326 VEGETABLE ORGANOGRAPHY. 



and Zygnemas hardly differ in their form and manner 

 of living : the former, which present traces of a move- 

 ment probably spontaneous, are placed in the animal 

 kingdom ; wliilst the latter, in which no movements are 

 observed, are considered to be vegetables. 



Among these doubtful genera, we must mention 

 Nostos, Diatoma, and in general all the Diatomeas of 

 Fries, which are usually classed among vegetables; 

 and the Sponges, which are referred to animals : in 

 these and several other analogous examples, the limits 

 of the two kingdoms are very difficult to be esta- 

 bhshed. 



END OF VOL. I. 



RICHARD CLAY, PRINTER, BREAD STREET HILL, LONDON. 



