VOL. VI.] REVIEWS. 135 



To this Mr. Bolam adds a footnote to the effect that since 

 the above was written his attention has been called to Mr. 

 Frohawk's remarks {Brit. Birds, Vol. III., p. .385), and the 

 controversy on the subject, but he is confident that these 

 are not young birds in their first plumage. That the 

 Cormorant does breed in this stage of plumage has been 

 proved already (c/. op. ciL, Vol. IV., p. 25). 



In conclusion, we must repeat that Mr. Bolam's book 

 deserves a lasting popularity among ornithologists, if only 

 by reason of its author's most excellent personal observations. 



H.F.W. 



Fra Fuglemaerkestationen i Viborg. By H. Chr. C. Mortensen, 

 with nine text -figures and an English summary : Reprint 

 from Dansk Ornifhologisk Forenings Tiddskrift, 1912, 

 pp. 98-127. 



This interesting paper on bird-marking opens with, a few 

 general historical remarks, beginning with the marking of 

 the young of tame White-fronted Geese by V. der Heyden 

 Baak early last century, and coming do^Mi to the various 

 inquiries of the present day. Mr. Mortensen's inquiry is 

 the oldest of those run on scientific lines : he started in 1890, 

 but his present methods date from some years later. He 

 was the first to mark great numbers of birds of different 

 kinds, and the first to use separate identification numbers 

 on his rings in place of mere date-marks. We note, however, 

 that he uses a separate series of numbers for each well-known 

 species ; this we regard as a pity. If one uses a single series 

 for all species (and all sizes of ring), one is not dependent on 

 learning the species of a reported bird (or even the size of 

 the ring) ; while if one does learn it, it serves as a valuable 

 check on the accuracy of the reported number. But Mr. 

 Mortensen uses certain checks not generally employed : he 

 notes on which foot the ring was placed, and whether with 

 inscription erect or inverted. Sometimes, also, in the case 

 of young Starlings, he has supplemented the ring by a notch 

 in the tail, or by cutting off a claw (with the end of a phalanx). 

 A considerable section is devoted to patterns of rings and 

 to ring-inscriptions : Mr. Mortensen has sometimes placed a 

 ring on each foot of a small bird to get a larger inscription, 

 and he condemns numbering on the inner surface as being 

 very Iial)le to wear away. He goes on to give a very decisive 

 negative answer to the question as to Avhether rings may 



