38 



LIFE, IX ITS LOWER FORMS. 



two lakes of equal dimensions. Sometimes the whole 

 bladder wrinkles and partially collapses into a rugose 

 column, and then slowly distends again, when the open- 

 ings are seen as they were before 



" The efferent stream pours out at each of these orifices, 

 carrying with it foecal matters from the interior, and any 

 light-floating atoms that may be in the vicinity, as I saw 

 with beautiful distinctness, by making the surrounding 

 water slightly turbid. 



" On my touching the bladder with the point of a needle, 

 it at once shrank up into a wrinkled column, but did not 

 retract, and presently distended again. Thus the specimen 

 exhibited very distinctly those characteristics of animal life 

 —sensibility to touch, and spontaneous movements." * 



* Tenby, S20. 



