42 4 Recent Literature. Auk 
migration flight of a flock of birds from their breeding grounds in the 
northeast to their winter quarters in the southwest ot Europe is thus 
acutely summarized : ‘‘ Let us suppose that we are dealing with one of the 
‘many hundreds’ which pass Heligoland on their journeys from ‘far 
eastern Asia.’ It is dusk—and the time for departure has arrived. 
Without more flocking together than has accidentally taken place during 
feeding time, all the residents in a particular area set out from their 
breeding grounds on a journey of two thousand miles or more. No 
food has been taken for some hours, and the winds being unfavourable 
near the surface of the earth, all rise toa height of at least 20,000 feet, 
whence guided by some unknown power, and at a speed of 150 to 200 miles 
an hour, they set out on their rushing and undeviating flight to the west 
of Europe. Here, however, the direction of the latter must be altered and 
a turn to the south executed in mid-air, which carries them, after a 
further flight, to the neighborhood of Heligoland, where again a second 
turn is accomplished and the remainder of the journey is performed in 
the old undeviating westerly direction, until dawn finds them at their 
goal on the shores of England; neither tired nor hungry after their great 
exertions.” This is a fair statement of Herr Gatke’s theories on this 
subject, and needs no comment to render their absurdity apparent to any 
thoughtful ornithologist. 
‘¢In estimating the value of his [Herr G&atke’s] theories,” says Mr. 
Whitlock (p. vi), “it must not be forgotten that they are based on obser- 
vations conducted in a very limited and somewhat exceptionally situated 
area; outside this area his personal experience seems to have been very 
small.” (Cf Auk, XIII, 1896, p. 138, 139). Add to this his lack of scien- 
tific training, his evident but doubtless unconscious tendency to exagger- 
ation, and an imaginative turn of mind, and we need not seek further for 
an explanation of the overdrawn statements and ridiculous speculations 
found in ‘ Heligoland.’ 
Mr. Whitlock has done good service to ornithology in publishing his, 
on the whole, temperate, and well-considered critique of a work that is 
both a valuable and an unfortunate contribution to ornithology, as the 
exaggerations and wild speculations it contains are the parts seized upon 
with greatest avidity by the thoughtless compiler for introduction broad- 
cast into the popular literature of ornithology. It need hardly be said, 
in conclusion, that Mr. Whitlock’s book will not prove very agreeable 
reading matter to the many who have idealized and idolized the author of 
‘Heligoland.’ —J. A. A. 
Suchetet on Hybrids among Wild Birds.!—In a thick octavo volume 
of 1154 pages Mr. Suchetet has brought together all the facts he has been 
1 Des | Hybrides | a | l'état sauvage | — | Regne Animal | —| Tome Pre- 
mier | Classe des Oiseaux | Par | André Suchetet.|.... [Motto] | — | 
Paris | Libraire J.—B. Bailliere et Fils | 19, Rue Hautefeuille, 19 | 1897 — 
Large 8vo, pp. clii--1002. ( Price, 28 fr. ) 
