658 Lewis . — The Life History of Griffithsia Bornetiana . 
Before the differentiation of the auxiliary cell, the nuclei may average 1*5 /x 
in diameter ; when the carpogenic branch is fully formed, the central 
nucleus of the auxiliary cell may reach a diameter of 6.5^ (Fig. 76). 
A similar change may take place in one of the nuclei of the other peripheral 
cells. 
The structure of the mature procarp is as follows (Figs. 73, 75) : The 
broad, flat basal cell bears on its upper border the central cell, which is 
also broad and rather flat. The central cell bears usually three peripheral 
cells which may or may not cut off sterile cells at their tips. One of the 
peripheral cells bears laterally the carpogenic branch, which consists of a 
basal cell, two intermediate cells, and the carpogonium with its trichogyne. 
The intermediate cells and the carpogonium are disposed in a straight 
line, which lies at right angles to a line passing through the basal and the 
auxiliary cells. 
All the cells of the procarp are multinucleate except those of the 
carpogenic branch. Of these the terminal cell and the two intermediate 
cells are uninucleate, and the basal cell of the carpogenic branch is usually 
binucleate. The connexions between the cells of the procarp appear to 
be similar in general to the connexions between neighbouring vegetative 
cells. 
Mention has been made above of the hairs which usually occur in the 
vicinity of procarps. 
The small size of the trichogyne and of the carpogonium renders 
Griffithsia Bornetiana a rather unfavourable object for the study of the 
details of fertilization, but it has been possible to make out the essential facts. 
A spermatium becomes attached to the trichogyne near its tip (Figs. 75, 77, 78). 
The spermatium is either applied directly to the surface of the trichogyne, 
or there may be a short tube connecting the two. Whether the nucleus of 
the spermatium divides at this stage, as is the case in Nemalion (Wolfe, 90 ) 
was not determined, though such an appearance as is presented in Fig. 78 
suggests that division may occur. A sufficient number of stages was 
not obtained to enable me to speak with certainty on the subject but 
the stages that were obtained seem to render it highly probable that the 
nucleus from the spermatium passes down the trichogyne, enters the 
carpogonium, and there fuses with the nucleus of the carpogonium (Figs. 
77 , 79 )- 
Immediately after fertilization the trichogyne becomes much twisted 
and falls off, leaving a short stump on the carpogonium (Fig. 80). Since 
the fusion nucleus stains very heavily, the details of its structure were not 
made out. However, because of this very capacity for taking up dyes, it is 
easily distinguished from the other nuclei of the procarp. 
Very soon after fertilization, the carpogenic branch begins to be 
withered, and the fusion nucleus is seen to be present in the auxiliary cell 
