348 



FIELD NOTES. 



GEOLOGY. 



Large Mammoth Tooth at Withernsea.— A very fine tooth 

 of a mammoth was recently found on the beach at Withernsea. 

 by a young- lady. It is one of the lower jaw teeth and weighs 

 9^2 lbs. Judg-jng from its excellent condition, it had only recently- 

 been washed from the clay. It is now in the Hull Museum. — T. S. 



BOTANY, 



Plant Associations near Pocklington. — An instance of 

 complicated plant associations was noticed on Allerthorpe 

 Common during the Pocklington excursion of the Yorkshire- 

 Naturalists' Union. Under ordinary conditions the place is 

 a flat bog, ID or 12 yards across. On the day we saw it (7th 

 August) it was almost dry. Apparently the dry summer, up tO' 

 that period, had brought about adverse conditions for bog- 

 plants. There did not appear to be any ground oozings of any 

 moment to supplement the rainfall. The bog plants were giving^ 

 way and 'dry-land' plants stepping in, creating for the time 

 being a most peculiar series of associations. The bog" plants 

 were Sphagnum, Menyanthes irifoliata, Glycerio Jiuitans, Potarno- 

 geton plantagineus , Raminculiis fiammula, Hydrocotyle vulgare, 

 Galium palustre, Juncus effusus, J. articiilatus, and Polytrichum 

 commune. The Sphagnum was apparently dead, while some of 

 the others had lost much of their wonted vigour. It is not often 

 one sees a tuft of Yorkshire Fog [Holcus lanatus) g"rowing" out 

 of a bed of Sphagnum. Nor does one expect to find the follow- 

 ing on boggy land in the company of the above plants : — Senecio- 

 vulgaris, Polygonum aviculare, P. Persicaria, P. ConvohmhtSy. 

 Chenopodium album, Potentilla anserina, Plaiitago inajor, and 

 Leontodon autumnale ; yet they were all there, five being' annuals, 

 the first, and the three last, perennials. The Corn Bindweed 

 {Polygonum Convolvulus) was actually insinuating itself among- 

 a tuft of rushes, and binding several rush stems in its embrace 

 as one sees it entwining corn stems in a cornfield. On 

 an adjoining bank Epilohium august if olitan and Potentilla 

 Tormentilla were flourishing", with Ranunculus repens at the 

 foot. Possibly the seeds of the intruders were bird-sown, 

 carried from the cornfields and waste grounds on the outskirts 

 of the common, the dry condition of the bog allowing these 

 plants to enter into competition with the weakened marsh 

 plants. — C. Crosslaxd, Halifax. 



Naturalist^ 



