Conservative *
traction takes place , consequently the
egg is not fertilized and a drone is
always the result. The production
of a queen bee is from an ordinary
worker egg , the larva insect being fed
by the workers upon a nitrogenous
food , known as "royal jelly. "
Some insectssuch as aphides ( plant
lice ) , reproduce their species both
by sexual fertilization and partheno-
genetically. Throughout the summer
there is a constant viviparous ( born
alive ) production of parthenogenetic
( without fertilization ) females.
These have as a rule.no wings. But
the reproduction of these .insects is so
rapid that the plants upon which they
live would be destroyed if another of
the species did not arise. Occasionally ,
therefore , females are produced , which
having wings , fly away to live upon
home other plant and to start a now
colony.
The progeny of these colonial aph
ides in turn resemble their grand
parent , rather than their parent , in
the fact that wings are usually absent ,
though the preservation of the species
is provided for by the occasional ap
pearance of a winged individual. The
phenomenon which I have just named
the likeness of the insect to its
grandmother , and not to its mother
is called metagenesis , or the altera
tion of generations.
As yet no male has appeared upon
the scene ; but colder weather , or
the scarcity of food , results in the
birth of males which fertilize the
females , and eggs are then laid. These
eggs do not usually hatch iintil spring.
Jfcl In concluding this" subject , it is de
sirable to say that we know very little
concerning the causation of sex ; that
high feeding has a decided tendency
to produce females , and that poor
feeding has a marked tendency to
produce males , has been established
beyond doubt. But there are other
factors in the problem factors of
which we are at present ignorant.
Any attempt to give a fuller ex
planation of the causation of sex
would be purely speculative , and
in my opinion , valueless , being un
supported by any scientific evidence.
Two Forces.
As the earth is kept in an orbit ,
which makes life possible by the bal
ance of the antagonistic centripetal
and centrifugal forces , so is that life
evolved and maintained by the bal
ance of the two conflicting forces of
heredity and variation. Heredity ,
that is , the principle which makes off
spring resemble" their parental organ-
ismsmay be considered as the centrip
etal force which gives stability to
species , while variation is like the
centrifugal force which tends to make
them develop into new forms , and
prevents organic matter from remain-
ing over consolidated in one uni
form mass.
As regards heredity , the consider
ations which have been advanced in
the early part of the references to sex
will enable the reader to understand
the principle upon which it is based.
When a moneron , or living piece of
pure protoplasm , or its successor , the
nucleated cell , propagates itself by
simple division into two parts , it is
obvious that eacli half must , in its
atomic constitution and motions , ex
actly resemble the original. If
amoeba No. 1 divides into amoebae
Nos. 2 and 8 , botli the latter two are
exact facsimilies of No. 1 and of one
another , and so are the progeny of
Nos. 2 and 8 through any number of
generations. They must remain
identical repetitions of the parent
form , unless some of them should
happen to be modified by different
actions of their surrounding environ
ment , powerful enough to affect the
original organization. The moot
point as to whether amoebae continue
to propagate indefinitely by sub
division , or whether at some period
propagation ceases unless two indi
viduals come together , is too techni
cal for discussion in this place.
In propagation by germs or buds ,
the same thing must hold good as in
propagation by fission , only , as the
offspring carries with it , not the
half , but only a small part of the
parental organism , its impress will
be less powerful , and the new organ
isms will more readily be affected by
external influences. When we come
to propagation by spores or single
cells , and still more to sexual propa
gation by the union of the cells of
two progenitors , it becomes more
difficult to see how the type of the
two parents , and of a long line of pre
ceding ancestors , can be maintained
so perfectly. Of the fact that it is
maintained , there can be no doubt.
Not only do species breed "true"
and remain substantially the same for
immense periods , but the character of
individual parents and their ancestors
repeat themselves , to a great extent ,
in their offspring. It is well known ,
of course , that the cross between the
white and black varieties of the
human species perpetuates itself to
such an extent , that a single cross of
black blood leaves traces for a great
number of generations. In the Spanish-
American states and the West Indies ,
where the distinction is closely observed
the term "octoroon" is
served , com
monly applied to Creoles who have
seven-eighths white to one-eighth
black blood in their composition. In
the case of what is called ' ' atavism , ' '
which means recurrence to the char
acter of ancestors more remote than
the immediate parents , some very re
markable phenomeona [ may be ob
served. Perhaps one of the most
striking cases is that of Lambert the
"porcupine man , " mentioned by Dar
win in "The Variation of Animals
and Plants Under Domestication. "
This man's body was covered with
warty projections which were period
ically moulted. Some of his children ,
and also some of his grandchildren ,
presented the same remarkable char
acteristic which , however , had not
been known to have been present in
any of his ancestors.
Long Distance Transmission.
In breeding animals , it is not un
common to find the peculiar features
of generations of ancestors long since
extinct , cropping up occasionally in
individuals.
Horses , having stripes like those of
the ass along the back and down the
shoulders , occasionally appear , whose
immediate ancestors for many gener
ations back showed nothing of the
sort ; and even stripes across the legs
like those of the zebra occur quite
unexpectedly , and testify to the com
mon descent of the various species of
the horse tribe from a striped ancestor.
How these ancestral peculiarities can
be transmitted through many genera
tions , each individual of which or
iginated from a single microscopic cell
which has been fertilized by another
cell , is one of the' greatest mysteries
of nature. In a single microscopic
cell there may be myriads of atoms
circling around one another and form
ing infinitesimal solar systems , so to
speak , of infinite complexity and
variety. Darwin's "Provisional The
ory of Pangeuesis" supposes that
some of the actual identical atoms
which formed part of ancestral bodies
ies are thus transmitted through
their descendents for generation
after generation , so that we are
literally "flesh of the flesh" of the
primaeval creature who developed in
to man in the later tertiary or early
glacial period. Darwin's hypothesis ,
however , has not met with any gen
eral acceptance. Haeckel has sug
gested the hypothesis that , not the
identcal atoms but their peculiar mo
tions and mode of aggregation have
been thus transmitted and he has
named this mode of transmission the
"Peregenesis of Plastids. " There
are any number of other guesses at
the truth , the theory of physiological
units of Mr. Spencer being the one
which involves the hereditary nature
of acquired characteristics , and the
"continuity of the germ-plasm" be
ing that of Weismann , who insists
that such characteristics are never
transmitted. It is sufficient to say
here that a solution of the various
problems of heredity is by no means
impossible.
Variation.
The principle of variation is quite