40 THE STRUGGLE FOE EXISTENCE. 



(ix) Density of foliage. The denser the crown of a tree is, 

 the smaller will be the quantity of undergrowth under it to feed the 

 flames and draw them up into the overhanging crown. Thus Hard- 

 wickia binata, owing to its open foliage, encourages a close under- 

 growth in the immediate vicinity of its trunk, the consequence being 

 that, when fire comes in, the heat below is so intense that the 

 highest crowns, notwithstanding that they may be quite green, take 

 fire and blaze up like tinder. 



(x) Spread and depth of crown. Amplitude and depth of 

 crown will have the same effect as density of foliage and will more- 

 over be a great protection to the leading shoot, i. e. the most 

 sensitive and important portion of the crown. 



(xi) Height of crown above the ground. The advantage of 

 greater height of crown is too obvious to require explanation. 



(xii) Ability to form at once a strong new leader on the death 

 of the original one. Greater facility in this respect is a very 

 conspicuous advantage, for it means little or no retardation in 

 upward development, a matter of the first importance during the 

 most critical phase in the life of a tree forming part of a leaf- 

 canopy. 



(xiii) Season of flowering and fructification . The fatal effects 

 of a conflagration occurring during the process of flowering and 

 fructification are self-evident. Most of the gregarious trees of 

 those parts of India, where forest fires are a regular annual scourge 

 except when special precautions are taken, flower after fires have 

 passed through, and complete their fnictification before the next fire 

 season arrives, e. c/., teak, Pterocarpus Marsupium, Bo&wellia serrata, 

 kliair, Hardivickia binata, Terminalia tomentosa, Anogeissus latifolia 

 and pendula, Dendrocalamus strictus, &c. 



(xiv) Season of fall of seed. It is a truism to say that if fire 

 comes in after the seed has fallen, there is very little chance of any 

 of it escaping. 



(xv) Ability of seeds or fruit to escape complete destruction by 



fire. Fruic with a hard or thick pericarp, like that of teak, Terminalia 



Chebula and belerica, Zizyphus asylopyra, &c., can stand a good deal 



of scorching without losing their germinative power. Hard dry 



fruit, even without a thick pericarp, like that of Terminalia tomentosa 



and Arjuna, also resist well. On the other hand, moist or oily seeds 



with a thin protective covering, like those of Bassia latifolia, sal, 



Pinus liun/t'folia, &c., are killed most easily of all. Very small seeds, 



like those of Celastrus senegalensis, most of the grasses, &c., often 



escape by being able to get into small crevices or cracks, &c. 



