228 
NATURE 
[OcToBER 23, 1913 
body and the model, the comparisons must be | lesser black-backed gull marked at Rossitten in 
made at velocities for which VI is constant—i.e. 
at velocities inversely proportional to the size 
of the body and model respectively. 
Enough has probably been written to direct 
- attention to the wide range and absorbing interest 
of the subjects discussed in this volume. 
CONCERNING BIRDS. 
(1) XI. Jahresbericht (1911) derVogelwarte Rossit- 
ten der Deutschen Ornithologischen Gesell- 
schaft. Teil II. By Prof. J. Thienemann. 
Peper 7s. 
(2) The Food of some British Wild Birds: a 
Study in Economic Ornithology. By W. E. 
Collinge. Pp. vi+1o9. (London: Dulau and 
Co., Ltd., 1913.) Price 4s. net. 
(3) The Bodley Head Natural History. By E. D. 
Cuming. With Illustrations by J. A. Shepherd. 
Vol. i., British Birds. Passeres. Pp. 120. 
(London: John Lane, 1913.) Price 2s. net. 
(1) N the second part of the eleventh annual 
report of the ‘ Vogelwarte,” or bird- 
watching station, at Rossitten in East Prussia, Dr, 
Thienemann sets forth the 1911 results of the 
migration inquiry. The method pursued is mark- 
ing the birds with numbered and addressed rings, 
and it continues to yield very interesting results. 
We notice that more than one black-headed gull 
born near Rossitten has been recovered in Eng- 
land, and a starling marked in the nest in Livonia 
on June 10, 1951, was shot on December 26, 1911, 
near Buckfast Abbey, South Devon. Other 
black-headed gulls from Rossitten were reported 
from Hungary, Croatia, Switzerland, and Pied- 
mont; and one marked at Munich was found again 
at Tunis. Best of all is the case of a Rossitten gull 
marked in the nest July 18, 1911, and shot in 
November in Barbadoes. We may recall the fact 
that a British marked gull has been reported from 
the Azores. , 
Some new records of German storks from Africa 
bring the total of such cases up to twenty-four. 
They include recoveries from the Mbomu-Ubangi 
basin (North Congo), German East Africa, and the 
Victoria. East district of Cape Province (the 
southernmost locality, 32° 46’ S.). Interest also 
attaches to storks recovered in Europe, for while 
most of those from Germany (east and west), Den- 
mark, and Holland have been found to migrate 
south-eastwards towards Asia Minor on their 
way to Egypt and further south, we have a second 
case of a West German stork migrating towards 
Spain. 
It is difficult to pick and choose among the in- 
teresting records, such as three hooded crows | 
recovered after intervals of more than six years; a 
NO. 2295, VOL. 92] 
autumn and reported from Servia after three weeks ; 
a young woodcock marked near St. Petersburg, 
July 3, 1911, recovered in dept. Gers, S.W. France, 
December 12, 1911; a wood pigeon marked in the 
nest near Dresden and obtained five months later 
in dept. Lot-et-Garonne, S.W. France; a rough- 
legged buzzard marked in the nest in northern 
Swedish-Lapland in July, and shot near Vienna 
four and a-half months later; an eagle (A. poma- 
vina) marked in the nest in Russian Kurland in 
July, and recovered two months afterwards in 
Southern Bulgaria. A discussion of certain rather 
puzzling movements of the red-legged faleon con- 
cludes this interesting paper. Dr. Thienemann 
is to be heartily congratulated on the success which 
has attended the inquiry which he so energetically 
pursues. ; 
(2) Mr. Collinge has done a very useful piece of 
work in presenting in compact form the results of 
his post-mortem examination of 3048 adult birds 
and 312 nestlings, and in giving along with this 
an up-to-date summary of what is known in regard 
to the food of the commonest British birds. We 
do not speak without feeling when we say that it 
is no light task to examine the food-canals of 
3000 birds, and to make sure, or as sure as one 
can, of the significance of their imperfectly pre- 
served contents. Mr. Collinge has done his work 
carefully, and the results are proportionately valu- 
able—helping us, none too soon, to get away 
from the practical mistakes engendered by preju- 
dice and hearsay evidence. Mr. Collinge has also 
been careful in his presentation of the work done 
by other observers. 
Attention may be directed to the interesting 
(but all too short) chapters on the food of nestlings, 
on the réle of birds in destroying or distributing 
the seeds of weeds, and on the relation of birds to 
forestry. Of the twenty-nine species of birds which 
have been especially studied by the author, only 
five are regarded as distinctively injurious, viz., 
the house-sparrow, bullfinch, sparrow-hawk, wood 
pigeon, and stockdove; six are regarded as alto- 
gether too plentiful, and consequently injurious, 
viz., missel thrush, blackbird, greenfinch, chaf- 
finch, starling, and rook; the blackeap is injurious, 
but not plentiful; the jay is held to be neutral; 
and the remaining sixteen are beneficial, most of 
them meriting protection, especially the owls, the 
wren, and the plover. It must be borne in mind, 
however, that these are average verdicts, and Mr. 
Collinge would doubtless agree that they require 
modification for different parts of the country. The 
book does not deal at all with fish-eating birds, in 
regard to some of which there is a warm difference 
of opinion—to be settled by gathering more facts 
