Page:The Zoologist, 4th series, vol 6 (1902).djvu/281

Rh Bleak, Roach, and small fry have appeared in all the reaches, from Putney upwards; while Smelts now ascend the Thames as they did before the river was polluted, and are freely caught at Chiswick. We may also hope for the plentiful appearance once more of the Crayfish, whose almost complete destruction was due to a disease, well known in France, which first appeared near Staines, and worked its way up the Thames.

We have heartily enjoyed the perusal of this nicely illustrated book, and trust that it may be the harbinger of other work on the natural history of our well-loved river.

with most books on county ornithology, this publication is distinctly novel, and written on a different method; the presence or absence of birds in Gloucestershire is discussed more on a philosophical than on a reporter's basis; the geological floor, with its consequent surface flora, is shown to have its influence in the distribution of our avifauna, and we at length feel that there is some reason for the presence of the rare bird that fell to the gun of the faithful recorder. Gloucestershire is thus considered as a dominant partner, and the presence of birds less of a chance occurrence. We are not attempting to spoil a good book by absurd panegyric, but we do recognize that Mr. Mellersh has proposed a philosophical basis for a recognition of even the birds of a single county. To find there is a reason to be adduced on natural causation for the presence of a bird is tantamount to our believing in a purpose running through the ages. We know that causation is often confused with theory by many writers, but the still small voice is yet recognized in biology, despite the discrepancies in rival suggestions. In fact, evolution is slowly becoming an orthodox idea in contradistinction to the theories of specialists and doctrinaires. Science is more concerned with the reason why a bird is in a certain habitat, rather than with the fact that it is there; and that is a question that the author of this book shows is capable of discussion. His enumeration may