UEODELA— AMBLYSTOMIDAE— A. MAVORTIUM. 517 



The principal point of interest regarding them is the fact that within a few, 

 years the larva and adult of these animals were referred to distinct genera 

 and species, and so described under the names of Siredon lichenoides and 

 Amblystoma mavortium ; but Professor Duine'ril, in 1865, having secured a 

 number of living specimens from the Southern Rocky Mountains, instituted 

 a series of experiments, and proved beyond a doubt that they were one and 

 the same species. 



Professor Cope also, by a study of a large number of specimens of 

 different ages, confirmed the statements of Dumeril and Professor Marsh, 

 and in the American Journal of Science and Arts, vol. xlvi, November, 1868, 

 published a paper to the same effect. 



It is but fair to Professor Baird to state that he knew and believed in 

 such a theory much earlier than any of these gentlemen. The following 

 paper* by Professor Cope, being of great interest, is here reproduced : 



" The late observations by various writers on the metamorphoses of 

 Amblystoma, especially those of Mr. Tegetmeier, indicate that some of the 

 principal facts in the history of the subject have been overlooked by all 

 of them. 



" In the first place, no one has seen any metamorphosis of true Siredon,— 

 Siredon mexicanus, Shaw (#. pisciformis, S.axoloU, and S. maculatus Auctorum — 

 which inhabits the lakes of Mexico, and of which the Smithsonian collections 

 contain numerous specimens. Whether it undergoes a metamorphosis is 

 entirely unknown to naturalists ; though I would express the belief that it 

 will be found to do so occasionally under suitable circumstances. No 

 Amblystoma have been brought from Mexico south of Tamaulipas and 

 Chihuahua by any of the various naturalists collecting for the Government 

 surveys. 



" In the next place, Professor Baird was aware of the metamorphosis 

 of all the North American species of Siredons many years before the observa- 

 tion of it in the Jardin des Plantes ; although at first he named one of them 

 Siredon lichenoides, treating it as a mature animal. He regarded these 

 creatures as larvce in his essay on the North American Salamanders, published 

 in Philadelphia in 1847. 



"From the American Journal of Sciouce and Arts, vol. i, February, 1871,89. 



