GLOSSARY. 493 



set free to begin independent life for itself." — H. S. Will- 

 iams. 



Differentiation. Unlikeness; applied teehnically to the 

 origination and augmentation of special differences be- 

 tween organs which were once nearly or quite alike. 



DiPLEUROGENESis. A term proposed by the writer to desig- 

 nate the two-sided or dimeric type of form assumed by 

 the members of the animal creation. Compare Centrogen- 

 esis. (Pages 16, 17, 18.) 



Domestication. The adaptation or habituating of a plant or 

 an animal to the care and breeding by man. 



Ecology. That science which treats of the inter- relationships 

 of organisms and of their relations to environment. The 

 study of the modes of life of animals and plants. Dar- 

 win drew most of his facts from ecology, rather than from 

 embryology, geologj', and the like. Written cacology in the 

 lexicons, but usage now drops the digraph. 



Environment. The conditions or circumstances in which a 

 plant or animal lives ; as the compound conditions of soil, 

 altitude, climate, struggle for existence, and the like. 



Evolution. The doctrine which supposes that one form of 

 life may give rise to another form of life ; that each form 

 was not necessarily specially created as we now see it, but 

 that it may have been derived, through modification or 

 variation, from some earlier form. Compare Development. 



Facies. The general aspect or appearance, as of a flora or 

 a collection of plants. How a thing looks, as compared 

 with related things. 



Feral. Wild. Existing in a state of nature, as distinguished 

 from a state of cultivation or domestication. 



Fortuitous. Accidental. In evolution discussions, used to 

 designate variations or attributes which appear not to be 

 due to any immediate or recognizable agencies, either 

 external or internal. (Page 24.) 



Gametophyte. The sexual generation or stage of the plant. 

 (Pages 18, 67 note.) 



Generalized. Used to designate organisms which have attri- 

 butes that fit them for a wide or common range of con- 



