information in regard to their struc- 
ture, and entirely overlooked their serial relationship with the 
eyes. 
Thomas? recognised two of these on the dorsal half of every 
5th ring, and tried in vain to inject them. 
Fermont® found six or eight of these on the dorsal half of 
every 5th ring, and pointed out the fact that the papillate 
rings follow immediately the rings in which the nephridial 
pores are located. “It is necessary,” he says, “‘in order to 
see them well, to examine a large Leech which has been 
immersed in boiling water, after having been gorged with 
blood.’”4 
1 Ebrard, ‘ Nouvelle Monographie des Sangsues Médicinales,’ Paris, 1857. 
* Thomas, P., ‘Mémoires pour servir a l’histoire naturelle des Sangsues,’ 
Paris, 1806. 
3 Fermont, ‘Monographie des Sangsues Médicinales,’ Paris, 1854. 
* The works of Thomas and Fermont are known to me only through Ebrard. 
