th's
fruitfulness? Again nothing. Yet both make for the nourishing spot.
Theories are put forward, most learned theories, introducing capillary
action, osmosis and cellular imbibition, to explain why the caulicle
ascends and the radical descends. Shall physical or chemical forces
explain why the animalcule digs into the hard clay? I bow profoundly,
without understanding or even trying to understand. The question is far
above, our inane means.

The biography of the Anthrax is now complete, save for the details
relating to the egg, as yet unknown. In the vast majority of insects
subject to metamorphoses, the hatching yields the larval form which
will remain unchanged until the nymphosis. By virtue of a remarkable
variation, revealing a new vein of observation to the entomologist,
the Anthrax flies, in the larval state, assume two successive shapes,
differing greatly one from the other, both in structure and in the part
which they are called upon to play. I will describe this double stage of
the organism by the phrase 'larval dimorphism.' The initial form, that
issuing from the egg, I will call 'the primary larva;' the second form
shall be 'the secondary larva.' Among the Anthrax flies, the function
of the primary larva is to reach the provisions, on which the mother
is unable to lay her egg. It is capable of moving and endowed with
ambulatory bristles, which allow the slim creature to glide through the
smallest interstices in the wall of a Bee's nest, to slip through the
woof of the cocoon and to make its way to the larva intended for its
successor's food. When this object is attained, its part is played.
Then appears the secondary larva, deprived of any means of progression.
Relegated to the inside of the invaded cell, as incapable of leaving
it by its own efforts as it was of entering, this one has no mission in
life but that of eating. It is a stomach that loads itself, digests and
goes on adding to its reserves. Next comes the pupa, armed for the
exit even as the primary larva was equipped for entering. When the
deliverance is accomplished, the perfect insect appears, busy with its
laying. The Anthrax cycle is thus divided into four periods, each of
which corresponds with special forms and functions. The primary larva
enters the casket containing provisions; the secondary larva consumes
these provisions; the pupa brings the insect to light by boring through
the enclosing wall; the perfect insect strews its eggs; and t