420 Mr. R. Meldola on Mimicry between 
strict analogy between the development of bodily structure 
and of psychological characters, both im individuals and in 
species. ‘The law of embryonic development formulated by 
Hickel as the ‘fundamental biogenetic law,” teaches that 
the individual, in the course of its development from the egg 
(ontogeny), recapitulates with more or less disguise and ab- 
breviation the phases through which its ancestors have passed 
in the course of the development of the race (phylogeny). 
Ancient characters are retained to a late stage of life only in 
cases where they are of direct service to the species, as, for 
example, in the retention of a subdorsal line by certain ocel- 
lated sphinx-caterpillars*. Why should not this same law 
be extended to instinct? If instinct is habit acquired during 
the former experience of the race, and accumulated and fixed 
by heredity, we may fairly expect that an animal, in the 
course of its mental development (psychological ontogeny), 
would pass through the stages of inexperience which were 
gone through by its ancestors in the course of their evolution. 
Only where an “instinct”? was of vital importance to the 
young would it become fixed upon the early stages of growth 
by the law of inheritance at corresponding periods. ‘The in- 
stinctive fear of bees shown by Mr. Spalding’s turkey may be 
acase in point. But if, as I believe, the knowledge of a 
nasty butterfly is not a matter of vital importance, there is no 
reason why young birds should know such species antecedent 
to experience. ‘This part of the discussion may, I think, be 
very well left at this stage pending the appearance of some 
satisfactory experiments with young tropical insectivorous 
birds and inedible butterflies. 
The arguments advanced by Mr. Distant in discussing the 
question of mimicry in his ‘ Rhopalocera Malayana’ are 
based on a consideration of the case of Huplea Distanti and 
E, Bremeri, and may be thus stated :— 
The male Huplea Distanti closely resembles L. Bremerz, but 
is distinguished by the possession of a ‘“ pseudo scent-gland.”’ 
To continue in the author’s own words :—“ It is at least a 
question whether the term ‘ mimicry’ should be used here, 
both species belonging (as I consider, and most entomologists 
till recently considered) to the same genus. All the species 
of Huplea with which we are acquainted, and as Mr. Wallace 
has informed us, have, with the remaining Danaine of the 
Old-World tropics, the ‘ same protective odour.’ in this case, 
if we adopt the explanation of mimicry for the resemblance of 
these two species, we must presumably consider 2. Distanti 
_* Weismann’s ‘Studies in the Theory of Descent,’ Engl. edit. Appen- 
dix, p. 529, 
