140 THE OSTEOLOGY AND MYOLOGY 



this event, in spite of their important teleological relations to the fore limb, they would not 

 form, morphologically speaking, an integral part of the muscles of that member. 



Be this as it may, it is certain that there are no muscles in the hind extremity to corres- 

 pond to these of the fore. Admitting some principle of antero-posterior symmetry, of 

 however extended or restricted application, this very fact, so far from invalidating such 

 an admission, rather confirms a belief in the theory. If the scapular arch were firmly 

 bound in its proper morphological position, as it is in most of the class of fishes, and as the 

 pelvic is in the present instance, it is a fair logical induction that these muscles would be 

 greatly reduced in number if they were not to wholly disappear. In view of these consid- 

 erations it would seem unreasonable to expect, conformably to any law of antero-posterior 

 symmetry, that the scapular muscles should be repeated in the pelvis. 



We may allude, in this connection, to a theory that supposes the morphological repre- 

 sentation of the scapular muscles in the pelvico-vertebral ligaments. Independently of 

 what has just been adduced, what is known regarding the transmutation of contractile 

 muscular, and inelastic fibrous, tissues, is sufficient to hold this presumption in abeyance. 



The pelvic arch, unlike the scapular, is immoveably attached to vertebrae, in what is not 

 known to be other than its true morphological situation. Its mode of union with the spine 

 may practically be considered the same as that by which most other haemal arches — notably 

 the costal — are joined. Of the several trunk muscles going to or from the pelvis, only one 

 gives intimation that it is a muscle of the posterior extremity, properly speaking, and this 

 intimation is by no means satisfactory. The caudal muscles arising on or in the pelvis are 

 palpably part and parcel of the vertebral series. The abdominal muscles likewise are as 

 evidently of the nature of the intercostal series, and only incidentally, as it were, attached 

 to the pelvis. The exception just alluded to is the psoas parvus, which has definite inser- 

 tion into the horizontal ramus of the pubis. This muscle I do not attempt to homologize ; 

 nor, so fiir as I know, has its homology been made out. Its scapular homologue is want- 

 ing ; did it exist it would naturally be looked for in somewhat the position of the subcla- 

 vius. It is questionably a proper muscle of the hind limb. 



Proceeding now from the hsemal arches themselves to the proximal segment of their 

 " diverging appendages," we straightway meet with farther difficulty. Six muscles, col- 

 lectively known as the " rotatores femoris," are found about the hip, proceeding from the 

 pelvis to the thigh, that have no scapulo-humeral homologues, so far as known. They are 

 the quadratus, pyriformis, two obturatores, and two gemelli ; the last two of which, how- 

 ever, are rather accessories of the obturator internns than distinct muscles, leaving really 

 only four. Of these, one is what Wilder would probably call a " long " muscle, as it ex- 

 tends beyond the ilium to the vertebral column. These muscles appear to be developed, 

 teleologically, to meet a special indication, which in the shoulder is fulfilled by the mode 

 of insertion of muscles homologous with the pelvic glutnei. I do not venture to surmise 

 what may be the true morphological import and relations of these rotatores, nor to suggest 

 that they may be glutasal dismemberments, although some features of at least one of them, 

 the quadratus, might be adduced in favor of such view. The obturatores scarcely afford 

 me basis for conjecture. 



The latissimus has thus far resisted all attempts that have been made to bring it satisfac- 

 torily into line. It is the ''long" direct flexor of the humerus. The femur has no such 

 muscle, unless it is found in the psoas magnus ; and to this view of the case there are 



