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BRYCE ; 
partially protruding from the bark, and were exposed on their 
outer surface. The exposed side was dead and dried up ; the 
inner side was still in living connection with the cortical tissue. 
It would be merely a matter of time till these nodules dried 
up completely and fell away with the bark scales. The writer 
has observed a similar condition on trees on estates, where 
the trees were much younger. In both cases other nodules 
were present which had joined up with the stem wood. 
In cutting sections of nodular cortex one may find, in the 
outer cortex, small reddish-black points, which are extremely 
brittle, and crumble away before the razor. They appear 
almost as foreign bodies lying in the cortex, and easily 
separate from the surrounding tissue . They c onsist of portions 
of the cortex, including abundant stone cells and some 
cortical cells and latex vessels, all saturated with tannin. 
Sections can with difficulty be obtained, and require treatment 
with concentrated nitric acid to render them transparent, the 
tannin being then dissolved. Stone cells are by far the most 
abundant ; the remaining tissue is normal. The tannin here 
is probably secreted as a means of protection against some 
injurious effect emanating from these points. The nature of 
these reddish-black points has not been determined. 
Nodules in Untapped Trees. ' 
The first material collected from an untapped tree consisted 
of two specimens obtained from near the base of a five-year 
old Hevea on the Government Experiment Station at Fera- 
deniya. Sections of these showed no latex vessels in the core, 
and the tannin cells so characteristic of nodules were entirely 
absent. These specimens were undoubtedly globular shoots 
derived from latent buds. 
It became evident that the statement that nodules occur 
on untapped trees required some definite proof of its accuracy. 
Accordingly, 2,000 trees seven years old and untapped were 
examined. These trees formed part of a field on an estate. 
The result was as follows : — 
I2I trees had globular shoots, i.e., 6*05 per cent. 
6 trees had nodular structures of various types, i.e.y *30 per 
cent. 
