428 Mr. F. Merrifield on Temperature Experiments 
hatched, beginning 15th May, and all of them pupated. 
Three were forced at 80°, producing in from six to 
seven days the characteristic black prorsa form; four 
others were, at from one to eight hours’ old, placed in 
the refrigerator on the 18th June, and remained there, 
at about 48°, till 80th or 31st August (seventy-three or 
seventy-four days), when, observing signs of emergence, 
I placed them in the room at about 65° to 70°, and there 
three of the four emerged in a day or two, the fourth not 
until thirty-two days more, 7.e., on the 2nd October. 
The remaining four were placed at 33° till 29th Sep- 
tember (eighty-four days), then moved to the refrigerator 
at about 48°, whence, after twenty days more, they were 
moved to the room, about 59°, three of them emerging 
respectively in ten, eighteen, and twenty days more 
(total 114-124 days). ‘The first of them was a cripple, 
and the fourth died. This left six of the eight subjected 
to a low temperature. These six all emerged in perfect 
condition, and were unmistakably of the true levana type ; 
two of those cooled, without having been iced, showing 
slight traces of the intermediate porima form, but the other 
four being of the pure levana type, and nearly as different 
in colouring from the three that were forced as one of 
the common fritillaries—say A. selene—is from a “ white 
admiral” (Z. sibilla). I exhibit examples of the two forms. 
I now proceed to describe some experiments on four 
species of the genus Vanessa. In reference to these I 
have had the great advantage of submitting the speci- 
mens experimented on in the manner described in this 
paper, to the careful examination of Dr. Dixey, whose 
paper on the phylogenetic significance of the wing- 
markings in certain genera of the Nymphalidx will be 
found in Trans. Ent. Soc. Lond. 1890, p. 89, and he has 
favoured me with valuable observations upon them, 
which I am permitted to append ; they are distinguished 
by being placed within brackets. The “series” and 
“spots 7” referred to in these observations are described 
in Dr. Dixey’s paper, and may be indicated generally as 
follows, V. urtice and V. polychloros being convenient 
examples for the purpose:—Four dark patches on the 
costa, continued in series more or less perfectly across 
the wings, distinguished by the Roman numerals I., II., 
III.,1V., the latter including the dark submarginal band. 
