This article is written in British English, which has its own spelling conventions (colour, travelled, centre, realise, defence, artefact), and some terms that are used in it may be different or absent from other varieties of English. According to the relevant style guide, this should not be changed without broad consensus.
In general, the article looks and reads well. Being a bit more specific, -
"Figure 2 bears a monograph "FR", lower left. Figure 7, of the penguin Aptenodytes patagonica is stated to be "from Brehm" (Brehms Tierleben)." - I think you could combine these two sentences into one.
We could do with some more wikilinks. Some I noticed were Zoological Society, London Zoo, sole, chameleon (at first mention), tree frog, horned lizard, Kallima butterfly,
"though he remains sceptical of cases "which are to be appreciated only by insects" as he considers that their vision might not be good enough to perceive it." - This somewhat complex sentence has "perceive it" at the end which jars with me.
"On mimicry, Allen is critical of Bates's theory, which "close scrutiny of these alleged cases ... shows that"" - In this sentence, I think you might miss out the words "close scrutiny of these alleged cases".
In the section called "The Auk", after "Allen writes that", I am confused as to what bits are quotation and what are not.
explicitly embedded in quote tag
In the Reception section, you mostly mention who the reviewer was (except for Allen) but you do not mention anywhere, as far as I can see, much about Beddard, his area of expertise, why his views might be considered important etc. Nor do you mention the publisher and the circumstances of publication, nor the subtitle (visible in the first edition title page).
added description of Beddard to 'Context'
subtitle listed in full in lead
full publication details in bibliography
I thought the Context, Approach and Structure sections good but was less happy with the Reception section. In some places I thought it "over quoted" - often indirect speech would have conveyed the same meaning and been clearer. However, that's just a personal view. By and large the prose is satisfactory. Cwmhiraeth (talk) 18:53, 28 May 2013 (UTC)
removed a number of direct quotes, rewritten in indirect speech
I believe I've answered all of these to date. Chiswick Chap (talk) 07:22, 29 May 2013 (UTC)