634 



RAD I AT A. 



cies of Medustc, two of Lizzia and two of Samia, have the power of producing young animals Ly 

 direct gemmation, and their development from a zoophytic form has not yet been observed. In 

 Lizzia and Sursia qctamifcra the buds are produced from the stomachal peduncles; but in the 

 other species of Sarsia, S. iirolifcra, they originate from the bulbs at the base of the tentacles, 

 wlicre tlioy may be seen attached in all stages of development. "What strange and wondrous 

 chanijes !" says he, after detailing his observations upon the last-mentioned minute Medusa. 

 "Fancy an elephant with a number of little elephants sprouting from his shoulders and thighs, 

 bunches of tusked monsters hanging, epaulette-fashion, from his flanks, in every stage of advance- 

 ment ! Here a young pachyderm, almost amoi-phous ; there one more advanced, but all ears 

 and eyes" on the riyiht shoulder a youthful Chuny, with head, trunk, toes, no legs, and a shape- 

 less body ; on the left, an infant better grown, and struggling to get away, but his tail not suffi- 

 ciently organized as yet to permit of liberty and free action I The comparison seems grotesque 

 and absurd ; but it really expresses what we have been describing as actually occurring among 

 our naked-eved Medusa^. It is true that the latter arc minute ; but wonders are not less won- 

 derful for being packed into small compass." 



Wonderfullv beautiful are many of these creatures in form and color, but, as we have before stated, 

 the amount of solid matter contained in their tissues is incredibly small. The greater part of their 

 substance appears to consist of a fluid, diflfering little, if at all, from the sea-water in which the 

 animal swims, and when this is drained away, so extreme is the tenuity of the membranes which 

 contained it, that the dried residue of a jelly-fish weighing two pounds, which was examined 

 by Professor Owen, weighed only thirty grains. Yet these creatures are capable of executing 

 movements with considerable vivacity — their disc contracts and dilates alternately by the action 

 of a band of what must be regarded as a muscular tissue — their tentacles are capable of seizing 

 upon and destroying, by a subtle venom, animals of far more complicated structure than them- 

 selves, and their delicate stomachs have the power of speedily digesting the victim. In fact, in 

 spite of the extreme delicacy of their texture, the Meduste are among the most voracious inhab- 

 itants of the ocean. Small fishes and Crustacea, and all the infinite multitude of minute marine 

 creatures, are seized and paralyzed by their deadly arms ; and as the mouth and stomach are 

 capable of almost indefinite dilation, the size of their prey often appears exceedingly disproportion- 

 ate. Of the voracity of one of the most delicate and beautiful species of the small Medusie inhabit- 

 ing the British shores, the Sarsia tubulosa, a little creature of the size and shape of a very small 

 child's thimble, Professor Forbes speaks as follows : " Being kept in a jar of salt water with small 

 Crustacea, they devoured these animals, so much more highly organized than themselves, vora- 

 ciously, apparently enjoying the destruction of the unfortunate members of the upper classes 

 with a truly democratic relish. One of them even attacked and commenced the swallowing of a 

 Lizzia ociopunctuta, quite as good a Medusa as itself. An animal which can pout out its mouth 

 twice the length of its body, and stretch its stomach to corresponding dimensions, must, indeed, 

 be * a triton among the minnows,' and a very terrific one too." 



Professor Forbes separates the Medusse into two great divisions, which we shall adopt as orders. 

 In the first of these the ocelli, or eye-like spots, surrounding the margin of the disc, are pro- 

 tected by more or less complicated membraneous hoods or lobcd coverings, while in the second 

 these organs are naked. Hence the former are called Stec/anojihthahnata^ Covered-eyed, the latter 

 Gymnophthalmata, or Naked-eyed. In the latter the ocelli, when present, are always placed on 

 the bulbs at the base of the tentacles, and frequently also on the interstices between them. In 

 the first order, on the contrary, they are always placed between the marginal tentacles. 



ORDER 1. STEGANOPHTHALMATA. 



The Medusse of this order often attain a gigantic stature : the Rkizostoma Cuvieri, a British 

 species, measures two feet, or even more, in diameter, while some of the inhabitants of tropical 

 seas are said to attain a still larger size. In calm weather they often swim close to the surface 

 of the sea, in such multitudes as to impede the motion of a boat through the water. Such a 



