the Flying-jUli Prohlcm. 



XM 



same as in other bony fislics (the cotl, for instance;). Tiic 

 nuinljcrs ou the siu-race ot" the litis arc tlie points where I took 

 the thickness of the luusclc by plunging a needle into it and 



in ofepoi/i. 



Shoulder airdU 



measuring the depth to which the needle entered, 

 notice the great length of the muscles in Exocoetus 



You ^vill 

 a longr 



muscle means a proportionate length of contraction. 



" there is a very marked difference in the size of 



the muscles of these two fishes 



." Believe me, yours faithfully, 



R. H. BURNE 



{Assistatit in Museum)." 



The above tracing seems to give, roughly, about 4i times 

 greater bulk of muscle to the Exocoetus than to the Hemi- 

 ramphus. With this light it will not be out of place to 

 requote and amplify the one '' proof,^' distinguishing the 

 addition by italics : — " The pectoral muscles of birds 



Ann. S Mag. N. Hist. Ser. 7. Vol. xviii. 25 



