88 



ANIMAL MECHANICS. 



tigate the relation between the cross sections of her muscles 

 and their respective tendons, with the following results : — 



A portion of the gastrocnemius muscle, two inches in 

 length, weighed in air, 1382 grs., and in water, 53.7 grs., 

 giving a specific gravity of 1.040. 



A portion of the tendon of the same muscle was found to 

 weigh in air, 21.25 grs., and in water, 2.80 grs, giving a 

 specific gravity of 1.152. 



From these data, the following cross sections of muscles 

 and tendons were readily calculated. 



Table XVI. — Cross Sections of Muscles in Pyrenean Mastiff. 



Muscle. 



Weight of 

 Muscle. 



Length of 

 Muscle used. 



Weight of 

 Muscle used. 



Cross Sections. 





Gastrocnemius, . . 



6.22 ok. av. 



2 inches. 



1382.0 grs. 



2.631 sq. in. 



2. 



Fl. carp, rad., . . . 



o-35 » 



1 „ 



74-3 » 



0.283 „ 



3- 



Fl. dig. long, (pedis), 



0.28 „ 



1 „ 



5 1 3 » 



°-'95 „ 



4- 



Ext. carp, rad., . . 



1.40 „ 



2 „ 



332-o » 



0 632 ,, 



5- 



Fl. carp, uln.,* . . 

 Fl. hall, long., . . 



o-38 „ 



2 ,, 



92-5 ,1 



0.176 „ 



6. 



i-59 » 



2 ,, 



357-5 » 



0.680 „ 



7- 



Biceps humeri, . . 



2. 1 1 „ 



2 ,, 



477-3 » 



0.909 ,, 



8 



Fl. dig. subl., . . . 



1.06 „ 



2 ,, 



167.6 ,, 



0.319 » 



9- 



Fl. dig. prof., . . . 



2-75 „ 



i* „ 



355 3 j > 



0 902 ,, 



10. 



Ext. carp, uln., . . 



o.47 „ 



2 



95-3 »» 



0.181 „ 



The cross sections of the corresponding tendons were found 

 to be — 



* The flexor carpi ulnaris consists of two muscles, of which one takes its 

 origin from the front of the inner condyle of the humerus, and the other from 

 the olecranon of the ulna. 



