April 18, 1872] 



NATURE 



485 



the doctrine of evolution. Prof. Schiodte, the eminent 

 Danish aoologist, has given us the most extended account 

 of the cave fauna of Europe, which has been translated 

 from the Danish into the Transactions of the Entomolo- 

 gical Society of London (new scries, vol. i., 1851). 



A pertinent question arises as to the time of the forma- 

 tion of these caves and when they became inhabitable. 

 As previously stated, the caves of the western and middle 

 States are in lower Carboniferous limestone rocks, though 

 the Port Kennedy cave explored by Wheatley and Cope * 

 is in the Potsdam limestone. They could not have been 

 formed under water, but when the land was drained by 

 large rivers. This could not have occurred previous to 

 the Triassic period. Prof. Dana in his '• Manual of 

 Geology " shows that the Triassic continent spread west- 

 ward from the Atlantic coast " to Kansas, and southward 

 to Alabama ; for through this great area there are no 

 rocks more recent than the Palteozoic." " Through the 

 Mesozoic period (comprising the Triassic, Jurassic, and 

 Cretaceous periods) North America was in general dry 

 land, and on the east it stood a large part of the time 

 above its present level." Though at the close of these 

 periods there was a general extinction of life, yet this was 

 not probably a sudden (one of months and even years), 

 but rather a secular extinction, and there may be plants 

 and animals now living on dry land, which are the lineal 

 descendants of Mesozoic and more remotely of Carbo- 

 niferous forms of life. So our cave animals may possibly 

 be the survivors of Mesozoic forms of life, just as we find 

 now living at great depths in the sea remnants of Cre- 

 taceous life. But from the recent explorations in the 

 caves of Europe and this country, especially the Port 

 Kennedy cave, with its remarkable assemblage of verte- 

 brates and insects, we are led to believe from the array 

 of facts presented by Prof. Cope that our true subter- 

 ranean fauna probably does not date farther back 

 than the beginning of the Quaternary, or post- Pliocene, 

 period. We quote his " general observations " in his 

 article on the Port Kennedy fauna : — 



" The origin of the caves which so abound in the lime- 

 stones of the Alleghany and Mississippi valley regions, is 

 a subject of much interest. Their galleries measure many 

 thousands of miles, and their number is legion. The 

 writer has examined twenty-five, in more or less detail, in 

 Virginia and Tennessee, and can add his testimony to 

 the belief that they have been formed by currents of 

 running water. They generally extend in a direction 

 parallel to the strike of the strata, and- have their 

 greatest diameter in the direction of the dip. Their 

 depth is determined in some measure by the softness of 

 the stratum whose removal has given them existence, 

 but in thinly stratified or soft material, the roofs or large 

 masses of rocks fall in, which interrupt the passage be- 

 low. Caves, however, exist when the strata are horizon- 

 tal. Their course is changed by Joints or faults, into 

 which the excavating waters have found their way. 



" That these caves were formed prior to the post-Plio- 

 cene fauna is evident from the fact that they contain its 

 remains. That they were not in existence prior to the 

 drift is probable, from the fact that they contain no re- 

 mains of life of any earlier period so far as known, though 

 in only two cases, in Virginia and Pennsylvania, have 

 they been examined to the bottom. No agency is at 

 hand to account for their excavation, comparable in 

 potency and efficiency to the floods supposed to have 

 marked the close of the glacial epoch, and which Prof 

 Dana ascribes to the Champlain epoch. An extraordinary 

 number of rapidly flowing waters must have operated 

 over a great part of the Southern States, some of them 

 at an elevation of fifteen hundred feet and over (perhaps 

 two thousand) above the present level of the sea. A cave 



ably not come under the head of cave insects. 



.vill bi; found in the Proc. 

 there enumerated would prob- 



in the Gap Mountain, on the Kanawha river, which I ex- 

 plored for three miles, has at least that elevation. 



'' That a]territory experiencing such conditions was suit- 

 able for the occupation of such a fauna as the deposits 

 contained in these caves reveal, is not probable. The 

 material in which the bones occur in the south is an im- 

 pure limestone, being mixed with and coloured by the red 

 soil which covers the surface of the ground. It is rather 

 soft but hardens on exposure to the air. 



" The question then remains so far unanswered as to 

 whether a submergence occurred subsequent to the de- 

 velopment of the post-pliocene mammalian fauna. That 

 some important change took place is rendered probable 

 by the fact that nearly all the neotropical types of the 

 animals have been banished from our territory, and the 

 greater part of the species of all types have become ex- 

 tinct. Two facts have come under my observation which 

 indicate a subsequent submergence. A series of caves or 

 portions of a ■jingle cave once existing on the south-east 

 side of a rang.^ of low hills among the Alloghany moun- 

 tains in WytUe Co., Virginia, was found to have been 

 removed by denudation, fragments of the bottom deposit 

 only remaining in fissures and concavities, separated by 

 various intervals from each other. These fragments 

 yielded the remains of twenty species of post-Pliocene 

 mammalia." This denudation can be ascribed to local 

 causes, following a subsidence of uncertain extent. In a 

 cave examined in Tennessee the ossiferous deposit was in 

 part attached to the roof of the chamber. Identical 

 fossils were taken from the floor. This might, however, 

 be accounted for on local grounds. The islands of the 

 eastern part of the West Indies appear to have been 

 separated by submergence of larger areas, at the close of 

 the period during which they were inhabited by post- 

 Pliocene mammalia and shells. The caves of Anguilla 

 include remains of twelve vertebrates,f of which seven 

 are mammalia of extinct species, and several of them are 

 of large size. These are associated with two recent 

 species of molluscs. Turbo pica and a Tiidora near 

 pupaforinis. X As these large animals no doubt required 

 a more extended territoi7 for their support than that re- 

 presented by the small island Anguilla, there is every 

 probability that the separation of these islands took 

 place at a late period of time and probably subsequent 

 to the spread of the post-Pliocene fauna over North 

 America." 



I think the reader will conclude from the facts Prof. Cope 

 so clearly presents, that the subterranean fauna of this 

 country does not date back beyond the Quaternary period. 

 These species must have been created and taken up their 

 abode in these caves (Mammoth Cave and those of Mont- 

 gomery County, Virginia) after the breccia flooring their 

 bottoms and containing the bones of Quaternary animals 

 had been deposited ; or else migrated from Tertiary caves 

 farther south, which is not probable, as it has been pre- 

 viously shown that those blind animals inhabiting wells 

 immediately die on being exposed to the light. (British 

 Sessile-eyed Crustacea, i. p. 313. Though this is true of 

 the Gammands, Mr. Putnam tells me that a blind craw- 

 fish lived several days in a bottle of water exposed to the 

 hght, and is thus as hardy as any crustacean.) 



♦ See Proceed. Amer. Phil. Soc, 1869, 171. 



t Loc. cit. 1869, 183 ; 1870, 60S. A fourth species of gigantic Chinchillid 

 has been found liy Dr. Rijgersma, which may be called Loxojnyltts \lnad- 

 7ans Cope. It is represented by portions of jaws and teeth of tliree indivi- 

 duals, it is one of the largest species, equalling the L. latidens, and has 

 several marked characters. Thus the roots of the molars are very short, 

 and the triturating surface oblique to the shaft. The roots of the second 

 and fourth are longer than those of the first and third. The last molar has 

 four dental columns instead of three as in the other Loxotttyli, -nd is tri- 

 angular or quac'rant-shaped in section : the third is quadrangular in section, 

 and has three columns. The second is the smallest, being only '6 the length 

 of the subtriangular, first. Length of dental series m. '063 or 2 '5 inches. 

 Palate narrow and deeply concave. There is but little or no lateral cony tric- 

 tion in the outlines of the teeth ; the shanks are entirely stra'ght. In its 

 additional dentinal column, this species approaches the genus Aiublyrhiza, 

 The large Chinchillas of Anguilla are as follows, Loxo7fiyli4S longidens^ Z- 

 latidens^ L. quadranSy and Atublyrkiza initridata, 

 X See Bland, Proceed, Amer, Phil, Soc, 1871, 58. 



