266 DR J. M. MACFARLANE ON THE 



other in the development of many long unicellular hairs, alike along the veins and 

 regions between. Those of C. Laburnum show a few hairs scattered near the apex of 

 the teeth only. In C. purpureas and C. Adami there is a considerable number of 

 stomata over the upper half of the calyx, three to four occurring under the D Zeiss 

 objective, while in C. Laburnum stomata are quite absent. The epidermal cells of 

 C. purpureus and C. Adami are chiefly quadrangular and straight walled below, but 

 become very sinuous above, and are larger than in C. Laburnum, which has polygonal 

 cells below that merge into elongated and slightly wavy cells above. 



The outer (lower) surfaces of the sepals in C. purpureus and C. Adami are glabrous ; 

 in the first one to three stomata may be traced under Zeiss' D, in the second five to 

 seven. The outer surface in C. Laburnum is densely covered with spindle-shaped hairs as 

 over the vegetative leaves, and eleven to twelve stomata may occur over the above- 

 mentioned area. 



The sepaline mesophyll tissue of C. purpureus shows in alcohol material a few dark- 

 brown, sharply-defined chloroplasts ; in C. Adami they are more abundant, of a paler 

 colour, and less sharply defined ; in C. Laburnum they are most plentiful, of a delicate 

 neutral- tint colour, and have a soft, rather ill-defined aspect. The colour and relative 

 sharpness of definition appears to be entirely due to tannin, which, existing probably as a 

 tannate of albumen, is precipitated by alcohol. 



It may further be mentioned that along the margins of the sepals of C. purpureus 

 and C. Adami there are not only long simple hairs but short spindle-shaped ones, with 

 wart-like thickenings, such as we meet with in great quantity in C. Laburnum. 



Petals- — (a) Standard, — The comparative shape and venation of the three standards 

 is well represented in Plate VIII. figs. 13a, b, c. The petals of C. Laburnum are glabrous 

 throughout, but the hair distribution of the other two is specially worthy of note. At 

 the junction of claw and blade in C. purpureus a line of hairs, about 125 to 130 in 

 number, fringe the margin and are inclined outward and downward ; in C. Adami there 

 are 60 to 65 similarly placed. These hairs, along with others placed on the same level, 

 are evidently intended to guard the nectary entrances. 



The lower half of the standard in C. pmpureus is traversed on its inner side by a 

 median groove, the bounding ridges of which are fringed by long, simple, intercrossing 

 hairs. The epidermal cells of the claw are elongate and narrow, but gradually widen out 

 upwards till above the middle of the petal they are quadrangular or polygonal. Their 

 walls are wavy in outline and are infolded ; their free surface also is slightly convex. 



The lower half of the standard in C. Laburnum is likewise traversed by a groove, but 

 its ridges are glabrous, the epidermal cells are like those of C. purpureus below, but 

 higher up they are not only zigzag and infolded, each cell swells out into a cone-shaped 

 papilla, and its surface is finely striate. In C. Adami the ridges which bound the groove 

 of the standard are beset by simple hairs ; the epidermal hairs most closely resemble those 

 of C. purpureus, but faint striae occur over the walls of the upper cells of the standard, 

 as in C. Laburnum. 



