line apparatus in a correlated substitutional modification for the performance of the static and equilibrative functions, and thus further support the author's views.
At a subsequent meeting of the Linnean Society, held on April 21st, Mr. W.P. Pycraft read a paper "On the Morphology of the Owls: Part I. Pterylography." In this, the first instalment of a series of papers on the affinities and phylogeny of the group, the pterylographic characters were alone considered, with descriptions of adults, nestlings, and embryos. The author remarked that so far as the distribution of the feather-tracts is concerned, the Owls resemble the Accipitres more nearly than any other group. They differ from them and resemble the Caprimulgi in the distribution of the adult and nestling down. The microscopical structure, however, of these down-feathers is accipitrine rather than caprimulgine. The nestling of the Accipitres is clothed by two kinds of down-feathers, for which the names "pre-plumulæ" and "pre-pennæ" were suggested; the nestling Owl and Nightjar are clothed only by down of the latter kind. The form of the external aperture of the ear seems to have been originally subject to variations, the most successful of which have become fixed by selection. In some cases there is a marked asymmetry, which may either be confined to the membranes surrounding the aperture or may extend to the skull itself. The author considered that the facts disclosed by a study of the pterylosis might justify a slight revision and rearrangement of some of the genera.
Mr. Ernest W.L. Holt, at a meeting of the Zoological Society of London, held on April 19th, read a paper on the breeding of the Dragonet (Callionymus lyra) in the Marine Biological Association's Aquarium at Plymouth, and made some remarks on the significance of the sexual dimorphism of this fish, the courtship and pairing of which were described in detail. The female was described as a promiscuous polyandrist, and seemed to exercise no sort of choice, taking the nearest male which appeared to be in a condition to further her object. The males were much more numerous, as well as larger, than the females. The brilliant yellow colour of the mature male was due to an excess of yellow pigment, which diffused into the skin. It had an acrid smell, and was highly irritating to the salivary glands. The blue colour was due to the optical properties of masses of "reflecting tissue" over a background of black chromatophores. Mr. Holt considered that the large fins and bright colours of the male of the Dragonet had been evolved by sexual selection proceeding on the lines of conspicuousness rather than on those of aesthetic charms, since the male seemed to be unable to see the female except at a very short distance, and
