326 SEA-SIDE STUDIES. 



tail in the light of muscular fibres, a supposition which is 

 very questionable. In the neighbourhood of this tail there 

 is usually a mass of food, or the indigestible remains of food. 

 Not that we are to look for a stomach in this animal — 

 nothing of the kind exists ; but in lieu thereof we find, as 

 in Infusoria, a number of vacuolce, or assimilatino; cavities, 

 which appear and disappear, according to need, formed out 

 of the contractile substance which is seen radiating in fila- 

 ments all through the substance of the animal, and which 

 M. Quatrefages * likens to the sarcode described by Dujardin. 

 In this curious animal, not a trace has been discovered of 

 vessels, nerves, senses, or indeed of any " organs " whatever. 

 It is a mass of animated jelly, with a mobile tail Its mode 

 of reproduction has been variously expounded, but the obser- 

 vations of Quatrefages and Krohn seem placed beyond a 

 doubt by those recorded in Mr BrightweU's paper, -j- proving 

 that they multiply by spontaneous subdivision. No one has 

 yet observed anything like reproduction by means of ova. 



To these Noctilucce the sea owes much of that brilliant 

 phosphorescence which at all times has been the marvel of 

 travellers. Place your vase in a darkened room, and strike 

 the glass, or agitate the water, and you will be delighted 

 with the spectacle presented. From every part brilliant sparks 

 appear and disappear, until at length no agitation of the 

 water will produce more ; their power is exhausted, as that 

 of the electric-eel is exhausted after a few shocks. You 

 want to know the cause of this phosphorescence ? Unhappily 



• A nnales des Sciences Nat. 1850, p. 231. 



t MicroicopicalJoumal, No. XX. 1857, p. 185. 



