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semimembranosus in the rhea and emu (Haughton, "Proceedings of 

 the Royal Irish Academy," 1866, p. 95), showing that this is a separate 

 element ; thirdly, in the Marsupials the biceps cubiti flexor is divided 

 completely ,and the coracoidean head is always radial in its insertion; 

 similarly in the crocodile, the only head of the biceps is a coracoid one, 

 and its insertion is as usual radial, and in Echidna the insertion is 

 radial and ulnar, as in the pig. These different reasons lead us to 

 believe that the short head of the arm biceps is the representative of 

 the long head of the biceps flexor cruris ; besides, in the cases noted in 

 my former paper, in which the biceps cubiti could be severed into two 

 parts, the coracoid portion was always prolonged into the radial tendon. 

 "We thus have to homologate the semimembranosus and semitendinosus 

 with the glenoidal head of the biceps and the brachialis anticus ; and 

 here we find some difficulties to be explained, which can best be done by 

 the hypothesis, that the type represented by the long head of the biceps 

 humeri in the upper limb corresponds to the tendon of origin of the 

 semimembranosus, and to the insertion of the semitendinosus. This may 

 seem fanciful, but it is indicated by three circumstances — firstly, the 

 origin of the semimembranosus is tendinous and elongate, like the long 

 head of the biceps ; it is also the nearest to the articulation of any of 

 these hamstrings, and the most external ; secondly, the insertion of the 

 semitendinosus and that of the biceps in part resemble each other in 

 being often fascial, and in being truly ulnar in many cases, especially 

 where there is but a single glenoidal origin for the muscle. Thus the gui- 

 nea-pig, porcupine, bearer, rabbit, and agouti, have only an ulnar inser- 

 tion; thirdly, that in the semitendinosus we always find a tendinous 

 intersection, the cicatrix of the union of the two segments, to which 

 my attention was directed by Dr. Bennett, but which is well known by 

 practical anatomists. The presence of this band of tendon is inexplicable 

 upon any other hypothesis, and this supplies all the conditions necessary 

 for its production. "We have no sign of the second junction, viz., the 

 union of the two other parts of the dissevered muscles in the semimem- 

 branosus, for that corresponds to the junction of the tendon with the 

 fleshy portion of the muscles. In my former paper I stated my belief 

 that the short head of the biceps represented the semimembranosus, 

 but that view I withdraw, and deem inadmissible ; and the glenoidal 

 portion of the tendon of this type we have represented in the lower 

 limb by the ligamentum teres coxae. The last element of the flexor 

 group, the belly of the semimembranosus, to which we should superadd 

 the origin of semitendinosus, has its representative in the brachialis 

 anticus, which is known by its close relationship to the adductor mass 

 (coraco-brachialis), by its coracoid (tibial insertion), and its being 

 placed usually on a plane internal to and deeper than the other ham- 

 strings or flexors. 



The muscles clothing the second series of bones of the typical limb 

 we find arranged in three groups : those specially devoted to the move- 

 ments of the individual bones, the one upon the other, constituting the 



