THE MUSCLES OP THE FORE-LIMB 39 



of the elbow-joint (Figs. 16 and 17). In an Oriental 

 Pygmy Shrew (Crocidura bottigi), again, the muscle is in 



FIG. 17. THE PRONATOR QUADRATUS AND INSERTION OF 

 PRONATOR RADII TERES IN Tupaia ferruginea. 



its bicipital form (Fig. 18). In all the Metatherian 

 Mammals the only origin of the M. pronator radii teres 

 is from the humerus, the nlnar head being absent. In 



FIG. 18. THE PRONATOR RADII TERES AND PRONATOR 

 QUADRATUS IN A CROCIDURINE SHREW. 



the lowly Monotremes the human deep head has been 

 asserted to be present, but it cannot be regarded as a 

 normal component of the muscle.* Among the Reptilia 



* At the time of delivering the' lecture I relied upon the latest 

 paper published upon the subject that by Gordon Taylor and 

 Victor Bonney (Jour. Anat. and Phys., vol. 40, p. 34) which 

 definitely asserted the presence of the ulnar head in Ornithorhyn- 

 chus and in Echidna. Since that time I have dissected the fore- 

 limbs of two examples of Ornithorhynchus and one Echidna 

 (kindly placed at my disposal by Dr. W. C. McKenzie), and 

 I find no trace of an ulnar head in any of these specimens, the 

 condition agreeing with that described by Rud. Kloster (" Anato- 

 mische Hefte," 1901, p. 671). 



