HARDWICKIA 347 



the first season and a maximum height of 2 ft. 6 in. by the end of the second 

 season, no dying back having taken place. It follows, therefore, that the 

 habit of dying back is not innate in the species, any more than it is in the sal, 

 teak, and many other species which die back under conditions sufficiently far 

 removed from the optimum. 



In other respects also it will be interesting to compare the habits and 

 requirements of the seedling in its natural habitat, as observed by Mr. Witt 

 in Nimar, with those which have been observed in twenty-one experimental 

 plots at Dehra Dun, where, however, the climatic conditions are very different 

 from those prevailing in the natural habitat of the tree, the normal rainfall 

 being 85 in. and frost being at times severe. It goes without saying that for 

 practical purposes a study of the habits and requirements of the seedling in 

 its natural home is of infinitely greater importance than if these are observed 

 under very different conditions, but the results obtained in the latter case are 

 certainly interesting, for though in some respects they differ from Mr. Witt's 

 observations, as might be expected, in others they corroborate them. The 

 conclusions regarding the habits and requirements of the seedling, based on 

 observations made under various conditions, may be summarized as follows : 



Root-system. The development of the taproot under natural conditions 

 has already been described. At Dehra Dun the root-system showed a tendency 

 to strong development, even where regular watering was carried out ; this 

 development extended to the lateral roots and was not confined to the taproot 

 as in the case of natural seedlings. By the middle of the second season nursery 

 plants had taproots up to 2 ft. 6 in. in length and 0-7 in. in diameter, with 

 lateral roots up to 1 ft. 7 in. in length. 



Drought. In the natural habitat of the species the seedlings are very 

 sensitive to drought, as has already been explained in describing the pheno- 

 menon of dying back. This fact has been corroborated again and again by 

 different observers, and it may be said without question that the great mortality 

 noticeable among the numerous seedlings which appear after a good seed-year 

 is due to drought, the excessive heat combined with desiccating winds pro- 

 ducing a degree of transpiration which the root-system in the parched soil 

 cannot make good. Even at Dehra Dun many seedlings were found to die 

 down partially or wholly in sunny situations from April onwards. 



Frost. In the natural habitat of the tree frosts are not severe enough 

 to do the seedlings any harm, and Mr. Witt notes that he has never observed 

 a single case of a seedling having been damaged in the slightest degree by 

 this agency. At Dehra Dun the frost was found to be severe enough to kill 

 back seedlings of the first year either partially or down to ground-level ; they 

 had good power of recovery, however, and invariably produced new shoots. 

 From the second year onwards they proved to be immune from injury by 

 ordinary frosts. 



Shape and development. The shape and development of the seedling under 

 natural conditions has already been described. At Dehra Dun some of the 

 seedlings commenced branching in the first year, while those which had been 

 affected by frost or drought assumed a bushy growth in the second season, 

 with long and rather straggling branches. Growth continued until December, 

 all the leaves had dropped by the end of February, and the new shoots appeared 



