Rev. Mr Coivan on the Natural JThtory oj Mailarja^cnr. 145 



insect are very irre^'ular ; for years tliey may never appear, and 

 then suddenly tliey come in clouds, darkening the air, or 

 filling the valleys below like a white vapour. As they gener- 

 ally settle on the ground before sunset for feeding purposes, 

 the natives gather them in basketsful, and for days and weeks 

 afterwards, they form regular articles of diet. 



Floe A. 



Our knowledge of the flora of Madagascar is as yet rather 

 defective, the collections which have come to this country 

 having been made in a very limited area. The family that 

 seems most common is the Hulnacem, and hence all plants 

 belonging to this family flourish well. Coffee wherever 

 planted, whether on the high plateau, on the fertile sides of the 

 great forest hills, or on the yet lower lands, is very productive. 

 In the western district we have a very distinct flora from that 

 of the east, but at this time it is little known. The natives 

 cultivate sugar-cane over the greater part of the island, for 

 the purpose of making native rum. The soil, like that of 

 Mauritius, seems especially suited for this plant, and the 

 canes are usually rich and productive. The central plateau 

 produces almost any kind of European plant, the valleys 

 being usually devoted to rich culture, while wheat and 

 potatoes grow well on the plains. Tobacco is grown and 

 largely used by the natives, but the plants are best on the 

 eastern edge of the plateau and clearing of the forest. Of 

 the ferns, and some other cryptogams, to which I have given 

 some attention, we know about 270 species, of which there 

 are 70 peculiar to the island, 109 are common to Madagascar, 

 Mauritius, and Bourbon, 28 of them are found in Bourbon, 

 and 4 in Mauritius, while 59 are found elsewhere. As far as 

 they can be traced, as a whole they have much nearer relation 

 to the same plants in Africa, than to any other part of tlie 

 world. 



VOL. VII. 



