GENERAL ZOOLOGY 



Fig. 10.5. A. locomotion in Hydra. Above, "inchwonn" locomotion, in which the distal end 

 is applied to the substratum and the basal end drawn up to attach beside it. Below, "somer- 

 saulting;" locomotion. Numbers indicate successive positions. B, Abraham Tremblew the 

 first serious student of hydras, with his young; pupils. {A, redrawn, and B, reproduced di- 

 rectly, from Abraham Tremblev, Histoire de Polypes, Levden, 1744. This monoa;raph contains 

 the earliest published accounts of the details of locomotion, feedina;, and reproduction in 

 hydras, masterful experimental studies of reE^eneration, and the first demonstration of the 

 animal nature of the polyps. See also Figure 12.13, p. 362.) 



The characteristic movements and reactions involved in feeding are well co- 

 ordinated. When a water flea or other small organism has been captured by 

 a single tentacle, the other tentacles usually take part in the transfer of the 

 prey to the mouth; however, a very small animal may be caught and transfer- 

 red to the mouth by one tentacle alone, without reactions by the others. The 



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