ON THE RELATION OF PALHOLITHIC MAN TO THE GLACIAL EPOCH. 407 
clay-gravel which undoubtedly contain derivative fossils. It will imme- 
diately occur to any botanist looking at the list that several of the 
plants, besides those marked as derivative, are species not likely to have 
lived with the dwarf Arctic willows and birch. But as we wish to use the 
list for the determination of the climatic conditions which reigned when 
the deposit was being formed, it is clear that we have no right first to 
reject certain species that seem to contradict the other evidence, and then 
to argue as though we were dealing with a homogeneous flora. We can 
say, however, that the fragile specimens, such as leaves, moss, and delicate 
seeds, which cannot have been washed out of an older deposit, all represent 
a homogeneous Arctic or high alpine flora. Trees, with the possible ex- 
ception of the alder, seem to have been entirely absent, and the climate 
was probably not unlike that of the cold treeless regions of North 
America and Siberia. 
Though so large a quantity of material was removed in our trial-pit, 
the number of leaves obtained in good preservation was not great ; we 
obtained, in fact, fewer good specimens than in 1888. The reason of the 
decay of the leaves must be sought in the fact that we struck the centre 
of the old channel, where the deposits are exceptionally sandy, and the 
circulation of the water is greatest. We were able to preserve only the 
smaller tough leaves of Salix myrsinites, though larger decayed ones are 
not uncommon. Of Betula nana we have not been able to save a single 
fragment, although leaves were seen on splitting the wet loam. The 
following species were obtained on washing the material :— 
Ranunculus aquatilis, L. ' Rumex crispus ? Z. 
5 sceleratus, Z. Urtica dioica? Z. [one seed]. 
aA repens, L. [derivative ?]. Betula nana, Z. 
Caltha palustris, Z. | Alnus glutinosa, Z. [perhaps derivative]. 
Viola palustris, Z. | Carpinus Betulus, Z. [derivative]. 
Stellaria media, Cy7. | Salix myrsinites, Z. 
Montia fontana, Z. | ,, herbacea, Z. 
Rhamnus Frangula, Z. [worn and deri- | ,, polaris, Wahid. 
_ vative]. | Ceratophyllum demersum, Z. 
Rubus Ideus, ZL. ' Taxus baccata, Z. [derivative]. 
Poterium officinale, Hook. /. | Sparganium ramosum, Curtis. 
-Hippuris vulgaris, Z. | Alisma Plantago, Z. 
Myriophyllum spicatum, Z. Potamogeton rufescens, Schrad. 
(nanthe Phellandrium, Zam. [fruit very | a crispus, Z. 
small]. ‘ pusillus, Z. 
Sambucus nigra, Z. [derivative ?]. a trichoides, Cham. 
Eupatorium cannabinum, Z. | - pectinatus, Z. 
Bidens tripartita, Z. [a starved fruit]. | Seirpus pauciflorus, Lightf. 
Taraxacum officinale, Wed. | »  setaceus, Z. 
Menyanthes trifoliata, Z. » lacustris, Z. 
Lycopus europeus, Z. | Blysmus rufus, Wahilbd. 
Ajuga reptans, Z. Carex incurva ? Lighty. 
Rumex maritimus, Z. Chara. 
Mr. Mitten has kindly examined the mosses from this deposit, and 
records the following species :— 
Amblystegium fluitans, Iitt., fragments of stem with leaves, the leaves as 
usual varying in form and length of nerve, this last in some unusually long. 
Acroceratium sarmentosum, Witt.; fragments of stem with leaves. 
Hylocomium squarrosum, Bruch and Schimp.; fragments of branches. 
Amblystegium stellatum, Witt. ; fragments of stems. 
