Shorea.] XL DIPTEROCARPE^E. 27 



range of hills between the Nerbudda river and the open country of Raipur, 

 and extends south to the Godavery river and the Northern Circars. The Pach- 

 marri hills mark the western limit of the tree in this belt ; the Sal on the sand- 

 stone of these hills and in the Deinwah valley at their foot is an outlying and 

 isolated patch of considerable extent, the last in that direction. The Sal tree 

 does not thrive on heavy binding soils ; it requires a loose soil which transmits 

 water freely. I have never found it on trap, and this probably explains its 

 absence on the greater part of the Satpura Range in Central India. Sal forests 

 are generally found on sandstone, on conglomerate, the gravelly and shingly 

 soil of the sub-Himalayan tract ; and the tree attains perfection where loose 

 water-transmitting soils are mixed with a large proportion of vegetable mould. 

 Sal is eminently gregarious. Wherever found, it is always the prevailing 

 tree ; a limited number of other species are associated with it, but they are 

 always less numerous in individuals. The climatic conditions within the area 

 occupied by the Sal tree may, as far as known, be expressed as follows : A 

 mean annual rainfall between 40 and 100 inches, and a mean temperature dur- 

 ing the four seasons within the following limits C. S., 55- 70 ; H. S., 77-85 ; 

 R.S., 80-88 ; Autumn, 74-77. As to extremes of cold, the Sal can stand several 

 degrees below freezing-point. I have seen the leaves frostbitten in the Kotri- 

 doon, and in Kangra and Hushiarpur it is exposed to severe cold. As to heat, 

 it will suffice to say that during the hot season the extremes in the Kamaon 

 Doons and the Deinwah valley are nearly as high as anywhere in Tndia, but 

 that the tree does not seem to stand the hot winds of the open plains in North- 

 West India. 



Sal is never quite leafless : the young foliage issues in March, with the flowers ; 

 the seed ripens in June, and germinates immediately, often before falling. 

 Large quantities of seed ripen, and an abundant crop of seedlings springs up 

 annually, clothing the ground with a dense mass of young Sal, to the exclusion 

 of other trees. The circumstance that the seed ripens at the commencement of 

 the rains, after the jungle-fires have passed through the forest, materially 

 assists the reproduction and spread of Sal. Other species of this family, 

 particularly the Ein tree of Burma (Dipterocarpus tuberculatus, Roxb.), also 

 produce a similarly abundant crop of seedlings, and form nearly pure forests of 

 great extent. The Sal tree coppices, but not under all circumstances. Regard- 

 ing its rate of growth, our information is as yet incomplete. The annual rings 

 in the wood are generally very indistinct ; and the individuals, the age of 

 which is known from other sources, are not numerous. For the Oudh forests 

 (Kheree Division), the following was assumed as the mean rate of growth when 

 the first regular plan for working them was framed in 1863 : 

 Age 15 years, girth 18 inches. 

 50 54 



80 J) 72 



Subsequent data seemed to indicate a somewhat slower rate ; and in 1868, Capt. 

 Wood's estimate was 65 years for 54, and 95 years for 72 in. girth. The follow- 

 ing cultivated trees of known age were measured by me in 1863 : 



Saharanpur, 13 years, girth 27 inches (average of 33 trees). 

 &v 54?r 



Calcutta, 25 69 



Under favourable conditions for instance, in the gorges at the foot of the 

 hills in the Nepal Terai the Sal tree attains 100-150 ft., with a clear stem to 

 the first branch of 60-80 ft., and a girth of 20-25 ft. But such dimensions are 

 exceptional ; as a rule, it attains 60-90 ft., with clear stems 30-40 ft. long, and a 

 girth of 6-8 ft. Young trees have generally a long narrow conical head of foli- 





