INSECTA. 
to distinguish them. The evidence for the specific identity of 
the two forms is stated by Walsh as follows:— If we "suppose, 
for argument's sake, that aciculata and spongifica are distinct 
species, then we are met immediately by the following difficul- 
ties : — 1st. Is it likely that two distinct species of Cynips should 
produce, on the same species of oak, galls which are undistin- 
guishablc? 2nd. Is it likely that when spongifica y as above 
shown, is so local that it is only found in one station out of fifty 
near Rock Island, aciculata should select that particular station 
instead of some other of the remaining forty-nine? 3rd. If 
aciculata is a distinct species, then we are compelled to believe 
with Hartig in the existence of agamous species, i. e. of species 
that propagate from year to year ad infinitum without sexual 
intercourse with a distinct individual." 
With regard to the function ,of C. aciculata Walsh states that 
as the 6 and $ of C. spongifica which come out in June only live 
from six ,to eight days, it is impossible that males should survive 
till October or till the following spring to copulate with the 
aciculata 2 • Hence he concludes, from analogy with Bees, &c., 
that " aciculata $ generates galls which produce by partheno- 
genesis male spongifictB exclusively, and that female spongific/B 
coupling in June with these males oviposit in the same month, 
in the young buds of the oak, — the eggs lying dormant till the 
following spring, when some of the eggs produce 2 spongificce in 
June, and some 2 aciculata; in the autumn or early in the follow- 
ing spring, which last in their turn, as before mentioned, gene- 
rate J spongific(B to appear in the following June." These ob- 
servations seem to point towards a solution of the mystery still 
surrounding the parthenogenetic reproduction of the Cynipidm, 
w hether the hypothesis propounded by the author should ulti- 
mately prove to be well-founded or not. His paper contains 
many interesting details with regard to the history of this 
group. • • , 
In an appendix (/. c. pp. 463-500) Walsh remarks on the re- 
lations between the true Gall-flies {Psenxdes) and the so-called 
Guest Gall-flies, or parasitic Cynipidae {Inquilina;) y and discusses 
the classification of these interesting insects. Following Hartig 
and Reinhardt, he separates the Cynipida; into two families, Cy- 
nipidm and Figitidas, for which he gives the following characters, 
L c. pp. 468, 469 
Cynipidae. Venter visible nearly throughout its entire length c? $ , more 
conspicuously so in 2f or if retracted wuthin the abdomen leaving a gaping 
suture below. The joint which is apparently the last ventral (ventral valve 
in $ ) very long, and forming in $ a sheath-like receptacle, convex below, 
concave above, which is occupied by the ovipositor. Sheaths of ovipositor 
erected in repose, either vertically or obliquely backwards and upwards, 
strongly divaricate with the ventral valve. Tip of 5 abdomen bluntly and 
widely rounded or truncate. Tip of c? abdomen angular or subangularly 
