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Delphinus EschricJiiii, Monodon monoceros, the otters, the beaver and 

 the water rat A more or less flattened cornea and spherical lens 

 have been found in these animals. With reference to the birds De 

 Blainville says, " all who dive not only to seize their food by the beak 

 as the ducks, but those which pursue their prey under water, as the 

 divers and similar genera, have eyes exactly like fishes, the crystalline 

 becoming more and more spherical, according to their habits, as 

 shown by successive comparison of the cormorants, ducks, divers and 

 loons." Now if the lens is spherical the cornea must be flattened, as 

 it has been found and described by Siebold and Stannius, and more 

 perfectly by M. Plateau. Among aquatic reptiles we have the croco- 

 dile and alligator with eyes like fish. Among the ophidians many 

 are aquatic, as Tropidonotus natrix and Eunectes murinus of Brazil; of 

 the serpents and of the vipers several species in the genera Hydro- 

 phis, Platurus, Apysura, Disteira, Pelamis, Acalypta, etc. 



The researches of Schlegel, Jules Cloquet and Soemmering have 

 shown the eyes of these animals to resemble those of the fishes. So 

 also the special studies of Bojanus, Albus and Dumeril and Bibron. 

 Of the batrachians, those who seek food under water also have a 

 spherical crystalline lens and flattened cornea more marked, accord- 

 ing as their habits are more aquatic, as M. Plateau shows by a com- 

 parative examination of Bufo vulgaris, Salamandra maculosa, Rana 

 temporaria, Triton alpestris, Rana esculenta and Triton punctatus. The 

 comparison with the eyes of fishes holds good also among the articu- 

 lates, those which are aquatic having more flattened corneas and more 

 spherical lenses. 



Dr. Jefiries described M. Plateau's method of determining the dis- 

 tance of distinct vision in the eyes of fishes and batrachians in air and 

 water. His examination of some fourteen species showed but a slight 

 difference in reference to the two media. He also exhibited enlarged 

 diagrams of M. Plateau's plates, giving sections of the eyes of the 

 pike, loach, eel, frog and gull. He remarked that this point was new, 

 and he had noticed it in his own dissections, but had not felt sure it 

 was not a post mortem change. He was, however, sure that too Uttle 

 attention had been paid by comparative anatomists in giving correctly 

 the outline of the section of the eyes of many of the animals. He 

 had, for instance, seen in the living animal that the cornea was almost 

 perfectly flat, yet the sections in the books are found giving a consid- 

 erable convexity to it. 



Dr. J. Wyman stated, as the result of a partial examina- 



