92 PROFESSOR OWEN ON THE AYE-AYE. 
What I have termed the ‘ derivative hypothesis’ of organisms, for example, holds 
that these are coming into being, by aggregation of organic atoms, at all times and 
in all places, under their simplest unicellular condition ; with differences of character 
as many as are the various circumstances, conditions, and combinations of the causes 
educing them,—one form appearing in mud at the bottom of the ocean, another in 
the pond on the heath, a third in the sawdust of the cellar, a fourth on the surface of 
the mountain rock, &c., but all by combination and arrangement of organic atoms 
through forces and conditions acting according to predetermined law. ‘The disposition 
to vary in form and structure, according to variation of surrounding conditions, is 
greatest in these first-formed beings; and from them, or such as them, are and have 
been derived all other and higher forms of organisms on this planet. And thus it is 
that we now find energizing in fair proportions every grade of organization from Man 
to the Monad. Each organism, as such, also propagates its own form for a time under 
such similitude as to be called its kind. 
Specific characters are those that have been recognized in individuals of successive 
generations, propagating similar individuals, as far back as observation has reached ; 
and which characters, not being artificially produced, are ascribed to nature. Instead 
of referring such characters to an originally distinct creation, the derivative hypothesis, 
whilst admitting their transmissibility and their maintenance for an unknown period 
through generative powers obstructive of departure from such characters, holds that 
observation has not yet reached the actual beginning of such species, nor the point at 
which variation stops. 
Now, the foregoing hypothesis is at present based on so narrow and, as respects 
the origin of life, so uncertain a foundation of ascertained facts', that it can be regarded 
only as a kind of vantage-ground artificially raised to expand the view of the outlooker 
for the road to truth, and perhaps as supporting sign-posts directing where that road 
may most likely be fallen in with. 
In the meantime different hypotheses, guesses, and beliefs have been propounded in 
explanation of the way of the origin of species. And the Aye-aye lends itself with 
advantage as a test of some of these. 
Buffon assumes the direct or immediate primitive creation of a certain number of 
organic forms, which may truly and intelligibly be called ‘types.’ These, left to the 
to his more cautious or reticent fellow-labourers. But I would offer this consolation to those whom Professor 
Grant stigmatizes as ‘‘species-mongers’’ (‘Tabular View of the Primary Divisions of the Animal Kingdom, 
&e.,’ 8vo, 1861, p. vi.) :—for all the intents and purposes of the descriptive and recording naturalist, species 
are constant ; they will last our time. When the existing binomial units of botanical and zoological specific 
lists cease to show their present distinctive characters, the Homo sapiens of Linnzeus will have merged into another, 
probably a higher, specific form. 
* Annales des Sciences Naturelles, 1861, p. 33 (Pasteur) ; i, 1862, p.277 (Pouchet ; able in refutation of 
objectors to Heterogeny, and full of resource in its support). 
