Dr. Dawsoiis ^Dawn of Life.'' 373 



an anticlinal fold in the gneiss. The dolomite is coarsely 

 crystalline, and quite free from admixtures with foreign 

 minerals, except near its junction with the gneiss. The 

 dolomite at the junction becomes charged with a great variety 

 of siliceous, aluminous, and magnesian minerals (quartz, pyro- 

 xene, hornblende, tremolite, calcite, serpentine, chiysotile, &c.), 

 all forming a mass with a banded structure following the 

 irregular cavities and pockets in the enclosing gneiss. It is 

 only where the banded portion of a vein joins the gneiss that 

 ^^ Eozoon " is found, specimens occurring attached to the walls 

 of the cavities. Mr. Burbank's description, which appears in 

 the ' Proceedings of the Boston Society of Natural History,' 

 is minutely and carefully given ; yet Dr. Dawson, we are 

 sorry to find, has ventured on derogating from its value with 

 the brief remark that " Mr. Burbank " [who, be it understood, 

 was at first a believer in '"'■Eozoon "] "has since maintained that 

 the limestones are not true beds ; but his own descriptions 

 and figures lead to the belief that this is an error of obser- 

 vation on his part"* ! Has not this " state of things ceased 

 to be desirable in the interests of science " ? 



15th. Noticing our statement that the laminated character 

 of Eozoon is a mineralogical phenomenon, of which we cited 

 instances, Dr. Dawson in his "short answer" asserts that 

 " the lamination is not like that of any rock, but a strictly 

 limited and definite form, comparable with that of Stromato- 

 jjora^^ (p. 190). We shall simply meet this gratuitous denial 

 with three facts not mentioned in our citation. 



If Dr. Dawson had before him, as we have, a Siberian 

 specimen (which no doubt is represented in many museums 

 and collections), consisting of alternating laminae of quartz 

 and brownish felspar, he would find that the lamination is 

 " strictly limited^' and of " definite form," and even fir more 

 Eozoon-//^e in this respect than Stromatopora concentrica. 

 Again, Prof. R. Harkness has presented us with a similar 

 specimen of granite from the isle of Han-is, Hebrides, dif- 

 fering simply in the two minerals being white and the laminae 

 slightly thicker. Our kind friend has also given us a spe- 

 cimen, from Fetlar, in the Shetlands, consisting of alter- 

 nating laminfe of sei-pentine and chrysotile, which in tlieir 

 " definite and strictly limited form " deserve to be thus desig- 

 nated more appropriately than the "^o^oo/i" represented in a 

 " Nature-print " in plate v. of ' The Dawn of Life.' 



But what is to be said of the Liassic ophite of the Isle of 



♦ ' The Dawu of Life,' footnote, v>. 4G. Mr. .Tohn B. Perry's minute 

 investigations completely establish Mr. Burbank's conclusions (see Proc. 

 Boat. Soc. Nat. Hist., April 1872). 



