182 



UNSEGMENTED WORMS. '' 



As these joints are pushed by younger interpolated buds 

 farther and farther from the head, they become sexually 



FIG. 88. Life history of Tcenia solium. After Leuckart. 



i. Six-hooked embryo in egg-case : 2. proscolex or bladder-worm 

 stage, with invaginated head ; 3. bladder-worm with evaginated 

 head ; 4. enlarged head of adult, showing suckers and hooks ; 

 5. general view of the tape-worm, from small head and thin 

 neck to the ripe joints ; 6. a ripe joint or proglottis with 

 branched uterus (cf. Fig. 87) ; all other organs are now lost. 



mature, developing complex hermaphrodite reproductive 

 organs. The ova are fertilised, apparently by spermatozoa 



