bird's-head zoophyte. 



121 



organs is not at all clearly ascertained, for they 

 seem to have bnt little connexion with the polyps 

 that inhabit the cells, and bow with as much 

 perseverance when the cell is empty as when it is 

 occupied by its living inhabitant. Many zoo- 

 phytes possess the bird's-head ; but as that species 

 which I have mentioned is perhaps the most 

 common, and is easily detected, it has been 

 admitted as the representative specimen. It 

 must be understood that when these creatures 

 are subjected to the action of a microscope, they 

 must be well supplied with water, or they will 

 die speedily. If the power is not very high, 

 the entire creature may be placed in a flat glass 

 cell, and slightly compressed against the side by 

 a glass plate. The microscope should then be set 

 horizontally, and will show the structures toler- 

 ably well. But if a higher power is requisite, 

 a portion must be removed, and placed in the 

 animalcule cage with which every good microscope 

 is furnished. A flat watch-glass, and a piece 

 of the thin microscopical glass used for covering 

 preparations, will make a good extemporised 

 animalcule cage, if the regular machine is not at 

 hand. 



Among the other members of the animal 

 kingdom that are popularly ranked as vegetables 



