166 Trans. Acad. Sci. of St. Louis. 



with A. mexicanus in having most of the yellow pigment in the 

 Malpighian cells. The cells are 22 jx long, each containing one 

 or more chromatophores. A small intercellular space occurs 

 below the Malpighian cells. Longitudinal striae of the osteo- 

 sclerids are not marked. Nutrient layer agrees with that of 

 the last species. Endosperm is well-developed laterally. All 

 of the cells of the endosperm contain protein. Embryo as in 

 A. mexicanus. For complete reactions see Table A. 



OxYTROPis, DC. (/^S'p^ma, Neck.) 



Anatomically this genus is closely related to Asti^agalus. 

 Endosperm is present in the species studied. One species was 

 studied by Chalon. 



Oyteopis Lamberti, Pursh. {S. Lamherti, Pursh, Lamb.) 



PI. XIII. f. 4. 



Testa and endosperm 170-175 /a. This, the so-called loco 

 weed, is said to cause disturbances in animals, but alkaloids 

 have not been found in the seed or any other part of the 

 plant. 



Malpighian. Cells 40-42 fx long. Cuticle somewhat un- 

 even ; the narrow well-marked cuticularized layer colors blue 

 with chlor-iodide of zinc; the light line occurs below the 

 cuticularized layer, and this also colors blue ; the remainder 

 of the cell-waU takes on a darker blue color. Cells contain 

 an abundance of pigment, tannin, and some plastic material. 



Osteosclerid. Cell-walls thickened, not prominently I- 

 shaped, but with an elongated intercellular space. 



Nutrient. Layer consists of thin-waUed elongated ceUs, 

 from ten to twelve rows. Pio;ment more abundant in lower 

 than in upper part. WaUs color blue with chlor-iodide of 

 zinc. 



JSndosperm. The aleurone layer consists of thick-walled 

 cells; the underlying thick- waUed cells of the reserve cellulose 

 become mucilaginous on the addition of water. The internal 

 part consists of thick- waUed, elongated ceUs. The ceUs con- 

 tain protein. 



Embryo. CeUs of the first row smaller, with thick exterior 

 waUs; cells below not so compact and with thinner walls. 



