G. GENERAL NATURAL HISTORY AND ZOOLOGY. 345 



but at the end of six months were much larger than brook 

 trout of the same age. On the 6th of April of the present 

 year Mr. Mather revisited the Au Sable River, remaining 

 there until the 12th. On the 8th he took spawn from two 

 fish, and on the 9th and 10th from several more. He brought 

 away 8000 spawn and 40 yearlings, the latter about five 

 inches long. He also packed 4000 eggs for Mr. N. W. Clark, 

 of NTorthville, Michigan, and gave him a considerable num- 

 ber of fish. These eggs, at the latest accounts, were thriving 

 finely, and the embryo was expected to hatch out very soon. 

 Live Stock Journal, May, 1875, 150. 



EESPIEATION OF THE LOACH. 



M.Rougemontjin speaking of the European fresh-water fish 

 known as the loach (Cobitis fossilis), says that when one of 

 these fish is placed in ordinary water it respires by means of 

 its gills, in a normal manner; but whenever the proportion 

 of oxygen falls below a certain minimum, the fish rises to 

 the surface and there takes in air, while bubbles charged with 

 carbonic acid escape at the anal orifice. It therefore appears 

 that the digestive tube itself performs the functions of respi- 

 ration, and that it is in this orsran that the blood finds the 

 oxygen necessary to its purification. This tube is thus equiv- 

 alent to an air-bladder, and when filled with air the fish 

 rises easily to the surface. The so-called air-bladder of the 

 fish is a small bony receptacle, situated under the first verte- 

 bra, and it is believed, in view of the small volume of air it 

 is capable of containing, that it is not a real air-vessel, but is 

 simply a resonant chamber communicating with the organ 

 of hearing, properly so called. 1 F, October 15, 1874, 162. 



MONOGEAPH OX THE ANGUILLIFOEil FISH. 



M. Dareste has communicated to the Academy of Sciences 

 of Paris a monograph upon the anguilliform fish, and espe- 

 cially the generas Anguilla, Conger, MyruB, Murce?iesox, and 

 Nettastoma, which he finds to possess comparatively few of 

 the anomalies observed in the subjects of a previous memoir 

 on the Symbranchidw. In Anguilla, to which the common 

 eel belongs, he finds evidence of the existence of only four 

 species. One of these, the A. vulgaris, is found throughout 

 the whole northern hemisphere, both in the New and the Old 



P2 



