38 TOILERS IN THE SEA. 



deposited in my vases, adhering to the glass, with 

 the pseudopodia extended in opposite directions. 

 Very frequently these tiny atoms were found, in the 

 morning, two, three, or even four inches up the sides 

 of the perpendicular glass vases, having crawled this 

 distance in the course of the night. And they never 

 remained long stationary ; the next morning would 

 find tnem in some remote part of the glass. The 

 night was manifestly their time of activity." And 

 again, ' One of my tanks was literally swarming with 

 a speries of Polymorphina. The individuals were of 

 various dimensions ; a large number having attained 

 the adult size. They studded the sides of the vessel, 

 the stones, and the slender weeds, adhering to the 

 filaments of the latter in such profusion as to cover 

 the whole contents of the vessel with white dots, con- 

 spicuous even upon the most cursory glance. These, 

 like the others, were constantly roaming ; they 

 crawled up and down the stems of the algae, and 

 over the various objects in the tank, never remaining 

 long in one station. On removing one from the 

 vessel to an aquatic cell for microscopic examination, 

 it was found to be entirely withdrawn ; but, in the 

 course of a few minutes the pseudopodia were seen 

 to be protruding their tips, and then they gradually 

 stretched and expanded their lines and films of 

 delicate sarcode, till in the course of a few hours 

 these would sometimes reach almost from side to 



