34 
FRIDAY, APRIL 28TH, 1905. 
Che Ebolution of the Vertebrate Skull. 
BY 
JAMES. THORNTON. CARTER, 
M.R.C.S., L.R.C.P. 
Illustrated by Lantern Slides. 
HIS Lecture was devoted to a careful study of the anatomy 
and development of typical skulls, considered in their 
zoological order. Fishes were first considered, and slides of the 
skull of Amphioxus, and certain specimens of Elasmobranchs, 
Ganoids, Dipnoi, and Teleostei were shown and explained. 
In a similar manner, skulls of certain Amphibians, Reptiles, 
Birds, Mammals, and finally Man were considered, and their 
respective differences pointed out. 
THURSDAY, MAY 18TH, 1905. 
Bistory of the Sonth Dotuns, 
BY 
Mr. J. H. A. JENNER, F.E.S. 
M* JENNER began with a reminder of what Gilbert White 
said of the South Downs after travelling on them upwards 
of thirty years. ‘I still investigate that chain of majestic 
mountains with fresh admiration year by year; and I think I 
see new beauties every time I traverse it.” Varying in thickness 
from 800 to 1,000 feet, the Sussex Downs had their origin in a 
chalk formation at the bottom of a deep ocean, and must have 
taken many thousands of years in formation. The strata, pro- 
ceeding upwards, consisted of the lower greensand, gault, uppe, 
