os - 
Feb, 2, 1871] | 
NATURE 
267 

at 656 Kirchhoff’s scale precisely corresponding to aniron line in 
the solar spectrum —also 3 at 1601, 1605, and 1607, the reversal 
of a well-known group of Chrowudz lines. The latter I believe 
are new in prominence spectra, 
C, A, YounG 
Eozoon Canadense 
I HAVE just observed that in your number for December 22 
a correspondent revives some of the old but often refuted ob- 
jections to the organic nature of Eozodn. - As the mail closes in 
a few hours, and [ have lectures in those hours, I cannot reply 
by this opportunity ; but shall crave a small share of your space 
next week to show that the objections stated are unfounded ; 
and to state what is now being done here in further illustration 
of this ancient and veritable fossil. J. W. Dawson 
M‘Gill College, Montreal, Jan. 16 
Tue battle for the Zozodn Canadnse may be left to Messrs. 
Carpenter, Jones, King, Rowney, and other eminent micro- 
scopists, but perhaps an outsider may be pardoned if he asks 
some anomalies to be explained. 
In the Ophytes of Bennabeola the mountain group in Conne- 
mara, or rather Yar-Connaught, Mr. Sandford proved the ex- 
istence of the Lozod2 Canadense, and his opinion was backed 
up by Mr. R. Jones and also, if I remember rightly, by Dr. 
Carpenter. There are acres upon acres of limestone in that 
country of the same age, and some of them on the same geo- 
logical horizon as the Ophytes, Ophicalcytes, Ophimagnesytes and 
Ophidolomytes ; yet, in no plaec, except where Ophyte or 
one of its varieties exist, has the Eozodnal structure been found. 
Furthermore, when the West Galway Ophytes are followed in 
depth they graduate into a Schistose-dolomyte that may be mica- 
ceous, felsitic, or quartzitic, and contains more or less calcyte ; 
yet in these dvlomytes there is no trace of the Eozoonal 
structure, 
These rocks of Yar-Connaught are said to be of Lower Si- 
lurian (Cambro-Silurian) age, by Sir R. I. Murchison, Prof. 
Harkness, and other eminent geologists. In other parts of the 
world will be found square miles tipon square miles of rocks, of 
the same geological age, often having inliers of limestones, yet 
in them there is no 402007 Canadense, it only being found in a 
peculiar rock (pseudomorph-dolomyte) in this small tract of 
Lower Silurian rocks, in Yar-Connaught. 
Yar-Connaught, Jan. 23 G, H. KINAHAN 

Ir my previous letter, as alleged by Dr. Carpenter, exhibits a 
complete misapprehension of the state of our knowledge of the 
above fossil, I cannot plead in extenuation a want of familiarity 
with the arguments he again brings forward in support of the 
organic theory. Had he, instead of explaining away imaginary 
difficulties, addressed himself to those that really exist, his 
reply would have possessed greater value. Let us examine how 
my objections have been met. 
Firstly, then, Dr. Carpenter cannot affirm that any specimen 
of Eozoén has been obtained from una'tered rocks. He can go 
no further than to say that his best specimens are from rocks 
that have undergone the /eas¢ metamorphic change. Thus it 
appears after all, that it is only a question of degree in metamor- 
phism; and when we consider that Logan, Dawson, Sterry 
Hunt, and himself, in their original papers, constantly alluded to 
these Eozodnal rocks as crystalline, highly crystalline, of ser- 
pentine marble, &c., we are enabled to judge of the value of 
the diminutives “‘ little ”’ and “ least,” now used when it becomes 
necessary to the argument to soiten down these expressions. 
Sir W. Logan, who isan authority on the subject, says : *—“tAny 
organic remains which may have been entombed in these lime- 
stones would, if they retained their calcareous character, be 
almost certainly obliterated by crystallisation, and it would only 
be by the replacement of the original carbonate of lime by a 
different mineral substance, or by an infiltration of such a sub- 
stance into all the pores and spaces in and about the fossil, that 
its fourm would be preserved.” It would be strange indeed if, 
during the millions of years since the deposition of the Lauren- 
tian limestones, they had undergone no change, and notwithstand- 
ing Sterry Hunt’s depositional views, the consensus of opinion is 
in favour of serpentine itself being a product of alteration, 
* Geological Journal,” No. 81,p. 48. 

Had Dr. Carpenter pointed out where serpentine pyroxene or 
loganite had been found in unaltered rocks, instead of dwelling 
upon the internal casts of foraminifera distinguissing the Green- 
sand formation, his remarks would have been more relevant to 
the subject. These casts, it is well known, are in glauconite, a 
hydrous silicate of protoxide of iron and potash. Whether or 
not the silicates replacing the sarcode bodies of the foraminifera 
dredged up by Capt. Spratt in the Aizean, are the resuit of 
precipitation from sea water, caused by the decomposition of 
the sarcodic substance, is quite immaterial to the argument ; but 
if, as is assumed, the chambers of Kozo6n were filled in the same 
manner with serpentine, and this chemical reaction was necessary 
to its precipitation, how are we to account for the serpentine in- 
vesting huge blocks of pyroxene, and the solid bands of the 
same mineral intercalated in the limestone? If, therefore, I ad- 
mit the possible infiltration of certain silicates into the dody of 
Eozoon—did such an animal ever exist—it is no help to those 
who favour the organic hypothesis. I have, however, neither 
affirmed nor denied such a possibility, as it is entirely outside 
of my line of argument. 
As regards hydrothermal action, which it appears is objected 
to if called in to aid my theories, I may say it is a matter of 
indifference what the agency be so long as the a/terafon is prove. 
It would take up too much of your space for me to go 
into the details of the ‘‘canal system,” ‘*nummuline layer,” 
‘« chamber casts,” ‘‘Stolon passages,” ‘‘ pseudopodial tubules ;” 
and such is unnecessary, as Profs. King and Rowney have pretty 
well exhausted the subject, and, to my mind, have conclusively 
proved the existence of identical forms of purely mineral origin. 
If, as is alleged, the canal system always crosses the cleavage 
planes, and is never between them, such would appear to be cor- 
relative mineral phenomena, and tells against the organic hypo- 
thesis. I object, however, to a question of such wide bearing 
being settled solely on the authority of Dr. Carpenter as a 
microscopist. It others are wrong, let him demonstrate the fact, 
which his great experience will more readily enable him to 
accomplish. 
If | have misconstrued the following passage into an admission 
which he now repudiates, I am ready to make ample apology ; 
perhaps, however, he will explain to what the term *‘ elsewhere” 
refers. After combating the notion that the 2wmemudine layer 
can be precisely parallel ina purely mineral produgtion, he says 
he is ‘‘ prepared to maintain the organic origin of Kozoon on 
the broad basis of cumulative evidence aflorded by the combina- 
tion in every single mass of an assemblage of features which can 
only be separately paralleled elsewhere.”* 
Such is Dr. Carpenter’s unbounded faith in Eozo6n—though 
every hypothesis attempting to bring it into the category of 
organic beings is beset with difficulties—that he would not be 
prised to find it existing now in the deep-sea bottom. There is, 
he says, no @ friori improbability in such an event happening, 
and indeed there 1s not, for the persistence of types is one of the 
most remarkable of zoological facts. But as the area in which 
Eozedn is to be found is enlarged, and the duration of its time 
lengthened, our difficulties increase. If the infilling material of 
the chamber casts is due to substitution during decomposition, or 
to direct deposition as suggested by Sterry Hunt, there is no 
possible reason why we should not find Eozoon in some of the 
immense masses of unaltered limestone which still exist. I 
repeat that it has never yet been found in such rocks, but always 
in those that have been metamorphosed. If again serpentine is 
not a product of alteration, why do we not find it in unaltered 
rocks? The inlerence is obvious, they are correlative pheno- 
mena, and therefore Dr, Carpenter must pardon me if I decline 
at present to adopt his views. Still I am open to conviction, 
and will freely admit my error when, after some of his deep-sea 
dredgings, he brings home the modern Eozoon fossilised with a 
silicate, and when, in addition, it is discovered in an unaltered 
limestone fossilised with serpentine pyroxene or loganite. 
T. MELLARD READE 

Blundellsands, Liverpool, Jan. 9 
The Eclipse Expedition 
How about the Eclipse Expedition, which, I presume, you 
helped to sanction? Linformed the public that it would prove 
a complete swindle, and so it has tuned out, As long ay such 
rofessional liars as the Astronomical Society are allowed to 
gull the nation, what chance is there of arriving at the truth? 
JoHN HAMPDEN 
* Geological Journal, vol. xxii. p. 22 
