448 Petch and Gadd .— The Replacement of the 
would give the palms an appearance very similar to that illustrated by 
Sharpies and Lambourne. 
Moreover, the method of inoculation used by Sharpies and Lambourne, 
though artificial, was in many respects similar to that by which the Ceylon 
palms had become naturally infected. They used a small gouge with 
which to bore into the tender central tissues in order to admit the infecting 
organism, whereas in the Ceylon specimens infection had followed the 
natural boring of a beetle or other insect. The Ceylon specimens may be 
regarded as being in a similar condition to that caused by the artificial 
inoculations of Sharpies and Lambourne. 
Cases in which the spike of unfolded leaves which terminates the 
crown of a coco-nut palm has decayed, 
while the growing-point has not been 
destroyed, have occurred in Ceylon on 
full-grown palms, though they appear 
to be very rare. In one instance it 
was found on examination that the 
apex of the embryonic tissue was 
blackened superficially, and the black¬ 
ened surface had cracked into numerous 
areolae, the cracks being about half 
a millimetre deep. The developing leaf 
rudiments were distorted, and consisted 
of a short stout mid-rib, with the close- 
packed rudimentary folded leaflets along 
Fig. 3. Longitudinal section through the each side, the outer ends of the leaflets 
stem of the same plant, almost medially . . 
through the growing-point, x §. being also blackened. It is clear that 
in such cases the decay has been 
arrested before the growing-point has been seriously attacked, and under 
such circumstances it would be expected that further growth would take 
place in the direction of the original main axis. It has not been possible 
to verify the latter supposition, because this condition has only been dis¬ 
covered after the palm has been felled. 
Sharpies and Lambourne claim that the bud which appeared at the 
side of the stem in their experiments is truly a lateral bud, and not the 
original terminal which has changed its direction of growth. They conclude, 
inter alia , that— 
* Owing to a very definite resistance exercised by the bud tissues of 
mature trees against infection, such organisms [i. e. saprophytic organisms 
inoculated into the bud tissues] in the absence of suitable conditions will 
not develop beyond a certain stage, marked by the death of the central 
shoot. If the central shoot dies, and the bud is invested externally with 
the invading organism, the bud tissues have the power of pushing out 
