818 Traiuactiotis. — Botany. 



When the styles arise they are curved over towards 

 each other, euclosmg a hollow (fig. 6), but they soou begin 

 to grow up straight, while the ovary begins to swell out 

 (fig. 6). The cells at the top of the style now begin to be 

 rounded off from one another, so that the beginning of the 

 stigma can be recognized (fig. 6, st.). Meanwhile the sta- 

 mens have been rapidly growing, and have differentiated into a 

 short filament surmounted by a large anther (fig. 6, / and a). 

 The origin of the pollen, however, is not yet visible. The 

 growth of the sepals and petals has been going on by vege- 

 tative division of the cells, and there is nothing particularly 

 to be noticed in these whorls till after the fertilization of the 

 flower. 



The stamens soon begin to form mother-cells in the usual 

 way, but the most interesting part of the flower is the gynoecium. 

 The stigmatic cells, which at first were found only at the 

 tip of the style, now spread downwards (fig. 7, st) and the 

 style rapidly becomes stigmatiferous right down to the ovary. 

 At the same time each carpel of the ovary begms to get hollow, 

 and a single ovule arises in each as a papillary outgrowth from 

 the central wall of the carpel (fig. 7, ov.). It grows rapidly 

 and curves downwards till it assumes an anatropous form, 

 while a coat grows round the nucellus (fig. 8, ov.). The ovule 

 is now pendulous, and grows rapidly, and about this time 

 the flower opens. I made a great many sections to try and 

 observe a second coat growing rouud the ovule, but failed. I 

 cannot say whether there is only one coat or two. I obtained 

 many sections showing the one coat growing up, as in fig. 8, 

 and many showing the complete ovule, but none showing a 

 second coat growing round it. 



All these forms of development may be observed between the 

 3rd and 27th of October. About the latter date the flower 

 expands. Transverse sections through it just before it opens 

 give the appearance of fig. 9, and fig. 10, In the latter 

 the fibro-vascular bundles of the petal show like two ridges on 

 the inner surface ; the anthers distinctly show the four loculi, 

 and the six styles are compressed into an irregular hexagonal 

 form. 



The growth of the anthers has not been noticed since the 

 formation of the mother-cells of the pollen. These divide and 

 give rise to four pollen grains each, before the pollen grains 

 become separated (fig. 12). The ripe pollen grains are much 

 larger than when first formed, and the cell-wall is thickened 

 in three places. In each grain there is a nucleus, usually 

 with two uucelli (fig. 14). 



After fertilization the petals swell up and become juicy; 

 when the fruit is ripe, the juice is a dark purple : the sepals 

 remain, but the stamens wither (fig. 13). Each carpel gives 



