XXXVlll 
is, however, quite different ^Yitll creatures of popular interest. 
Thus, in writing a popular work on Zoologj^ or in casually men- 
tioning a well-known animal in a work of still more general 
character, we should employ onl)'' a single name, as, for instance, 
the horse, the giraffe, or the peacock, thus adopting the mono- 
n3'mic method; hut if the object were less generally known, we 
should speak of the death's-head moth or the peacock butterfly, 
which, if we wished to apply the scientific names, we should call 
Sphinx Atropos or Papilio lo, one of the two names being un- 
questionably a classificational one ; but if we speak of these two 
insects to a Lepidopterist we must be still more precise, and call 
them Acherontia Atropos and Vanessa lo ; and this triple set of 
names. Sphinx (Acherontia) Atropos, is precisely what has been 
long adopted by many writers. " It is," as was well observed by 
the late Robert Brown, " analogous to the method followed by the 
Romans in the construction of the names of persons, by which 
not only the original famil}^ but the particular branch of that 
family to which the individual belonged, was expressed. Thus 
the generic name corresponds with the nomen (Cornelius), the 
name of the section with the cognomen (Scipio), and that of the 
species with the prrenomen (Publius)." 
Under the title ' On the Origin and Metamorphoses of In- 
sects,' Sir John Lubbock has published a volume containing a 
very carefully compiled and arranged view of the different kinds 
of transformations undergone b}'' insects from their earliest em- 
bryonic state to their adult form, illustrated by manj'' figures, 
with a view to tracing the original type of form from which all 
the different variations have been derived, and which is assumed 
to be found in the genus Campodea, a minute animal allied to 
the Lepismidfe, first described by myself in the Transactions of 
our Society. Sir John Lubbock sums up his views thus: — "It 
seems to me evident that while the form of any given larva 
depends to a certain extent on the group of insects to which it 
belongs, it is also greatly influenced by the external conditions to 
which it is subjected ; that it is a function of the life which the 
larva leads and of the group to which it belongs." No one, 
I think, can object to the first of the above proi^ositions. Whilst 
admiring the excellent manner in which Sir John Lubbock, like 
Mr. Darwin, has worked out his facts, I however, for one, cannot 
adopt an opinion that the form of the larva of any given species 
