(J4 THE STETJGGLE FOB EXISTENCE. 



seasons may be used up in producing an abundance of flowers and 

 fruit; and so on; 



(vi) On the absence or occurrence, during the process of fructi- 

 fication, of accidents due to parasites, insects, fires, &c. 



(vii) On infrequency of seeding: the longer the interval between 

 one seeding and the next, the larger will be the accumulation of 

 reserve matter in the tree for the formation of fruit and seeds. Hence 

 the profuse seeeding of bamboos, Hardwickia binata, deodar, &c. 



Of two species possessing equal longevity, that which seeds at an 

 earlier age is often also the one that seeds more abundantly. For 

 instance, teak, babul, Anoc/eissus, sissu, sal, &c., are fertile before 

 they are hardly out of the low pole stage and are also amongst those 

 of our species, which are the most prolific. 



Some species require a larger sum total of heat than others in 

 order to flower, and hence also to seed. Hence comparatively poor 

 seed crops where a species occurs in a climate appreciably colder 

 than that of its main habitat. This is most conspicuously illustrat- 

 ed by thoss species which are accommodating in respect of varia- 

 tions of climate, as for instance, teak, Pinus longifolia, &c. 



It has already been pointed out that without a completely devel- 

 oped crown no species will seed abundantly. From this it follows 

 that the more shade-enduring a species is, the less insolation, and, 

 therefore, the less isolation does it require. Hence, in a more or 

 less full canopy, the more shade-enduring species, cceteris paribus, 

 have a decided advantage over the rest in perpetuating themselves 

 in the crop. Another result follows from the same fact. If trees 

 oi various species have grown up for a long time in a leaf-canopy 

 too close together to allow any to flower, and if the canopy is then 

 suddenly opened out, those trees that can soonest form a complete 

 crown will be the first to seed abundantly, and the species theybelong 

 to must, therefore, tend to predominate over the rest. This power 

 of recovery is not necessarily proportionate to shade-enduring capa- 

 city, for deodar, a remarkably shade-enduring tree, is known to 

 take at least 12 years, after being released from a close leaf-canopy ? 

 to bear any considerable quantity of seed. Moreover, the time that 

 any species takes to recover will be longer, the colder the locality is. 



In the case of some species, as, for instance, Hardicickia binata, 

 sissu, khair, &c., once the trees have put forth blossoms, subsequent 

 very hot or cold weather scarcely affects the ultimate develop- 

 ment and ripening of the fruit. "With others, on the contrary, such 

 as sal, teak, deodar, &c., unfavourable weather, if it does not result 

 in the destruction of the entire crop of flowers, nevertheless allows 



