INTRODUCTORY ESSAY. 25 



form, is often the only guide we have to their origin. To us 

 it appears that but one legitimate conclusion may be drawn 

 from the facts ; and that, taking the broadest view of the case, 

 while it is diflBcult, on the one hand, to reconcile the acknow- 

 ledged tendency of varieties and hybrids to revert to their 

 original state, with the fact that the floras of remote areas, 

 possessing similar climates, are permanently and prominently 

 different in their main elements; on the other, it is equally 

 remarkable that the majority of the plants found wild or 

 cultivated in all climates, are not specifically changed by any ; 

 and this, whether they are of species that have been thus 

 widely spread for ages, or such as have been introduced by 

 man in later times. 



In the Botanical Gardens at Calcutta many thousands of 

 plants from all parts of the world have been cultivated with 

 more or less success, and some have become denizens of the 

 soil ; but in no instance has such a change of character been 

 produced as could justify the suspicion that specific marks 

 might be obliterated by even such violent contrasts of climate 

 as Calcutta and Australia, or Calcutta and the Cape of Good 

 Hope, afford. On the contrary, the seedlings seem infallibly 

 to resemble their parents for generation after generation, al- 

 tered perhaps in size, and more frequently in habit, and ac- 

 commodating themselves to the seasons of India, but remain- 

 ing true to their botanical characters. 



With regard to the specific effects of climate on plants, 

 they are extremely difficult of appreciation, the observer sel- 

 dom having the opportunity of becoming familiar with the 

 same species under very different climatic influences, at one 

 and the same time. This is, however, an essential point, for 

 nothing is so fallacious as recollections of the habit and ge- 

 neral appearance even of very familiar plants. We have our- 

 selves -repeatedly gathered some of the commonest English 

 weeds in foreign countries without recognizing them, though 

 they differed in no respect, even of habit, from those we had 

 been familiar with from childhood, — so deceptive are the ef- 



e 



