59 



partitioned off at intervals by the transverse v/alls of the 

 endoderm cells, and studded alonj; its len,";th with numerous 

 p;listening bead-like bodies, the nematocysts. Above each 

 of tiiese thread-cells a palpocil projects like a thoi'n 

 (Fig. 31). The capsule has a slip;htly unusual form, long 

 and bean-shaped (Fig, 32), Examination with a high power 

 objective, focussed down into the water upon the extended 

 tentacle shows with considerable distinctness a ganglion 

 cell of glistening highly refractive appearance, lying 

 close to each nematocyst (Fig, 32, g.c). In every case 

 this ganglion cell is situated distal to the thread capsule 

 toward tJie free end of the tentacle (Fig, 32 ) . A thin 

 strand of nervous tissue runs in each direction from the 

 ganglion cell, towards the nematocyst pi'oxiraally , towards 

 the free tip of the tentacle distally. It is visible for 

 only a short distance, ?iowever, soon vanishing into the ec- 

 todermal tissue, and none of its branches or terminations 

 are to be followed. It evidently innei'vates the nettling 

 capsule, near the base of which it can be seen. 



In the gonosome the nematocysts are carried out onto 

 the ectoderm of the growing tentacle in s itu , as in the 

 larva. Further growth in the extent of ectoderm is brought 



