474 THE ZOOLOGIST. 
animal beats the air during its spring, 7.e., that it alternately 
opens and closes its pectoral fins.” 
* * * * * * * 
I will now pass to my own observations on the flight of 
Flying-fish, made during a voyage from San Francisco to Yoko- 
hama, on the steamer ‘City of Peking,’ reserving till the last 
the consideration of the recent elaborate paper of Professor Carl 
Mobius.t 
Of the nearly twenty-three days that elapsed between depar- 
ture and arrival (1st to 24th August, 1879), at least ten were 
favourable for the study of the question under consideration. 
Aware that these fish are now generally regarded as skimmers 
rather than flyers, notwithstanding the testimony of very trust- 
worthy observers to the contrary, I determined to satisfy myself, 
if possible, on this one important point. 
I found the most favourable place for observation to be the 
bow of the steamer, and the best hours to be in the morning 
from five till eight or nine o’clock, and in the afternoon between 
three and six o’clock. Observations made when the air was quiet 
and the sea } perfectly smooth, so that the fish could often be seen 
before they left the water, were the most satisfactory and 
conclusive. A stiff breeze, a billowy sea, a tossing ship, and an 
easy chair are not conditions which facilitate accurate observa- 
tion, and to such conditions, doubtless, is to be attributed the 
itl-suecess of many who have undertaken to decide this question. 
* * * % * * Ed 
Under the favourable conditions just mentioned, it is by no 
means difficult to determine whether the fish executes any flap- 
ping movements with its pectoral fins. As I have seen them 
come out of the water directly under my eyes, I have been able 
to see distinctly the individual flaps of the large pectorals, while 
the ventrals were held in quiet expansion. The flapping move- 
ment, which is quite regular and rapid—so rapid that it is not 
easily recognised at any great distance until experience has 
sharpened the eye—may be continued for the whole or a part of 
the flight ; but is generally discontinued after the first few rods, 
and the course completed by a pure skimming or sailing move- 
ment. In some cases I have seen the flapping of the fins renewed 
* «Die Bewegungen der flicgenden Fische durch die Luft” (Zeitschrift fiir Wis- 
senschaftliche Zoologie, Supplement to vol. xxx., p. 343, 1878). 
