294 Royal Society : — 



the Rhynchophora manifested by the transfer of a function 

 from the posterior to the anterior part of the body, and the 

 linear extension of the latter, in accordance with this " change 

 of base.^^ 



The principles of classification of Rhynchophora, and their 

 division into families, will be discussed in a subsequent memoir. 

 It is, however, proper to observe that the peculiar construction 

 of prothorax above described as characteristic of the Rhyncho- 

 phora is not exhibited in the Bruchidae, which family, as ob- 

 served by Lacordaire (Gen. Col. vii. 600) should be viewed as 

 closely related to, if not actually a portion of, the great family 

 Chrysomelidae. 



PROCEEDINGS OF LEARNED SOCIETIES. 



ROYAL SOCIETY. 



June 20, 1867. — Lieut.- General Sabine, President, in the Chair, 



" On some Elementary Principles in Animal Mechanics." By 

 the Rev. Samuel Haughton, M.D., Fellow of Trinity College, 

 DubUn. 



There are some elementary principles in animal mechanics 

 which are so natural that they may be assumed as probable, and 

 as such, have not received from observers the attention they really 

 deserve. 



Among these principles I select for illustration the two follow- 

 ing:— 



i. The force of a muscle is proportional to tlie area of its cross 

 section. 



ii. Tlie force of a muscle is proportional to tTie cross section of 

 the tendon that conveys its influence to a distant point. 



i. In order to test the first of these statements, I made a careful 

 examination of the cross sections of the muscles that bend the fore- 

 arm and leg, in a very finely developed male subject, with the 

 following results : — 



Neglecting the slight efiect of the supinator radii longus in 

 flexing the forearm, I found the cross sections of the biceps 

 humeri and brachiaus to be as follows : — 



Cross section. 



1. Biceps humeri 1*914 sq. in. 



2. BrachicBus 1'276 „ 



3190 



The cross sections of the muscles that bend the leg were found 

 to be in the same subject : — 



