THE LEECHES OF MINNESOTA 49 



portion secreting the spermatophore. This must, however, remain 

 a matter of conjecture until more is learned concerning- its habits, 

 as neither spermatophores nor other methods of reproduction have 

 been observed. The atrium (a, Fig. 15, PI. D) is lined dorsally 

 with long columnar epithelium which is continuous with the glan- 

 dular epithelium of the vas deferens communis. This epithelium be- 

 comes very much shorter at the base of the atrium, losing its glan- 

 dular appearance and in the narrow opening joins the cuboidal, 

 ectodermal epithelium which lines the bursa, (b, Fig, 15, PI. D.) 



The female reproductive organs consist of the ovaries, (ov, 

 Figs. 4, PL C, 11 and 12, PI. D) and a pair of simple sacks lying 

 nearly horizontally in segments XIII and XIV between the two 

 sperm ducts. Near the anterior end each ovary sends a branch 

 ventrally which, turning toward the median line, unites with the 

 branch from the opposite side and opens on the surface by means 

 of the female pore, ( 9 , Fig. 3, PI. C and Figs. 11 and 16, PI. D). At 

 its anterior end the ovary forms a caecum which extends forward 

 in front of the female pore nearly to the atrium of the male ducts. 

 It is entirely probable that the ovaries would be much larger in 

 older specimens taken when the eggs were approaching maturity. 



Glands. 



Oesophageal and Salivary Glands. 



The oesophageal glands, (oeg. Figs. 4, 9 and 10, PI. C) are 

 paired glands lying in somites X and XI which empty by a short 

 duct into either side of the oesophagus in somite XI. The lumen 

 of the glands is large and open and sends off numerous short pockets 

 or alveoli. The whole gland is lined with a columnar epithelium 

 of striated gland cells. The striation in these cells is very pro- 

 nounced and extends from the free end of the cell clear through to 

 the wall resting on the basement membrane. Between these cells 

 are wedged, here and there, smaller supporting cells (sc. Fig. 10, 

 PI. C) containing small, darkly staining nuclei. In the short duct 

 which joins the oesophagus, the gland-cells gradually become 

 smaller, at the same time losing their striations, and pass over into 

 the regular oesophageal epithelium. 



These glands are not to be confused with the salivary glands 

 ("Ffalsdriissen" Apathy, '98) which are in all cases unicellular, 

 and are, in this species, widely distributed among the tissues 



