. Beginners' Zoology . FiG. 35. — Hydra (muchenlarged). 24 BEGINNERS ZOOLOGY. Fig. 30. — Nettling Cell. II. discharged, and I. not discharged. nately elongating and rounding the foot. Can you dis-cover other ways by which it moves. Does the hydra always stand upon its foot ? Lasso Cells.—Upon the tentacles (Fig. 35) are numer-ous cells provided each with a thread-like process (Fig. 36) which lies coiled within thecell, but which may bethrown out upon a waterflea, or other minute animalthat comes in reach. Thetouch of the lasso paralyzesthe prey (Fig. 37). Thesecells are variously calledlasso c
. Beginners' Zoology . FiG. 35. — Hydra (muchenlarged). 24 BEGINNERS ZOOLOGY. Fig. 30. — Nettling Cell. II. discharged, and I. not discharged. nately elongating and rounding the foot. Can you dis-cover other ways by which it moves. Does the hydra always stand upon its foot ? Lasso Cells.—Upon the tentacles (Fig. 35) are numer-ous cells provided each with a thread-like process (Fig. 36) which lies coiled within thecell, but which may bethrown out upon a waterflea, or other minute animalthat comes in reach. Thetouch of the lasso paralyzesthe prey (Fig. 37). Thesecells are variously calledlasso cells, nettling cells, orthread cells. The thread is hollow and is pushed out by the pressure of liquid within. When the pressure is withdrawn the thread goes back as the finger of a glove may be turned back into the glove by turning the finger outside in. When a minute animal, or other particle of food comes in contact with a tentacle, how does the tentacle get the food to the mouth } By bending and bringing the end to the mouth, or by shortening and changing its form,
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