248 THE ENTOMOLOGIST. 
bean, was then largely in excess of what it is now: it was 
then from three to five in a bean; and now the average 
number, per bean, is certainly a decimal fraction of one. 
Here is a crumb of comfort for the sufferers.—H. Newman. ] 
The Gall Midge of the Ash (Cecidomyia botularia, Win- 
nertz).—It often occurs that, long before autumn, particularly 
in dry seasons, the foliage of the common ash (Fraxinus 
excelsior) shows signs of premature decay by turning sere 
and yellow on certain sheltered branches, which eventually 
shed their leaves much earlier than their neighbours. If we 
ask the cause of this, we are generally told that the leaves are 
blighted. But “blight” is such a convenient term when we 
want to gloss over our superficial knowledge of the diseases 
of plants, that we have long made up our mind not to 
be contented with this explanation. In the present instance 
our observations extend over four years’ occasional investi- 
gations in Kent and Surrey. We meet with such unhealthy 
branches on trees of all ages as early as July and August, 
but it is in September that their yellow hue strikes us most 
forcibly. For example’s sake, we single out one limb, and 
describe its condition as seen in September. Here and there 
we see one intact leaf, standing out by its greenness, but the 
rest are more or less discoloured, and, moreover, distorted, 
irregular in shape, and folded or crumpled up. We look for 
a common mark, how to distinguish these disfigured leaves 
from the normal ones, and we find it in a peculiar partial 
thickness of the midrib, which, besides, exhibits a longitu- 
dinal channel in many instances. Up till this time we have 
only been viewing the upper surface of the leaves; let us, 
therefore, inspect their underside as well. We raise the 
branch up, and the cause of its blighted appearance is 
explained. Every discoloured and disfigured leaf exhibits 
on its leaflets a more or less slender swelling of the midrib or 
of the stalk itself; in some leaves the whole midrib, from 
base to tip, is thus incrassated, and the lateral parts of the 
leaf folded from edge to edge; in others their basal part 
alone is swollen up, and their anterior part more or less 
abortive. ‘These pod-like swellings or galls are covered with 
a whitish or brown pubescence, and their juicy consistency 
shows that they serve as receptacles, diverting the sap, 
originally intended to supply the whole leaf; hence the sere 
