Page:The Zoologist, 4th series, vol 2 (1898).djvu/521

Rh It is interesting to hear that a specimen of Scutigera coleoptrata, a South European centipede, was recently captured at Colchester. This is the second time that its occurrence in Great Britain has been recorded. The first time it was introduced amoug a quantity of old rags into a papermill near Aberdeen, where, being protected by heat, it bred and has become established.

discovered in the stomach of a Cachalot by the Prince of Monaco during one of his expeditions has been determined as indistinguishable from the common Eel, and this points with great emphasis to the fact that this form, whose habits are so obscure, must at times take to the open sea.

nature of the water supply being of immense importance to the welfare of humanity, especially of that portion living in communities, it may be well to refer to a paper written by Mr. Geo. W. Rafter, "On Some Recent Advances in Water Analysis and the Use of the Microscope for the Detection of Sewage," though published as long ago as 1893 in the 'American Monthly Microscopical Journal,' and which was read before the Buffalo, N.Y., Microscopical Club:—

The complete details of these various studies are too extensive to be given at length, and we may merely refer to some of the results at Hemlock Lake, where plant forms have been identified as follows:—Chlorophyceæ, 20; Cyanophyceæ, 15; Desmidiæ, 14; and Diatomaceæ, 41—making a total of plant forms of 90. The maximum quantities of some of these minute plants per 100 cubic centimetres are—Protococcus, 2000; Anabæna, 20,000; Cœlosphærium, 34,000; Asterionella., 40,000; Cyclotella, 60,000; Fragillaria, 25,000; Stephanodiscus, 60,000. The total number of animal forms is 92, of which 3 are classed as Spongidæ, 10 as Rhizopoda, 29 as Infusoria, 2 as Hydroida, 14 as Rotifera, 3 as Polyzoa, 21 as Entomostraca, 1 as Malacostraca, and 10 as insect larvæ. As to maximum quantities of animal forms observed, we find among Infusoria— Dinobry on, 12,000; Glenodinium, 25,000; and Vorticella, 9600.

The quantities of minute life present in Hemlock Lake, while apparently large, are in reality quite small, as will be readily appreciated by reference to a statement of the number present in Ludlow reservoir, Springfield, Massachusetts, where the following maximum quantities per 100 cubic centimetres have been observed:—of the Diatoms, Asterionella and Melosira, 405,600 in April, 1890; Cœlosphærium, 157,600 in August, 1889; Chlorococcus, 322,400 in October, 1889: of animal forms the infusorian Dinobryon showed 364,400 per 100 cubic centimetres in February, 1890. But even the large quantities of minute life found at