NOVEMBEK 15, 1912] 



SCIENCE 



681 



favorable one for the embryos than one con- 

 taining only ISTa and Ca. The experiments 

 on which this statement is based are tabulated 

 below and can be compared with the earliei 

 ones. 



among them a specimen of the CcEciliid 

 amphibian Dermophis mexicanus Peters. The 

 scales of this animal are minute, oblong to 

 suboval, superficially similar to those of 

 Ichthyophis. The essential structure is also 



Time of acclimatization 120 hours. 



Average strength of preparatory solution in Na .199 per cent. 

 Average strength of preparatory solution in Ca .0105 per cent. 

 Average strength of preparatory solution in Mg .0199 per cent. 



Conclusion. — The ability of amphibian eggs 

 to develop in sea water is dependent on the 

 principle of ionic antagonism. In addition 

 to this, however, their power of acclimatiza- 

 plays an important role, for it not only enables 

 them to withstand the passage from dilute to 

 strong solutions, but the opposite process as 

 well. Thus larvEe which have just reached a 

 point where they fail to react to tactile stim- 

 uli in solutions which do not bring about 

 dehydration, either because the solutions are 

 too weak, or because the larvas have been ac- 

 climated, will if transferred to fresh or dis- 

 tilled water recover in from one to two hours. 

 If in addition to this we remember that the 

 species found by Pearse is probably racially 

 acclimated to the conditions under which it 

 lives, his findings do not appear inexplicable. 

 Otto Glaser 



Zoological Laboratory, 

 University of Michigan, 

 July 15, 1912 



THE SCALES OP DERMOPHIS 



In Science, July 28, 1911, p. 127, 1 described 

 the scales of the Asiatic amphibian IcMhyo- 

 pMs, pointing out their resemblance to certain 

 fish scales. Early this year my wife and Mr. 

 Earl Morris obtained a number of amphibians 

 and reptiles at Quirigua, Guatemala,^ and 



* These were very kindly determined for us by 

 Dr. L. Stejneger. It may be worth while to give 

 the list, as a contribution to the knowledge of 

 their distribution: Leptophis mexicanus (Dum. & 

 Bibr.), Streptophorus atratus sebce (Dum. & 



the same, but the cell-like areas, instead of 

 being more or less brick-shaped, are long and 

 narrow, usually pointed at the ends, as 

 though compressed. The scales of Ichthyophis 

 are finely granular, but Dermophis shows 

 little of this. The structure of the Dermophis 

 scale is even more like that of the eel 

 Synaphohranchus pinnatus than is that of 

 Ichthyophis. 



On the whole, the correspondence in minute 

 structure between the scales of the two Ooeei- 

 liids examined, from opposite sides of the 

 world, is very striking. It is evident that in 

 the Coeciliids, as well as in the more primitive 

 types of scaly fishes, scale-structure is ex- 

 tremely persistent. It is proper to say, how- 

 ever, that the two genera are otherwise rather 

 close in structure, and it remains to be seen 

 whether the scales of more divergent genera, 

 such as Cryptopsophis or Oymnophis, present 

 any marked differences. 



t. d. a. cockerell 



University op Colorado 



mineral content of volanic ashes from 



KODIAK^ 



Following the recent eruption from Mount 

 Katmai (the first week of June, 1912) samples 

 of the volcanic debris falling near the Agri- 

 Bibr.), Ameiva undulata Gray, Bufo valliceps 

 Weigm., Byla haudinii Dum. & Bibr., Dermophis 

 mexicanus Peters, Spelerpes ( ? rufescens Cope, 

 condition poor). 



^ Published by permission of the Secretary of 

 Agriculture. 



