60 Prof. A. Macalister on the Myology 



inner condyle to tlie metacai-pal bone of the first finger, and to 

 the trapezium bone at its base. In the Orycterope Mr. Galton 

 mentions that it arises from the external condyle (a misprint, 

 I suppose, for internal)^ and that it is inserted into a sesamoid 

 bone and into the styloid process of the radius : these peculia- 

 rities of insertion were described by Prof. Humphry. In the 

 Armadillo it is inserted into the outer of the bones of the se- 

 cond row of tlie carpus (trapezio-trapezoid of Mr. Galton). 



Palmaris longus is larger than the last, and has a corre- 

 sponding origin ; its insertion is into the palmar fascia, and 

 into the pisiform and unciform bones. It is quite separate 

 from the flexor sublimis digitorum, although in Dcisypus they 

 are closely connected — an arrangement described by Theile as 

 an anomaly in human anatomy, and noticed (Proc. Royal Irish 

 Acad. Dec. 9, 1867) as the thirteenth variety of the palmaris 

 by myself. In the Orycterope the same fusion of palmaris 

 and superficial flexor occurs (Humphry). Rapp describes it as 

 absent in M. tamandua ; but the '' Spannmuskel" recorded by 

 him is in reality only a variety of it displaced in its origin. 

 In \he, Myrmecojjhaga didactyla Meckel described the palmaris 

 as united to the flexor carpi ulnaris — a condition which I have 

 also found as an anomaly in human anatomy (variety 15 in 

 the paper above mentioned). 



Flexor carpi ulnaris arises by two heads, from the internal 

 condyle and from the olecranon process — its two origins being 

 separated by the ulnar nerve, and overlying the anconeus in- 

 ternus ; its insertion is into the pisiform and unciform bones, 

 annular ligament, and base of third metacarpal bone. It has 

 no condyloid head in the*Armadillo and Orycterope (Galton), 

 but has two portions in the latter, deep and superficial, but 

 both ulnar in origin. It is very complex in M. didactyla 

 (Meckel), being quadrifid, three being true ulnar flexors and one 

 palmaris lono-us : the three former may represent the condyloid 

 head of the Ai, and the two ulnar origins in the Orycterope ; 

 and this "\\'Ould give us a clue to its complexity of arrangement. 



In the Ai, in consequence of the singular method of j^rogres- 

 sion and mode of life of the creature, the digits are closely 

 flexed, with the prominent hooked nails incurved to the palms j 

 and while the flexor muscle of the digits is undivided, it is 

 impossible, without tearing, to extend these even to a right 

 angle with the palm. These tendons are bound down at the 

 wrist by an enormously strong annular ligament, which passes 

 from the scaphoid and trapezium bones to the unciform, pisi- 

 form, and third metacarpal bones. Each flexor tendon has a 

 special fibrous and synovial sheath, underneath which it tra- 

 vels. The palmar fascia is in reality a continuation of this 



