Mr. T. V. WoUaston on the Tarphii. 379 



truth of sense. But those who akeady acknowledge this twofold 

 aspect of truth will accept the doctrine of limits, in a general 

 signification, as embodying a principle not the less certain because 

 incapable of actual demonstration ; and, accepting it generally, they 

 will not feel themselves compelled to admit that all life has sprung 

 from a single germ (the only logical conclusion of the transmuta- 

 tionists, and not the " analogical " one, as has been asserted), through 

 the mere fact that a truth of pure reason is discovered to be, in its en- 

 tirety, unproveable. 



I do not apologize for this slight apparent digression, as the reader 

 will immediately perceive why I have been led into it. If we can 

 estabHsh the com-iction that the doctrine of limits is (in the nature 

 of things) essentially a reasonable one, we shall not be regarded as 

 " inconsistent " for holding variability to be an inherent principle 

 (more or less expressed according to the elasticity of each indi-vidiial 

 species, and therefore strongly so in some, whilst it is scarcely trace- 

 able in others*), and yet denying its existence, in all instances, except 

 to a certain (a 2^riori undefinable) extent — an extent, however, which 

 we may ascertain approximately by observation, leaving our reason 

 to supply, from analogy, what sense (not being omniscient) is of 

 course unable, at a single glance, to take in. 



But lest I should be accused of merely theorizing, and of insisting 

 upon old scholastic definitions which it is the fashion now-a-days (at 

 least in those who have not stuched them) to regard as obsolete, and 

 since, if there be any reality in the distinctions which I have dwelt 

 upon, they ought to bear the strictest analysis, it will not be con- 

 sidered irrelevant, even in the present paper, if we test them by the 

 most common-place example we can select. Let us take, then, the 

 genus Homo. It is quite impossible to define rigidly the exact 

 growth of the human species. No amount of observation will teU 

 us either its maximum or its minimum. Nevertheless, in spite of 

 this, we are perfectly certain that its bounds are strictly circum- 

 scribed ; for it is a matter of plain reason (of which we are as sui'e 

 as we are of our own existence) that no man wiU ever attain the 

 height of the monument, and likewise that no one was ever so small 

 as the fabled denizens of Lilliput. Yet ive cannot prove tliis. And 

 why? Because it is merely a "truth of reason." "VVe can take a 



* The domestic pigeon, in its various artificial phases, may be cited as a good 

 instance (not entirely, perhaps, an original one) of the former category ; whilst 

 the common Lady -bird {Coccindla 1 -punctata), which occurs in nearly every 

 country of the Old World, and at all elevations, without the slightest appreciable 

 change in its specific characteristics, will sufiice as an instance of the latter. 



