,;j 



8 Notes and Comments. 



extremes of cold and heat, and provided with abundant 

 Diatoms as food. .New reproductive bodies are given off and 

 effect a lodgement elsewhere, and carnivorous animals of 

 various kinds prey on the colonies thus diffused. The final 

 result may be the occurrence, in the water-pipes of a town. 

 of thousands of individuals or masses the weight of which 

 must be estimated in tons, of various fresh-water animals. 

 Not only do these tend to restrict the effective size of the pipes, 

 but their decay, especially at the approach of winter, sets free 

 branches of Polyzoa and Hydroids, which give rise to serious 

 trouble by blocking strainers and taps, besides resulting in 

 the fouling of the water and the encouragement of the growth 

 of Bacteria, some of which (the " Iron Bacteria") have the 

 most far-reaching consequences. 



BOTANICAL SOCIETY AND EXCHANGE CLUB. 



There have recently been issued the report for 191O of the 

 Botanical Society and Exchange Club of the British Islands, 

 Vol. IV., Pt. 5, pages 393 to 550, by Mr. G. Claridge Druce ; 

 also the Report of the Botanical Exchange Club, by Messrs. 

 W. H. Pearsall and D. Lumb. Vol. IV., Pt. 6, pages 551 to 600 ; 

 also Second Supplement to Botanical Society and Exchange 

 Club Report for 1916, by G. Claridge Druce, pages hoi to 653. 

 Each of these contains much matter of interest to northern 

 botanists. 



GEOTERESY. 



In the Journal of the Royal Geographical Society Mr. W. 

 Coldstream writes : — ' I have found the need of a word to ex- 

 press the idea of operations for the protection of the suface of 

 the earth. I found no single English word to express the idea. 

 " Protective Forestry " covered a considerable part of that 

 which had to be expressed, but not the whole, for there are 

 other modes of protection besides planting ; for instance, 

 barrages, embankments, etc. Finding no general word for 

 the purpose, I have proposed the word " Geoteresis " or " Geo- 

 teresy." (I suppose, if it came into English use, it would have 

 the penultimate short.) It would include protection against 

 (1) erosion by torrents, rivers and sea, and (2) submersion by 

 those agencies, and also by sand drift and silt deposit. I 

 venture to think that it would be convenient, and that it is 

 almost a necessity, to have some such word in discussing such 

 questions as the action of torrents, the denudation of the sur- 

 face by forest clearings and excessive grazing, also erosion 

 of river banks and also of the sea coast. Perhaps "Geoteresy," 

 with its adjective " Geoteretic," is as convenient and expressive 

 a word as can be found.' 



Naturalist, 



