COMPARATIVE ANATOMY OF THE CUCURBITACE^. 39 



verse section presenting an appearance like that of a water-plant 

 (PL IV. Fig. do). This peculiar character of the root of Adino- 

 stemma racemosum is not to be wondered at, when we consider that 

 this plant always grows in the neighbourhood of a stream or in 

 moist places, it having evidently acquired the character of a water- 

 plant in order to adapt itself to its surroundings. 



Starch'fjrains mid Crystals, Reserve starch-grains of 

 appreciable size are contained in old roots of the following species : 



Diaiiic'tor of tlie large starch-gruin.-i. 



Gymnostemma cissoides 0.023 mm. 



Trichosanthes multlloha 0.020 ,, 



T. japonica 0.020 „ 



T. cuGumeroides 0.018 ,, 



3Ielothria japonica 0.017 ,, 



Luffa cyllndrica O.OIG „ 



L. acutangula 0.014 ,, 



Actinostemma racemosum 0.010 „ 



Citimllus vulgaris 0.009 „ 



Cucurbita Pepo 0.008 „ 



Crystals of calcium oxalate are met with in the old roots of 

 Momordica Cliarantia, Luffa cylindrica, L. acutangula, Lagenaria 

 vulgaris, Benincasa ceriferaj Cucumis sativus, C. Melo, &c., those 

 of Momordica Cliarantia being the most remarkable in size and 

 quantity. 



Tubers. Tubers are found only in Trichosanthes cucumeroides, 

 T. japonica and T. multiloba. They occur in simple or grouped 

 forms and attain an enormous size. A transverse section of a tuber 

 shows a great degeneration of fibro-vascular bundles, the paren- 

 chyma itself being much increased so as to serve as a reserve tissue. 



