YORKSHIRE NATURALISTS AT HATFIELD CHACE. 



87 



El'odium cicutariu7n L'Herit., Riibus siiberedus {v£ir. f is sus?), Dipsaats 

 sylvcstris L,, Sderarithiis annuus L., and Hordeuin murinum L., 

 Senecio sylvaticus L. was very fine and abundant in the sandy lanes 

 bordering the Chace. The total number of observations on marking 

 the London Catalogue was found to be 142. 



Mr. H. T. Soppitt supplemented the botanical report by stating 

 that about thirty species of fungi were collected on or near the 

 Chace, including Ag. (iMyce?ia) leptocephala Pers., Ag. {Psilocybe) 

 ericcEus Pers., Cort. {TeIa?nonia) limonius Fr., Cort. {Derfnocybe) 

 ciiinamo7rmis Fr., Cort. {Hygrocybe) casianeus Fr., Lactarius subdulcis 

 Fr., L. rufus Fr., L. glyciosmus Fr., Marasuiius oreades (abundant), 

 Calocera viscosa Fr., Phragmidiiim rtibi Pers., P, violaceuvi Schl., 

 Rhytisma andromedcs Fr., and Hypoxylon concejitricuni Grev. 



For the Geological Section Mr. S. A. Adamson, F.G.S., secretary, 

 reported that the excursion presented a fine field for the microscopists 

 and botanists (promoted now to the rank of botanologists !), but left, 

 as was thought, comparatively little for the geologists to do. No 

 welcome escarpment or delightful quarry welcomed the eyes of the 

 hammermen, and long did their well-used tools hang idly by their 

 sides. Still, the day was not without charm, and, indeed, profit also ; 

 an opportunity was presented of viewing a wide extent of primeval 

 bog, and also of being informed how this was changed into fertile land. 

 The party, under the guidance of Messrs. Rimes and Batty, set out 

 in the direction of Lindholme, passing through the village of Hatfield 

 Woodhouse on the way. In every direction could be seen long straight 

 drains and dikes, the work of the old Dutch engineers, who, in the 

 fens and bogs of this district, found ample scope for their special 

 talents, and gave the locality a strong resemblance to their own 

 Holland over the sea. The transformation of heath and morass into 

 fertile and profitable land was explained to be by the process of 

 ' warping that is, the tidal rivers are allowed to overflow the peat 

 levels, until the fine silt held in suspension is deposited. The waters 

 are then dammed out and the process repeated, when a thick deposit 

 of fine impalpable mud is gradually laid down ; this being worked 

 into the land produces a rich and fertile soil. The sand and mud 

 composing this warp originates from the wasting of the cliffs and 

 shores of Holderness, and is brought down by the H umber. More 

 silt is carried into the rivers by the tide than is brought down b>- 

 them.. Mr. Sollit stated some years ago that in a gallon of water 

 taken from the Humber when it was agitated by the tide there were 

 from 315 to 320 grains of this fine deposit, some of it so exceedingly 

 fine that it did not settle to the bottom of a vessel after a spare 

 of ten hours. This silt was analysed, and a sample taken off Brough 



March 1888. 



