wl 



BARBER-FRUITS AND SEEDS OF CUCURBIT ACE \E 



299 



join. No cuticle is present; the thickening, however, is continued 



tojoi 



on the inner wall. 



2. Subepidermal layer (sub) . — 



Small thin- walled cells, 13 p in dia- 

 meter, with intercellular spaces, 

 make up one layer. Additional 

 cells of the same type are present 

 below the radial walls of the 

 epidermis, making the tissue two 

 cells thick in those places. 



3. Sclerenchyma (scl). — As in 

 Echinocystis, there is one layer 

 of radially elongated cells form- 

 mg a palisade layer, 230 /u. in 

 width , which is best seen in cross- 

 action. The cell cavities are 

 narrow, constricted about 70^ 

 :r om the outer wall, from which 

 constriction branches radiate 

 toward the outer wall. This is 

 repeated at the other end, the 

 constriction being slightly nearer 

 the inner wall. In surface view 

 the cells are sinuous and indefi- 

 ■Mj arranged. 



4- Parenchyma. — The outer 



Us are small and thin- walled 



'/>') and the several middle layers 



c °nsist of large stellate cells and 



). All of 



(P 



Sky os angulotus L. 



these layers are sclerenchyma- 

 '-ed. About ten layers of 

 spongy parenchyma, the cells 

 ! ecrea *ing in size inward, form the 

 lnn er ti ssues (/>*). These cells 



J** chlorophyll, which gives ^^ia^e.ains. 

 e ll -ue a distinct green color. X160. 



Seed 



FIG. ^TV^KHknn consist - 

 in cross-sect.cn ; S, sperm 



ing of ep, e f der -! m :"V s-Ll-celled 

 layer, scl, ^*H^*U*i »P«W 

 outer Parenchyma f - >Xd par . 



parenchyma. ^, sma en dosperm. 



C, cotyledon ** + * c 



