40 



NA TURE 



[November ii, 1909 



way his appreciation of the work of the association 

 and the honour done him in electing him the 

 president for the year, and he thought he could do 

 this by offering to defray the cost of the die of a 

 suitable medal for the purpose suggested by Mr. 

 Lowden. On the proposal of Mr. Innes, seconded by 

 Dr. Juritz, it was; resolved to accept this offer with 

 many thank-;, and to name the awards the " Goold- 

 .Adams " medals. 



The Bloemfontein Museum deserves an article to 

 itself ; the members of the association were shown 

 over the collections, and from cupboard and cranny 

 objects of the utmost value were unearthed, including 

 meteorites, stone and iron ones. Karroo fossils, early 

 printed books, engravings, manuscripts, Bushmen 

 implements, and a complete quagga skin. The collec- 

 tions urgentlv need proper accommodation, and it is 

 hoped that the visit of the association brought home 

 to the authorities some realisation of what a valuable 

 asset for the town they had in their museum. 



Dr. R. T. A. Innes was elected honorary secretary 

 for the Transvaal and Free State, and Dr. C. F. 

 Juritz for Cape Colony and Rhodesia, Dr. R. T. 

 Lehfeldt honorary treasurer. 



.At the close of the meeting forty-five members left 

 for a train and wagon trip to Basutoland, the railway 

 authorities having placed a special train at the dis- 

 posal of the association. 



AMERICAN CAVE VERTEBRATES.^ 



PROF. EIGENM.ANN has brought together in an 

 attractive and copiously illustrated quarto 

 volume the results of his investigations on the cave 

 fauna of America, upon which he has been engaged 

 for many years. He points out that each cave is a 

 separate environmental unit requiring special con- 

 sideration, but all share to a greater or less extent 

 certain common features, viz. the reduction or total 

 absence of light and the relative constancy of other 

 physical conditions, such as temperature. 



The blind cave vertebrates form a very mixed 

 faunistic group, derived from a variety of epigean an- 

 cestors. It appears, however, that " a certain predis- 

 position in habit and structure must be present to 

 enable a species to dispense with light and to live 

 in caves." No mammals appear to have become 

 especially adapted for permanent cave life, though, of 

 course, many spend a large part of their lives in 

 such situations. They may be " twilight animals," 

 but they still have normal eyes. The same is the 

 case with birds, and there are also no cave reptiles, 

 which is remarkable when we consider that many 

 snakes and lizards are blind, and burrow under- 

 ground. 



It is amongst the amphibia and fishes that true 

 cave vertebrates are to be found. Two of the North 

 American salamanders, of the genus Spelerpes, which 

 habitually live in caves, still possess what appear to 

 be normal eyes, while two others, of the genera 

 Tvphlotriton and Typhlomolge, have their eyes quite 

 degenerate, resembling in this respect the European 

 Proteus. The .\mblyopsidcE are the typical North 

 -American cave fishes. " .Ml the members of this 

 family, eight in number, have degenerate eyes ; five 

 have mere vestiges ; six permanently live in caves ; 

 one is known onlv from a spring, and another from 

 open streams." More remarkable is the fact that in 

 Cuba two sightless fishes, Stygicola and Lucifuga, 

 belonging to a marine family many of which are 

 blind, have become adapted to the fresh waters of 

 caves. 



• " Cave Vertebrates of America. A Study in Deeenerative Evolution.' 

 By Prof. Carl H. Kigentnann. Pp. ix4-24i. (Washington: Carnegie 

 iQog.) 



NO. 2089, VOL. 82] 



Space forbids us to follow the author in his detailed 

 and interesting discussion of the origin of the cave 

 fauna. We mav note, however, that he seems inclined 

 to regard blindness as an antecedent rather than as. 

 a consequence of cave life, for it is only animals which 

 are already accustomed to find their food by the sense 

 of touch or smell whicli could ever establish them- 

 selves in complete darkness. In Amblyopsis, and 

 other blind fishes, great numbers of special tactile 

 organs are developed, especially about the head, and 

 these serve for ascertaining, by disturbances in the 

 water, the whereabouts of prey. 



In the case of the loss of colour, however, which 

 is such a general character of animals living in per- 

 petual darkness, it is different, and Prof. Eigenmann 

 regards this character as due in the first place lo the 

 direct influence of the environment upon the indi- 

 vidual. To quote his own words, " The bleached 

 condition of animals living in the dark, an individual 

 environmental adaptation, is transmissible, and finally 

 becomes hereditarily fi.xed." This conclusion is based 

 upon the fact that in .Amblyopsis the bleaching takes 

 place even when the young are reared in the light. 

 " Natural selection cannot have affected the coloration 

 of the cave forms, for it can be of no consequence 

 whether a cave species is white or black. It could 

 onlv affect the coloration indirectly in one of two 

 wavs : first, as a matter of economy, but since the 

 individual is in part bleached by the direct effect of the 

 darkness, there is no reason why natural selection 

 should come into play at all in reducing the pigment 

 as a matter of economv ; second, Romanes has supposed 

 that the colour disappeared through the selection of 

 correlated structures, a supposition he found scarcely 

 conceivable when the variety of animals showing the 

 bleached condition was considered." It appears to 

 us that these conclusions are of great interest and 

 importance, and that Prof. Eigenmann has made out 

 a strong case for the inheritance of acquired characters 

 in this instance. In the case of Proteus it appears 

 that the bleached condition has not yet become heredi- 

 tarilv established, for this animal becomes darker when 

 exposed to the light. Possibly, after all, tlie inherit- 

 ance or non-inheritance of acquired characters is 

 largelv a question of time, or, perhaps better, of the 

 number of successive generations which have re- 

 sponded ontogenetically to the particular stimulus 

 which evokes the character in question. 



•A great part of the volume is devoted to the con- 

 sideration of the structural changes which accompany 

 the degeneration of the eyes, and the author has given 

 us a large amount of verv valuable information on 

 this difficult subject, including a detailed account of 

 the development of the eye of .Amblyopsis. From many 

 points of view this interesting work will well repay 

 a careful perusal. Arthur Dendy. 



THE PRESERVATION OF NATURAL 

 MONUMENTS IN GERMANY.' 



THE German Government has been, for the last 

 two vears, organising a national system for the 

 preservation of the natural monuments of the country. 

 During the last year the scheme has developed in 

 comprehensiveness, and has produced gratifying 

 results. There are now forty local committees, and 

 at the end of last year the first Congress for Natur- 

 deiikmalpflege in Prussia was held at Berlin. A con- 

 siderable number of valuable reports has been issued; 

 the present volume, edited by the energetic Govern- 

 ment Commissioner for the Care of Natural Monu- 

 ments, Prof. Conwentz, contains a report of the con- 



1 '■ Beitrage zur Nalurdeiikmalpflege." By Prof. H. Conwentz. Heft j. 

 Pp. 157-296. (Berlin : Gebriider Bornt-aeger, 1905.) Price 2 marks. 



