al cells at thoir outer ends, as s^iown in Fig, 1'6) , 

 These secondary fibrous layer cells resembled very 

 closely at t!;is stage tliose of the primary fibrous 

 layer, and I see no reason to suppose that they would 

 not have developed fibres at the proper time. Here 

 then the epidermis seems to have been more plastic 

 than the tissue under the injured spot, and whatever 

 influences ai'e at v/ork on the subepidermal layer are 

 also exerted on any cells which occupy this position. 



The fibres are developed in this layer shortly 

 before the time that the anther is to open. They are 

 developed on the side and bottom of each cell. Around 

 the top posterior and bottom of the pollen sac, there 

 is a groove (Figs. 14, 15), In the bottom of this 

 groove no fibres are developed, and the cells moreover 

 b'jcome quite thin-walled, so that they readily break, 

 and thns form the line of dehiscence of the anther. 

 As Lee en; du Sablon (S) has shown for anthers in gen- 



