1 899-] Proceedings of Irish Societies. 107 



spend a portion of their lives under water. Such was the case with 

 seals, water-voles, beaver, and hippopotamus. In other groups the 

 adaptation to aquatic life is complete, and the animal has lost the 

 power of maintaining itself on land and spends its whole life in water. 

 To this group the whale belongs. The lecturer showed lantern views of 

 the principal kind of whales, and pointed out their leading characters. 

 Certain anatomical peculiarities were then pointed out, which lead 

 Professor Kukenthal to believe that the toothed whales and whalebone 

 whales have a different origin. The toothed whales have sprung from 

 some primitive mammals, whose backs were covered with a hard 

 exoskeleton, while the ancestors of the whalebone whales were land 

 animals with a hairy covering for the skin. The flippers of whales are 

 modified fore limbs of mammals, with adaptations and modifications to 

 suit aquatic life. In the number of bones in the flipper the whale closely 

 resembles the extinct Ichthyosaurus. This is not a conclusive proof 

 that both have sprung from a common stock, though it may be fairly 

 assumed that both represent a modification of different types as an 

 adaptation to the same mode of life. The hind limbs are not to be 

 detected on the surface of the body, but embedded in the trunk are 

 certain bones, rudimentary hip, thigh, and in some cases leg bones, but 

 of a very small size. The significance of their presence supports the 

 theory that the Cetacea were originally four-limbed animals. Many 

 facts about the teeth of whales were then stated. In dealing with the 

 tail as an organ of locomotion, the lecturer said there are no data to 

 decide the relative efficiency of a whale's tail as compared with a modern 

 screw propeller, but there is at least one point in which the tail has an 

 advantage — its internal structure is specially adapted to its function, its 

 fibres run in the direction to give the maximum of strength with the 

 minimum of material. The lecturer discussed the various theories as to 

 the origin of whales. He favoured the view that the toothed whales 

 were a more ancient group, and differed more from ordinary mammals 

 than the whalebone whales. The attempts to prove that the whales 

 have descended from the Carnivora or the Ruminants had not been very 

 successful. On the whole, the facts at present known favoured the 

 hypothesis that both groups of whales departed at a very remote period 

 from the primitive mammalian stock, the evidence at present available 

 being too incomplete to justify any dogmatic assertions. In conclusion, 

 the Professor expressed his indebtedness to Miss Clara Patterson, a 

 member of the Club, for assistance given in the preparation of the 

 numerous illustrations. 



February 9.— Geoeogicai, Section. —Prof. G. A. J. Cole lectured on 

 "The Volcanic North; how Ireland became an Island." He briefly outlined 

 the geography of Palaeozoic times when a great continent existed to the 

 north of the British Isles, he indicated the changes in geography till the 

 beginning of the Tertiary period, and then dealt in detail with volcanic 

 phenomena in Tertiary times, tracing the connection of local activities 



