160 Evolution and Adaptation 
are brilliantly colored. On this theory we also understand 
the exceptions to these rules. We comprehend why Danaids, 
Heliconids, Euploids, and Acracids, in fact all diurnal butter- 
flies offensive to the taste and smell, are mostly brightly marked 
and equally so on both surfaces, whilst all species not thus 
exempt from persecution have the protective coloring on the 
under surface and are frequently quite differently colored 
there from what they are on the upper. 
“Tn any event, the supposed formative laws are not obliga- 
tory. Dispensations from them can be issued and are issued 
whenever utility requires tt.” 
Dispensations from the laws of growth! Does not a 
philosophy of this sort seem to carry us back into the dark 
ages? Is this the best that the Darwinian school can do 
to protect itself against the difficulties into which its chief 
disciple confesses it has fallen ? 
Weismann lays great emphasis on the case of the Indian 
leaf-butterfly, Kallima inachis ; and points out that the leaf 
markings are executed “in absolute independence of the 
other uniformities governing the wing.” 
“The venation of the wing is utterlyignored by the leaf 
markings, and its surface is treated as a tabula rasa upon 
which anything conceivable can be drawn. In other words, 
we are presented here with a dzlaterally symmetrical figure 
engraved on a surface which is essentially radially symmetri- 
cal in its divisions. 
“T lay unusual stress upon this point because it shows that 
we are dealing here with one of those cases which cannot be 
explained by mechanical, that is, by natural means, unless 
natural selection actually exists and is actually competent to 
create new properties; for the Lamarckian principle is ex- 
cluded here aé zuztio, seeing that we are dealing with a for- 
mation which is only passive in its effects: the leaf markings 
are effectual simply by their existence and not by any func- 
tion which they perform; they are present in flight as well 
