HARDWICKE'S SCIENCE-GOSSIP. 



175 



Secondly : the strike of the igneous rock is 

 parallel to the flanking Cambrian deposits, differing 

 most distinctly from the discordant relations of the 

 gneiss and newer rocks in the North-West of 

 Scotland, and entirely agreeing with the parallelism 

 of the Cambrian and Silurian strata in North Wales. 

 On this Murchison lays great stress.* 



Thirdly, the absence of the Lower Cambrian rocks 

 which attain such an enormous development within a 

 comparatively short distance to the north ; and their 

 absence is all the more extraordinary, when we 

 remember that Longmynd rocks occur only nine 

 miles south of the Malvern Hills on a direct line 

 with the great fault that has brought both to the 

 surface. This inlier, which for many years has been 

 a great thorn in the side of the Archeanists, is a small 

 boss of hard silicious schistose rock with many 

 quartzose veins. That it is really a member of the 

 Longmynd series, is supported by an overwhelming 

 weight both of evidence and opinion : in 1879, during 

 the excursion of the Geologists' Association, this 

 rock was visited under the guidance of Dr. Callaway 

 and Dr. Hicks, who state in their report, t that those 

 members acquainted with the Longmynd in other 

 areas acknowledged its close resemblance to those 

 rocks, both in mineral character and state of 

 induration. Since this date Dr. Callaway has, to use 

 a recent political phrase, "chucked up the sponge," 

 and abandoning the attempt, made in the report 

 quoted, to explain away this knoll of rock, has 

 confessed % that it is Longmynd. This admission is 

 of the greatest value, as we can easily see how the 

 movements that intruded the syenite into and altered 

 the Longmynd rocks at Malvern, should have 

 brought up on the same great line of fault, crumbled 

 and contorted, a fragment of the same rock, which on 

 any other theory is inexplicable. 



But some readers may impatiently ask, What on 

 earth does it matter whether these Malvern rocks are 

 Fre-Cambrian or Cambrian ? And whether, as the 

 difference is so slight, discussing so apparently 

 trivial a point at such detail is not the mere 

 affectation of specialists ? To such the answer is 

 simple. If one were to debate whether a bed was 

 Triassic or Liassic, it would be a mere matter of 

 classification, of which most naturalists would know 

 nothing, and for which they would care less. But 

 this is no mere question of nomenclature : a great 

 fundamental point is at issue, and on the conclusion 

 at which we arrive, depends the interpretation of the 

 whole record of the world's history in Pre-Cambrian 

 times. Should we accept the Archean teaching, we 

 must abandon those old views of the absolute 

 uniformity of nature, which Lyell made the foundation 

 stone of much of the geology of the last forty years. 



* It is of course possible to point out isolated instances in 

 ■which this is not the case, but as a general rule the strikes are 

 parallel. 



t " Proc. Geol. Assoc." 1879, vol. vi. part 5. 



X "Quart. Journ. Geol. Soc." toI. xxxvi. p. 537. 



We shall return to the petrological creed that Werner 

 taught a century ago, and believe that gneiss and 

 schists were deposited by chemical precipitation in 

 some boiling ocean "when the earth was young," 

 and must hold that just before the Cambrian era 

 some great change, for which we know no reason, 

 and of which we have no satisfactory evidence, passed 

 over the earth. These are but some of the cloud of 

 intricate and complicated problems, that we raise or 

 allay, as we decide one way or the other, and a 

 complete revolution of our petrological ideas hangs in 

 the balance. 



It is from no desire of rushing into a great contro- 

 versy, regardless of the difficulties in the generally 

 received interpretation, or of the great names arrayed 

 in the ranks of the new school, that I venture to 

 submit these few notes, but, that the views advanced 

 by Mr. Watts should not, by being unchallenged, 

 appear to be endorsed ; and that the conclusions 

 arrived at by men, whose lives having been devoted 

 to geological mapping had attained an experience 

 and skill still unrivalled, should not be lightly cast 

 aside ; and in the hope that fellow students of 

 geology may be induced to pause before adopting a 

 theory, however plausible and pretty it may appear, 

 or however ably and persistently it may be advocated, 

 without the most careful consideration of both sides 

 of this complicated and interesting subject, and of 

 the momentous issues involved in the discussion. 



NOTES ON NEW BOOKS. 



THIRDS I have kept in Years gone by, by W. T. 

 JLJ Greene, M.A., M.D., F.Z.S., &c. (London: 

 L. Upcott Gill). Dr. Greene has evidently a kindly 

 feeling for his pets, and discourses in a pleasant 

 style on their habits and the best ways of keeping 

 them, including frequent directions for dieting and 

 medicine. His list of birds is a long one, contain- 

 ing both British and foreign, and his book is illus- 

 trated with coloured plates, and provided with a 

 table of contents. It may be a question in the case 

 of some birds, whether their lot is happier or not in 

 captivity than in freedom. On the one hand they 

 suffer the loss of liberty, and are liable to disorders 

 due to an unnatural diet, bad housing or other mis- 

 management, but on the other hand they are protected 

 from the contingencies of an outdoor life, and are 

 generally sheltered from the attacks of their natural 

 enemies. Anyhow, if birds are to be kept in captivity, 

 they are not likely to fall into more experienced hands 

 than those of Dr. Greene, and perhaps some of the 

 pity might be better expended if bestowed on the 

 captives before they come into such keeping as his. 



The Birds of Lancashire, by F. S. Mitchell 

 (London : Van Voorst). This book is an example of 

 that Saxon energy which enables a man, though 

 engaged in business, to find time to devote attentioa 



