COMPARATIVE ANATOMY OF THE CUCUIIBITACE.E. 51 



sometimes elevated with the epidermis ubove the surface of the 

 hitter, as if they were supported by short thick hairs. 



o. Trichomes on tlie stems are of four kinds : (i.) sharp- 

 pointed conical trichomes, (ii.) blunt-ended conical trichomes, (iii.) 

 short-stalked glandular trichomes and (iv.) long-stalked glandular 

 trichomes. The glandular trichome of Trichosanthes cuanneroides 

 is especially characterized by having a single enlarged terminal 

 cell ; that of Benincasa cerifera, by having two processes at the 

 apex ; and that of Cacurbila Pepo Ijy having the head consisting 

 of two cells one overlying the other. 



4. There are four types of the distribution of the sieve-tubes 

 in the stems : (a) vascular-bundle sieve-tubes, (b) ectocyclic sieve- 

 tubes, (c) cntocyclic sieve-tubes, and (d) commissural sieve-tubes. 

 Luffa cylindrica and L. acuUn^guh have those of the first and 

 third types ; Äci'niodemma racemosum, 31elothri<( jdponica, Schizo- 

 l^epon bryonkefoUus, var. japonicus, Momordica Charantia, Oitrullus 

 vulgaris, Cucumis sativus, C. 3Ielo, Benincasa cerifera, Lagenar'ut 

 vulgaris, Trichosanthes cuct/meroides, T. japonica, T. muUiloba and 

 Gytnnostemma cissoides, those of the first, third and fourth ; and 

 Cucurbita Pepo, all four types. 



Ö. Khizomes occur in Melothria japonica and Gymnostemnia 

 cissoides. They are long and thick, having at several nodes 

 three scales, which are anatomically distinguished as a shoot, a 

 leaf and a tendril. They are full of starch-grains, those of 

 Gymnostemma cissoides being the largest (0.06 mm. in diameter) 

 contained in any of the organs of the Cucurbitaceie. 



6. In the rhizomes the collenchyma, sclerenchyma and 

 fibro-vascular bundles are considerably reduced. Their degenera- 

 tion is much greater in Melothria japonica. than in Gymnostemma. 

 cissoides. 



