198 The Ohio Naturalist. [Vol. VIII, No. 1, 



EARLY STAGES IN THE DEVELOPMENT OF THE FLOWER BUD. 



The buds of the same head taken July 21, 1906, showed quite 

 a diversity of stages in development, but the youngest one was 

 practically the very beginning of the flower. The incipient bud 

 arises as a small cylindrical body, from the periphery of the 

 crown of which appear the incepts of the four sepals. These are 

 somewhat transversely flattened cones, the apices of which turn 

 inward (Fig. 1). 



In the flower representing the next stage in development, 

 found upon this same receptacle, the incepts of the four petals 

 were seen. These are inere papillae at this time (Fig. 2). They 

 arise at the base of the sepals, on their median side and alternate 

 with them. 



A third stage of development was also found upon the same 

 head. In this the four incipient stamens (Fig. 3) take up the 

 same position with respect to the petals that the latter did with 

 reference. to the sepals. The petals have become much thickened, 

 while their truncated apices are approaching each other. 



The gynoecium has its beginning the latter part of July, as 

 shown in figure -i of material collected on the 28th. A ridge- 

 like ring develops at the base of the stamens. This grows 

 upwards forming the style with a definite stylar canal. In addi- 

 tion to this it may be noted that the apices of the petals have 

 met. These tightly joined petals thus serve as a protection 

 during the winter season. 



All of the flowers on a single receptacle collected August 5th 

 showed no further progress in development. Some vere even 

 youngei than those of the last period. 



Flowers of August 11th showed a general development. This 

 was especially manifested in the elongation of the four sets of 

 organs. In addition to this the stamens were becoming differ- 

 entiated into anther and filament. From the sides of the lower 

 portion of the stylar canal, arise the two incipient ovules (Fig. 5). 



Sections of flowers collected August ISth show (Fig. 0) that 

 the basal portion of the original, cylindrical bud has l)ecome 

 differentiated as the ovulary. The incipient ovule has bent 

 upon itself and is now growing upwards forming the anatropus 

 type. 



DEVELOPMENT OF THE MALE GAMETOPHYTE. 



As has already been stated, the stamens begin to be differ- 

 entiated into a filament and anther as early as August 11th. 

 Internal development has been alike active and the hypodermal 

 archesporial cells of the incipient anther are enlarging. From 

 this time until the next date, August ISth, progress is even more 

 rapid. The archesporial cells have not only divided into the 

 primary parietal and primary sporogenous layers, but these have 



