332 
ILLUSTRATIONS. 
Plate IV. 
FORMS OF CELLS. 
Fig. 23. — Transverse section of the pith of Trade.scantia Virginicu : 
(I), intercellular space ; ( VV ), wall. 
Fig. 24. — Transverse section of the stem of Phytolacca decamha 
showing collenchymatous cells beneath the epidermis. 
Fig. 25. — Transverse section of calamus showing a large oil-secre- 
tion cell and smaller cells containing starch, and large 
intercellular spaces (I). 
Fig. 26. — Transverse section of pyrethrum : (R), oil-secretion res- 
ervoirs with oil globules; (I), cells with sphere crys- 
tals of inulin, such as separate in alcoholic material ; 
(L), cells containing irregular masses of inulin, as 
found in dried material. 
Fig. 27.— Longitudinal section of Cncurbita Pepo : (S), sieve cell with 
protoplasm-like contents, and transverse walls (sieve 
plates) showing simple pores. 
Fig. 28. — Longitudinal section of Cucurbita Pepo showing various 
forms of ducts: (A), annular; (S), spiral ; (I)), double 
spiral; (C), close annular ; (R), reticulate. 
Fig. 29. — Ducts of glycyrrhiza rhizome : ( W), wall ; (B), bordered 
pores ; (P), oblique simple pores. 
Fig. 30. — Longitudinal section of taraxacum showing branched 
laticiferous tissue (L). 
