162 



&guatic JLitt 



ers, of Persia, it follows that a similar 

 degree of salinity should be simulated in 

 the aquarium, in fact it is absolutely 

 necessary, especially insofar as breeding 

 is concerned. Further, inability to re- 

 produce in the aquarium the precise con- 

 ditions of its native environment may ac- 

 count for the small numbers the Ger- 

 mans were able to rear. A temperature 

 of about 75 degrees seems best suited. 



An investigation of an epidemic among 

 the fish in the St. Lawrence River at Og- 

 densburg, N. Y., was made by the Bu- 

 reau of Fisheries during the first week 

 in July. E. A. Cooper, superintendent of 

 the New York Fish Hatchery, had re- 

 ported that large numbers of fish were 

 dying in the ponds and also in the river. 



The epidemic was at its height during 

 the first two weeks in June and then 

 decreased rapidly in severity. At the 

 time of the investigation the disease had 

 entirely disappeared from the ponds and 

 only a few diseased fish were taken in 

 the river. None of these appeared to 

 be seriously affected by the disease. 



The fish taken in the river showed two 

 distinct types of lesions on the skin. On 

 the bullheads and catfish the infected 

 areas were very distinct, about x / 2 to i- 

 inch in diameter and bright red in color, 

 due to the complete destruction of the 

 epidermus, thus exposing the inflamed 

 dermis beneath. 



The diseased areas in the skin of bass 

 and suckers had a very different appear- 

 ance. They were irregular in shape and 

 so indistinct as to attract attention only 

 on close examination. The most marked 

 characteristic was a faint reddish border 

 around the scales, due to a slight extra- 

 vasation of blood into the epidermis. 



A microscopic examination of sections 

 of skin from the infected areas indi- 

 cates that the disease in bullheads and 

 catfish is probably distinct from that in 



the bass and suckers. In the former the 

 disease is apparently due to bacteria 

 which are present in enormous numbers 

 in the disintegrating epidermis. These 

 bacteria are not present in the lesions on 

 bass and suckers, and the cause of this 

 disease is at present problematic. 



The manufacture of pearl buttons 

 from mussel shells began in 1891 and 

 the rapid increase in the business soon 

 threatened the destruction of the mus- 

 sels. The United States Government in 

 consequence entered upon a series of in- 

 vestigations as to the practicability of 

 propagating mussels artificially. This is 

 a commercial problem, yet success de- 

 pends upon a knowledge pi the life 

 history of the mussel, which has been 

 gained by various investigators in 

 theoretical work. The life history is 

 unusual. After the young mussel de- 

 velops from the egg to a larval form 

 called "Glochidium," barely visible to the 

 naked human eye, it is discharged into 

 the water where it develops further or 

 dies, depending on whether it has an 

 opportunity to attach itself to some fish. 

 If chance favors it, it takes up the life 

 of a parasite until far enough developed 

 to leave the fish, drop to the bottom of 

 the stream, and enter upon the life of 

 the adult mussel. The task, therefore, 

 of artificially breeding mussels, involves 

 the bringing together of suitable fish and 

 the young, almost microscopic, glochidia. 

 Investigations have shown that a mod- 

 erate sized fish may successfully carry 

 from one thousand to two thousand of 

 these parasitic guests. — American Mu- 

 seum Journal. 



Patience is the ri^ht bower of success. 



Jordanella floridae has been safely 

 transported to Australia, where it has 

 bred in the ponds of H. E. Finckh, Esq. 



