No. 129J 253 



necessary to pass two walls. The roof, supported by prop pillars, 

 must be covered with moss contained between thin rafters, well 

 covered above and below by thick coats of plaster, to shed rain 

 and prevent the transmission of heat. This cover must be at 

 least a foot thick. 



[Revue Horticole, Paris, June, 1850.] 



Gremechela, 23d May, 1850. 



DATE PALMS OF AFRICA. 



Extract of a letter from M. Paul Merat, an officer of the French 

 army, to his father. Dr. Merat: — 



" We are here on the confines of the great desert, in the Aures 

 Mountains, on the south of the Province of Constantine, where 

 few Europeans have penetrated. The climate here is extremely 

 variable. In day time, we have a temperature of 30 to 50 de- 

 grees centigrade, equal to 70 or 80 degrees of Fahrenheit; and 

 yet the nights are so cold as to require fire. On the 29th of 

 April last we had snow, and the highest elevations have it during 

 summer. 



The land appears to be very fertile, as it bears a luxuriant 

 vegetation ; but there is very little cultivation here, and I hardly 

 see anything but barley and a little luzerne. 



Not far from here, in the desert, there is an oasis of date trees, 

 which furnishes part of the subsistence of the neighboring tribes. 

 There are two sorts of date palms, you know, — the male, which 

 gives no fruit, but which fertilizes the female palms, which yield 

 the dates. This distinction was known to Pliny. Of about 1000 

 or 1200 palm trees which compose this oasis, there are but twelve 

 or fifteen males. At Sidi Akla, further ofl' in the desert, in an- 

 other oasis, there are but two males. The organs of fructification 

 of this vegetable are contained, for each sex, in an immense pod 

 or spathe, which, at ma.turity, bursts with a report like a pistol. 

 That of the male opens fifteen days before the female. 



As soon as the female flowers are open, the Arabs cut off the 

 male flowers and shake them over the females, or attach the male 



