222 Trans. Acad. Sci. of St. Louis. 



pious and cartilaginous. Epidermal cells mucli smaller than 

 those of the parenchyma, two rows of palisade cells. Reserve 

 material consists of fat and aleurone grains Prosopis. 



Eumimoseae. 



Cuticularized layer well marked, Malpighian cells thick- 

 walled; osteosclerids 1-shaped, reduced, and essentially like 

 the sclerotic cells of the nutrient layer ; epidermal cells of the 

 cotyledons smaller than those of the parenchyma, palisade 

 cells in several rows. Reserve material consists of fat and 

 aleurone grains. 



1. Osteosclerids I-shaped DesmantJius. 



1. Osteosclerids not I-shaped Schrankia. 



Acacieae. 



Cuticularized layer a narrow zone, Malpighian cells thick- 

 walled, not greatly elongated ; osteosclerids I-shaped ; endo- 

 sperm much reduced. Epidermal cells of the cot^dedons 

 smaller than those of the parenchyma, one row of palisade 

 cells Acacia. 



SUMMARY. 



Under the general head of macrosclerids I have discussed 

 quite fully the Malpighian cells, with reference to the light 

 line, which I believe to be chemically and physically modified. 

 The light line occurs in widely separated orders. The Mal- 

 pighian cell separates at the light line, that being a point of 

 least resistance. The Malpighian cells are either lignified or 

 consist of cellulose. In some cases the cells are only par- 

 tially lignified. They are lignified in some Leguminosae, also 

 in some other orders. These cells always contain tannin and 

 usually some pigment. The cuticularized layer is well devel- 

 oped in Medicago and Gymnocladus. The function of the 

 Malphighian cells is largely one of protection. 



The osteosclerids vary in different tribes, as shown in the 

 synopsis; they usually carry pigment and tannin. The walls 

 are not infrequently provided with longitudinal pore-canals. 

 The nutrient layer in the immature seed is well developed. 

 When the seed reaches maturity this layer becomes much 

 compressed, its function, that of supplying nourishment to 

 the developing seed, ceases when the ripening process begins. 



The mycotic layer is much compressed and may be looked 



