50 A Second Cooperative Studt/ of " Vespa Vidgaris " 
(B) Greatest length of cell h taken inside thickened end of veins. 
(C) Length of cell /from point to further inside point on the/^' vein. 
(D) Greatest breadth of wing from X to wherever found, i.e. XY. 
(E) Distance apart of J and H, measured inside veins of cell /. 
(F) Greatest length of cell d, measured inside cell. 
(G) Distance apart of points P and Q measured inside cell I. 
The same indices were also determined by Miss Thomson, namely : 
H=\OODIA, K = 100 Bj A, 
I =100 EjD, L=100C/A, 
J = 100 G/D, M = 100 Fl A. 
The correlations selected for comparison were those of the previous memoir, i.e. 
A and D, G and F, I and K, I and L. 
A and G, G and D, M and J, 
A and E, B and E, L and /, 
A few additional correlations were ascertained, as it was thought desirable to 
put on record the degree of resemblance between right and left wings in at least 
one species of wasp. 
The analytical determination of the biometric constants was carried out by 
Miss J. Bell, and as there were 188 individuals it seemed sufficient in this case to 
form grouped correlation tables and calculate the correlations in the usual product 
moment manner, adjusting with Sheppard's corrections. 
(3) On the relative Sizes of the mean General Population and of the mean Nest 
Queens. 
Table I gives the general results. 
Now, judged by the probable errors, we should conclude that the mean 
population queen was in all absolute sizes of the wing less than the mean queen 
of our special nest*. But a word ought to be said as to the possibility of a per- 
sistent difference between the two measurers. We fully recognised the difficulty 
of changing the measurer in the middle of the work, but circumstances did not 
permit of other action. Accordingly, to diminish personal equation. Miss Thomson 
practised for some time on Miss Wright's slides, and after a time adjusted her tube 
length until she got ocular readings in absolute agreement for all practical 
purposes with Miss Wright's f. But on determination of the magnifying power, 
* E and G are the only characters about which any doubt could arise, and as the means of the other 
characters are in all cases significantly less, these doubts may be discarded. 
t The degree of accordance may be illustrated by the following measurements on Queen 100 of 
Miss Wright's series : 
Miss E. Y. Thomson : 9-20 5-34 4-35 2-68 -99 2-22 -97 for A io G respectively. 
Miss A. Wright : 9-20 5-35 4-36 2-68 -99 2-23 -97 „ 
