THE PROPAGATION OF THE GOLDFISH 



o 

 Pi 



Common Goldfish. 



Two long bodied Japanese long- 

 tailed Goldfishes. 



Three short-bodied Japanese 

 double-tailed Goldfishes. 



He also pointed out that "the large number of capillaries in the huge 

 tail of fine specimens of the 'Kinyiki' and KIN- YU races indicate that the 

 caudal fin may possibly serve in a very important way as an adjunct to 

 branchial respiration", and that "the immense fins of the Japanese double- 

 tailed goldfishes have been developed partially in physiological response 

 to artificial conditions of respiration, that were not as favorable as those 

 enjoyed by their wild congenetors", and, " that the dorsal, anal and caudal 

 fins may be so modified as to minister in an important way to the needs 

 of respiration." Also, "the fact that the very long fins are only fully devel- 

 oped at a very late period of the growth of the animal, is in harmony with 

 the view that the hypertrophy of these organs is associated with a correla- 

 tive degeneration of the muscles of the trunk, and possible use of these 

 structures with their great amount of surface as respiratory organs, in the 

 restricted and badly aerated tanks and aquaria in which they have been 

 bred for centuries." 



The very red color of the blood in the arteries and capillaries of the 

 fins would indicate the correctness of this hypothesis. 



The comparisons of the telescopic-eyed goldfishes are equally interest- 

 ing. Professor Ryder states that " the eye-ball becomes greatly elongated 

 in the direction of its optic axis. Sometimes the difference between the 

 axial and equatorial diameter is as much as three millimetres, constituting 

 an extremely myopic form of eye-ball. The form of the eye-ball in the 

 common races is flat or hypermetropic in character. A gradual passage 

 from the hypermetropic to the myopic form is shown in the following 

 table, as based upon actual approximate measurements of the eye-balls of 

 individuals of the three races. The size and shape of the globular lens 

 is not appreciably diflFerent from that of the other races with smaller eye- 

 balls. It would therefore, seem impossible for the image formed by the lens 



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