198 H. B. GUPPY^ M.B., F.IJ.S.E., OX PLANT-DISTKIBUTION 



diminution of the population from war or famine which has thrown 

 land out of cultivation, as in Palestine. 



AVas not the decay of prosperous regions, owing to a change of 

 climate, caused hy wasteful destruction of forest, as well as those 

 already cited, and has not land planted M'ith vegetation, especially 

 trees, led to increased rainfall and the introduction of new plants 1 

 Is not this the case in Egypt ? 



As to the dispersa,l, how are we to account for such cases as the 

 appearance in India of large specimens of the Adansaria digitata, 

 which is an important member of a genus confined to Africa and 

 Australia (as Mr. Guppy says) 1 I have seen this magnificent tree, at 

 one time thought to be the oldest tree in the w^orld, in the ruins of 

 Mandra, the famous capital on the Xarbuda of the Sultans of 

 Malwa, and it is found in other parts of India. Some believe it was 

 introduced by the Portuguese only 300 years ago ; others put back 

 its introduction to a much earlier date. 



In any case, is not too much importance attributed to time in 

 these questions 1 If the Portuguese theory regarding the intro- 

 duction of the Baobab into AYestern India is accepted, only 300 years 

 are required for a wide dispersal. Of other cases we have more 

 accurate knowledge. Most of the European garden vegetables now 

 in use in India, we learn on the authority of the Physician Bernier, 

 were first introduced into the country a few centuries ago. 



The Emperor Baber has told us that before his time there was 

 little f l uit in the country, and it is certain that tobacco was unknown 

 before the Moghul period, because the Emperor Jehangir, like so 

 many other great Sovereigns of the time, threatened its use with death. 



Instances such as these might be multiplied indefinitely, I think, 

 in proof of the view that human agency is of immense importance 

 in plant distribution. 



Mr. Martin L. House. — The theory of the author of this 

 learned paper is that every order or tribe was at the first created 

 over a large proportion of the Earth's surface, and that, by the 

 accidents of climate, exposure to wind or sun, elevation and 

 character of soil, each split up into manifold genera and species 

 more and more remote from one another over the vast region once 

 covered by the original order or tribe. This agrees with the view 

 of Linnieus, himself — whose reverent spirit none can impugn — for 

 lie thought that " Omnipotence created the orders, climate shaped 



