48 Proceedings of ike Royal Society of Victoria. 



although approximated more by them than anything else known, 

 and therefore this feature alone is of no avail in support of 

 a terrestrial volcanic theory. Even Professor Stelzner admits 

 this when describing the hollow specimen from Kangaroo Island, 

 of which he says that an exact parallel case of such a natural 

 glass is not known to him either from literary descriptions or 

 from collections. 



Darwin says that the obsidianite he examined seems to have 

 been embedded in some reddish tufaceous matter. In one 

 specimen from Mount Elephant which has come under my notice 

 I also observed a material bearing a very similar character ; but 

 as it comes from a volcanic region, it may have gathered it when 

 it fell, and there would be no special interest attached to its 

 presence. Darwin's specimen, however, came from a part 

 hundreds of miles distant from any known crater, and, if he is 

 correct in his surmise, it certainly is a point in favour of a 

 terrestrial volcanic origin. If this theory is a correct one, little 

 evidence has as yet been brought forward to establish it ; but 

 their discovery over such an immense area, their remoteness in 

 some instances from any points of eruption, and the absence of 

 evidence in others that they are due to local volcanic outbursts, 

 and, finally, the want of proof that they have been transported, 

 are in themselves obstacles difficult to explain away by any such 

 hypothesis. 



We have now to consider the non-terrestrial or meteoric 

 theory. In the first place, it at once afibi'ds a satisfactory 

 explanation of their indiscriminate and widespread mode of 

 occurrence, and for this alone deserves serious attention. ^Ir. 

 Verbeek goes so far as to say that they may have been ejected 

 from the moon during the quaternary or perhaps pliocene periods, 

 l)ut as this involves a discussion on the origin of meteorites, it 

 would evidently be out of place to ofter any remarks about it. 

 Neither is it desirable that we should do so, as we are only 

 concerned generally witli a non-terrestrial origin. 



Two objections may be urged against this theory, namely, 

 their regular form and their composition, both being entirely 

 different to that obtaining in known meteorites. How the shapes 

 could have been assumed under conditions compatible with a 

 meteoric origin is purely a matter of conjecture. It seems 



