56 



MR. C. BAILEY ON THE STRUCTURE ETC. 



but I have found botli globose and elongate pollen in the 

 anthers of the Lancashire Naias graminea. The globular 

 form is represented in fig. 79, and the elliptical form is 

 given in fig. 80^ both drawn to the same scale. Undoubtedly 



Fig. 79. 



Fia:. 80. 



the pollen is globular in its early stages^ but^ after select- 

 ing "what appeared to be perfectly mature anthers just at 

 the period of dehiscence^ the pollen which emerged was 

 found to be globose^ as drawn_, in one anther, and elliptico- 

 cylindrical in another anther. Whether the globose pollen 

 ultimately passes into the elliptical form, and thus the 

 latter represents the mature pollen, or whether there is a 

 dimorphism in the pollen-grain, I cannot pronounce; I 

 can only certify to the occurrence of both forms in plants 

 from the same station, and that the globose form is much 

 the rarer of the two. 



In its fresh state the pollen-grain is of a pale yellow 

 colour, and its contents are granular. It must be produced 

 in great abundance, as I have frequently found it in a free 

 state in the water of the glass jars which have held the 

 living plant during these investigations ; grains also occur 

 floating about in the chloride of calcium solution which I 

 use for mounting the dissections of the plant for perma- 

 nent microscopic examination. 



