290 NOTES ON DIPTEROCARPS. 
The sclerenchyma fibres are in bundles of 8-30 and anastomose ; 
but not across the lines where the fruit-wall is ruptured. In their 
absence at these spots hes the weakness which associated with a 
shghtly lesser thickness, locates the rupture of the dead tissues 
under the pressure of the growing seedling within. 
A comparative study of the distribution of these sclerenchyma 
fibres in the fruit-wall of the Dipterocarps, and above all of their 
relationship to the way in which the young plant makes it way out, 
seems to be most desirable; but it will be a long time before suffi- 
cient material for it can be got together. 
Before the fruit-wall gives way, the growing embryo has 
endured a period of compression: and if the distribution of the 
pressure is made abnormal, it stows itself in a modified way. 
Insect-punctures and other forms of injury to the fruit-wall change 
this pressure: and a slightly greater resistance to being pushed 
against the wall in the placentae of the tree 815 appears to be the 
force which leads to so many of that tree’s fruits curving as in 
figure 2 above. In these curved fruits the placenta is along the 
less convex side, and the dorsal cotyledon almost always just ex- 
cludes the placentar from the apex of the fruit cavity. In a more 
or less straight fruit the embryo in side view is thus :— 
NOE 
both cotyledons reaching the apex, but the placentar alone the base. 
But with the pressure abnormal and particularly if the injury has 
passed through the fruit wall reaching the embryo as for instance 
a Hemipteron’s tongue is generally meant to do, various changes 
affecting sometimes one side, sometimes another side of the embryo, 
appear; the embryo may then be unilateral or the dorsal cotyledon 
may have lost position or the placentar coyledon as in the two 
further diagrams here following. In the one the placentar coty- 
ledon seems to have sustained a set back; and in the other the 
dorsal, the results of which have been in the one to produce an em- 
bryo closely similar to that of Vatica Wallichw (see Jour. Str. Br. 
Roy. As. Soc. no. 81, p. 76, figures 209-212), and in the other an 
embryo suggesting somewhat that of Balanocarpus maximus (see p. 
4 of the same). 
Jour. Straits Branch 
