XXVI PEOCEEDINGS OF THE 



10. Extract of a letter from Mr. R. P. Greg, F.G.S., Coles Park, 

 Buntingford, to the Secretary, stating that badgers were not un- 

 common in the Rib near Euntingford, and that his keeper had shot 

 one last August. 



11. " On a Singular Disease amongst the Deer in Cassiobury 

 Park." Py the Presiolent. (F/V^ep. 111.) 



12. "On Natural Selection in Rabbits." By the President. 

 {Vtde^. 112.) 



The attention of the Society was also drawn to some photographs 

 showing peculiar markings on the panes of glass of a conservatory, 

 sent by Lieut. R. B. Croft, F.L.S., who was desirous of eliciting 

 suggestions as to their origin. 



Several Members exhibited objects under their microscopes, and 

 other interesting Natural History objects were exhibited. 



Field Meeting, IGxn June, 1878. 

 Hertford and Ware. 



The northern edge of the London Tertiary Basin passes for a 

 considerable portion of its course through the County of Hertford, 

 and Avithin the last few years several places along this line of 

 outcrop have been visited by the Society, in conjunction with the 

 Geologists' Association of London. On this occasion the neigh- 

 bourhood of the county town was selected for investigation, and 

 members of the two societies met at the Hertford Station of the 

 Great Northern Railway at half-past ten, the County Field Club 

 forming by far the larger party. Professor John Morris, F.G.S., 

 had kindly consented to explain the geological features of the 

 district, the Honorary Secretary having made the necessary arrange- 

 ments for the day, and selected the route to be taken. 



The first place visited was Hertford Castle, near which there 

 are still standing, completely overgrown with ivy, the ruins of a 

 much older structure, once an important fortress, supposed to have 

 been built by King Alfred. Near this fortress flows the River Lea, 

 from which the moat by which it was surrounded could have been 

 easily filled. 



From the Castle the route lay through the churchyard (All 

 Saints'), famed for its fine avenue of chestnuts, 200 years old, 

 and thence through Balls Park, the seat of the Marquis Towns- 

 hend, to Mr. Lines' brickfield, between Rush Green and Hertford 

 Heath, the first point of geological interest. Before, however, 

 the brickfields were visited, a chalk-pit near afforded Professor 

 Morris the text for an interesting address, in the course of 

 which he showed that the flints immediately above the chalk 

 were of a different colour from that of the flints in the chalk, some 

 chemical change having given them a green coating. The presence 

 of this thin layer of green-coated flints, known to borers as the 

 " Bull's Head Bed," was a proof that we had the true surface of 



