46 THE GOLDFISH AND ITS CULTURE. 
carpenter lays shingles on a roof, being disposed in such a way 
that the friction incident upon the movement of the fish in the 
water is reduced to the smallest proportion. As the fish grows 
older and larger the scales increase in size. 
Near the middle of the body and running along each side of the 
fish, there is a line or row of scales that possess peculiarities distin- 
guishing them from other scales. 
These scales are pierced with a tubular aperture, and the tubes of 
which they are the exit are quite distinct, and form the so-called 
‘lateral line.” Through these 
tubes a slimy substance or mu. 
cous is exuded, which covers the 
entire body, seemingly for the 
\ purpose of making the fish water- 
J proof and of further reducing the 
friction in the water. These 
tubes always point from the ma- 
SCALE FROM LATERAL LINE. (Enlarged.) trix, or root of the scale, towards 
the tail of the fish. It is scales of this description that naturalists 
refer to when seeking to learn the species to which the fish belongs, 
because the peculiarities of their structure differ in them. (See 
illustration. ) 
The next thing most noticeable are the jims, these being named 
according to their location upon the body of the fish and subserve 
various purposes. The fectoral fins (fig. a.) are those situated in the 
place corresponding with the fore-legs of animals, the ventral fins 
(fig. b.) being placed where the hind-legs of animals are found. 
The dorsal fin (fig. c.) is that one found upon the back of the fish. 
That fin situated behind the anus receives its name from that part, 
and is known as the anal fin (fig d.), while the tail of a fish is prop- 
etly called the caudal fin, (fig. e.) 
