THE ENEMIES OF COFFEE :—WHITE GRUB. 231 
game where a sentence is whispered and passed along 
from one to another in quick succession. 
The larva or grub is very different in structure and 
mode of life from the perfect insect. As such it grows 
to its full size without any notable change and without 
developing wings, and then passes as a pupa into a rest- 
ing state, anchoring itself firmly by means of its mandi- 
bles during which stage the wings are developed and it 
takes up the adult or imago form. 
Now what I maintain respecting this grub is as follows, 
and I can prove that it holds good in the district where 
I made my observations. The chief food of the grub is 
not the healthy rootlets of the coffee tree, but those 
rootlets after having been rendered suitable and palat- 
able by the ravages of a fungus, the mycelia of which in 
many cases are visible to the eye and which permeate the 
tissues of the root. This fungus I have observed on 
making sections of the roots in various stages of its life. 
Some have supposed that I said the grub lived on this 
fungus alone and they might well ask the question where 
could the grubs obtain sufficient food. After the root- 
lets are diseased the grubs devour the dainty morsels 
and. leave the roots bare and polished, I do not assert 
that the fungus never appears without the doctor grub: 
in fact the grub is no doctor at all; he is rather a 
scavenger removing the diseased organic matter as 
rapidly as he is able ; but when such fungi and diseased 
tissues are in abundance there is every inducement held 
out to the cockchafer to deposit its eggs, for then the 
offspring when hatched will be well provided for. 
In reply to another gentleman, the grub may be 
noticed travelling downwards to the extreme rootlets, 
for such being the most delieate will be liable to be 
attacked first, the rest following in due course. 
As to the cause of this fungus, I am convinced that 
in the districts I visited, Ythanside and estates sur- 
rounding, itis due to various circumstances, such as 
decaying stumps on their journey back to the place from 
whence they came—to sourness of soil—to stagnation 
giving rise to growths of low vegetable types, none more 
common than the liverwort, and what can be more indic- 
ative of excessive moisture and acidity ? 
When the grub is found around healthy trees, which 
one planter suggested was against my theory, I observed 
they were after rotting bulky manure deposited to holes 
and other decaying matter. 
As a rule I do not believe that the larve of the 
coleoptera live on healthy tissues of plants but on those 
already attacked by disease. That the beetles, the or- 
- ganization of which is different, prey on healthy tissues 
is well-known. One gentleman asks why such powerful 
