•336 Lieut.-Oul. C. D. Diiinfoid on 



like motion of the fin-wings may be easily observed as the 

 large flying-fishes break water almost under the vessel's bow. 

 This flapping motion of the fin-wings is not, however, long 

 maintained, but as soon as the fish is well started in the air 

 apparently passes into a vibratory motion of the appendages 

 so rapid as to be almost beyond human visual perception." 



Quite so. That is the to-be-expected flight of an cx- 

 ce])tionally low-ratio flyer having special added natural 

 disabilities. Before long it will be the accepted one for 

 flying-fish. 



More about the Pectoral Muscles. 



Since writing the foregoing I have received a communi- 

 cation from Prof. C. Stewart, F.R.S., Conservator of the 

 ^fuseum of the Royal College of Surgeons, who kindly 

 gives me permission to use the results of a dissection made 

 at the ]Museum for ihe purpose of compariug the pectoral 

 muscles of the flying-fish with those of a nearly related non- 

 flying fish. 



I quote from the letter of Mr. Burnc, who made the 

 dissection : — 



" Royal College of Surg-eons of England, 



Lincoln's Inn Fields, 



London, W.C, I'^th June, 1900. 



"Dear Sir, — I have made a dissection of the 



pectoral muscles of a flying-fish {Exoco^tus sp.) and of a 

 nearly related fish of much the same build, but without the 

 enlarged pectoral fins {Hemiramphus). Both were speci- 

 mens from our store-room, and although in pretty good 

 condition had evidently been in spirit for a considerable 

 time. I enclose you tracings of the drawings I made. The 

 two of the external view were drawn with a camera, and the 

 Hemiramphus, which was rather less in girth than the 

 Exoccctus, was so much enlarged as to have the same girth 

 about an inch behind the pectorals. I thought that body- 

 srirth sufficiently far behind the fins not to be influenced bv 

 their degree of development was the best standard of size to 

 take — better than length, for instance. As a matter of fact, 

 the fish were very much the same length, the Exoccetus being 

 rather the longer. 



"The drawings,! think, explain themselves. The flying-fish 

 muscles were, as you see, considerably larger, both in area and 

 in thickness, th&nm Hcniira/up/ius, and the same was the case 

 with the muscles on the deep surface of the fin. In their 

 arrangement they were much the same in both fish and the 



