( xliii_) 
bird-theory by speakers whose competence and opportunities 
for observation were quite beyond dispute. Further impor- 
tant evidence on this point had been lately given by M. Piepers 
(Congr. Internat. Zool., III., p. 460) who had studied the 
question in Sumatra and Java for twenty-eight years. In 
that time M. Piepers had seen four cases only of butterflies, 
two belonging to the ‘protected’? genus Huplwa, being 
attacked by birds; and his paper referred to the fact that 
neither Pryer, after twenty years’ observation in Borneo, 
Skertchley nor Scudder had seen or accepted such a 
phenomenon. M. Piepers had arrived at the sufficiently 
striking result that mimicry had nothing to do with Natural 
selection. 
The premisses necessary to support either theory of 
Mimicry had been unduly neglected. For example, though 
evidence existed to show that the models were protected and 
inedible, the proof of the edibility of mimetic butterflies had 
not received enough attention; it was necessary to Bates's 
theory, and all the more so since Dr. Dixey’s work on the 
‘¢ Millerian’”’ character of certain Pierine. These theories, 
indeed, were really working hypotheses, the object of which 
was to suggest experimental work tending to prove or 
disprove them ; they were not yet to be put forward dogmati- 
cally as true and as convincing proofs of Natural selection. 
To insist that these homceochromatic groups owed their 
origin merely to the educational requirements of birds had 
led, in his view, not so much to a development as to a 
stifling of broad speculation on and inquiry into the problem. 
The facts presented by the Ithomie (s. lat.) had scarcely 
been touched upon in the discussion. Almost every colour- 
type among these insects, however insignificant in appearance, 
was represented by species of two or more of the genera into 
which the old genus /thomia had been divided; so that the 
Ithomie might be said habitually to exist as homceochromatic 
pairs. The coloration of many of these pairs, consisting of 
nothing but afew black patches and a white or yellow patch on 
a transparent ground was far from exhibiting the striking 
features which one was led to believe were characteristic of 
warning colours. 
