FISH 



2184 



FISH 



early Aryan peoples in connection with the 

 cult of the family (see ARYAN). As specifically 

 applied to the ancient religion taught by Zo- 

 roaster and still practiced by his followers in 

 India and Persia, the term is rather mislead- 

 ing. In the Zoroastrian cult, fire is employed 

 simply as a symbol of the divine being. After 

 death the soul was supposed to hover about 



its earthly abode for a period of three days, see ANTIDOTE. 



On the fourth day, Sraosha, the good spirit, 

 bore it aloft, closely beset by demons, who 

 sought to relieve him of his precious burden. 

 Fires were then lighted by the friends of the 

 deceased in order to embarrass the evil spirit. 

 See ZOROASTER. 



FIRST AID TO THE INJURED. See sub- 

 head, in article WOUNDS. For related topics, 



.ISH, a water-inhabiting (aquatic) animal, 

 the lowest in the order of vertebrates, or back- 

 boned animals. It is distinguished from the 

 higher forms of animal life in that it breathes 

 through gills and its limbs take the form of 

 fins. Although there are a vast number of 

 species of fish, now estimated at about 13,000, 

 there is more similarity among the different 

 species than there is among the various kinds 

 of most other animals. The majority of fish 

 have elongated bodies, tapering at both ends 

 to present slight resistance to the water. The 

 general form has become modified to meet the 

 requirements of surroundings, but 'not suffi- 

 ciently so to alter the general type, of which 

 the trout and salmon are good examples. 



Fish have cold, red blood and are usually 

 covered with scales growing in the skin and 

 overlapping like the plates in suits of armor 

 or shingles on a roof. The heart of a fish per- 

 forms the same functions as does the human 

 heart. By it the blood is pumped through the 

 system, first being purified by passage through 

 the gills. The backbone is loosely jointed, 

 enabling a fish to turn and twist in a manner 

 impossible to animals of a higher order. Most 

 fish possess an air bladder found in no other 

 animals, but its purpose is not clear. By some 

 authorities it is regarded as a balance, weight- 

 ing or lightening the body as required. The 

 fins, usually in pairs, are typical of the fore 

 and hind limbs of quadrupeds, but have not 

 yet reached an equal stage of development. 



Reproduction. Many fish are absolutely 

 without anxiety concerning their eggs or young. 

 The eggs are deposited in chosen localities, on 

 rocks, weeds or at the bottom of streams and 

 there left to hatch or be destroyed, as chance 



may determine. The loss of eggs and young 

 is very great, for almost every species is the 

 prey of larger fish; so in order to preserve the 

 existence of species a vast number of eggs is 

 deposited. A cod produces about 10,000,000 

 eggs annually, but beyond depositing them, 

 does nothing to insure their preservation. 

 Other fish, however, are examples of parental 

 care and forethought. The humble stickleback 

 builds a nest of sticks carefully plastered to- 

 gether with gummy excretion, and when the 

 eggs have been deposited stands guard until 

 the young are hatched. Bass and sunfish also 

 guard their eggs. The salmon and the shad 

 ascend rivers to deposit their eggs; the eel 

 reverses this process by returning to the sea 

 to spawn. The eggs of sea fish are hatched 

 more quickly than those of fresh water species. 

 In the sea the loss among the young is greater 

 than in rivers and bodies of fresh water, as 

 there are more species to prey on each other. 

 Some sea fish hatch from the eggs forty-eight 

 hours after deposit; the eggs of the brook 

 trout require three months for hatching. 



Food of Fish. Some fish are omnivorous, 

 that is, they eat both vegetable and animal 

 matter; others eat only vegetables, and others 

 again confine their diet to smaller fish, of their 

 own or other species. The appetite of most fish 

 appears to be equal to that of the robin. In 

 carnivorous, or flesh-eating fish, the mouth is 

 very large and the stomach so elastic that 

 even small fishes are able to swallow others 

 nearly as large as themselves. Some species of 

 fish live entirely on minute particles of matter 

 strained from the water. 



Some Interesting and Remarkable Fish. 

 Reference has been made above to the stickle- 



