On the Mode of Propagation of Tree-Frogs. 377 



sally which Sterry Hunt made some time ago in the 'American 

 Journal of Science ' on those holding " extravagant views " of 

 pseudomorphism — " In this way we are led from gneiss or 

 granite to limestone, from limestone to dolomite, and from 

 dolomite to serpentine'''"^ ^ and so on. 



We are glad, however, to welcome our opponent as a member 

 of the pseudomorphic corps, which we cannot but think will 

 be all the stronger for his membership. 



Still, in the face of a fact of common occurrence to us, 

 Dr. Dawson states that " in no instance " had he observed the 

 " nummuline layer to pass into chrysotile," as it has been 

 represented by us ; but it is remarkable that in the specimen 

 above noixcQdi a. portion of the same layer (" icalls of the skele- 

 ton ") is " represented " by " serpentine " (incipient chryso- 

 tile we have no doubt) with " traces " of the tubuli (" canals "), 

 and that it becomes completely changed into true nummuline 

 tubulation (" is clearly traced into connexion with " other 

 portions " still existing as calcite ") ! 



Dr. Dawson, after stating that he has not seen " the chevron ' 

 arrangement" represented in "fig. 7" of our plate in the 

 'Annals ' for October 1874, mentions that " Mr. Weston 

 was struck with the inaccuracy of the representations in this 

 plate." W^e could excuse either party for expressing his 

 doubts ; but the charge of " inaccuracy " is so plainly made 

 that it must not be passed over. We cannot accept statements 

 unless they are made in propria persona. This has not been 

 done by Mr. Weston ; therefore, although we should be glad 

 to have the reasons of one " who has prepared and examined 

 microscopically hundreds of specimens of Eozoon,^^ we must 

 call upon Dr. Dawson to publish his reasons as to wherein 

 lies " the inaccuracy of the representations in this plate." 

 Meanwhile, we may declare in the most emphatic manner that 

 in eyery essential point our " representations " ai^e accurate. 



XXXIX. — Notes on the Mode of Propagation of some Ceylo- 

 nese Tree-Frogs^ with Description of two new Species. By 

 Dr. Albert Gunther, F.R.S., Keeper of the Zoological 

 Department, British Museum. 



[Plate XX. fig. C] 



Our knowledge of the mode of propagation of extra-Euro- 

 pean Batrachians is restricted to a very small number of 

 species ; and from the few singular facts with which we have 

 become acquainted, we may expect that most interesting dis- 



* ' Chemical and Geological Essays,' p. 287. 



