33 
[ 293 ] 
curately determined. Upon raising many of the scales in the fall 
of the year, we find them destitute of the eggs of the bark louse 
which should naturally fill them at this season. Iu their place we 
find a confused and discolored mass which we suppose to be the 
remains of the legitimate occupants, that is, -the egg shells and the 
iried up body of the mother louse. 
Amongst this debris the minute Acari are sometimes seen, and 
;o them the ruin is generally attributed. But in most instances, 
so tar as 1 have observed, no Acari are found, and some scales are 
fimost wholly empty, so that if the Acari caused the destruction 
n both cases, they must, in the former instance, have done their 
vork and left, and in the latter they must have devoured the 
nother louse, egg shells and all. But it is of no consequence to 
is who or what has wrought the ruin, so long as the bark-lice are 
lestroyed. The important question is, what proportion of the 
>ark-lice are destroyed, by any and all causes, and what part 
ernain to propagate the race for another year ? 
Mr. Walsh, after examining many hundreds of scales in the 
ummer of 1867, stated that the largest proportion which he had 
ver found with their contents destroyed, was two-thirds. From 
bis form of expression we infer that it was only in certain cases, 
r perhaps localities, that so large a proportion were abortive, and 
bis destruction he attributed solely to Acari. 
The following observations will exhibit the matter in a more 
efinite light. 
On or about the twentieth of September, I examined all the 
3ales on four twigs, taken from different trees, and from two 
ardens remote from each other, with the following result: 
r hole number of scales.. 
amber of scales with round holes, through which the Chalcides had escaped.116 
amber of scales having under them the larvae of the Chalcides. 95 
amber of scales, the contents of which have been destroyed by Acari, or unknown 
causes.... 85 
sales with ragged holes eaten by Coccinellae..... 7 
sales containing more or less sound eggs. 27 
Whole number.. 
Oct. 20th, examined four twigs taken from different trees : 
hole number of scales.284 
Yol. 11—37 
