36 



EVENINGS AT THE MICEOSCOPE. 



of sea-water is a small fragment of sea-weed, and at- 

 tached to one of its slender filaments you maj see three 

 or four tiny knobs of jelly, elnstered together like a 

 bunch of grapes. These are animals ; each endowed 

 with a distinct life, but associated together by a com- 

 mon stalk, which maintains the mutual vital connexion 

 of the Avhole. It is one of the Social Tunicata, and is 

 named Peropliora Listeri. 



Though each globose knob is no larger than a small 

 pin's head, it is full of organs which carry on the 

 various functions of life ; and, because the whole tis- 

 sues are as transparent as crystal, they allow us to 

 watch the processes with perfect ease. Take a peep at it. 

 It is a gelatinous sac, of a form intermediate be- 

 tween globular and 

 cubical, flattened on 

 two opposite sides, 

 with a sort of Avart 

 at the summit and 

 another at the side, 

 each of whicli is 

 pierced with a purs- 

 ed orifice. The up- 

 per of these orifices 

 admits water for re- 

 spiration and food ; 

 the latter passes 

 throu2;li a disfestive 

 system, and is dis- 

 charged throuofh the 

 side orifice. The digestive orijans lie on that flattened 

 side, which is farthest from your eye, and are therefore 

 dimly seen. 



rEnoriior.A. 



