significance of the variations, &e. rel 
15 undoubtedly blue-centred in each hind wing. Reasons 
for considering this a character that belonged to the 
earliest members of the Vanessa group may be found in 
Trans. Ent. Soc. Lond., 1890, p. 97, et seq. 
The marks referred to above under (2) are exceedingly 
minute, but still certainly visible in a fair light. They 
occur in only one of group D. In this insect the right 
side has III. 10 to 14, and perhaps 15, the left side III. 
10 to 14, indicated by very minute patches of blue scales, 
somewhat like the rudimentary ocellus in V. w, but 
even smaller. One specimen of the intermediate group 
C has similar indications of III. 12 to 14. 
The marginal blue (8) is in all probability an extension 
of the blue often seen on the marginal side of the large 
blue-centred spot IV. 15 in normal specimens of V. 
atalanta, and appears to represent that survival of the 
original bluish ground colour which is visible in A. niphe 
close to the margin, and especially at the anal angle of 
the hind wing, externally to those remains of the ground 
colour from which are developed the blue centres of IV. 
(ibid., p. 101). 
To other characters seen in specimens of C and D, 
such as the remarkable alterations in the under side of 
the hind wing, and the suffusion of the fore wing with 
- white and lavender scales, I am not able to assign any 
phylogenetic import. 
A fair proportion of the effects of both heat and cold 
thus seem to point in the direction of reversion to an 
older form than the normal V. atalanta. But what is 
especially noticeable is—that in the first case (that of 
heat) the form approached is P. callirrhoé, a very near 
relative of V. atalanta ; while in the second case (that of 
cold) the approach is to a still more ancestral form, 
such, indeed, as may be supposed to be the common 
progenitor of Vanessa, Pyrameis, Hypanartia, and Grapta. 
General Observations. 
Is it possible that a disturbance of natural temperature 
conditions, whether in the direction of heat or cold, can 
produce in a monomorphic species a tendency towards 
reversion? Mr. Merrifield’s experiments seem to go 
far towards answering this question in the affirmative. 
It need hardly be pointed out that Weismann’s results 
with A. levana and P. napi, as also Edwards’s with 
