312 THE AMERICAN MONTHLY [Oct. 



On the Seeds and Testa of Some Cruciferae. 



By L. H. PAMMEL. 

 ames, iowa. 



WITH FRONTISPIECE. 

 Continued from page 2J4, 



Camelina sativa, Crantz. 



Pod obovoid, four to six lines long, smooth, reticula- 

 ted, margined from beak down along placental side with 

 smaller ribs between them. Seeds light brown, one line 

 long, minutely pitted, caulicle prominent, running 

 lengthwise with a prominent groove between it and the 

 cotyledons. Cotyledons incumbent. "^ 



Seed coats consisting of four layers. The outer epi- 

 dermal cells not much longer than wide, on the addition 

 of water become mucilaginous and well stratified. On the 

 addition of chloral hydrate stratification more evident. 

 The cell-walls difi"erentiated into several different sub- 

 stances. The second layer not always developed. Cells 

 ol third layer with thick walls and brown pigment, fol- 

 lowed by a narrow layer of thick walled brown cells. 

 The first row of cells of endosperm, rather thick walled, 

 filled with protein grains, the other layers of unequal 

 development, cells elongated, thickwalled ; followed by 

 cells of embryo; these conlain protein grains and fat. 

 EXPLANATION^ OF THE FIGURES. 



I. July text, page 209, (Reprint, page 7). Brassica nigra: a, mucilag- 

 inous cell before the addition of water; b, after addition of water; 3, brown 

 thick -walled cells; 4, parenchyma cells; 5, aleuroue layer; 5-6, endosperm; 

 7, cells of embryo. B. sinapistrum: c, mucilage cells exiDanded; 4, endos- 

 perm in figure to the left, embryo in figure to the right. 



II. September frontispiece (Reprint, page 12). Sisymbrium altissimum, 

 S. officinale and Capsella barsa-pastoris: The upper row of cells consists of 

 mucilage cells; the lower row contains embryos; about midway between 

 may be seen the endosperm. 



III. September text (Reprint, page 13). Lepidium virginicum. 1, mucil- 

 age cells; 3, 4, endosperm; 5, cells of embryo; b, mucilage cells when 

 moistened. 



IV. October frontispiece (Reprint, page 15). Brassica alba: Upper row, 

 mucilage cells; third and fourth rows, endosperm. Camelina sativa: upper 



*Harz. 1. c. p. 924. Fig. 71. 



