DISCORDANT NATURE OF OPINIONS AS TO STRUCTURE 397 



constatations que j 'avals faites sur la structure de la meteorite de Lesves. 

 J'avancais des lors que toutes out ete soumises a des phenomenes analogues 

 a ceux que nous montrent les loches terrestres metamorphisees par cataclase 

 et je concluais que pour un grand nombre d'entre elles, on ne doit pas admettre, 

 a cause de leur aspect clastique, qu'elles sont de uatur tuface." 



And again : 



"Je rejette I'origine polygene qu'on avait attribuee a la generalite des 

 meteorites chondritiques et que je les considere comme des roches cristallines 

 qui out subi Taction du metamorphisme dynamique."' 



And still further : 



"Je me range done sans hesiter avec ceux qui n'admettent pas que ces masses 

 cosmiques soient des agglomerations de produits volcaniques incoherents." * 



These diametrically opposed views, each of which had numerous sup- 

 porters, can, as it seems to the writer, be explained only on the ground 

 of an insufficient amount and variety of material for the study on the 

 results of which the opinions were based. The fact would seem to have 

 been overlooked that chondrules occur in greatest abundance and most 

 perfect development in stones the tufEaoeous nature of which is most pro- 

 nounced. It is well nigh inconceivable, further, that structures like those 

 shown in figure 1, plate 2, should have been produced through crushing 

 forces, as argued. The fact that the same mineral occurs in such a variety 

 of forms also shows conclusively that they must have originated under 

 different conditions, which could not exist in closely adjacent portions of 

 the same magma. This last has been pointed out by Borgstrom" and 

 others. That a certain amount of internal crushing and disintegration 

 has taken place in many stones is unquestionable and will be referred to 

 later. 



In that which follows I shall assume, then, that the tuffaceous nature 

 of these stones and of the "Kugelchenchondrite" in general is no longer 

 questioned. As to the possibility of such having undergone metamor- 

 phism, there is among those who have written on the subject less diversity 

 of opinion. 



Sorby, writing in 1877, says:* 



"Taking, then, all the above facts into consideration, it appears to me that 

 the conditions under which meteorites were formed must have been such that 

 the temperature was high enough to fuse stony masses into glass ; the particles 

 could exist independently one of the other in an incandescent atmosphere, sub- 



" The present wiitei- can but feel that could M. Renard study the Cumberland Falls, 

 Kentucky, stone he would modify somewhat his view. 

 •^ Trans. Roy. See. of Canada, 1904. p. 94. 

 8 Nature (London, England), vol. 15, 1877, pp. 495-498. 



