204 THE ENTOMOLOGIST’S RECORD. 
on the former there are black spots, some of them forming an oblique 
black row across the wing, a series of black marginal spots, and no 
darkened nervures, and, when the imago is about to emerge, so that 
its markings show through the transparent pupal wing, it is seen 
that its nervures run between the black marginal spots on the pupal 
wing, which in no way correspond with the broadening out of the 
mareinal terminations of the dark nervures on the imaginal wines. 
There is great variety in the black markings on the pupal wing; in 
some they are fey and small, in others they expand and unite so that 
more than half the wing is black. The eround colour of the pupa 
varies from bright oreenish- yellow to whitish- ervey. As might be 
expected of an insect whose larva pupates by ‘preference on stems 
screened by foliage, ite colour is not very greatly affected by its sur- 
roundings. On comparing some which had had yellow or orange 
surroundings with others which had had dark ones, it was shown that 
the former tended to vellow ground colour, and the latter to grey 
having also an increase of the dark spots with which the thorax and 
abdomen are thickly strewn. Mr. Merrifield also exhibited some 
enlarged coloured photographs of the green and dark forms of Papilio 
imachaon, obtained by causing the larvee to pupate on green, yellow or 
orange surfaces, and on dark ones respectively. In answer to Mr. 
Jacoby he stated that though, when the pupa first appeared, it was 
always of the green form, it vhad also, if it was goime to be a dark one, 
from the moment of its appearance a very few minute subdorsal and 
sublateral dark spots, and a little darkening of the anal end. ‘The 
darkening began to spread im an hour or two, and at an ordinary 
temperature was complete in much less than 24 hours. Whether the 
pupa was to be green or dark was determined by the surroundings to 
which it had been exposed before it had cast off the larval skin, and if 
it was going to be a dark one, the dark colouring came on exactly the 
same in complete darkness as in heht. 
On June 28th the Yorkshire Naturalists’ Union had a delightful 
outing in the Colne, Holme and Meltham valleys. That this was 
largely due to the excellent arrangements carried out under the mature 
guidance of the exceedingly popular President, G. T. Porritt, F.L.S., 
F.E.S., goes without saying. <A large number of well known 
naturalists were present—the Rey. W. W. Fowler, Dr. H. Corbett, 
Messrs. W. Tunstall, 5. L. Mosley, W. Denison Roebuck, J. H. 
Rowntree, representing amone others the entomological section. 
Associate members were present from all parts of the county, as well 
as from the adjacent counties, and after the various outings, a return 
was made to Crosland Hall, the residence of the President, where the 
members were most hospitably entertained by Mr. and Mrs. Porritt 
and their family. The satisfaction of the party was complete, and as 
the Rey. W. W. Fowler remarked when proposing a vote of thanks to 
the President and to Mrs. Porritt for their hospitality, ‘ everything 
had contrbuted to their enjoyment, and they were all delighted.” To 
southerners the virility of the Yorkshire Naturalists’ Union is a matter 
for wonder, but there can be no doubt that such sturdy Yorkshiremen 
as My. Porritt have largely contributed to this end. 
Dr. Corbett records (Nat., p. 222) the simultaneous appearance of the 
‘co-migrants Pyrameis cardui and Plusia gamma at Doncaster, on June 
17th, 1900. 
