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Show 1892.] VARIATION IN SECONDARY SEXUAL CHARACTERS. 58j natural size, was obtained by Sir George Baden Powell in Petro-paulovski harbour, Kaintschatka, on Sept. 8, 1891. Before describing this fish as new I have satisfied myself, by a careful comparison with the original description, that it cannot by any means be referred to Ophidium ocellatum, Tilesius, which it strongly resembles in general appearance. Notwithstanding the several different names which have been bestowed upon it, this Ophidium ocellatum, obtained at Petropaulovski, has not been rediscovered since its description in 1811, and its affinities are altogether uncertain. 3. O n some cases of Variation in Secondary Sexual Characters, statistically examined. By W . B A T E S O N , M.A., Fellow of St. John's College, Cambridge, and H. H . B R I N D L E Y, M.A., St. John's College, Cambridge. [Received November 15, 1892.] It is a familiar fact that many insects are provided with long, chitinous horn-like processes of various shapes and forms. Such horns are sometimes present in both sexes, but more commonly they attain their chief development in the male only. Among beetles the most striking examples are found in the Lamellicorns, many of which have horns of great size on the head, or on the thorax, or on both. Analogous developments are seen in the great mandibles of the males in some Lucnnidee, of which the Stag-beetle (Lucanus cervus) is a common representative. In the majority of these forms the similar parts of the females are either not produced at all or are much smaller. Now in many species having these curious horns in the male sex, it has long been observed that the males are not all alike in the degree to which the horns are developed; but that, on the contrary, some of the males may bear massive horns of prodigious size, while other males of the same species have hardly any horns at all, being in fact very like females. The males with the great horns are in common parlance known as "high" males, those with the rudimentary horns being " low " males. A good series of figures illustrating the phenomenon is given by Darwin \ and examples of such Variation in Odontolabis &c. are exhibited in a show-case in the Natural History Museum at South Kensington. The phenomenon of great Variation in the development of horns present in the males as a secondary sexual character is not peculiar to beetles, though in them it perhaps reaches a climax. A similar case is presented for instance by the Common Earwig (Forficula auricularia), in which the terminal forceps are in some males no larger than those of the female, while iii others they are three times the size. 1 ' Descent of Man,' 1871, vol. i. pp. 368-375. |
