ZOOPHYTES. 747 



assume their well-known form. Experiments were made on a species of Chrysaora, by 

 Sir John Dalyell, with the following result : When first sent into the world, the young 

 Mtxlusoj were little flat, worm-like creatures, too minute to be examined by any except 

 the highest powers of the microscope. By degrees, these tiny beings settle down to 

 one spot and affix themselves, the body lengthens, arms begin to be shown, and after 

 a while the strange creature is developed into the being known as the Hydra tuba. 



Satisfied apparently with its condition, the Hydra remains in the same spot for some 

 time, and produces a number of young Hydras, which sprout like buds from its sides, 

 and, when separated, resemble their parent. Here we might naturally imagine to be 

 the end of its history, for with almost all animals, when a being is able to produce 

 young it is considered as having attained the utmost development of which it is cap- 

 able. The Hydra, however, has yet other phases through which to pass. Towards 

 spring, its body becomes much lengthened and wrinkled, so as to form a number of 

 folds, just as if a series of threads had been tied tightly round it, one below the other. 

 The upper rings now rapidly expand and the folds deepen, until the animal resembles 

 a number of saucers regularly increasing in size, laid upon each other. The edges of 

 each saucer are developed into two cleft rays, and in this condition the animal proves 

 to be the beautiful zoophyte discovered by M. Sars, and called the Strobila. 



These are indeed strange vicissitudes in life, changes more marvellous than even 

 those wrought by water and magic words in the old days when Haroun Alraschid ruled 

 the faithful. There is yet more to come. The uppermost and largest disc or saucer 

 now lengthens its rays and assumes the form of an unmistakeable, though shallow- 

 disked Medusa. Its arms rapidly gain strength, the attachment becomes hourly 

 weaker, until at last the whole disk is broken away, and floats into the wide sea in its 

 new form. 



How wonderful is this phenomenon, and how full of interest is the study of animate 

 nature ! Here we have a being which first enters into active existence in a shape like 

 that of the infusorial animalcules ; then changing into a hydra, and while in this state 

 becoming the parent of a numerous offspring ; then developing into a Strobila ; and 

 lastly breaking up into a series of Medusae. 



ZOOPHYTES. 



QUITTING the Acalephae, we come to the vast class of Zoophytes, or animal plants, so 

 called, because though really belonging to the animal kingdom, many of them bear a 

 singularly close resemblance to vegetable forms. Their substance is always gelatin- 

 ous and fleshy, and round the entrance to the stomach are set certain tentacles, used 

 in catching prey and conveying it to the stomach. These tentacles are armed with 

 myriads of offensive weapons contained in little capsules, and capable of being dis- 

 charged with great force. Organs of sight, smell, taste, and hearing seem to be totally 

 absent, though it is possible that an extended sense of touch may compensate the 

 creature for these deficiencies. 



Without entering further into the constitution of these singular beings, we will pro- 

 ceed to the examination of the various groups into which they have been divided. 



IN the family of the Lucernariadae, the tentacles are arranged in detached groups, a 

 peculiarity whereby the creatures may easily be recognized. These organs are placed 

 upon the outer edge of the membranous and expanded disk, in the centre of which is 

 the squared mouth. They are mostly found adherent, as may be seen by the illustra- 

 tion, by a stem to some object, but they can swim with tolerable rapidity, their bodies 

 pulsating like those of the Medusae. None of them attain any great size, the largest 

 being about one inch in height. Pink is their usual color. 



