516 TRANSACTIONS OF SECTION D. 
What is the explanation of these phenomena? The resemblances can 
scarcely be fortuitous, inasmuch as they are not confined to one or two 
species, but run through a long series of forms in each genus. Probability 
is much against a merely accidental resemblance under such circumstances 
as these. Nor is the suggestion of a common influence of geographical 
surroundings adequate, for the resemblances only apply to obvious features, 
not to points of minute structure. Again, specimens of both genera, widely 
differing in appearance, may be found living under the same geographical 
conditions. The resemblances can scarcely be, to use Professor Poulton’s 
term, ‘syncryptic’ ; for the upper surfaces of the wings, where the likeness 
is chiefly exhibited, are remarkably conspicuous. A certain amount of 
community in pattern may be due to affinity, but this will not explain the 
close correspondence between some species of the two genera, together with 
the wide divergence between others. 
The only feasible explanation seems to be mimicry. This is supported by 
various considerations, especially by the local coincidence of the mutually 
assimilated forms. The mimicry may perhaps be Batesian, Adelpha supply- 
ing the models and Chlorippe the mimics ; on the other hand, at least one 
species of the latter genus is known to be common, and therefore unlikely to 
be a mimic in the usually received sense. On the whole there is some reason 
to think that this is a case of the mutual approach of inedible forms, a 
conclusion, however, that needs to be tested by experiment and observation 
in the field. 
5. Histiology of the Eye of Pecten. By W. J. Daxtn. 
6. Coral Reefs. By J. Stanuey Garpiner, F.EF.S. 
