90 



(9) Pallisade parenchyma mostly occupies four-tenths of the thickness 

 of the blades, sometimes exceeding six-tenths in Cucurbita Pepo, where 

 the pallisade cells may be arranged in double rows. 



(10) The petioles are solid in general, excepting in Cucurbita and 

 Benincasa, in which they are hollow. The number of fibro-vascular bundles 

 varies from 5 (Actinostemma, Melothria, and Gymnostemma) to 13 {Cucur- 

 bita). 



(11) Stoma ta on the cotyledons are in many cases present on both 

 the upper and lower surfaces. Momordica charantia, Trichosanthes ja- 

 ponica, and Gymnostemma cissoides form an exception to this rule, the 

 former two having the stomata on the lower surface and very rarely on 

 the upper surface, while the last one has them exclusively on the under 

 side. 



(12) The number of stomata found on the tendrils is nearly the 

 same in all species. The number of fibro- vascular bundles varies from 4 

 (Actinostcmma, Gymnostemma) to 9 (Citrullus). 



(13) Tubers are coniined to the genus Trichonsanthes. The largest 

 starch-grains contained in the roots are those from the tubers of Tricho- 

 santhes multiloba (0.04 mm. in diameter). 



(14) In the old roots of Momordica the fibro-vascular bundles have 

 a double arrangement at the angled portions as in the old stems. 



(15) The young roots of Actinostcmma have remarkably wide inter- 

 cellular spaces. 



(!()) The epidermal cells of the fruits may be radially flattened, 

 cubical, and radially elongated. Cucumis sativus is characterized by having 

 the epidermal cells four times longer radially than tangentially, and Benin- 

 cast t hispid a by having a tangential septum in many cells. 



(17) In the fruit-tissue a sclerenchymatous ring, either complete or 

 incomplete, is generally formed. In Cucurbita, Schizopepon, Cucumis 

 sativus, and C. Nolo, however, it is entirely absent. 



(18) The anatomical structure of the fibro-vascular bundles of the 

 Lvffa-ix\\\t deserves notice by the fact that the well-developed sclerenchyma 

 surrounds the remaining weakly-developed portion of the bundle, the whole 

 forming a spongy tissue. 



(19) Into the tubercles on the surface of the fruit of Momordica 

 charantia a branch of the fibro-vascular bundles enters. Nothing of this 

 kind can be observed in other genera. 



(20) The sieve-tubes have a characteristic distribution in the fruits. 

 Besides those found in the phloem there are isolated sieve- tubes in the 



