FIG 45. Hydra. A vertical section of entire animal; B, portion of transverse 

 section, highly magnified: C, two large ectoderm cells: D, endoderm cell cf 

 H. viridis ; E, large nematocyst; F, small nematocyst; G, sperm; a, ingested 

 diatom; bd. l t bd. z , buds; chr, chromatophores; cnbl, cnidoblast; cnc, cnidocil; 

 ect, ectoderm; end, endoderm; ent. cav, enteric cavity; eiit. cav 1 , its prolonga- 

 tion into the tentacles; _ft, flagellum; hyp, hypostome or manubrinm; int. c, in- 

 terstitial cells; m.pr, muscle processes; ntth, mouth; tnsgl, mesoglcea; net, 

 large, and tttc 1 , small nematocysts; ttu, nucleus; av, ovum; ovy, ovary; psd, 

 pseudopods ; spy, spermary ; vac. vacuole. 



100 



