14 
to be entirely wanting. In the last named genus they may he 
found m 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. Strengthen- 
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 are obtained for 
generic grouping. 
Undifferentiated farenehyma. 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 probably most 
concerned in the growth of the pericarp. 
Each carpel primarily contains two ovules, one of which soon 
becomes aborted, although it is developed sufficiently to display 
its nucellus 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-vascular bundle enters each carpel at 
% 
its base, thus making it a lateral out-growth 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 the ovules. These lateral bundles pass in the 
carpellary wall to the very summit of the carpel, and then send a 
branch 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 cdse, as in Compositce, 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 
