( lxii ) 
experimenter were the production of specimens representing 
(a) Local forms, such as constantly occur in nature in certain 
definite localities ; in Vanessa urtice, Pyrameis cardui, and to 
some extent in Papilio machaon and Vanessa antiopa: (b) 
Aberrations, like those which now occur in nature; in JV. 7o, 
P. cardui, and Argynnis aglaia: (c) Phylogenetic forms, 
““which may have either existed in past epochs, or may 
perhaps be destined to arise in future:” in certain cooled 
V. io and V. antiopa and certain warmed JV. atalanta, and the 
reverse respectively. Noting the remarkable circumstance 
that the same conditions lead to such diverse effects in 
different species—the changes wrought in one species being 
entirely within the limits of its variation at the present day, 
while in another they far surpass those limits,—he suggests 
that the species coming under the former category are the 
phylogenetically older, and those belonging to the latter are 
the phylogenetically younger. The author found that the 
high temperature of 104° F. rapidly caused death in nearly all 
the species tested—P. machaon and G. C.-album proving least 
sensitive—but low temperatures prolonged for even four 
weeks were much better tolerated ; and it was thought that 
this favoured the conclusion that the species so tested ‘ were 
constrained in past ages to accommodate themselves much 
? 
more to lower than to higher temperatures.” 
In the edition of his ‘‘ Handbuch” which appeared in 1896, 
Standfuss recapitulated the cases published in 1894, and 
added mention of a warmth experiment with Gonepteryx 
rhamni which had the effect of inducing in the females some 
indications of the yellow colouring of the males. He also 
gave excellent coloured figures of most of the more marked 
variations resulting from temperature treatment, some of 
them exhibiting marvellous divergence from the normal form 
now existing in nature. 
Before turning to Weismann’s memoir of 1895, it will be 
convenient to refer briefly to Standfuss’s recent and elaborate 
treatise issued during the present year (1898).* After re- 
* « Experimentelle Zoologische Studien mit Lepidoptern. A. Tem- 
peratur-Experimente.” (Denkschr. Schweiz. Naturf-Gesellsch., xxxvi, 
i, 1898.) 
