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Show 1906.] ON BREEDING EXPERIMENTS WITH LEPIDOPTERA. 125 young (see text-fig. 48). The little Lemur was born while the parents were in Mr. Gilbert's possession. The pair were turned out into a garden in the first week of July 1905 and left out until the 24th of that month; and Mr. Gilbert was inclined to believe that the mating took place during this period of freedom. However that may be, the young one was born on Sept. 26th; and if Mr. Gilbert's surmise as regards the time of pairing be correct, the period of gestation may be estimated as between ten and twelve weeks. For the first twTo months of its existence the little one clung to its mother's breast. It afterwards transferred itself to her back, as shown in the photograph, which represents the animal when 20 weeks old, or about half-grown. Towards the end of January (that is to say, when some four months old) the young one began to go about on its own account, always returning, however, to its mother's back when disturbed by anyone entering the room. By the middle of February it was partly weaned, and was feeding readily upon bananas and milk. Dr. A. Smith Woodward, F.R.S., F.Z.S., exhibited a new drawing of the skeleton of the Triassic Rhynchocephalian, Rhyncho-saurus articeps, from the Keuper Sandstone of Shropshire. He pointed out the differences between this ancient reptile and the modern Sphenodon, especially noting the great expansion of its coracoids and ischia, and the probably diminutive size of its sternum. He inferred from the everted rims of the upwardly-turned orbits, and from the sigmoidal bend of the femur, that Rhynchosaurus was to a great degree aquatic in habit. The following papers were read :- 1. On Breeding Experiments with Lepidoptera. By L. DONCASTER, M.A., F.Z.S., Mackinnon Student of the Royal Society, and the Rev. G. H. RAYNOR, M.A., F.E.S. [Received December 28, 1905.] (Plate VIII.*) I.-ANGERONA PRUNARIA. (Plate VIII. fig. 1.) (Experiments by L. Doncaster.) In the summer of 1903 I began breeding-experiments with Angerona prunaria and its var. sordiata, in order to find out how the two forms behaved in inheritance. M y material was obtained from two sources : pupae of both varieties were bought from a dealer, and Mr. C. P. Pickett of Leyton gave me eggs which he had bred. In neither case did I know the ancestry of the * For explanation of the Plate, see p. 133. |