206 New Natural History Books. 
The Age of Mammals in Europe, Asia, and North America, by H. F. 
Osbourn (635 pp., The MacMillan Co., 18/6net). This volume contains ‘ The 
Harris Lectures, delivered at North-western University,’ and is dedicated 
to Huxley and Balfour, the author’s British teachers, the influence of 
whom is apparant throughout the work. In an admirable Introduction 
Prof. Osbourn refers to the Rise in Paleontology, Darwin’s Influence, the 
Influence of American Discovery, the Origin of Mammals, the geographic 
or space distribution of mammals, their geologic or time distribution, 
fossils, zones, etc. He then deals in detail with the various geological 
discoveries that have been made, in their order, and by the aid of numerous 
maps, diagrams, photographs, and restorations, makes one of the most 
comprehensive and scholarly contributions to paleontology that we have 
seen. The work is the result of many years’ study on the comparison of 
the new and old world life; and many, besides geologists and zoologists, 
will find ‘ The Age of Mammals’ of value. The work certainly deals with 
the subject most thoroughly, and will be the text-book thereon for many 
years to come. 
The Book of Migratory Birds met with on Holy Island and the Northum- 
berland Coast, to which is added descriptive accounts of Wild Fowling 
on the Mud Flats, with notes on the General Natural History of this 
district, by W. Halliday (258 pp. London: John Ouseley, Ltd. 5/- net). 
We suppose there is some good purpose served in printing this book, 
but at present we have failed to see it. It is not a book of migratory 
birds; it has but little, and certainly nothing new, on the question of 
migration ; and ifit hasa good sale, we opine it will be due to its somewhat 
misleading title. Its subtitle, too, is also wrong, unless we are very 
much mistaken, as surely there are no Cassowaries and Ostriches and 
Ostrich farms on Holy Island ? And what can the ghastly representation 
of ‘St. Cuthbert on Holy Island being offered the Bishopric of Hexham ’ 
have to do with the migration of birds, unless it is that his face (if repre- 
sented aright) was the cause of the birds’ first migration from holy Holy 
Island ? The illustrations, too, are about on a par; the photo of the 
“Climmers’ at Flamborough (though Flamborough is not referred to) and of 
nests and eggs of birds from all over—anywhere almost but Holy Island, 
can have little bearing upon either migration or Holy Island. And any- 
one can tell that the angelic, not to say holy expression on the Great Crested 
Grebe (facing page 135), stamps it as a fraud. The author has been 
fortunate in getting the permission of different writers to reprint their 
papers on quails on Hatfield Chase, Yorkshire ; Marking of Woodcock, 
etc., but what possible connection can these have with either migratory 
birds or Holy Island? and the chapter on Seal Hunting in Greenland has . 
surely been inserted as a joke. The ‘arrangement’ of the book (if we 
can flatter it by using that word), is extraordinary. We certainly think 
that both author and publishers would have been well advised if they had 
allowed some capable ornithologist to go through the MSS. before publica- 
tion; though possibly had this been done, the work would never have 
seen the light. A ‘ Book of Migratory Birds,’ it is not, but a scrap-book 
of miscellaneous -notes, chiefly of the birdy, birdy, talky, talky type, 
it may be we can only wonder at the possible nature of the * valuable help ' 
that has been given by the various gentlemen enumerated in the Preface, 
and we hope they are satisfied with the result. However, the author 
himself tells us that ‘man is but mortal, and his best work is oft-times a 
sorry attempt.’ Amen. 
How to Know the Trees, by Henry Irving (Cassell & Co., 180 pp., 3/6 
net) is of a very useful type, and the outstanding feature of this 
book is the series of excellent photographs of the trees and their various 
parts, by Mr. Irving, who has earned a good reputation for his botanical 
photographs. It will prove a useful guide to beginners anxious to identity 
the various trees in the field. 
Naturalist, 
