SECTIONAL TRANSACTIONS.— D. 341 



Genus Thawnatosnurus. 



Thamnatosaurus niegacephalus (Stutchbury). To this genus should be referred the 

 type skeleton of Plesiosaiirus megacephalus described by Stutchbury in 1846 (Q.J.G.S. 

 vol. ii. p. 412, pi. 18). The specimen came from the Lower Lias of Street, Somerset. 



Incerta sedis. A worn and incomplete cervical vertebral centrum from the Lower 

 Lias of Weston was described by Owen in the Report of the British Association for 

 1839 (p. 77) imder the name of P. subtrigonus. There is no doubt of the specific 

 distinctness of the specimen, but its affinities are uncertain. 



Likewise of unknown affinities is the cervical vertebra from the Rhaetic bone bed 

 at Aust Cliff described by Owen as P. Costatns (op. cit. p. 80). Probably this species 

 should be referred to a new genus which would also include the undescribed skeleton 

 labelled Pleisosaiirua brachycephalus. This latter specimen is from the Lower Lias of 

 Bitton, Gloucestershire, and though completely disarticulated has been mounted in 

 plaster by someone who must have been familiar with its original appearance. On 

 careful examination practically all the skeletal features of importance can be made 

 out. The specimen is not P. brachycephalus but a species closely allied to P. rosiratua. 

 Finally, there is in the collection a small cervical vertebra mounted upside down, and 

 partly obscured, in plaster. No history is attached to the specimen, but it bears the 

 name Plesiosaunia depressus given to it by Owen. This name has not been published 

 and is not even a manuscript name. As the specimen, in its present condition at 

 least, cannot be regarded as specifically determinable the name must be regarded as 

 invalid. 



The Bristol Collection is therefore very representative. Plesiosaurus cosiatus and 

 Eretmosaurus rugosus occur in the Rhaetic ; the latter is also common in the Lower 

 Lias and in addition has Upper Lias affinities : thiis the most important periods of 

 Plesiosaiurian history are represented. The Upper Jurassic form, Peloneusies, was 

 probably derived from a longirostrine plesiosaur allied to P. rostratus. 



Mr. M. A. C. HiNTON. — Extinct Cave Fauna of the Bristol District. 



Afternoon. 

 Excursion to Wookey Hole and other cave.s. 

 Excursion to the Bri,stol Zoological Gardens. 



Tuesday, September 9. 



Dr. F. B. TuRCK. — The Cell and its Fluid in the Process of Growth and 

 animal Metabolism. 



Various mechanical, physical and chemical agents were employed in animals to 

 release the ' wound hormones.' The degree of injury made by these agents was kept 

 below the lethal or shock-producing effect and, by careful adjustment in the experiments, 

 also kept below the morbid effect. 



It wa^ learned that when shock and death was avoided and the morbid stage was not 

 reached, that a stimulating effect resulted with acceleration of growth and metabolism. 

 This acceleration of growth and metabolism was established by spacing the nuld forms 

 of mechanical, physical and chemical injuries at regular time intervals. 



The tissue fluid released by these various injuries was secured and injected into 

 fresh animals, about once or twice a week, according to the degree of concentration. 

 This resulted in the stimulation of growth and metabolism similar to that in the animals 

 which had been injured in the milder form. 



The heated extract, up to 140°C, of this tissue fluid, was as active as the original 

 tissue fluid substance. On burning off the protein, but retaiAng some of the organic 

 residue with the mineral content, the injected mixture was active in producing the 

 stimulating effect in growth and metabolism. Breeding experiments showed the 

 favourable effect in the offspring and demonstrated the transmission from parent to 

 the embryo. 



Tables of conductivity and pH and spectrographs are included. 



