9 6 



MANUAL OF ZOOLOGY 



SECT. 



bodies, the stinging-capsules or nematocysts (Fig. 41), serving 

 as weapons of offence. Each consists (A) of a tough, ovoid 



A. 



W> C7i^ 

 ^^ //* ; 



cnb 



FIG. 41. Nematocysts of Hydra. A, undischarged ; B, discharged ; C, nerve- 

 supply ; cnb. cnidoblast ; cnc. cnidocil ; nu. nucleus ; ntc. nematocyst ; n-v.c. 

 nerve-cell. (From Parker's Biology, after Schneider.) 



capsule, full of a gelatinous material, and invaginated at one 

 end in the form of a hollow process continued into a long, 



