200 THE VINE UNDER TROPICAL HEAT. 



the return of spring is there represented by the exu- 

 berant growth produced by the advent of the rainy 

 season. In our next, or polar section, we hope to be 

 able to cite numerous remarkable instances of the 

 similarity of effects produced by the apparently oppo- 

 site functions of great heat and great cold. 



In connection with this question of the winter rest 

 of plants, we may state that when trees or plants are 

 introduced into the tropics from temperate regions, it 

 is found that their constitution suffers severely from 

 the loss of this period of repose, and if they do not 

 actually die, they dwindle and refuse any longer to 

 ripen their fruits. This was observed in the case of 

 peaches, cherries, and other European fruit trees, in- 

 troduced into Ceylon they grew freely, but became 

 evergreen, and then, as if exhausted by perennial excite- 

 ment, ceased to produce. A similar failure followed 

 the introduction of the vine into the gardens of Jaffna 

 here, however, a most interesting experiment was made 

 to test the possibility of obtaining a season of rest by 

 the agency of heat, instead of cold, and it succeeded 

 perfectly. 



Sir J. Emerson Tennent informs us that: 



" Mr. Dyke, the government agent in whose garden they 

 grow, conceiving that the activity of the plants might be 

 equally checked by exposing them to an extreme of warmth 

 as by subjecting them to cold, tried with perfect success the 

 experiment of laying bare the roots in the strongest heat of 

 the sun. The circulation of the sap was thus arrested, the 

 vines obtained the needful repose, and the grapes which 

 before had fallen almost unformed from the tree, are now 

 brought to thorough maturity, though inferior in flavour to 

 those produced at home." * 



* Ceylon, by Sir James Emerson Tennent, 1859. Vol. i, Ch. 3, p. 89. 



