STUDIES ON SOME EXTRANUPTIAL NECTARIES. O 



mostly on material collected in the Botanic Garden of the Tokyo 

 Imperial University, and I wish here to express my sincere thanks 

 to him. The results are given in tlie following chapters. 



II. Anatomy of some extranuptial nectaries. 

 A. Structure of extranuptial nectaries in general. 



All the extranuptial nectaries, which I have studied, may be 

 classified under two types : the first including the nectaries, which 

 develop from epidermal cells ; and the second, those which originate 

 from a group of cells, both epidermal and hypodermal. 



The first type. 



a. Polygonum sachcdinense. 



Here we have the nectary in the form of a shallow elliptical 

 basin of a slightly reddish colour. It is tolerably large, the 

 longest diameter reaching sometimes 4 mm. It is composed of a 

 group of glandular papillae, each of which consists of three parts, 

 viz., crown, style and base. The crown is built up of a bundle 

 of narrow prismatic cells, regularly arranged in a single layer 

 on the style cells ; the number of the cells in each bundle varies 

 from 16 upwards. The height of the cells is three or four times 

 their diameter. Sometimes the cell is divided into two parts 

 by a tangential wall. 



The style cells are fewer in number than the crown cells, 

 and lie close to one another. Each style cell is in shape a 

 polyhedron, the upper wall of which is convex. The cuticle 

 covering the whole surface of glandular papillae is slightly thick- 

 ened around the style. 



Immediately below each style cell and on the same plane 



