i8 C O N C H O L O G Y. 



fo much in fome, as to appear different 

 fpecies. All orders of Animals vary in 

 like manner in their different fexes, as 

 well as in their different flages of life^ 

 Thus for example, the Tadpole feems a 

 different fpecies from the Frog ; the Cater- 

 pillar from the Butterfly ; the Flamingo 

 bird when young is quite white, but when 

 of a certain age of a beautiful fcarlet ; 

 the cornigerous quadrupeds that fhed their 

 horns alfo run through feveral flages, 

 before their horns are complete. Thefe 

 changes we are acquainted with, becaufe 

 they are always obvious to us, and are 

 wrought on animals that are our com- 

 panions, and breathe in the fame ele- 

 ment. It is otherwife with the animals 

 of the deep, the knowledge of which 

 we acquire only by accident ; and it is 

 even impoffible for us to follow them 

 in their various growths and changes, 

 by the moft affiduous obfervations. 



I there- 



