﻿the Physiology of Tendrils 



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Table II. 



Measurements of tendrils stimulated and quickly killed. Sets of cells 

 airectly opposite in the same section were measured. 



Convex Side 

 Number of Cells. Length. Average 



Concave Side 

 Number of Cells. Length. Average 



Epidermis io 



8 

 6 



4 



Epidermis io 



8 



5 

 5 

 3 



ioo 

 95 



IOO 

 IOO 



IO 



ii. 9 

 16.6 



25 



IOO 



105 



104 

 95 



IOO 



IO. 



13. 1 



20.8 



19. 



33- 



Epidermis 12 



7 

 . 8 



9 



Epidermis 12 



8 



7 

 7 

 5 



100 



IOO 



105 



IOO 



IOO 

 IOO 



108 



IOO 

 IOO 



8.3 



14-3 



12.5 



II. I 



8.5 



12.5 



154 



14-3 

 20. 



The average length of the four sets of cells of a straight ten- 



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dril were 19, 17.8, 14.5, 15.6 with a grand average length of 

 16.725. The average lengths of the cells from the convex sides 

 were 14.5 and 16.2 with a grand average of 15.15. The average 

 length of the cells from the concave sides of the same tendrils 

 were 11.25 and 13. 



It is found, as a result of these measurements, that the cells of 

 the concave side have undergone such diminuition in the longitud- 

 inal axis as to measure less than the average normal cells and less 

 than the corresponding cells of the convex side. The cells of the 

 convex side have not increased beyond the average of normal 

 cells. It is evident, therefore, that the curvature of the tendrils is 

 to be ascribed to the action of the cells becoming concave. This 

 action presumably resembles that of the pulvinus of 

 Such mechanism is in fact demanded by the structure of the ten- 

 dril and the rapidity of the curvature necessary to make the motion 

 efficient and economical. 



Morphological Changes due to continued Pressure. 



The greater portion of the t ndril is usually engaged with the 

 support and the free basal portion is rarely a centimeter in length. 

 After the apical portion has engaged the support the b. .1 port.on 

 becomes curved in some instances sufficiently to form one com 

 Plete spiral. In no instance, however, was the arrangement of tin 



Mimo 



