2 THE ENTOMOLOGIST’S RECORD. 
resemblance to a ‘lady-bird, and the Coccinellide are known to be 
distasteful to insectivora.”’ Again in 19012° I repeated this statement, 
but added—<“ At the same time Clythra may be distasteful on its own 
account, and thus provide an example of Miillerian mimicry, a 
question which | hope to settle this year.’ As mentioned in my paper 
on “The Life History of Clythra quadri-punctata, L.” (Trans. Ent. 
Soc. Lond. 1902 11-28) I proved the Clythra to be distasteful by 
experiments with various birds, lizards, marmosettes, etc., at the 
Zoological Gardens. We therefore see that it is a case of Mullerian 
mimicry, and I now think that the Coccinella is a mimic of the 
Clythra, aud not vice versa as I originally suggested. The Clythra’s 
eggs, larve, and pupe occur in the ants’ nests, and it is a commoner 
and more widely distributed species—it ranges from Sutherland in 
Scotland to Cornwall and the Isle of Wight. This suggests that the 
Coccinella is of comparatively more recent phylogenetic development ; 
and it is also highly specialized as regards the male genitalia. 
It has been suggested that as the shape of C. distincta is very 
different from that of Clythra, it can not be a mimic of the latter; but 
mimicry can be valuable in spite of differences in shape, furthermore 
that shape may be very stable and difficult to alter, as probably here, 
for it runs through many allied species. Everyone will agree that C. 
distincta is more like Clythra than is the common CU. 7-punctata, as the 
shape is aciually a little longer, and the spots much larger than in the 
latter. I have also been told that as the size of the spots varies in other 
species of Coccinellida—for example my subspecies boreolitoralis of the 
common eleven-spot Lady-bird, C. undecimpunctata, L., which occurs 
on the coasts in the north and west—these also ought to be mimics of 
Clythra. Variation occurs independently in different species and may 
produce the same results for different reasons, and one might just as 
well maintain that C. distincta ought to occur on sandy coasts! 
Coccinella distincta and Clythra quadripunctata are frequently found 
together on the trees over, and flying round the nests, and it must be 
admitted that by those who are not Entomologists, Coleopterists, or 
specialists, they might well be mistaken for each other. 
My friend Professor W. M. Wheeler writes in one of his charming 
papers [‘‘ The Parasitic Aculeata, a Study in Evolution” Proc. Amer. 
Phil. Soc. 58 1-40 (1919)}—‘* There is undoubtedly much to be said in. 
favour of the opinion commonly held by entomologists that the fruit- 
fulness of their investigations is apt to be directly proportional to the 
intensity of their specialization, but it is also true that this very 
specialization may often preclude an adequate appreciation or even a 
recognition of phenomena that would profoundly impress the worker 
who possesses more general biological interests.”’ This statement is 
not inapplicable to the subject in question. 
Both species are distasteful, both exhibit warning colours, and it 
would be an advantage to the Coccinella to have shared any experi- 
mental tasting by young birds, etc., with the Clythra, which would help 
to protect it in the winter when birds are hungry and will sometimes 
eat insects they would not otherwise touch. 
The Clythra dies off in the summer, whereas, as we have seen, the 
Coccinella passes the whole winter on the trees over the rufa nests. 
If it be admitted that it is an advantage to the latter to resemble 
the former, then natural selection would have seized on any small 
