94 UNIVERSITY OF COLORADO STUDIES 



Stalks thus united. Miss Ethel Sargant ^ has recently published a 

 provisional list of plants which show this peculiarity. • 



From a glance at Fig. 4 the general structure of the seedhng will 

 be understood. The hypocotyl is short; the primary root is soon 

 replaced by a number of adventitious roots. All parts of the plant 

 are glabrous, or nearly so, although the leaves bear a few short trichomes 

 to be seen only with the compound microscope (Fig. 8). From the 

 very first the leaves are palmately cleft and toothed; later leaves are 

 more deeply incised (Fig. 13). The cotyledons have the usual Ranun- 

 culaceous form, being oval or elliptical in outline. In texture they 

 are herbaceous. Veins in the cotyledons are only recognized with 

 ease after the specimens have been in alcohol for a time. 



Certain differences are apparent in the structure of the epidermis 

 of the leaves and cotyledons, as will be seen by a glance at the figures. 

 In the cotyledon, the epidermis of the upper (Fig. 5) and lower (Fig. 6) 

 surfaces is much alike. The cell outHnes are quite wavy. Some 

 stomata are present on the lower surface, while none are to be seen 

 above. As would be expected, the leaf shows a more speciahzed con- 

 dition. The cells of the upper surface have only a slightly wavy out- 

 line (Fig. 7), and there are no stomata. On the other hand, the lower 

 epidermis is made up of cells with very wavy outlines, and there are 

 numerous stomata and some short, club-shaped trichomes (Fig. 8). 



In studying vertical sections of the leaf -lamina (Fig. 9) and blade of 

 the cotyledon (Fig. 10) marked differences are seen. A distinct paUsade 

 of vertically elongated cells is found in the former, and a few of these 

 palisade cells are branched above so as to be V or Y shaped. No 

 true palisade is formed in the cotyledon, but instead there are about 

 two rows of rather spherical cells very loosely arranged with large 

 intercellular spaces. The vascular tissue of the cotyledon is slight in 

 amount, the bundles being quite small. 



The cotyledon-stalks are united for about half their length in the 

 same way as those of Delphinium occidentale, described by the present 

 writer.^ A similar condition has recently been noted by Miss Neata 



1 Annals of Bot. 17: 73. 1903. ^ Minn. Bot. Studies. 2: 417-421. 1900. 



