430 MUSCLES. 



The tendons of the last two muscles are much connected with 

 each other, and are spread in the form of a membrane on the 

 back of the thumb, after the manner of the extensor tendons of 

 the fingers. 



10. The Indicator, 



Is a small muscle on the back of the ulna, concealed by the 

 extensor communis and extensor ulnaris. It arises, tendinous 

 and fleshy, from the back of the ulna, commencing near its mid- 

 dle, and from the contiguous part of the interosseous ligament. 

 It terminates in a tendon which goes through the same fossa 

 with the extensor communis; it afterwards is joined about the 

 head of the first phalanx to the tendon of the common extensor 

 belonging to the fore finger. 



With the tendon of the extensor communis, it is inserted along 

 the back of the fore finger as far as the base of the third phalanx. 



It extends the fore finger.* 



SECT. V. OF THE MUSCLES OF THE HAND. 



The Palmaris Brevis, 



Is just below the skin, at the inner side of the palm of the 

 hand. It consists of separate fasciculi unequally divided, and 

 arises from the anterior ligament of the wrist, and from the ul- 

 nar side of the palmar aponeurosis. 



It is inserted into the skin and fat at the inner margin of the 

 hand, and covers the muscles of the little finger. 



It contracts the skin of the hand. 



* Varieties. This muscle is subject to many modifications? sometimes it is di- 

 gastric; sometimes it is double, and the second head goes to the middle finger. In 

 the latter case, anatomists have recognised a disposition similar to that of the short 

 extensors of the toes, and also an arrangement corresponding with what occurs in 

 some species of the ape. As a general rule, it is admitted that the most of those 

 varieties in the muscular system, commonly called anomalies, are only indications 

 on the part of nature of the alliance between the structure of man, and that of the 

 lower orders of animals. In this point of view, they are both instructive and 

 amusing, and are well deserving of attention. 



