20 NORWEGIAN JER-FALCON 
and beneath the tail, in the adult. While young it resembles the young 
of the Greenland and Iceland Falcons, but is smaller. — Degland. 
Measurement. Male — From tip of beak to end of tail twenty inches, (Paris.) 
Expanse of wings twelve inches and a half to thirteen inches and a quarter. 
Tail seven inches two lines to seven inches eight lines. Middle toe, without 
claw, one inch ten lines. Tarsus two inches three lines. Female — About 
one tenth larger. — Schlegel. 
The bird with which. I commence my description of the important 
and interesting family of Falconidce, has been the subject of much 
controversy among ornithologists. Some authors maintain there is only 
one genuine species of Jer-Falcon. Others, and I may say the greater 
number of the naturalists of the present day, admit there are two — 
while the opinion has been rapidly gaining ground of late years, that 
there are no less than three. 
The subject is one of considerable interest in Natural History, and 
although it forms no part of the plan of this work to enter into 
controversial discussions, it is no less the duty of him who conducts 
it, to lay before his readers a brief statement of the case as it now 
stands, and the reasons which have induced him to include the bird 
at the head of this description, among those which are observed in 
Europe; and as therefore distinct from the other two species which 
have occurred in England. Nay, I believe, strictly speaking, the 
Jer-Falcon now under discussion has been killed in England; but as 
the authors of our British works have only described and figured one 
bird under the general name of F. Islandicus, I have thought it 
better to give a figure of the F. Gyr-falco of Schlegel, and to state 
the reasons of that eminent naturalist for claiming specific distinction 
for this bird. 
When Gould published his work on the "Birds of Europe," in 
1837, he alluded to the statements made by Falconers who bring over 
trained Falcons for sale to this country, that there was a decided 
difference between the Norwegian and Iceland birds, and he asks the 
question — are there two species? Temminck had previously described 
one species only, F. Islandicus, and had given Falco Islandicus Can- 
dicans of Latham, Gmelin, and Meyer, as the female; while he con- 
founded Falco Saccr, the bird next to be described, with the Falco 
Gyr-fcdco of authors, which he considered the young of F. Islandicus. 
A year after Mr. Gould's work appeared, Mr. Hancock sent a 
memoir to the "Annals and Magazine of Natural History," in which 
he described two Jer-Falcons as existing among the English specimens, 
under the name of F. Islandicus ; and to these birds he gave the 
