Dr Dalton jun. on the Proteus anguinus. 339 



tatus 6^ inches long, and that of a Proteus anguinus 8| 



inches long : 





Triton. 



Proteus. 



Hemispherical lobes, 



5 millimetres. 



4% millimetres. 



Tubercula Quadrigemina, 



2^- jj 



^2 55 



Cerebellum, 



n » 



n 5, 



The two brains could hardly be distinguished from each 

 other, except for the fact that the olfactory nerve in the Pro- 

 teus runs forward for some distance as a trunk along the inner 

 side of the membranous olfactory canal, while in the Triton 

 it breaks up into branches immediately on leaving the ante- 

 rior extremity of the brain. 



It will be seen that the suppression of the visual organs in 

 these animals is not by any means complete. There are, 

 however, other creatures existing in the same localities with 

 the Proteus, in which the eyes are altogether absent. Two 

 species of Crustaceans are found in the caves of Carniola, 

 viz., Palcemon anophthalmus and Titanethes albus, both of 

 which are colourless, diminutive in size (not more than one 

 inch long), and, so far as they have been examined, entirely 

 destitute of eyes. They are supposed by some to be the na- 

 tural food of the Proteus. I am informed by Mr Kollar, of 

 the Vienna Zoological Museum, that a species of spider, en- 

 tirely blind, has also been discovered in the same caverns. 



There is much resemblance, in regard to the condition of 

 the eyes, between the Proteus and Lepidosiren paradoxa. In 

 the two specimens of Lepidosiren dissected by Prof. Bischoff, 

 and described by him in a monograph on the subject, the eyes 

 were " hardly a line in diameter," though one of the animals 

 measured over three feet in length. The opening of the eye- 

 lids is wanting, also, in Lepidosiren as in Proteus, and the 

 eyeball is completely covered by the integument. So little is 

 known, however, of the mode of life of Lepidosiren, that it is 

 impossible to determine whether the cause of the imperfec- 

 tion be the same in both animals. 



Very little is yet known with regard to the mode of repro- 

 duction of the Proteus ; and particularly it is altogether un- 

 certain whether the animals are oviparous or viviparous. Dr 

 Joseph Hyrtl, Professor of Anatomy at the University of 

 Vienna, states that he has found, at the extremitv of the ovi- 



"y2 



