242 Canadian Record of Science. 



obtained are now presented as supplementary to those 

 already recorded. 1 The leading subjects for inquiry, not 

 previously dealt with, concerned (1) a determination of the 

 force developed during the formation of tendril spirals, i.e., 

 to what extent, if any, does the formation of the double 

 spirals involve a direct and measurable strain ? Owing 

 to circumstances developed daring the progress of the 

 experiments, and to be detailed later, this consideration 

 could not be dealt with in any extended series of observa- 

 tions, and the question had to be approached from another 

 standpoint, the proposition then resolving itself into a con- 

 sideration of the tensile strength of already formed spirals 

 at different stages of maturity. 



Owing to the abundant facilities most courteously placed 

 at our disposal, both in the Physiological Laboratory and 

 the Botanic Garden of Harvard University, it has been pos- 

 sible to collect a large amount of evidence, which goes far 

 to settle the questions involved, of which the following is a 

 condensed summary. 



For the determination of the various considerations pre- 

 sented, as large a number of representatives of the order 

 was selected as could conveniently be brought under obser- 

 vation. The genera represented, as also the total number 

 of species observed, are as follows : — 



Species. 



Megarrhiza 1 



Rhynchocarpa 1 



Sicyos 2 



Totals, 9 22 



Species. 



Benincasa 1 



Citrnllus 1 



Cucumis 1 



Cucurbita 3 



Lagenaria 8 



Luffa 4 



All of these species were employed in determining the 

 tendril type, and most of them were used for observations 

 relating to tensile strength and other considerations. One 

 genus {Lagenaria) was studied under glass, while all the 

 genera were studied out of doors, several of them under 

 different conditions of exposure and training. 



General considerations seemed to render it highly pro- 

 bable that, if the tendril of Cucurbita were not the true type 



1 Trans. R. Soc. Can., IV. 



