6o2 



MURRE— MUSCULAR SYSTEM 



Ploceidse (Weaver-bird), which are distinguished for their familiarity 

 with man, their gregarious habits, their depredations on the rice- 

 crops, and their ingenious Nests, to quote Mr. Hodgson (Asiat. 

 Researches, xix. p. 155), who not only Anglified the word but 

 Latinized it, making it the title of a genus to which he assigned three 

 species, while Dr. Sharpe in 1890 (Cat. B. Br. Mus. xiii. p. 326) 

 referred to it no fewer than twenty-six. Many of them are among 

 the commonest of exotic cage-birds. 



MURRE, a name applied by fishermen indifferently to Guille- 

 mot and Razor-bill. 



MUSCULAR SYSTEM. Muscles constitute what is generally 

 called "flesh," and are composed of fibres, each of which is an 

 elongated cell of contractile tissue surrounded by a thin sheath of 

 connective tissue, the whole being held together by an outer sheath 

 of connective, and frequently elastic, tendinous tissue. The fibres 

 are arranged with their long axes in the dkection of the action or 

 pull of the muscle, and each is intimately connected with a nerve- 

 cell, stimulation of which causes contraction, and consequently 

 draws together the parts to which the whole muscle is attached. 

 In the Muscles of the Skeleton the attachment nearest to the axis 

 of the body is called the "Head" or "origin"; the attachment 

 furthest from the same is the " Tail " or " insertion " — no matter 

 which extremity is the pundum jixum : the intermediate portion 

 is the "Belly" or "Body." 



In Birds, as in other Vertebrates, there are two fundamentally 

 difterent kinds of Muscles : — 



1. Involuntary or unstriped Muscles, which are generally of slow 

 or rhythmical action, such as all those of the viscera, and the 

 true cvitaneous Muscles, such as those attached to the root of the 

 feathers. 



2. Voluntary or striped Muscles, in which each fibre under a 

 microscope seems to consist of a great number of alternate dark 

 and light disks, which cause a transverse striation. 



The Muscle of the Heart is in some degi^ee intermediate between 

 those two kinds. 



The nomenclature of Muscles has always been difficult. Names 

 like Musciilus deltoides or M. gracilis aflbrd no information, and the 

 physiological method of naming a muscle from its function permits 

 only a limited application. The most preferable way is to use a 

 compound word, of which the first portion should indicate the 

 origin, and the second the insertion, further distinction, when 

 needed, being secured by an additional adjective — as M. ilio-tibialis 

 internus. Where the old names of human anatomy can be used 

 without mistaken homology, they may be well applied to Birds, as 

 with M. latissimus dorsi or M. biceps, even though the words M. 



