47 



by a wide detour to Portesham, where they were hospitably enter- 

 tained by Dr. and Mrs. Colley March to tea. The excursion is 

 described on page 39, being mainly ot Archaeological interest, but 

 there were several points visited of importance to geologists. 

 Amongst these were beds of Tertiary gravel overlying the chalk on 

 Black Down, next the Valley of Stones, so called from the prostrate 

 sarsen stones with which it is partly covered. The conductor here 

 gave an account of the manner in which these stones are believed to 

 have been derived from Tertiary deposits and of the " creep " by 

 which they are supposed to have proceeded to the bottom of the 

 valleys. Dr. Ord supplemented this by a statement as to their 

 silicious constituents, and remarked upon the signs of stratification seen 

 in the arrangement of the large water-worn pebbles and the finer con- 

 stituents in the bigger stones. Signs of what Dr. March considered 

 to be deglaciation — scratchings by ice-action — were discovered on one 

 stone and photographed by Miss Hawker. Interesting examples of 

 chalk valleys, with evidences of old vents or water channels, were then 

 visited. Further on Dr. March pointed out what he believed were 

 further examples of ice-action, in support of the opinions advanced 

 in his paper, " Dorset during the Glacial Age," page 71. These he 

 described as " roches moutonnees," and " perched blocks," also an 

 area covered with flint rubble and earth which he considered might 

 represent the remains of a glacial moraine. After tea Dr. March 

 showed his large collection of flints and other stones, chiefly obtained 

 in the neighbourhood of Portesham, on which he bases his views as 

 to the glaciation of Dorset. These were examined with much 

 interest and it was generally agreed that their condition was not easy 

 of explanation under the usual geological hypotheses, A few of 

 these scratched flints are illustrated on Plate IV, page 71. 



Chairmen : Dr. Dixon and Dr. Thomas. 



The work of these Sections has been continued on the lines 

 laid down during the previous year. The summer work of these 

 Sections has been largely identical, so it has been decided to combine 

 the account of their respective work. During the winter session the 

 Microscopical Section held five meetings, which were as follows : — 



Dec. 9th. A description of the more interesting specimens 

 found during the summer, by Dr. Dixon ; and an exhibition 

 of specimens under microscopes, by members. 



Jan. 24th. A practical demonstration of the methods used in 

 studying the structure of leaves, by Dr. Dixon. 



Feb. 28th. A short account of Argulus foliaceus (the fish 

 parasite) by Dr. Thomas ; also an exhibition of slides 

 under microscopes, by members. 



