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birds that have great powers of flight have a prominent 
middle ridge or keel. The bones of the wing were 
compared with those of other animals, including man, 
and it was shown how these bones had been adapted 
to their particular use in the various groups of animals. 
Mr. Martin then went on to describe the structure and 
development of feathers, and showed that they are 
essentially the same as hair, scales, and nails. He 
touched on such points as the bony ring round the 
eye, which enables the sight to be adjusted auto- 
matically; the nictitating or winking membrane for 
clearing the surface of the eye of dust, a rudiment of 
which is still to be found in the inner corner of the 
human eye ; the beak and its adaptation to the various 
kinds of food of birds; and the development of the 
embryo within the egg. The last part of the lecture 
was devoted to describing the different orders into 
which birds are divided, a British bird being taken as 
a type in each case, and the principal points of its 
life-history, etc., detailed. At the conclusion of his 
lecture, Mr. Martin referred to the excellent work 
being done by the Society for the Protection of Birds, 
a work which all bird-lovers should support. 
Friday, 13th November, 1903. Sir Samuel Wilks, 
Bart., F.R.S., in the Chair. 
Dr. J. W. Williams, F.L.S., exhibited the Ammo- 
nite (Ammonites bifrons), a common Whitby fossil, 
reported to have been found in the Tube boring in 
Heath Street, and pronounced it ‘‘a fraud.” He gave 
many reasons for the belief that at a very recent date 
it had been in an aquarium, and, apart from that, 
stated that it was impossible for any Ammonite to be 
found in its natural place in the formations of Hamp- 
stead Hill. Hampstead Hill, he explained, was com- 
posed of London clay, capped by a thin layer of 
Bagshot sand, and resting upon a layer of rocks, known 
