100 JOURNAIv AND PROCEEDINGS 



almost exclusively upon living animals or vegetable matter 

 not yet disorganized. Plants, on the other hand, feed upon 

 inorganic or disorganized substances, or if they generally, or 

 perhaps always require more or less of organic matter, it is 

 that from which life has departed and which is more or less 

 in a state of decomposition, and may have lain dormant for 

 ages. The habitation of plants is therefore more immediately 

 and often more exclusively dependent on circumstances of 

 soil, climate and geological conditions than that of any other 

 class of organized beings. The distribution of plants is the 

 most complicated. Fixed and immovable as is the individual 

 plant, there is no class in which the race is endowed with 

 greater facilities for the widest dispersion. Birds with their 

 enormous powers of rapid locomotion, who will at certain sea- 

 sons traverse thousands of miles in search of food return to 

 their native haunts to rear their progeny. During the last few 

 days we have had the proof of this by the return in consider- 

 able numbers of our old familiar friends the Robins. Plants 

 on the other hand cast away their offspring in a dormant state 

 ready to be carried to any distance by these external agencies 

 to which I will refer later on in these notes, which we may 

 deem fortuitous, but without which many a race might perish 

 from the exhaustion of the limited spot of soil in which it is 

 rooted. Modern, or comparatively modern invasions from 

 distant regions to the more or less complete extinction or con- 

 traction of the original are much more frequent in the case of 

 plants than of animals. 



Until the advent of what is now known as the Evolution 

 theory or doctrine of gradual development of organic forms 

 by descent and variation, which is now almost universally ac- 

 cepted in some form by men of science. The place a plant 

 or animal occupied on the earth's surface, or the time when it 

 first appeared did not signify much. Each species was sup- 

 posed to have had an independent origin. It was perceived 

 that the organization and constitution of each plant must be 

 adapted to the physical conditions in which it was placed, but 

 this consideration only accounted for a few of the general 



