u 



to be entirely wanting. In the hist named genus thev may be 

 found ni the very tips of the prominent ribs, the position usually 

 held by strengthening cells being occupied by large and loose 

 parenchyma, the other structures remaining normal. Stiengthen- 

 ing cells are thus unlike in elements and position, are in groups of 

 varying size and distinctness, or in bands, or may be wanting en- 

 tirely. From these facts important characters arc obtained for 

 generic grouping. 



Undifferoitiatcd farciicliv))ia . This has merely the negative 

 character of not being transformed into either strengthening or 

 secreting cells. Its abundance is dependent upon the development 

 of the strengthening cells. It will be seen, however, that 

 although it furnishes no diagnostic characters, it is probablv most 

 concerned in the growth of the pericarp. 



Each carpel primaril\- contains two ovules, one of which soon 

 becomes aborted, although it is developed sufficiently to display 

 its nucellub and integuments, as well as its anatropous character. 

 The other ovule eventually occupies the whole space of the 

 ovarian cavity. 



The fibro-vascular connection of the ovules with the plant 

 axis is as follows: A fibro-vascuiar bundle enters each carpel at 

 its base, thus making it a lateral out-growtli from the axis, while 

 the axis itself continues its growth in the carpophore. The car- 

 pellary bundle almost at once subdivides into five branches, and 

 these branches ascend the carpellary wall beneath the five primary 

 ribs. 



The two lateral bundles (that is, those beneath the lateral 

 ribs) are the largest, as they contain the fibro-vascular elements 

 to be distributed to th.e ovules. These lateral bundles pass in the 

 carpellary wall to the very summit of the carpel, and then send a 

 brancj inwards and downwards into the funiculus of the anatro- 

 pous ovule. The remaining elements of the fibro-vascular bundle 

 pass on to the floral organs and stylopodium. It will be seen that 

 in this case, as in Compositcc^ the ovules arc lateral outgrowths. 

 A point or two in the development of the ovule may be mentioned 

 in this connection. At first both ovules lie in the summit of the 

 ovarian cavity, but soon, by the development of the funiculus, one 

 is thrust toward the bottom, with the micropyle near the center of 

 the cavity. It is in this position that the pollen tubes are seen to 



