IN CEYLON. 
63 
The tendency for the median cotyledonary trace to abort 
is what one may expect in those species where the cotyledons 
are defunct at such an early period, and the prolongation of 
the epicotyl traces into the root is rendered necessary since 
nutritive substances cannot be absorbed from the endosperm. 
The fact that the embryo shows these structures fully 
differentiated points to a past history in connection with 
these curious developments. 
The traces of the cotyledons are provided for the conduc¬ 
tion of food materials absorbed from the endosperm to all 
parts of the seedling ; in those species with persistent 
cotyledons they are the only vascular tissues present during 
the first few weeks or months of the seedling’s life. If the 
absorbing tissues and the reserve food are cut off from the 
seedling during this phase, the young plant must die if the 
epicotyledonary traces are not prolonged into the root to 
establish a connection between the growing point of the stem 
and the new absorbing tissues constituted by the primary 
root. 
It is very doubtful whether such developments can be 
accomplished in one generation, and the definiteness of the 
median trace abortion and epicotyledonary prolongation are 
sufficient evidence that the curious mode of development 
has been going on for many generations past. 
There are, however, several facts which point to a very 
unstable condition. Seedlings of the same species show 
considerable variation in the degree of differentiation of the 
different tissues, and also in the behaviour of the vascular 
strands in the region of the collet. In one seedling the 
epicotyledonary and median cotyledonary traces were absent 
from the primary root at a distance of 2 cm. from the 
apex ; at this point only the four lateral cotyledonary traces 
were present, though in the hypocotyl the six cotyledonary 
and two epicotyledonary bundles were in evidence ; in this 
case the median cotyledonary trace had apparently suffered 
complete abortion at a point which had not yet been reached 
