AMERICAN CATFISHES. 39 



The water at the disposal of the a(]uariuin ia that which comes from the Vanne, 

 whose temperature is 15° C. (59° F.) in Au<,'ust and 9° C. (48.2° F.) in December. 

 It is hardly probable that this temperature is sufficiently high for the reproduction of 

 the catfish. At any rate, those which we have in our aquarium, no matter to what 

 variety they belong, have never spawned. 



When the American catfish were transferred to basin No. 6, they were all alive and 

 well , although they had not grown perceptibly. Since that time none of them have died, 

 as far as we have been able to observe, for these fish have a habit of keeping in their 

 holes and never coming out during the day, so that they are hardly ever seen. In 

 basin No. 1 we had some of considerable size, and in order to assure ourselves of their 

 existence it became necessary to empty the basin and carefully search for them at 

 the bottom between the rocks. Even then we did not always succeed in finding 

 them. I have, therefore, reason to believe that seven catfish which the Acclimati- 

 zation Society has given us are still in existence, and the first time the basin is 

 emptied I will search for them again in order to make sure. 



The latest information regarding the European introduction is 

 found in a Httle work entitled "Der amerikanische Zwergwels (Small 

 Cat-fish) und der Fleckenwels (Spotted Cat-fish) in Deutschland," 

 by Max von dem Born-Beneuchen, published in 1891. On page 7 

 the author states that in the summer of 1885 the committee of the 

 German Fisheries Society received from Prof. Spencer F. Baird in 

 Washington 50 young catfish, which were turned over to his care, 

 and that they were placed in a pond with muddy bottom where 

 there was a great deal of " Wasserpest" and a depth of about 2 meters. 

 They have done very well and increased. Since those brought 

 from America and those held in other fish hatcheries have increased 

 so prolifically, he believes that the small catfish can now be regarded 

 an acclimated fish. 



Von dem Born-Beneuchen goes on to say that from 1887 to 1890 

 he had reared 2,225 one-summer old {einsommerige) small catfish; 

 300 were placed in a lake, 10 breeders and 665 one-summer old fish 

 were given to other fish hatcheries and aquariums, and he now 

 possesses 325 small catfish, for the most part mature (laichfdhig) . 

 On page 8 he continues: 



Mr. Fred Mather sent me from the United States Fishery Commission in December, 

 1888, a quantity of spotted catfish from the Ohio River. Of these, 18 arrived at Be- 

 neuchen in good condition, and in February, 1891, 16 fish still lived. They have 

 not yet spawned, although they are already mature in 1890. 



o 



