Reviews and Book Notices. 
263 
microscopical examination, assisting in the identification of the common 
microscopic organisms found in drinking water, and interpreting the results 
in the light of environmental studies. Its second purpose is to stimulate 
a greater interest in the study of microscopic aquatic life and general 
limnology from the practical and economic standpoint. As the present 
is the third edition, the success of the work is demonstrated. We can 
only say that it is exceptionally thorough, and every possible point appears 
to have been illustrated with diagram or photographs, while the coloured 
plates represent the more important organic contents of water, such as 
Diatoms. Rotifera, etc. 
Waves of Sand and Snow and the Eddies which make them. By 
Vaughan Cornish. London : Fisher Unwin, 383 pp., 10s. net. Those 
who are familiar with Dr. Vaughan Cornish’s lectures and the numerous 
beautiful photographs with which he illustrates them, will be glad to 
have the present volume in which so many of them have been reproduced. 
The marvel is that the author has brought together so much information 
and so many interesting facts relating to so special a subject. He com- 
mences with an account of desert sand dunes which will certainly appeal to 
geologists interested in the Trias and other sandstone formations. He 
shows that sand ripples in the form of enormous dunes can be a very 
serious geological factor, inasmuch as in some cases they are shown 
to have entirely covered up large forests. On snow waves, and snow 
ripples he also gives much valuable information of a like kind, and many 
of the photographs and illustrations he gives are truly remarkable; the 
snow mushrooms, nine feet across, suspended from the tops of telegraph 
poles, etc., being specially noteworthy. The second part of the volume 
deals with the ripple marks and current marks, and illustrates many 
curious forms of ripples, and describes their origin and formation. The 
final part of the book refers to miniature deltas and ‘ mackerel skies.’ 
There is a bibliography and a brief index. The author appears to have 
travelled widely in order to obtain material for his volume, which we 
can safely say is the most complete treatise of this very difficult subject. 
Plant Life in the British Isles, by A. R. Horwood J. and A. Churchill, 
pp. xiv. and 254. Price 6/6 net. The author’s aim in writing this book 
is to introduce the beginner to the better known orders of British plants 
and interest them in the life histories of the commoner species. The 
features of the larger groups are first dealt with and then follow brief 
accounts of representative and common species. Stress is laid on habitat 
and the importance of this on distribution, and much of interest is given 
about many of our wild plants. Curiously enough, the author seems to 
have overlooked several species whose structures, forms, and life histories 
are of the greatest importance in relation to habitat, and whose peculiarities 
of distribution, as well as the great area they cover, present the most 
interesting problems in British vegetation. The introductory chapter is 
rather loosely written and unsafe to place in the hands of young students, 
e.g., on page 10 we are told that one of the functions of leaves is ‘ the 
conveyance of moisture to the roots, ’ and that ' there is no arrangement 
to convey water ’ in water plants. On page 1 1 he says that the ‘ Butter- 
cup Group has a batrachian section from which the land forms have been 
derived,’ while on page 42 he says that Ranunculus repens is a further 
example of a transitional form of buttercup leading on to the water 
buttercups.’ On page 22 we learn that a flower 1 is fertilised by the 
passage of the pollen grains down the stigma and the style to the ovary.’ 
The fruits of composites are said to be ‘ the product of a single carpel,’ 
and that the fruits of the Willow herbs are ‘ provided with a tuft of hairs.’ 
The book is illustrated by 73 photographs, most of which are quite good, 
but fig. 12 though it might serve as an illustration of a fruiting branch, 
certainly does not show the ‘ Flowers of the Lime.’ 
1914 Aug. 1. 
