53 MR. C. BAILEY ON THE STRUCTURE ETC. 



whicli simulates the style^ and at the point where it 

 reaches the chamber which contains the ovule it becomes 

 slightly constricted (fig. 71) ; but immediately below the 

 constriction it widens out into a cupola-shaped cavity, 

 whose upper portion, or roof, is lined with a few unicellular 

 hairs (figs. 72 & 73). Below this cavity is the ovule. The 

 accompanying drawings (figs. 67—73) illustrate the female 

 flower in some of its stages of development. 



No portion of the pistilhferous flower bears any spines 

 similar to those which occur on the bracts and leaves; 

 such spines are present in some of the species of Naias, 



XI. The Antheriperous Flower. 



The male flowers are not so numerous as the female 

 flowerSj and they grow intermixed with them. Although 

 I have frequently found plants of Naias graminea in which 

 none but pistilliferous flowers could be detected at the 

 period of examination, such tendency towards dioecism 

 never showed itself when anther-bearing flowers were 

 present. When the latter occurred on a plant pistilliferous 

 flowers were invariably present, and oftener than not side 

 by side with them (see figs. 67 & 68). 



My observations of the anther do not quite coincide 

 with the descriptions and figure given by Dr. Magnus ; I 

 have consequently given a larger number of illustrative 

 drawings of this organ. The drawing of Dr. Magnus is 

 reproduced on Plate VII. i,n fig. 35. 



When young they are oval-shaped bodies borne upon a 

 very short stalk (see figs. 74 & 76). So much do they 

 resemble the anther of an ordinary flowering-plant that I 

 was a long time in realizing that the outer body which I 

 was examining was the membrane which formed the peri- 

 anth. The perianth closely invests the anther throughout 



