Bihliogrcq^liical Notices. lO.j 



But Dr. McCook advances certain arguments in an attempt to prove 

 that in the case of H. vcnatoriu man, at least, has nut been one of 

 them ; for wo read on p. :^G!), vol. ii., " . . . . the following facts 

 warrant the theorj' that the Iluntsman Spider has become cosmo- 

 politan by the action of nature, independent of the aid of man : 

 first, the early discovery of the species as already widely distributed ; 

 second, its presence at so many diflerent insular points nearly or 

 altogether contemporaneously with first visits of commercial nations ; 

 third, the existence of the species or its close allies among the fauna 

 of the tropical interiors of continents far distant from coast-lines ; 

 fourth, the variations, chiefly in colour, which have been observed, 

 and whicb would seem to require for their development a longer 

 period than that which has transpired since the commencement of 

 commercial communication with the localities in which the varia- 

 tions have been wrought." 



Each of these arguments, however, is open to criticism — (1 and 2) 

 II. venatorui has only been known for about 140 years, having been 

 described by Linnaeus in 1750 or thereabouts. What evidence, then, 

 is there that the species was widely distributed when the world was 

 first circumnavigated 200 years before Linmeus wrote ? Again, 

 supposing that Sir Francis Drake had brought examples of this 

 species from all the localities that his vessel passed on his voyage 

 round the world, what would this have shown ? Merely that the 

 distribution of the animal was not to be attributed to him. It would 

 give no information whatsoever to justify the assumption that the 

 spider had not been carried by previous visitors. Or, again, if it 

 was an ascertained fact that H. venatoi-ia was an inhabitant of the 

 Antilles when Columbus first made known to Europeans the exist- 

 ence of these islands, would any one have the right to conclude 

 therefrom that the spider had not been introduced there by man ? 

 Dr. AlcCook seoms to have lost sight of the fact that this spider may 

 have been carried to the various localities where it is found by far 

 earlier colonists than history has any record of. AVas the dingo not 

 introduced into Australia by man because we do not know the date 

 of its first appearance there ? (3) "What conclusion in support of 

 Dr. McCook's view can possibly be drawn from the fact that the 

 spider is found inland as well as on the coast ? What is to prevent 

 such a species from travelling to the interior when once it has 

 effected a landing ? Are we to conclude that the common rat 

 and the common cockroach have not been brought to England 

 in ships because they are not confined to our seaport towns ? 

 (4) \Yith regard to the proposition respecting the colour variations, 

 it is certain that Dr. McCook would be doing great service to zoology 

 if he would publish what information he possesses on the question 

 of the length of time required for the development of such varia- 

 tions. Undoubtedly evidence should be produced to show that 

 certain varieties occur in certain localities. Otherwise we may well 

 be excused for asking what reasons there are for thinking that tho 

 variations in colour are the result of a wide-spread range. It may 

 be characteristic of the species to vary quite apart from it« being 



