602 MURRE--MUSCULAR SYSTEM 
Ploceid (W EAVER-BIRD), which are distinguished for their familiarity 
with man, their gregarious habits, their depredations on the rice- 
crops, and their ingenious Nxsts, 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 direction 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 punctum fixum: the intermediate portion 
is the “ Belly” or “ Body.” 
In Birds, as in other Vertebrates, there are two fundamentally 
different 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 cutaneous 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 degree intermediate between 
those two kinds. 
The nomenclature of Muscles has always been difficult. Names 
like Musculus deltoides or M. gracilis afford 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. 
