CYDIPPE I BEEOE I NOCTILUCA. 549 



the lateral tendrils subsequently uncoil themselves, to be drawn-in 

 again and packed-up within the cavities, with almost equal sudden- 

 ness. The liveliness of this little creature, which may sometimes 

 be collected in large quantities at once by the Tow-net, renders it 

 a most beautiful subject for observation when due scope is given to 

 its movements ; but for the sake of Microscopic examination, it is 

 of course necessary to confine these. Various species of true 

 Beroe, some of them even attaining the size of a small Lemon, are 

 occasionally to be met with on our coasts ; in all of which the 

 movements of the body are effected by the like agency of Cilia 

 arranged in meridional bands. These are splendidly luminous in 

 the dark, and the luminosity is retained even by fragments of their 

 bodies, being augmented by agitation of the water containing them. 

 425. Very different, however, is the structure of another little 

 globular jelly-like animal, the Noctiluca miliaria (Fig. 282), to 



Fig. 282. 



Noctiluca miliarig. 



which the diffused Luminosity of the Sea, a beautiful phenomenon 

 that is of very frequent occurrence on our shores, is chiefly attri- 

 butable. This animal, much resembling in appearance a grain of 

 boiled Sago, is just large enough to be discerned by the naked eye, 

 when the water in which it may be swimming is contained in a 

 glass jar exposed to the light ; and a Tail-like appendage, marked 

 with transverse rings, which is employed by the animal as an 

 instrument of Locomotion, both for swimming and for pushing, 

 may also be observed with a hand-glass. Near the point of its 

 implantation in the body is a definite Mouth, on one side of which 

 a projecting Tooth has been seen by Mr. Huxley ; and this mouth 



