1914-1915.] 



177 



stages — e.g., loss of ornamentation, superfluity of dead matter, loss 

 of power to coil(Ammonoideaand Gastropoda) — assumption of elon- 

 gate or eel-form by Fishes, and the loss of teeth by Vertebrates. 

 One of the prime signs of extinction of groups is exaggeration of 

 body size. Also the small size of the brain and the loss of 

 defensive power. These points were illustrated by a slide of 

 Diplodocus. The vast periods required by evolution were explained 

 by reference to the great mountain building, the movements of 

 the Alps and Himalayas in Tertiary time. This enormous period, 

 estimated by many writers at approximately 7,000,000 years, is 

 represented in the evolution of the Horse by the loss of four toes 

 of Eocene Horses and the evolution of the present one-toed 

 Horse. Finally the lecturer touched upon the rhythm of evolution 

 and its bearings on man's position and his possible successor. 



At the conclusion of the lecture a discussion took place on 

 the subject, in which Mr. R. J. Welch propounded a theory that 

 the sudden extinction of the large Reptiles might have been due 

 to faulty digestion. Mr. C. M. Cunningham drew attention to the 

 reduction in numbers of many animals which is at present going 

 on ; and the President, after thanking Dr. Charlesworth for his 

 lucid treatment of a difficult subject, alluded to "Welch's dyspeptic 

 theory." 



Subsequently Mr. C. C. Middleton was elected a member of 

 the Club. 



" RECENT ADVANCES IN GLACIAL GEOLOGY." 



The fourth Winter meeting was held in the Museum on 16th 

 February — the President, Mr. R. LI. Praeger, occupying the chair — 

 when a lecture on above subject was delivered by Mr. W. B. 

 Wright, B.A., F.G.S., Senior Geologist of the Geological Survey of 

 Ireland. 



He pointed out that the study of Glacial and post-Glacial 

 deposits at the present time is concentrated mainly on the ranging 

 of these deposits in chronological sequence, and the determination 



