MORPHOLOGY 



63 



thr 



•i ;: 



J) 



extr 



W%s^ 



t > 



trb 



trg 

 trb 



rt 



Fig. 22. a, b, cortical region of Frontonia leucas, with embedded and 

 extruded trichocysts (Tonniges); c, d, embedded and discharged tricho- 

 cysts of Dileptiis anser, X4200 (Hayes); e, two extruded trichocysts of 

 Paramecium caudatum, X1530 (original), ci, cilium; ec, ectoplasm; en, en- 

 doplasm; extr, extruded trichocyst; p, pellicle; rt, root of trichocyst; 

 th", thread of trichocyst; tr, trichocyst; trb, bulb of trichocyst; trg, 

 trichocyst granule. 



