H + 



THE GUIDE TO NATURE. 



brethren ; but under the care of the 

 breeder, they are preserved and trans- 

 mit to some of their progeny these 

 desired peculiarities. 



How these tendencies are trans- 

 mitted to the ova has never been fully 

 determined, but in crustaceans, ba- 

 tracia, reptiles and fishes heredity is 

 stronger than in the higher forms of 

 animal life, especially so with fishes, 

 and the partly double bodies of the 

 parents influence the young and tend 

 to a preservation of these peculiarities. 

 These may, in a measure, be a benefit, 

 as the large and duplicated fins with 

 their great amount of surface will 

 serve as important adjuncts to gill res- 

 piration in the confines of the usually 

 badly aerated tanks and aquaria. This 

 is also indicated by the very red color 

 of the blood in the arteries and cap- 

 illaries of the long^tailed goldfishes. 



Duplication of the anal fin consists 

 of two fins placed side by side. Then 

 they serve the same purpose as the 

 single fin in guiding the movements 

 of the fish. But with some breeds 

 having abnormally large and unwieldy 

 double tails, the duplicate anal fins 

 are placed at an angle to each other 

 and by their flapping motion largely 

 take the place of the tail in swimming, 

 as its muscles are atrophied and the 

 long double tail becomes an actual 

 hindrance to the fish, which swims by 

 movements of the body muscles and 

 not bv those of the tail. 



The normally constituted tail of the 

 goldfish consists of a single, slightly 

 bifurcated, vertical blade at the ex- 

 tremity of the spine, articulated so 

 that it is flexible in all directions. 

 Abnormalities of the caudal fin vary 

 considerably and have been made 

 characteristic of different breeds. A 

 gradual transition from the single to 

 the double tail can be traced which 

 has also been further developed, as 

 the appended diagrams will show. The 

 simplest transition state from single to 

 double is seen when the tail, normal in 

 other resoects, has the ventral (lower) 

 edge slightly furrowed with a median 

 line or groove, the greater part of the 

 tail being vertical and median. This 

 indicates the first tendency to a double 



■tail. When the division extends fur- 

 ther up, the lower half of the tail may 

 be double. This is known as a "tri- 

 pod-tail" and is not desirable to the 

 expert fancier. Sometimes the du- 

 plication extends quite to the upper 

 margin and is joined only at the dorsal 

 (upper) edge, which produces two 

 complete blades joined at the first rays 

 on a line with the back of the fish. 

 This form is known as the "web-tail." 

 These halves may be flattened into a 

 horizontal plane and then the double 

 tail is represented as a single piece 

 and is known as the "dolphin-tail," the 

 desired form in the Celestial telescope 

 goldfish. 



Another form is when the tail is 

 normal in outline but in place of a 

 single tail it is present in duplicate ; 

 that is, two single tails separated quite 

 to the base, directly vertical on the 

 same plan, of exactly the same shape 

 and conformation and parallel to each 

 other. This is the true "fan-tail" and is 

 characteristic of that breed of gold- 

 fish. 



A further development is the "fringe- 

 tail," an immense, drooping, double 

 tail, divided to the base and floating 

 behind the fish like a great mass of 

 dainty lace, much longer than the body 

 of the fish, of which each half is exactly 

 like the other in conformation, length, 

 droop and texture. This very long 

 growth of tail is only acquired after 

 the maturity of the fish, though the 

 expert can detect the tendency in very 

 young fishes. 



All these forms of duplicate fins are 

 oresent in the breeds now cultivated 

 in the United States ; but Doctor S. 

 Matsubara, Director of the Imperial 

 Fisheries Institute at Tokio, mentions 

 three other forms: the "arrow-tail" in 

 which the upper half of the tail is in 

 duplicate and the lower half single ; the 

 "rudder-tail" in which the double up- 

 per half is horizontally expanded and 

 the single lower half vertical ; and the 

 "bag-tail" which consists of a double 

 tail joined at both the dorsal and ver- 

 tical edges. 



Some of the young of American bred 

 fishes show indications of a triple de- 

 velopment of tail but none have as 



