448 llev. H. C. McCook on the Cutting Ant of Texas. 
with certain double annual flowers, if admitted to throw 
some light upon the inquiry, yet require an efficient superin¬ 
tending human intelligence, which cannot be supposed to 
have its analogue in the perpetuation and development of 
ant forms, unless, indeed, we may believe that the evolu¬ 
tion hypothesis implies and requires the interposition of a 
Personal Intelligence infinitely superior to that of both ant 
and man. 
The precise sense in which the workers may be called 
“ sterile ” admits of some question. Sir John Lubbock has 
recently shown that parthenogenetic eggs are sometimes pro¬ 
duced by worker-ants in artificial formicaries, from which 
males alone are hatched. This is according to the analogy 
of other Hymenoptera, as, for example, bees and wasps. 
Here, then, there may be possible escape from Mr. Darwin’s 
difficulty more satisfactory than that which he himself sug¬ 
gests ; for it is conceivable that an opportunity might thus be 
opened for the transmission of a profitable variation which 
might arise in a worker. Still the difficulty appears im¬ 
passable. One must suppose the growth and maturity of 
one such parthenogenetic male, produced from a worker with 
such useful modification, to have been contemporaneous with 
the maturity of the females of a “ swarm ; ” this male, toge¬ 
ther with the males hatched directly from eggs laid by the 
queen, shall have gone forth, as is the habit of ants, in the 
regular marriage flight, or “swarming;” and therein shall 
have met a virgin queen. As the modification thus supposed 
to be transmitted must, on the hypothesis, be very minute, it 
could have been saved from obliteration only by supposing it 
fortified by the recurrence of other contingencies of like cha¬ 
racter in succeeding generations. Mr. McCook therefore con¬ 
cluded that the development by natural selection, according 
to Mr. Darwin’s hypothesis, of so many and widely varied 
forms as exist in the cutting ant, requires a series of contin¬ 
gencies so multiplied and remote as to forbid a reasonable 
hope of its probable occurrence, even with the additional 
favouring circumstance of occasional males parthenogeneti- 
cally produced. 
He added that some of the points which Mr. Darwin had 
raised as to the structure of the driver ant of Africa were 
being carefully examined by him in the case of Atta fervens , 
with the best microscopic helps at his command. Thus far, 
however, after a quite careful examination, nothing that can 
suggest the idea of an interblending of the castes by rudi¬ 
mentary forms had been discovered. The lowest castes of 
minims, in all specimens examined with special reference to 
