1894.] MICROSCOPICAL JOURNAL. 335 



seed coat well developed in one genus of the order 

 should be entirely absent in another genus especially 

 when we consider the slight variability of these struct- 

 ures. 



The inner coat consists normally of two parts ; an 

 outer layer of thin parenchyma, and an inner layer with 

 cells regular in outline, thick walled, often striated on 

 the inner side, and thin walled toward the surface. Its 

 color is pale yellow or dark brown. The striations often 

 pass into the cell cavity as ascicular projections. Some- 

 times, however, the cells are so compressed as to be 

 scarcely visible. This layer is always thickened at the 

 micropyle, but in some cases more than in others. In 

 all pod forms except Paeonia it is elongated into a cylin- 

 der passing in most cases to the surface of the seed. 

 This I have termed the collar of the micropyle. In the 

 center of this tissue there is generally a trace of the 

 former tubular canal of the micropyle. This is more dis- 

 tinct in the more generalized forms. 



The outer seed coat is often much modified to serve as 

 a protective organ, especially in the pod forms, and con- 

 sists of two layers. In the pod forms the outer layer 

 consists of one row of latterly compressed cells with 

 thick walls. Their cavities often contain dark coloring 

 matter, and their outer walls form papillae on the surface. 

 In the achene forms the cells become oblong, rectangular, 

 or irregular in outline, and are so thin walled as to be 

 scarcely distinguishable from the next layer. In all pod 

 forms the cells bend in around the collar of the micro- 

 pyle and thus line the orifice. In Paeonia, at maturity, the 

 layer is continuous over the micropyle. The inner layer 

 is composed entirely of parenchyma containing dried 

 protoplasmic bodies and rarely nuclei. It is thickened 

 in the region of the raphe the vascular strand of which 

 always passes through its tissue. 



The carpels of the Ranunculaceae are either smooth 



