G. NATURAL HISTORY AND ZOOLOGY. 289 



rare in which, when a sufficient quantity of poison lias been 

 fairly introduced, death has failed to supervene. 



The remedies indicated by these gentlemen as most desir- 

 able are such as mechanically prevent the entrance of the 

 poison to the circulation namely, the ligature and the cau- 

 tery; but these, to be available, must be applied immediate- 

 ly. Stimulants, such as alcohol and ammonia, are useful, es- 

 pecially where the poison is severe but not fatal. Other an- 

 tidotes are apparently inert. Artificial respiration continued 

 long enough to admit the elimination of the poison from the 

 breathing organs, is serviceable under some circumstances. 

 12 A, IX., 294. 



COMPOSITION OF THE CARTILAGE OF THE SHARK. 



According to Petersen and Soxhlet, the fresh cartilage of 

 the shark is composed of organic matter, 8.03 per cent.; 

 chloride of sodium, 16.69 per cent.; other inorganic matter, 

 1.08 per cent, (total inorganic, 17.77 per cent.) ; water, 74.20 

 per cent.; and the dried cartilage contains 4.80 per cent, of 

 nitrogen, which is fifteen per cent, of the organic matter; 

 the latter belonging no doubt to the albumen group: whether 

 identical with chondrine from common cartilage was not in- 

 vestigated. The ashes gave chloride of sodium, 94.24 ; soda, 

 0.79 ; potash, 1.64 ; lime, 0.40 ; magnesia, 0.05 ; sesquioxide of 

 iron, 0.27; phosphoric acid, 1.03; sulphuric acid, 1.88 percent. 

 The occurrence of a tissue so rich in chloride of sodium is an 

 interesting physiological fact, especially since the flesh sur- 

 rounding it is comparatively wanting in salt, the fresh meat 

 containing only 1.16 per cent, of incombustible matter. 

 The salt must therefore either be in chemical combination 

 with the constituents of the tissue, or there must be a species 

 of attraction in the cartilage for salt, which prevents the 

 diffusion of the strongly saline fluid of the cartilage with 

 the less saline of the flesh. 18 C, August 27, 1873, 553. 



DEVELOPMENT OF TEETH IN THE ARMADILLO. 



In studying the development of the teeth of the armadillo 

 {Tatusia peba), Mr. Tomes finds, contrary to what would 

 have been expected, that in their earliest stages the first in- 

 dications of their differentiation are manifested by the forma- 

 tion of an "enamel organ" as in those of higher mammals; 



N 



