1879 *] /s Organic Variation Fortuitous ? 353 
the mimetism is to be useful must be — rare. Now, according 
to hypothesis, it is only very numerous species which are 
likely to yield individuals possessing the required variations. 
Another difficulty is to be found in the metamorphosis of 
certain Dipterous inserts. Instead of the tissues ot the larva 
being transformed into those of the perfect insedt, they seem 
to be melted down, except at certain spots, into a semi-liquid 
substance, from which the tissues of the perfect insedt are 
afterwards re-developed. Mr. Mivart bases on this excep- 
tional fadt an argument against the all-sufficiency of Natural 
Seledtion. 
To the contention that geological time is too short for 
Darwin’s theory, few geologists and biologists will attach 
much importance. The very discrepancies in the calcula- 
tions of the mathematicians and physicists who have under- 
taken to fix a maximum limit — discrepancies which are in 
the proportion of 1 to 40 — might provoke a smile. 
From all these considerations, and from many others which 
we cannot here particularise, Mr. Murphy concludes that 
organic species and their peculiarities are due not alone to 
the accumulation of fortuitous variations, but to Intelligence. 
Still he does not hold that the intelligence which diredts the 
formation of organic strudtures is necessarily conscious, nor 
that such strudtures and their adaptations are the diredt 
work of Creative Wisdom : he considers it “ more reasonable 
to believe that organic progress has been effedted not by a 
fresh exertion of Creative Power at every one of the innu- 
merable stages, but by a principle of Intelligence which 
guides all organic formation and all motor instindts, and 
finally attains to consciousness in the brains of the higher 
animals, and to self-consciousness in the brain of Man.” 
He thus, equally with Darwin, avoids making God respon- 
sible for the imperfedtions of the organic world, for the 
existence of parasitic worms, &c., which on the hypothesis 
of the Old Natural History “ can only be regarded as instru- 
ments of torture devised by the Creator, and whose existence 
no writer of Bridgewater Treatises has yet even attempted to 
reconcile with His infinite wisdom and benevolence.” 
An important consideration, which would well repay spe- 
cial notice did space allow, is that the construdtive instindts 
of social insedts — bees, wasps, and ants — cannot be inherited 
in the diredt line, because these instindts are possessed by 
the workers alone, which are non-reprodudtive. This, how- 
ever, is only partially corredt. Female wasps, humble-bees, 
&c., especially at the first establishment of a new colony, 
enjoy none of the exemption from labour which falls to the 
lot of the queen hive-bee and of female ants. 
