114 Canadian Record of Science. 



July 19th. 



Andromeda ligustrina. Muhl. 

 Alnus incana. Willd. 

 Nyssa multiflora. Wang. 

 Staphylea trifolia. L. 



Indeterminate Period. 



Ampelopsis quinquifolia. Michx. 

 Celastrus scandens. L. 

 Ehus. Sp. 

 Vitis. Sp. 



This, therefore, gives us the following percentage quanti- 

 ties, showing cessation of growth at different periods : — 



May 1st, commencement of growth. 

 June 1st, cessation of growth in 51.5 p. c. 

 June 15th, " " 24.2 " 



July 19th, " " 12.1 " 



Indeterminate period " 12-1 " 



Growth in length having ceased at these periods, the 

 energy of the plant then becomes directed to thelignification 

 of tissues and the deposition of reserve material for growth 

 the following year. These changes, however, involve of 

 necessity, a continual decrease in the contained water. The 

 data above, also, show that the majority of plants complete 

 their longitudinal growth within the first six weeks of the 

 growing season ; that most of these complete their growth 

 in from three to four weeks ; and that, as the season advances, 

 the number of plants still growing rapidly diminishes until 

 the middle of July, after which there are left but few, those 

 being plants like the grape, which continue to grow to the 

 very end of the season. 



A graphic representation of these changes will enable us 

 to institute a comparison with the relations of seasons to 

 hydration of the structure. The lower figure of the chart 

 is the curve expressing this decrease of growth with advanc- 

 ing season. A comparison of both curves will sbow most 

 conspicuously, that that period, during which growth for 



