THE ELM. 71 



that it is not one of those trees which, with the oak 

 and the pine, can claim to be absolutely indigenous 

 that is to say, growing upon British soil as one of 

 the original gifts of nature, instead of owing its 

 importation to the hand of man. The subject to 

 which this question forms an opening is one of the 

 most curious and interesting that botanists and 

 physical geographers have to consider. It involves 

 not only the natural laws and the accidental pro- 

 cesses by which plants have been diffused over the 

 face of the earth, but the problem of the primitive 

 seats of particular species. Looking at the ancient 

 forests and the immortal meadows, at the lilies that 

 brighten the quiet pools and river-inlets, far away 

 in the most secret solitudes of the country; or at 

 the saxifrages that sprinkle the mountain-slopes 

 with their beautiful stars of gold or delicately- 

 speckled white, we think most naturally that these 

 things, or at all events that the plants which were 

 their ancestors and progenitors, have occupied these 

 self-same spots ever since the beginning. And 

 doubtless this is true of very many of the forms of 

 life that surround us. But very many others have as 

 certainly been derived from localities more or less 

 distant. Migration has been no less steady on the 

 part of plants, sometimes as the result of natural 

 causes, sometimes under the influence of man, and 

 this, upon his part, either knowingly or uncon- 

 sciously, migration, we say, has been no less steady 



