38 THE BOTANICAL 3IAGAZINE. ^yoX. xxy. Ko. 289. 



The '' Kama " (or literally kettle), which name is given to the 

 spring at the bottom of the swamp, is no other than the spring 

 of the underground water. 



The depth of the swamp is uniform and its study is of a 

 little interest. The central part which is inhabited by the 

 submerged plants is about 2m deep in a ordinary state but in 

 high water (in earh- summer and autumn) it becomes often 

 3.5m deep, and in low water (in mid summer) often 1.7m. The 

 littoral part shallower than 2m is the habitat of swimming 

 hydrophytes and helophytes. This fact comes necessariK^ from 

 the origin of the swamp, upon which I shall return in later 

 pages. 



The surrounding hills clad with conifers (Pinus Thumbergii, 

 P. densJBora, Cryptoweria japonica, &c) are composed of a few 

 sandy layers covered b}- a laj^er of loam. The latter la3'ers 

 imply (especially in the villages Fuze and Kamenari) the fossils 

 of Mollusca and Echinodermata, which belong according Dr. 

 ToKUNAGA^^ and others,-^ to the diluvial epoch. I have there 

 collected 28 species of fossils. 



Beneath these sand}' laj^ers comes a compact la^-er of clay 

 and sand. The underground water flows probably over this 

 compact la^-er. At the bottom of the swamp we find a 

 humus soil black-brownish in colour and sulphur-like in smell. 

 This soiP^ contains a large quantity- of the relics of diatoms, and 

 often is interwoven with plant textures and shows a neutral 

 reaction. The swamp is a very fitted abode for fishes, as eels, 

 wels, carps, pond smelt and etc. The water is not fresh and 

 has an unpleasant smell ; It is so very clear in a calm day, 

 that we can see the beautiful foliage of submerged plants at 

 Im down from the surface of the water, but on a windv dav it 

 soon becomes brownish, because the waves disturb the muddy 

 shore and bottom. 



1) ToKDNAGA : Fos-'^ils from the envirors of Tokio, Jour. S'ci. Coll. Imp. Univ. 

 Tokyo. Vol. 21. Art 2. 



2) The Journal of the geological society of Tokyo, Vol. 11. p. 401 (Japanese) 

 S) Compare, WARMl^•G I.e. p. 6''. "Ordinary humus." 



also, ScHiMPER I.e. p. 118-120. " Der milde Humus." 



