"Only one species (_Trapa natans_, Willd.) has disappeared from our islands. Its fruits, which Mr. Reid found abundantly in one locality, agree with those of the plants found until recently in the lakes of Sweden. Four species (_Prunus speciosa_, L., _[OE]nanthe Tichenalii_, Sm., _Potamogeton pterophyllus_, Sch., and _Pinus abies_, L.) are found at present only in Europe, and a fifth (_Potamogeton trichoides_, Cham.) extends also to North America; two species (_Peucedanum palustre_, Moench, and _Pinus sylvestris_, L.) are found also in Siberia, while six more (_Sanguisorba officinalis_, L., _Rubus fruticosus_, L., 5 _Cornus sanguinea_, L., _Euphorbia amygdaloides_, L., _Quercus robur_, L., and _Potamogeton crispus_, L.) extend into western Asia, and two (_Fagus sylvatica_, L., and _Alnus glutinosa_, L.) are included in the Japanese flora. Seven species, while found with the others, enter also into the Mediterranean flora, extending to North Africa: these are _Thalictrum minus_, L., _Thalictrum flavum_, L., _Ranunculus repens_, L., _Stellaria aquatica_, Scop., _Corylus avellana_, L., _Yannichellia palustris_, L., and _Cladium mariscus_, Br. With a similar distribution in the Old World, eight species (_Bidens tripartita_, L., _Myosotis cæspitosa_, Schultz, _Suæda maritima_, Dum., _Ceratophyllum demersum_,, L., _Sparganium ramosum_, Huds., _Potamogeton pectinatus_, L., _Carex paludosa_, Good., and _Osmunda regalis_, L.) are found also in North America. Of the remainder, ten species (_Nuphar luteum_, Sm., _Menyanthes trifoliata_, L., _Stachys palustris_, L., _Rumex maritimus_, L., _Rumex acetosella_, L., _Betula alba_, L., _Scirpus pauciflorus_, Lightf., _Taxus baccata_, L., and _Isoetes lacustris_, L.) extend round the north temperate zone, while three (_Lycopus europæus_, L., _Alisma plantago_, L., and _Phragmites communis_, Trim), having the same distribution in the north, are found also in Australia, and one (_Hippuris vulgaris_, L.) in the south of South America. The list is completed by _Ranunculus aquatilis_, L., distributed over all the temperate regions of the globe, and _Scirpus lacustris_, L., which is found in many tropical regions as well." He remarks that these plants, while including species now very widely scattered, present no appreciable change of characters. Above this bed are glacial clays, which hold other species indicating an extremely cold climate. They are few in number, only _Salix polaris_, a thoroughly arctic species, and its ally, _S. cinerea_, L., and a moss, _Hypnum turgescens_, Schimp., no longer found in Britain, but an Alpine and arctic species. This bed belongs to the beginning of the Glacial period, the deposits of which have as yet afforded no plants in England. But plants occur in post-glacial and upper-glacial beds in different parts of England, to which Carruthers thus refers: