ANIMAL MECHANICS. 89 



Table XVII. — Cross Sections of Tendons in Pyrenean Mastiff . 



Tendon. 



Length used. 



Weight of do. 



Cross Section. 



1. Gastrocnemius, . . • 



2. Fl. carp, rad., .... 

 i Fl die*, lone* (rjedis\ 



4. Ext. carp, rad., . . . 



5. Fl. carp, uln., .... 



6. Fl. hall, long., .... 



7. Biceps humeri (scapular \ 



8. Fl. dig. subl., .... 



9. Fl. dig. prof., .... 

 10. Ext. carp, uln., . . . 



2 inches. 

 5 



5 



3 » 



3 „ 

 2 



4 „ 

 2 ,, 

 if „ 

 2 ,, 



30.27 grs. 

 8.6 „ 

 65 „ 



14.0 

 4-9 „ 



13-3 



19.6 ,, 

 14.6 ,, 

 36.2 „ 

 »«-5 >i 



0.0520 sq. in. 

 0.0059 „ 

 0.0045 „ 

 0.0160 ,, 

 0.0056 „ 

 0.0228 



0.0449 ,, 



0.0251 

 0.0830 „ 

 0.0197 „ 



From the preceding Tables we may easily construct the fol- 

 lowing : — 



TABLE XVIII. — Ratio of Cross Section of Muscle to that of Ten- 

 don in Mastiff. 



Muscle. 



Ratio of Cross Sections. 



I. 





50.6 



2. 





48.0 



3- 





43-3 



4- 



Extensor carpi radialis (long, et brev.), . . . 



39-5 



5- 



Flexor carpi ulnaris (olecranalisj, .... 



3'-4 



6. 





29.8 



7- 





20.2 



8. 





12.7 



9- 





10 9 



10. 





9.2 



If we suppose, as we have already done in the case of 

 human muscles, that the strength of the tendon is intended 

 to be divided between the pull exerted upon it by the muscle 

 and the strain caused by external forces ; and also suppose 

 that 50.6* represents in the mastiff the proportion of cross 



* This coefficient is taken from the gastrocnemius muscle, and exceeds that 

 taken from, the radial tendon of the biceps humeri in man ; this difference is, no 



