102 Trans. Acad. Set. of St. Louis. 



and Oesterle 267. Brandza 26, 116-117. pi. 8. f. 9). 

 In Sterculia heterophylla the Malpighian cells form the second 

 layer. The outer portion consists of parenchyma cells with 

 granular contents. The Malpighian cells are greatly elon- 

 gated, with two light lines. A wide line occupies the upper 

 part of the cell; below it, occur a series of narrow canals, 

 which contain air. The canals extend into the cell-wall. The 

 dark appearance of the cell at this point is due to the con- 

 tained air. The narrow light line occurs in the upper part of 

 the cell. With chlor-iodide of zinc it assumes a straw color. 

 The lower part of the light line gradually becomes darker, 

 finally bluish-black. Chemically, it appears therefore to dif- 

 fer from the remainder of the cell-wall. It is not, however, 

 typical cellulose. When treated with phloroglucin the light 

 line appears to color slightly, but this is due to the underlying 

 cells. The light line appears in strong contrast with the col- 

 ored portions. The lower walls of outer parenchyma layers 

 also show the lignin reaction. The lignin test does not quite 

 correspond to Mattirolo's results on S. xtlatanifolia , where 

 the reaction is more pronounced. The nutrient layer contains 

 no lignin, except the vascular elements. 



Malvaceae. The following writers have discussed the testa 

 or part of it. Duchartre (327); Lohde (396) ; Strand- 

 mark (254); Mattirolo (401); Harz (99, 2:736-750. /. 

 34-35)', Bretfeld (306); Junowicz (128); Hanausek (361, 

 /. i-5); Rolfs (435); Brandza (26, 111-115. pi. 7. f. 

 9-14. pi. 8. f. 1-5); Mell (406); Guignard (354, 141- 

 153. /. ^6-6'(9); Godfrin (71). 



The narrow, well-marked light line of Malvastrum angustam 

 occurs close to the exterior cell- wall of the Malpighian cell. The 

 light line colors brown changing to a dark brown, with chlor- 

 iodide of zinc. The remainder of the wall also takes on the 

 same dark color. The cell-wall becomes so deeply colored 

 that nothing of its structure can be made out. Phloroglucin 

 colors the light line but slightly, the lower part coloring very 

 rapidly. In general the reactions are the same as those given 

 by Mattirolo for Gossypium, except that it is not so deeply 

 colored. 



In Gossypium herhaceum the narrow light line runs close 



