366 ME. J. BESWICK PEEEm ON THE 



as already mentioned, a tendon from the soleus series. The tendons are distributed 

 respectively to the bases of the distal phalanges of the 1st, 2nd, 3rd, and 4th digits 

 (that to the 3rd digit being the largest). The tendon to the 1st digit presents a remark- 

 able arrangement. It passes through a cleft between the 1st and 2nd metatarsal bones 

 to attain the flexor aspect of the hallux, grooving the trochlea of the metatarsal phalan- 

 geal articulation. On the under surface of the tendon of this muscle is a lumbrical 

 muscle which springs solely from it. It is inserted into the proximal phalanges of the 

 2nd and 3rd digits. 



Besides these muscles there are an extensor and flexor brevis hallucis, and a flexor 

 brevis and abductor minimi digiti. These muscles present no remarkable peculiarities 

 in their attachments. The same may be said of the cephalic, cervical, and abdominal 

 muscles'. 



The muscles ofbirds present considerable uniformity in disposition, more so than their 

 multitudinous difi'erences in external configuration and diverse habits would lead us to 

 infer. What tendency there is to muscle-change culminates in a great measure into a 

 difference in degree of development. In a bird that cannot fly, the muscles of the wing 

 are of an impoverished kind ; in birds which use their wings the muscle are large and 

 substantial ; and intermediate between modified and abundantly developed muscle-tissue 

 there are many shades of difference. 



However interesting muscular anatomy may be, as applied to birds only, it is of a 

 secondary character to the broader view which must be considered — namely, general 

 morphology. Every one in the habit of dissecting animals and comparing one with 

 another cannot fail to be impressed with the wonderful adhesion manifested to one type 

 or plan. There is more or less absolutely a general similarity, with minor illustrative 

 differences, the latter indicating evolution, but not by any great and untraceable strides, 

 but by an easy gradation, which seems to continue uninterruptedly irrespective of 

 function. There is one fact — and a significant fact it is — that muscles are met with in 

 birds, which are of not the slightest use, just as we meet with them in animals higher in 

 the scale. But these muscles are as important to the morphologist as the ruins of 

 ancient cities, old castles, and other time-shattered remnants of architectural design and 

 skill are to the archeologist. The former are illustrative ruins of natural structures, as 

 the latter of artificial ones. It must not be inferred that function, circumstantial con- 

 ditions and other operative agents do not play a prominent part in muscle-evolution ; 

 there can be no doubt that they do ; but these are the lesser lights which disport them- 

 selves round the adapting master power. 



In the OjJisthocomus the muscles of both upper and lower extremities are remarkably 

 well developed, especially those of the latter. 



' I am sorry that a combination of circumstances has prevented me consulting the extensive bibliography 

 which exists on Avian myology. 1 have simply described what I found, and named the muscles as nearly in 

 accordance with their analogues in the higher animals as I possibly could. 



