IN CEYLON. 
59 
testa sufficiently to allow the cotyledons to escape prior to 
detachment. 
The cotyledons, though they have attained their full 
dimensions and are exposed to light, never take on the work 
of assimilation as in the case of the species wdth normal 
persistent cotyledons. They are at first pale yellow in colour, 
but within twenty-four hours show signs of death, and within 
thirty-six hours become black and shrivelled. They may, 
however, still adhere to the cotyledonary node by the bases 
of their short petioles. 
The point of interest in this curious suicidal mode of 
development is that the disconnection of the cotyledons 
seems to have been provided for long before the actual 
detachment takes place. Ungerminated embryos show a 
conspicuous epicotyledonary axis usually with a minute pair 
of interlocked leaves at the apex. In those species with 
persistent cotyledons such an enhanced epicotyledonary 
development does not present itself until three or even five 
months subsequent to the full exposure of the cotyledons. 
By the time the cotyledons are detached the epicotyledo¬ 
nary leaves are well developed ; they are also provided with 
a palisade tissue, and on exposure take on the work of 
assimilation usually allotted to the cotyledons. Further¬ 
more, the first epicotyl leaves usually form an opposite 
pair of interlocked leaves, and thus remind one still more 
forcibly of cotyledons. When the epicotyl leaves form an 
opposite pair these usually persist alone for many months ; 
this suggests most strikingly that their enhanced develop¬ 
ment has really been an effort, and internal evidence 
indicates that it is associated with abortion of cotyledons, 
which appears to have been taking place through many 
generations. 
The majority of our species show this detachment of 
cotyledons and enhanced development of epicotyledonary 
leaves which take on the work usually assigned to cotyledons. 
The cotyledons never acquire palisade tissue, but this layer 
