Tendrils of Cucurbitacece. 



24:1 



the ' • tensile strength " is that determined within the limits 

 of elasticity of the spiral: — 



Tensile Strength of Tendrils. 

 Wt. in gr. L. M. = C. M. 



No. 



Cm 



O . 



a Oh 



Scg 



Hi 



1 



2.3 



4 



7.1 



5 



2.5 



6 



3.3 



7 



5.6 



8 



3-3 



9 





10 



2.0 



11 



3^0 



a 



2.5 



b 



5.0 



c 



5.0 



d 



8.9 



e 



8.2 



f 



6.8 



g 

 h 



12lo 



l 



8.2 



J 

 k 



7.6 

 11.5 



1 



6.3 



m 



12.7 



n 





Tensile 

 Strength. 



101. Ogr. 

 36.0 " 

 76.0 " 

 161.0 " 

 156.0 " 

 216.0 " 

 373.0 " 

 160.0 " 



488.0 " 

 338.0 " 

 323.0 " 

 203-0 " 

 203.0 " 

 101.0 " 

 148.0 " 



203.0 'i 



266.1 " 

 301.1 " 



626.0 " 



266.1 " 

 396.0 " 



206.0 " 



141.1 " 



Breaking 

 Strain. 



i-Ogr. 



488.0 gr. 

 423.0 " 

 360.0 " 

 360.0 " 



366.6 

 666.0 



B 



d'fi 

 £ 9? 



Remarks. 



Lagenaria vulgaris. 

 Sicyos. Coiled one day. 



Megarrhiza fabacea. 



Lagenaria maxima. 



Megarrhiza fabacea. 



Sicyos. 



Megarrhiza fabacea. 

 Lagenaria vulgaris. 

 Cucurbita pepu. 



Strain of 366. gr. caused 

 separation of tissues, & 

 446.gr. broke tendril. 



Lagenaria vulgaris. One 

 day coiled. 



As all of the above determinations were made with ten- 

 drils which were comparatively fresh and soft, though in 

 different stages of maturity, it would appear evident that 

 the strain which a spring is capable of supporting must vary 

 with maturity of parts, becoming greater with age. It was 

 easily found that, in coiled tendrils, the distinction between 

 the band of bast along the lower side, and the softer tissues 

 of the upper side, was much more prominontly marked than 

 before coiling, and when such tendrils, at the proper stage 

 of maturity, were subjected to a carefully augmented strain, 

 it was found possible to cause a complete separation of the 



