148 



NATURE 



[June i6, 1892 



specimens which they have noticed, in various branches 

 of the animal kingdom, yet, as a rule, both such collections 

 and the reports upon them are more or less unsatis- 

 factory to professed naturalists ; partly because they 

 usually represent mere fragments of the fauna of the 

 regions explored, and partly because inexperienced col- 

 lectors often pass over the most interesting species, and 

 bring back common and wide-ranging forms of compara- 

 tively little interest. 



Alpine climbers in particular, as a class, have done so 

 little for zoology in Europe or the Caucasus, that we 

 hardly expected that Mr. Whymper, whose reputation for 

 daring, determination, and endurance, puts him among 

 the most distinguished of Alpine climbers, would now 

 turn his attention to zoology. He has, however, shown 

 the best possible example to his confreres by his Great 

 Andean expedition ; and has proved that it is possible 

 without in any way neglecting the special objects of his 

 journey, to do most valuable zoological work ; and as the 

 higher regions of the Andes have been neglected by pro- 

 fessional collectors, who depend more or less on their 

 success for payment of expenses, the proportion of new 

 Coleoptera brought home by him is very great. Owing, 

 no doubt, to the late Mr. Bates's good advice, Mr. Whym- 

 per has secured the assistance of many specialists of 

 eminence in describing his collections, and the work is 

 profusely illustrated with wood-cuts of the highest 

 class, better by far than many of the coloured illustrations 

 which often appear in scientific periodicals. 



The total number of species collected amounts, accord- 

 ing to Mr. Bates, to about one thousand, but the Diptera, 

 Lepidoptera-Heterocera, Hymenoptera (except the ants), 

 and Arachnida have not been described, on account of 

 the difficulty of finding anyone to work them up ; and as 

 the birds do not seem to have attracted much of Mr. 

 Whymper's attention, and fishes are almost wanting in 

 the higher mountain streams, the greater part of the book 

 is taken up by descriptions of the Coleoptera by Messrs.* 

 Bates, Sharp, Gorham, OUifif, and others. Messrs. God- 

 man and Salvin have written a chapter on the butterflies, 

 but of these very few occur at elevations of 10,000 feet 

 and upwards ; and only two Satyridae, two species of 

 Lycasna, two Pieris, and two Colias, were taken at or 

 above 12,000 feet. This is a strong proof of the poverty 

 of the high Andes in endemic forms, as compared with 

 the high Alps of Europe and Asia, where, notwithstanding 

 the severity of the climate, a large number of species are 

 found at elevations which, when allowance has been made 

 for the latitude, are much higher than these. This may 

 be accounted for to some extent by the weather, which 

 appears to be, in the high Andes of Ecuador, very wet 

 and windy during the whole year. It is farther explained 

 by the late Mr. Bates in the following remarks, taken 

 from the introduction which he has contributed to the 

 volume : — 



"It seems to me a fair deduction from the facts here 

 set forth that no distinct traces of a migration during the 

 lifetime of existing species, from north to south or vice 

 versa, along the Andes have as yet been discovered, or 

 are now likely to be discovered. It does not follow, how- 

 ever, that the Darwinian explanation of the peculiar dis- 

 tribution of species and genera on mountains in the tropi- 

 cal and temperate zones, and in high latitudes of the 

 Old World, is an erroneous one. The different state of 



NO. I 181, VOL. 46] 



things in the New World is probably due to the existence 

 of some obstacle to free migration, as far as regards in- 

 sects, between north and south, both during and since 

 the Glacial epoch. The problem, like most others relat- 

 ing to geographical distribution, is a complicated one ; 

 but there are one or two considerations, likely to be 

 overlooked, which may tend to its solution. One is the 

 great altitude at which the vigorous denizens of the 

 teeming tropical lowlands flourish on the slopes of the 

 Andes. Mr. Whymper found, for example, species of 

 many of the genera of Longicorn Coleoptera characteris- 

 tic of the lowland forests at altitudes of 9000 and 10,000 

 feet, and Kirsch has recorded numerous species of Lam- 

 PyridcB, LycidcB, and other families belonging equally to 

 tropical American forest genera, as met with by Reiss 

 and Stiibel in Colombia and Ecuador at 12,000 feet. In 

 Ecuador all the warm moisture brought by the eastern 

 trade-winds is not intercepted even now by the wall of 

 the Andes, and wherever that falls, in the depressions, 

 conditions of climate and vegetation will be created suit- 

 able to these encroaching tropical forms. If we add to 

 this the barrenness and generally unfavourable conditions 

 of the zone above those altitudes, there can be little won- 

 der that temperate forms have not freely passed along the 

 Andes. Another consideration is that there may have 

 been a breach of continuity of the land in Glacial times, 

 at the Isthmus of Panama, sufficient to prevent free mi- 

 gration. It may, further, be legitimate to speculate on 

 the possibility of the Andes being lower in the tropical 

 zone during the Glacial epoch. A few hundred feet lower 

 than the present altitude, combined with the copious 

 warm rains which must have accompanied the age of ice, 

 would present conditions undoubtedly favourable to the 

 spread of tropical forms over the whole area which would 

 successfully resist the invasion of high northern or 

 southern species. The main principle in distribution, 

 however, is that forms sooner or later, and in proportion 

 to their intrinsic and extrinsic facilities of dissemination, 

 will find their way all over the world to wherever the 

 conditions inorganic and organic are favourable to their 

 acquiring a footing. That these facilities are possessed 

 in a higher degree by plants than insects and some other 

 groups of animals may be a sufficient explanation of the 

 fact that so many species of plants have surmounted the 

 obstacles to their passage from north to south during the 

 last Glacial epoch, while few or no insects have done so. 

 The more distant, or generic, relationship between the 

 insects of Chili and those of the north temperate zone 

 can only be explained on the assumption of a migration 

 at some epoch far more remote than the last Glacial 

 epoch." 



Mr. Whymper's book as a whole is a remarkable ex- 

 ample of his talent as an explorer, a mountain climber, 

 and an accurate observer both of physical, geographical, 

 and natural history phenomena, and though we have 

 waited eleven years for its appearance, nothing has been 

 lost and much has been gained by this delay, and his 

 book will take rank among the very best works of scien- 

 tific travel which have ever been written. 



H. J. Elwes. 



THE HISTORY OF EPIDEMICS. 

 A History of Epidemics in Great Britain from a.d. 664 

 to the Extinction of Plague. By Charles Creighton, 

 M.A., M.D. (Cambridge: University Press, 1891.) 



THE task undertaken by Dr. Charles Creighton in 

 writing a history of epidemics in Britain from 

 664 (the year of the first pestilence recorded by an 

 authority that can be regarded as contemporary) to the 



