Dr. A. Giinthei' on the Geographical Distribution of Reptiles. 223 



without the supply of food necessary for preserving the energies of 

 the vital functions *. Dr. A. Smith himself v^as an eye-witness how 

 several specimens of Brachymerus fasciatus were found in a lethargic 

 state in a hole of a tree, completely closed, conspicuously open before 

 and grown together afterwards. Such a tenacity of life is never to 

 be observed in a Snake : the higher the temperature the greater is 

 the need of food ; and a Snake having endured fasting during six or 

 nine months always dies. Moreover, the tenacity of life in the Ba- 

 trachians is proved by their power of reproduction, which has never 

 been observed in a Snake. If we add the fact that Snakes do not 

 produce many eggs or young ones, that they are able to propagate 

 only when several years old, that they incur continual dangers by 

 their numerous enemies, and that they are deprived of the means of 

 performing distant journeys, we must consider it as the natural con- 

 sequence, that no species will spread so far as Batrachians. These 

 are enabled to endure temporary physical disadvantages, to traverse 

 localities without the regular supply for their life, and to make up 

 yearly for the lost number by a numerous offspring. More or less 

 confined to a fluid element, they are favoured by another agency for 

 an easier spreading. But these facts are really applicable to a com- 

 paratively small number of species only ; and the question why we 

 do not find all these peculiarities equally exhibited in all the Batra- 

 chians or in a great part of them, is as difficult to be answered as 

 why one species is richer in individuals than another : but it is 

 remarkable that just those species which are spread over the widest 

 range are also those distinguished by an intensity of individuals. 



On the other hand, we find Snakes almost entirely limited to the 

 original locality of the individual: but if the individuals are restricted 

 to the soil which gave them birth, the whole group, formed by such 

 individuals, is likewise stationary ; and if there be different creations, 

 corresponding to the different natural divisions of the earth's sur- 

 face, such a group as the Snakes must be best adapted for proving it, 

 because here the agencies are wanting by which a species or a genus 

 is spread over a larger part of the globe in the course of time, thus 

 becoming mixed with foreign forms. 



After these preliminary remarks, I proceed to the special objects of 

 our inquiry ; and we shall then see what conclusions can be formed 

 in comparison with those of the ornithologist f. According to the 

 above-stated peculiarities of the life of Snakes, there is no cosmopo- 

 litan species, and we can find only a few examples where one and the 

 same species extends over the borders of the neighbouring region 

 (cf. p. 226, Naja haje, Echis carinata, Zamenis ventrimaculatusy and 

 pp. 233, 234, some species ranging from the Nearctic region into the 

 Neotropical, and vice versd). Among the genera we do not find one 



* Cf. " Observations on the Common Toad, and on its long abstinence from 

 food," by John Brown, Esq, (Ann. & Mag. Nat. Hist. 1842, vol. x. p. 18a). 



t As for the systematical denominations adopted, I refer to the ' Catalogue of 

 Snakes' {Crotalidce, Viperidoe, Hydrides, Boidce) by J. E. Gray, London, 1849, and 

 to my * Catalogue oi Colubrine Snakes in the Collection of the British Museum/ 

 London, 1858. 



