The common frog . position is that of supination,and the bones of the fore-arm are situate side by side. When the arm and hand hang down, but theback of the hand is turned forwards, the positionis that of pronation, and the radius crosses overthe ulna. When we rest on the hands and knees,with the palms to the ground, the fore-arms are inpronation. Muscles which tend to place the fore-arm and handin the position of pronation are termed pronators ;those which, by their contraction, tend to render itsupine are called supinators. It is somewhat surprising to find in an animal sonearly related to f
The common frog . position is that of supination,and the bones of the fore-arm are situate side by side. When the arm and hand hang down, but theback of the hand is turned forwards, the positionis that of pronation, and the radius crosses overthe ulna. When we rest on the hands and knees,with the palms to the ground, the fore-arms are inpronation. Muscles which tend to place the fore-arm and handin the position of pronation are termed pronators ;those which, by their contraction, tend to render itsupine are called supinators. It is somewhat surprising to find in an animal sonearly related to fishes ,as Menobranchns definiteflexors, extensors, pro- and supi-nators essentiallylike those of higher animals ; and these distinctionsonce established, persist up to man himself withincreasing complications. VII.] THE COMMON FROG. lO! The muscular conformity between the highest andlowest of typically-limbed vertebrates is strikingly-^shown by the structure of the thigh and le^, the Grsn:. ^-V-Ji^-xr:^;, ^V ? —Muscles of Ventral Surface of Menobranchus. On the right side, super-ficial muscles; on the left side, deeper muscles, the niylo-hyoidei, pectoralis, andexternal oblique being removed. Also superficial flexor muscles of right pectorallimb of Menobra7ichiis. B, biceps; CB^ and CB^, coraco-brachialis • CHEcerato-hyoideus externus ; EO, external oblique ; FE, flexor longus ; GH eenio-hyoid ; MH- and MH-^, mylo-hyoideus ; OH, omo-hyoid ; P, P^ and A pec-toralis ; R, rectus; 6, subclavius; SH, sterno-hyoid ; SE, supinator lonsus-1, triceps. ** io6 THE COMMON FROG. [chap. leading muscles of these parts in the frog being so\ like those of man that the practice of calling them bythe same name is abundantly justified. The perfection of mans hand has been justly thetheme of panegyric, esteemed as widely as it is delicacy and multiplicity of the motions of whichit is capable are of course greatly due to the numberand arrangement of the muscles with which it i
Size: 1258px × 1986px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, bookpublisherlondo, bookyear1874
