

BARBER 



-FRUITS AND SEEDS OF CUCURBITACEAE 



295 



,. Sckrenchy ma (,d).-This layer differs somewhat from the 

 Jesponding layer of the other cucurbitaceous seeds. Instead 



corresponding uiyci ui *uv v ~™~ — 



conspicuously elongated cells arranged end to end m rows, they are 



but slightly if at all elongated 

 and very irregularly distri- 



buted , 



showing 



only the 



faintest indications of an 

 end-to-end arrangement. In 

 other respects, that is as 

 regards thickness and sinu- 

 ousity of the pitted walls, 

 they are similar. 



4. Parenchyma. 



One 



layer of small and some- sub — - 

 what spongy cells forms the 



outer tissue (p 



They 



are thin-walled, pitted, and 

 clerenchymatized. Below 

 are several other layers of 

 more or less spongy paren- 

 chyma, the cells decreasin 

 in size toward the inner 



cr 



(P 



5. Inner epidermis. — 

 This layer consists of small, 

 thin-walled cells. 



Pkri sperm 



" '.—An epidermis of lon- 

 gitudinally elonaatpfl rells 



25> 



ep — 



Seed 



tudinally elongated cells 



With a cuticle covers a num- 

 ber of lay 



Fig. 25. 



... .ross-sect 

 ep, epidermis, 



Parenchyma. 

 Endosperm 



Citrullus vulgaris Schrad 

 ,. n s - spermoderm coasting of 



- *, sclerenchymatized paren 



sclerenchyma, p, »■ ^ jy, perisperm; 



rers of thin- walled chyma, p», inner P arenC ^ n with e p t epidermis, 



E, endosperm; C, coty e o , ^.^ 



and mesophyll, containing at, 



cell thick. In 



/: •— This is the only spe- CC U t hick. m 



c 'es studied in which this layer is more than co. ^ ^^ 

 bhinocystis hbata there are occasional broken- ^ 



th e thick-walled protein 



are occasional dh»- he cell 



layer, but in the present specie 



