64 LEISURE-TIME STUDIES. 



was thus turned completely inside out; the exterior superficies- 

 of the polyp had become the interior." 



The operation thus described was occasionally frustrated 

 in a manner by the hydrse ; since, in less than an hour, 

 Trembley observed some specimens to succeed in restoring 

 themselves to their natural position. This observer pre- 

 vented the latter result in one or two instances, by spitting 

 the polype, a needle being passed through the body close 

 under the mouth ; and when thus impaled, the animal, with 

 wisdom which humanity might sometimes advantageously 

 imitate, accommodated itself without murmur to the exigencies 

 of its position. Trembley appears to have taken the state of 

 the appetite of his polypes, as a very natural and rational 

 test of their state of health after being operated upon. He 

 remarks that a hydra which had been turned inside out 

 ate " a small worm two days after the operation ; " whilst to 

 conclude, he tells us that " the same polyp may be succes- 

 sively inverted, cut in sections, and turned back again, with- 

 out being seriously injured." After the recital of these 

 experiments to which, seeing that the hydra possesses no 

 traces of a nervous system, the most tender-hearted anti- 

 vivisectionist could offer no objection we may well question 

 whether the hydra of zoology is not, after all, a more 

 wonderful animal than its mythical and fabulous namesake. 



The attentive consideration of these features in our 

 polype's biography, naturally suggests some remarks on the 

 nature of beings which possess powers so wondrous of resist- 

 ing and of recovering from serious mutilation and injury. In 

 virtue of what description or amount of vitality, it may be 

 asked, or on what supposition, can we account for the amaz- 

 ing reparative powers of the hydra? The answer to this 

 question may be prefaced by the remark that the hydrse are 

 not singular in respect of their fertility under apparently dis- 

 advantageous circumstances. As already remarked, the sea- 

 anemones may be subjected to the ordeal of trial by slicing 

 and chopping, with favourable results as far as the artificial 

 increase of the race is concerned. But animals occupying 



