212 Trans. Acad. Sci. of St. Louis. 



consists of a single row of cells, in some cases considerably 

 elongated, followed by the vitreous starch layer. The cells 

 are densely filled with larger compound starch grains, the 

 component parts are five-sided (PI. XVII. 8). 



Bromus ciliatus, L., var. purgans, A. Gray. In speaking 

 of the genus Fesluca the statement was made that it is 

 closely allied to Bromus. Both genera are very closely allied 

 to Brachypodium from an anatomical standpoint. I have 

 elsewhere indicated that several species of the genera Bromus 

 and Brachypodium were studied by Harz. 1 In Bromus the 

 palet partially adheres to the caryopsis especially in the 

 groove. The epidermis and the underlying cells of the palet 

 are thin-walled and toward the groove very much smaller. 

 The pericarp consists of dark-colored cells somewhat longei 

 than broad, relatively thin-walled, of one or two rows. The 

 cells of the testa are thicker-walled and dark brown. The 

 outer portion of the nucellus consists of large thick-walled 

 stratified cells. On the addition of water the thick walls 

 expand and are partially converted into mucilage. In the 

 groove the nucellus increases from one to a dozen rows of 

 cells; the cells are likewise thick-walled but they are not 

 stratified as in the outer layer. The inner part of the nucellus 

 is compressed. The aleurone layer consists of a single row of 

 relatively large cells. The starch cells are very much larger 

 than the aleurone and thick-walled as in Festuca. They con- 

 tain a large number of simple starch grains, and an abund- 

 ance of protein elements (PI. XVIII. 3). 



HORDEAE. 



This tribe contains the economic genera Hordemn, Triti- 

 cum, and Secale. All works treating of the economic food 

 products have usually given short accounts of the structure 

 of the fruit, testa and endosperm. I shall refer to some of 

 these papers under each genus. 



Triticuniy L. There are excellent accounts of the structure 

 of Triticum by Harz, Tschirch & Oesterle, 2 Hanausek, 3 



1 1. c. 1232./. 15S. 2 l. c. 3 ]. c> 



