DEVELOPMENT OF T^NIA NANA. 



659 



form and size. The latter is, however, very insignificant, and is even 

 less than in Tcenia echinococcus, for according to my measurements 

 the total length does not amount to more than O018 mm. The dis- 

 tance between the two roots is O015 mm., and that between the end 

 of the anterior root and the point of the claw 0*0076 mm. 1 



Soon after the appearance of the segmentation one notices in the 

 centre of the individual segments a bilobed accumulation of dark 

 granules, which become more abundant and distinct posteriorly, and 



FIG. 342. Proglottides of Tcenia nana ( x 100). (A.) With female 

 genital glands; (.) With formation of eggs commencing; (C.) In 

 mature condition. 



gradually assume more definite forms. In addition to these there 

 appears after a time a sharply defined club-shaped organ, which, near 

 the anterior border, runs through the joint in a transverse direction, 

 and sometimes projects with its rounded and thickened end as far as 

 the middle of the latter. In the interior of this club there is a cylin- 

 drical passage, the end of which is enlarged into a spherical cavity. 



There can be no doubt that this structure is part of the male 

 organs, and performs the functions of a cirrhus or cirrhus-pouch ; in- 

 deed, I have sometimes seen its point protruding for a short distance 

 beyond the sharp border of the joint. 



[In the drawing (Fig. 341, A) the posterior root ia represented as too short ; it 

 should be twice as long. R. L.] 



