Page:The Zoologist, 3rd series, vol 2 (1878).djvu/132

110 the foliage. The whole phenomenon was comparable to the production of honeydew from the Lime by the agency of Aphides.

Then followed a paper "On the Shell of the Bryozoa," by Mr. Arthur W. Waters. The points he more particularly drew attention to were the great difference of the young and old cells, caused by a constant growth of shell substance, so that the older zooecia become closed up. This growth progresses at various rates. Passing through the shell are tubes filled with corpuscles of the chylaqueous fluid, which thus become oxidised. The supposed nervous filament of the colonial connection the author believes to be rather for the supply of material from one part of the zooarium to another. He further suggests that the varying thickness of the plates in the walls of the colonial connection should be used as a factor in specific determination, and especially would it be useful in comparing recent and fossil forms. There is a possibility of the avicularia and adventitious tubes being homologous, and helping to maintain the vitality of the colony when the polypides have disappeared.

Messrs. A.G. Agar aud C. Berjeau were elected Fellows of the Society.

The President, having put the motion, it was unanimously resolved to present an address to Professor C. T. Ernest von Siebold on his approaching jubilee.—

February 5, 1878.—Prof. F.R.S., Vice-President, in the chair.

The Secretary read a report on the additions that had been made to the Society's Menagerie during the month of January, and called especial attention to a Japanese Wild Dog (an animal apparently allied to the "Dhole" of India and the "Dingo" of Australia), presented by Mr. Harry Pryer, of Yokohama, January 1st; and to a young Penguin (probably Spheniscus Humboldti), purchased January 24th.

Prof. Mivart read a paper entitled "Notes on the Fins of Elasmobranchs, with Considerations on the Nature and Homologies of Vertebrate Limbs," wherein the author detailed his dissections of the fins of Elasmobranchs, which dissections had convinced him that the paired and azygos fins are of similar nature. He represented them as having all resulted from the centripetal growth and evalescence of a primitively distinct series of cartilaginous rays developed in longitudinal folds, of which one was dorsal, one ventral, and two were lateral. He also advocated the view that the limbgirdles result from the further centripetal growth of the evalescing limbcartilages, which growth seeks a point d'appui, the pectoral limb-girdles in fishes shooting upwards and downwards as well as inwards to obtain a firm support, and, at the same time, to avoid the visceral cavity. He contended that the archipterygium was not to be sought for in Ceratodus, which he