34 



Isabel C. Cookson 



Fig. 1. — Stages in the Complexity Anther Formation. 



a. Shows the^ simplest stage of anther formation in which a single 



loculus is present. 



b. Translation stage from unilocular to bilocular condition. 

 O. Bilocular anther. 



•d. Trilooular anther. 



•e. Transition stage from trilocular to quadrilocular condition. 



s. Point at which dehiscence takes place. 



t. Cells rich in tannin. 



In Plate III., Fig. 5, is figured a vertical section of a young an- 

 theriferous petal, the anther of which contains four loculi. Here 

 the lamina is feebly developed, so that the whole structure, petal 

 and anther, strongly resembles the appearance of a similar sec- 

 tion of a normal anther. Pollen grains and a tapetal layer are 

 present in each pollen sac. 



In Text figure 2, the section represented is one of a more 

 mature petal. The tapetal cells have disappeared, whilst the 

 mechanical elements of the anther are strongly developed. The 



