they wings to escape by flying, and generally go in large bodies easily found and approached." Mr. Belt, however, concludes that the Spider is thus protected against the attacks of small insectivorous birds.[1] Subsequently, however, Mr. Herbert H. Smith has reaffirmed what Mr. Belt denied—"the Spiders eat the Ants," and "they eat the particular Ants which they mimic. At all events, we verify this fact in a great number of cases, and we never find the Spiders eating any but the mimicked species."[2] Dr. Scharff thinks "that the colours of Slugs in Ireland are at all ages, as a rule, protective";[3] while Mr. Adams is inclined to think "that climate may be a factor in the matter." He has "taken more brilliant forms, and those more abundantly in the South of England (where the climate is warmer), than in the North." Again, "all along the south coasts of England and Wales, Cardigan Bay, and the west coast of the Isle of Man, and the north coast of Ireland (all of which are noted for a mild climate), I have taken coloured forms abundantly; while on the coasts of Lancashire and North Wales, and the east coast of England from the Thames to the Tees (where the climate is more bracing), I have no personal records for anything but the type."[4]
In plant-life such resemblances are not uncommon. In parasitic fungi "the fructification of Polyporus betulinus strongly resembles the whitish bark of the birch, and that of P. fomentarius, parasitic on old beech trees, exhibits the same pale grey as does the trunk of a beech."[5] There is a butterfly common in certain parts of the Argentine which Dr. Seitz at first mistook for the European Vanessa (Araschnia) levana, so closely does it resemble that butterfly in colour, in the notching of the wings,
- ↑ 'The Naturalist in Nicaragua,' pp. 314–5.
- ↑ 'Brazil, the Amazons, and the Coast,' p. 223.
- ↑ 'Slugs of Ireland,' p. 554.
- ↑ 'Coll. Man. Brit. Land and Freshwater Shells,' 2nd edit. p. 23.
- ↑ Kerner and Oliver, 'Nat. Hist Plants,' vol. i. p. 166.
The genus Volucella comprise large flies which mimic Humble-Bees in colour and form. As observed by Mr. Pocock: "It was long supposed that the females were thus enabled with impunity to enter the nests of Humble-Bees, and lay their eggs amongst those of the proper owners." But these mimics of Humble-Bees also "visit for the same purpose the nests of Wasps, to which the flies bear no particular resemblance."
