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Show 18S7.] VALUE O F C O L O U R A N D M A R K I N G S IN INSECTS. 267 8. A few, probably transitional, forms may be unconcealed, and yet not very conspicuous ; these may possess unpleasant qualities or may be eaten readily. 9. The likes and dislikes of insect-eaters are purely relative, and if pressed with hunger the most disagreeable and highly conspicuous insects may be eaten. Hence probably the relatively small number of species which adopt such a means of defence. 10. It seems probable that when one Vertebrate eats an unpleasant insect, and another refuses it, the former has conquered its prejudices, having originally disliked the insect. 11. In the sexually mature forms warning colours can be distinguished from sexual colours by their distribution on the surface of the body, by the way in which they are displayed in flight, by their type of pattern, and the colours employed. The sexual colours and patterns are beautiful, the others conspicuous. Nevertheless, to the modified taste of a highly conspicuous insect, the warning colours probably possess value as sexual adornments. 12. The conspicuous appearance has relation to the injury which would be inflicted by the experimental "tasting" of certain enemies, e. g. Birds and Lizards ; but nevertheless, other enemies, which do not inflict injury in tasting, e. g. Frogs, have taken advantage of the warning colours to a limited extent. 13. Insects which evade their enemies by protective resemblance and attitude, rapid movements, or habits of concealment, & c , are generally palatable, but they may often possess an unpleasant taste or smell which may or may not protect them from enemies. 14. In a very small number of species the most perfect form of protective resemblance may coexist with a most unpleasant taste. 15. Mere size alone may protect a species against certain of its smaller foes. 16. Comparing the different stages in Lepidoptera, unpleasant attributes appear to arise in the larval stage, and they then often pass through the two other stages attended or unattended, in one or both, by warning colours. 17. The most highly specialized protective colours probably also possess value as sexual adornment. Considerably over 100 species or stages of insects have been experimented upon, and the results are described in the Tables given in this paper. Looking at these results as a whole, it is seen that the various defensive measures may exist in almost any combination, and that the present condition of a species is in large part an outcome of the means of protection in past struggles. Just as in a long-contested battle the same position may be taken, lost, and retaken, but never held a second time with quite the same significance as before, because of all that has happened as a result of the previous occupation and of all that has happened since in other parts of the field, so in the ever-changing relations between a species and its enemies the structural and functional means of defence may be taken |
