antigone at Calcutta. Of other members of this great order, Tetrapteryx paradisea has bred at Knowsley, a Porphyrio in Sicily, and the Gallinula chloropus in the Zoological Gardens. On the other hand, several birds belonging to this order will not breed in their native country, Jamaica; and the Psophia, though often kept by the Indians of Guiana about their houses, "is seldom or never known to breed." (18/55. Dr. Hancock in 'Charlesworth's Mag. of Nat. Hist.' volume 2 1838 page 491; R. Hill 'A Week at Port Royal' page 8; 'Guide to the Zoological Gardens' by P.L. Sclater 1859 pages 11, 12; 'The Knowsley Menagerie' by D. Gray 1846 p1. 14; E. Blyth 'Report Asiatic Soc. of Bengal' May 1855.)

The members of the great Duck family breed as readily in confinement as do the Columbae and Gallinae and this, considering their aquatic and wandering habits, and the nature of their food, could not have been anticipated. Even some time ago above two dozen species had bred in the Zoological Gardens; and M. Selys-Longchamps has recorded the production of hybrids from forty-four different members of the family; and to these Professor Newton has added a few more cases. (18/56. Prof. Newton in 'Proc. Zoolog. Soc.' 1860 page 336.) "There is not," says Mr. Dixon (18/57. 'The Dovecote and Aviary' page 428.), "in the wide world, a goose which is not in the strict sense of the word domesticable;" that is, capable of breeding under confinement; but this statement is probably too bold. The capacity to breed sometimes varies in individuals of the same species; thus Audubon (18/58. 'Ornithological Biography' volume 3 page 9.) kept for more than eight years some wild geese (Anser canadensis), but they would not mate; whilst other individuals of the same species produced young during the second year. I know of but one instance in the whole family of a species which absolutely refuses to breed in captivity, namely, the Dendrocygna viduata, although, according to Sir R. Schomburgk (18/59. 'Geograph. Journal' volume 13 1844 page 32.), it is easily tamed, and is frequently kept by the Indians of Guiana. Lastly, with respect to Gulls, though many have been kept in the Zoological Gardens and in the old Surrey Gardens, no instance was known before the year 1848 of their coupling or breeding; but since that period the herring gull (Larus argentatus) has bred many times in the Zoological Gardens and at Knowsley.

There is reason to believe that insects are affected by confinement like the higher animals. It is well known that the Sphingidae rarely breed when thus treated. An entomologist (18/60. Loudon's 'Mag. of Nat. Hist.' volume 5 1832 page 153.) in Paris kept twenty-five specimens of Saturnia pyri, but did not succeed in getting a single fertile egg. A number of females of Orthosia munda and of Mamestra suasa reared in confinement were unattractive to the males. (18/61. 'Zoologist' volumes 5-6 1847-48 page 1660.) Mr. Newport kept nearly a hundred individuals of two species of Vanessa, but not one paired; this, however, might have been due to their habit of coupling on the wing. (18/62. 'Transact. Entomolog. Soc.' volume 4 1845 page 60.) Mr. Atkinson could never succeed in India in making the Tarroo silk-moth breed in confinement. (18/63. 'Transact. Linn. Soc.' volume 7 page 40.) It appears that a number of moths, especially the Sphingidae, when hatched in the autumn out of their proper season, are completely barren; but this latter case is still involved in some obscurity. (18/64. See an interesting paper by Mr. Newman in the 'Zoologist' 1857 page 5764; and Dr. Wallace in 'Proc. Entomolog. Soc.' June 4, 1860 page 119.)]

Independently of the fact of many animals under confinement not coupling, or, if they couple, not producing young, there is evidence of another kind that their sexual functions are disturbed. For many cases have been recorded of the loss by male birds when confined of their characteristic plumage. Thus the common linnet (Linota cannabina) when caged does not acquire the fine crimson colour on its breast, and one of the buntings (Emberiza passerina) loses the black on its head.

Charles Darwin

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