144 Trans. Acad. Sci. of St. Louis. 



a constriction in the middle ; large intercellular spaces between 

 the cells. Upper and lower bars equal. 



Nutrient. Cells thin-walled, irregular, of a yellow color ; 

 lower part of the layer is much compressed and the cell-walls 

 contain more pigment. The layer also contains the vascular 

 elements. 



Endosperm. Though the statement is made that the seed 

 of this species is without endosperm, it has the same amount 

 as L. pusillus. The cells are elongated, thick-walled, con- 

 taining protein grains. 



Embryo. The cell-walls thickened, consisting of reserve 

 cellulose. Starch absent. Cells contain fat and protein. 



PAPILIONACEAE — Trifolieae. 



The tribe Trifolieae is represented by three genera in the 

 Manual, only one of which is indigenous, Trifolium. Most 

 of the species of this genus are introduced. An anatomical 

 study of the seed gives additional reason for maintaining 

 this as a distinct tribe. The cotyledons contain small starch 

 grains and most of the species are provided with endosperm. 

 The osteosclerids, so far as they have been studied, are longi- 

 tudinally striated in all of the genera examined, Trifolium^ 

 Ononis, Trigonella, Medicago, and Melilotus. The African 

 and Asiatic Parochetus has not been examined. The walls 

 are not longitudinally striated in the related Lotus and 

 Tetragonolohus. 



Trifolium, Tourn. 



There are several excellent accounts of the structure of the 

 seed, by Sempolowski, Harz, and Nadelmann. My studies 

 are inserted here so that the species may be compared with 

 others. Endosperm is well developed but variable in thick- 

 ness. Walls of the testa and endosperm 91 /i to 140 fi in 

 thickness. 



Teifolidm pratense, L. 



PI. IX. f. 6-6b. 



Malpighian. Cells are 56;^ long. Surface view of the cells 

 prismatic; pore-canals extending from the center; the cuticle 



