270 BOTANICAL GAZETTE [april 



railroad tracks in Madison, Wisconsin. They were fixed in 

 Flemming's strong, medium, and weak fixatives, the first named 

 giving the best results. Young buds, flowers, and seeds of £. splen- 

 dens were fixed in various fixing solutions, including Flemming's, 

 Carnoy's, and JuePs, and acetic alcohol fixatives. The best results 

 in this case were obtained with the latter, the Flemming solutions 

 failing to penetrate soon enough, due to the great amount of 

 latex in all portions of the plants. The material was obtained 

 during March and April 1916, from plants grown in the greenhouse. 

 Sections were cut 5 or 6 /x in thickness. Some sections of embryos 

 10 n thick were made. Flemming's triple stain was used with good 



results. 



Observations 

 Euphorbia Preslii 



t 



Cyathium 



The first evidence of the formation of the cyathium in this 

 species is the appearance of a papilla (fig. 1, p) between 2 bracts 

 (b) at the end of a peduncle. At the base of this papilla, staminate 



in\> 



grow 



cyathium 



small 



(p). The carpels (c) of the pistillate flower appear 

 :he papilla and gradually grow up about it, forming 



stigmas (fig. 4, sg) . The inv 



staminate 



The 



staminate 



in the early stages of the history of the pistillate flower only the 



stigmas project beyond the neck of the involucre. The pistillate 

 flower consists of a single pistil, whose trilocular ovary terminates a 

 stalklike structure which is jointed below to the pedicel (fig. 32). 

 Soon after fertilization the stalk of the pistillate flower elongates, 

 causing the pistil to project from the cyathium and nearly to close 

 the opening of the involucre. When a stamen is nearly mature 

 a depression appears, marking the point of juncture of the pedicel 

 and the filament. Secondary staminate flowers arise as branches 

 from the older ones (fig. 3, s 2 ). This description of the develop- 



