64 HALF-HOURS IN THE GREEN LANES. 



selves. Within each globe may be seen smaller 

 globes, fashioned precisely like the parent. Even 

 within these enclosed young, not unfrequently you 

 may perceive a third generation in embryo ! When 

 viewed through the microscope with a higher power, 

 the green spots seen at the crossing of the lines, are 

 made out to be yonidia, or zoospores, by means of 



Fie. 56. 



Volvox globator. 



whose cilia, or hairs, probably the volvox is enabled 

 to move through the water. 



Much rarer than the preceding aquatic forms, but 

 a species which it is very likely may be met with in 

 our old tarn, is the beautiful fresh-water polyzoon, 

 Plumatella one of the most exquisite objects in the 

 entire animal creation. It is very nearly allied to 

 the " sea mats " (Flustra) of our coasts, so that its 

 organisation is really very complex, being little 



