246 Canadian Record of Science. 



grains, of the corresponding divisions, was afterward deter- 

 mined experimentally. 



July 7th, the tension balance was placed in position in 

 the plant house for a tendril of Lagenaria to grasp. The 

 first tendril failed to secure a hold, but on the 10th the 

 second tendril grasped the loop firmly, and on the 12th it 

 completed its double spirals. Inasmuch as both balance 

 and vine were firmly secured, there could be no variation of 

 distance between the tendril base and the point of attach- 

 ment to the balance, without its being indicated on the scale 

 of the latter. 



Although the formation of the double spiral began on the 

 10th, and was completed on the 12th, no evidence of strain 

 was manifested. The tendril continued to mature nor- 

 mally, but up to the 19th of July, during which time the 

 coils became slightly closer, no evidence of strain was 

 apparent, and the connection was therefore severed. It 

 was most evident from this trial that, since the relation of 

 vine and point of attachment remained unchanged, there 

 could have been no shortening of the tendril in the forma- 

 tion of the coils, but that the total increase of tissue was 

 sufficient to compensate for their formation. It had pre- 

 viously been surmised that the increase of parts after coiling 

 we Id not fully compensate the shortening due to coiling. 

 In order to determine how far this result was the expres- 

 sion of a general law, many measurements were made, all 

 of which proved to be of a confirmatory nature, and we 

 therefore feel justified in asserting that these tendrils, in 

 the formation of their spirals, fail to exert a strain equal to 

 5 gr. It would also appear that, during the formation of 

 the spiral, while all parts must of necessity elongate some- 

 what, the special increase of tissue is on the convex side of 

 the tendril, hence in those soft tissues where the bast is 

 known to be least abundant, and where the vibrogen is 

 prominent, this will appear more strikingly later on. 



For the reasons already given, resort was had to simple 

 springs for a determination of the strength of already 

 formed spirals in various stages of maturity. The more 

 important results appear in the following table, in which 



