1878. ] Recent Literature. 809 
The. plan recommended is as follows: Charge a fire extin- 
guisher in the usual manner with bi-carbonate of soda and sul- 
phuric acid ; add to the water one spoonful of crude carbolic acid 
to every eight gallons of water. Apply this to the tree and the 
force from the extinguisher will convey the fluid to all parts’ of 
the tree alike ; the disposition of the insects to settle upon the 
lower surface of the leaf and limb serve to further this plan. Two 
applications should be made upon the same tree; the first, three 
weeks after first deposition of eggs, and the second, four weeks 
from the first application. If the work is delayed the insects 
become strong and the strength of the solution must be increased, 
which would be liable to injure the tree itself. The actual cost 
is not exceeding twenty cents an application, which is trifling 
compared to the cost of replacing the tree. That the experiment 
may prove successful it is necessary to make the work thorough 
throughout a locality, since ina short time they return from the 
infested trees. 
Examining the male Z. acericorticts since my previous article, 
I find my doubts confirmed with reference to the non-existence 
of the two halters or balancers in the place of lower wings. 
After close examination with a high power and living specimens, 
I fail to find them, and conclude that in this species they do not 
exist, or if at all, in a rudimentary state. 
M. V. Signoret states that when the male Lecanium is prepared 
to come out it lifts that membrane which rests slightly fixed by 
the head end. Observation with this species shows this is not 
reliable with all Lecanta. When the male of this species is 
about to emerge from the larval scale, it backs out with the wings 
closely adhering to the body. The empty scales will, upon ex- 
amination, be found closely attached to the leaf or limb at the 
head end, while at the opposite end it is loosened. 
:0: 
RECENT LITERATURE. 
MACALISTER'’S ZOULOGY OF THE VERTEBRATES.! — This little 
-manual is chiefly concerned with the morphology of the classes 
and orders of vertebrate animals, with slight, condensed references 
to their habits, physiology and classification, but with no chapters 
$ treating of their et ads E distribution, or geological suc- 
1 Zoblogy of je Verlebrate Beco By ALEX. MACALISTER, M.D. Specially 
“Aner for American Students, by A ‘s. PACKARD, Jr., M.D, Ne ew York, ey 
Holt & Co., 1878. co tan wee oir 
