The Scottish Naturalist. 71 



tions," and of this feature of his scientific character the present 4 

 theory is instanced as a signal example. Yet Forbes himself 

 says, "in issuing it, I do so keeping in view a vast number of 

 individual facts, and base it on the results of investigations of 

 no small extent." To lay these before the scientific world in 

 detailed or tabulated shape will be the work," he added, "of 

 more leisure than can at present be given to the task." That 

 leisure never came. We may say of him, adopting the language 

 of Geikie in reference to Jukes, who left behind him similarly 

 a newly originated but unproven view of the Devonian rocks, 

 that he was removed from among us before he had time 

 adequately to work out the views which he had sketched. He 

 was a trained and most skilful adept in Palaeontology, and 

 though his suggestion has not been adopted by the general body 

 of geologists, there must still linger in many minds the convic- 

 tion that a view which had recommended itself to so earnest 

 and experienced a palaeontologist is well worthy of serious con- 

 sideration. It is true that Forbes in his theorising soared high ; 

 but, though it may be that he had to struggle with a tendency 

 to indulge "the use," rather than to observe " the limit of the 

 imagination in science," it is also true that he had the keenest 

 sense for facts and unrivalled powers of observation, and that he 

 seldom soared on a foolish or a fruitless flight. It would be 

 strange indeed if this polar arrangement should to his practised 

 eye have seemed a true reading of nature, whilst it had no 

 actual standing in fact at all. 



At all events, stand or fall it must, according as the facts 

 shall be found to determine. It is the facts on which it pro- 

 fesses to build that can alone be made the means of its removal. 

 It must be accurately apprehended in its own terms in the first 

 place, and then in those terms shown to be an inaccurate inter- 

 pretation of nature. Now the only criticisims, or at least the 

 principal ones that I have seen, those of Pictet and Wallace, 

 both follow close on Forbes's proposal, and the latter, re- 

 peated afresh last year, are certainly chargeable, so far, with 

 an inexact apprehension of the doctrine they deal with ; and 

 curiously, with that kind of misapprehension, against which its 

 author gave a special caution. It is to be observed that the 

 theory makes no affirmation about the amount of life, in indi- 

 viduals or in species, at any epoch on the earth. The number 



