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THE AMERICAN NATURALIST [Vol. XL 



and found it excellent: it is our intention to recommend it as 

 food, but not until our investif]^ations are complete." 



Their great tenacity of life is a matter of frequent comment. 

 They seem to be able to live for months without food. They 

 have been left for three or four hours out of water and are then 

 easily revived. After severe mutilations they recover, but not- 

 withstanding this great vitality they seem to fall easy victims of 

 a fungus which has not as yet been determined specifically. jSIr. 

 Browne (Milner, 74) of Grand Haven, Michigan, states that 

 "some years ago, an epidemic seemed to prevail among the Meno- 

 branchi in Grand River, in the month of June, and that their 

 carcasses were washed ashore by hundreds, so that they lined 

 the banks of the river and the mill-men were obliged to throw 

 the bodies off into the current, to be carried down stream to pre- 

 vent the offensive stench that was wafted into the mills from the 



Castinff of Epidermis.— Knee\a,nd ('57) states that Necturus 

 sheds its epidermis in the winter. "They shed their skins at 

 this season; I have had several with the old skin hanging to the 

 new in shreds and patches, which are washed off by the water 

 in two or three days, leaving the colors of the new skin very 

 bright; the edges of the tail are then so thin and transparent 

 that the network of blood vessels can be seen with the naked 

 eye." 



While endeavoring to obtain a photograph of Necturus on 

 February 9, 1897, Mr. A. H. Cole, one of my students, observed 

 the animal cast its epidermis. His notes read as follows: "The 

 epidermis as a thin layer appeared to have loosened from the 

 entire surface of the body, appearing frosty-white with bubbles 

 of air. The loosened epidermis was split along the mid-dorsal 

 line, its free edges floating upward in ragged streamers. On the 

 following day none of the epidermis remained excepting glove- 

 like portions which were yet attached to the feet; these portions 

 were not cast until two days later." 



Breeding Habits. — Although more than a century has elapsed 

 since Necturus became an object of special study on the part of 

 both American and European naturalists, no one seemed fortu- 

 nate enough to obtain embryological material until Professor 



