i6o 



PRACTICAL MICROSCOPY. 



' Descriptive and Analytical Botany/ by J. D. Hooker ; 

 Sachs' 'Text-Book of Botany' (Clarendon Press); Balfour's 

 ' Manual of Botany/ 



ZOOPHYTES. This division includes the Hydrozoa and 

 the Actinozoa, both of which furnish many objects for 

 study. In the first class we find the Hydra viridis and 

 H. fusca, which may be collected without much trouble 

 from streams and pools; it is visible to the unassisted eye, 

 though it can only be satisfactorily examined by the aid 

 of the microscope. Fig. 146 shows H. viridis as it usually 

 occurs attached to duckweed, and in the same manner it 

 is often found on Anacharis alsinastrum and other water 

 plants. 



FIG. 146. 



Another order of the Hydroid Zoophytes is the Tubu- 

 larida, of which Tubularia ramea is a specimen. It is com- 

 monly called the "branched pipe coralline," and is a 

 marine organism ; in fact, all the Tubularida are marine 

 with the single exception of the genus Cordylophora, which 

 inhabits fresh water. The Tubularia ramea may be seen 

 in Fig. 147. 



Amongst the Actinozoa are the sea-anemones, the coral 

 polypes, and the Cydippe (Pleurobrachia pileus). 



