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Psyche 5:269-272, 1888.

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August-December iSSg.1 P-s'2'"cHE. 269
before, except that the yellow granules
were very indistinct; and the obliques
next the head could hardly be traced.
The other obliques were bright pink,
edged with deep blue-purple. Caudal
horn was green at base. and blue-purple
elsewhere, the LLblue-purple" being of
the exact tint of very ripe inkberries.
Horn short in propoi tion to size of the larvae.
The spiracles were dark in ovals of
white, these ovals being encircled by
faint blue-purple lines. They were
small, and merged in the pink obliques
on six segments, but conspicuous on the
others.
2 October. Stopped eating, being
then 63 mm. long.
to October. Pupated.
The pupa was 31 mm. long, neither
stout nor slender, with a tongue-case g
mm. long, and lying close against the
body. Its color was green at first, and
showed the dark obliques on the abdom-
inal segments, but in two days it be-
came bright hrown. There was a
point on the anal end, but no hook.
THE MALE ELEMENT THE ORIGINATING FACTOR IN THE DEVELOPMENT OF SPECIES.
BY JEROME MCNEILL, MOLINE, 11.1..
Professor W. K. Brooks, in his study
of the philosophy of heredity1 has
advanced a new theory which offers a
reasonable explanation of the means by
which ancestral characters may be pre-
served in any species and at the same
time new variations transmitted to pos-
terity. Without attempting to state the
theory in full (this is the more unneces- sary because it is probably known to a
large majority of the readers of PSYCHE), it will be sufficient for the present pur- pose to say that the author considers
that "the male element is the originat-
1 The law of heredity, by W. K. Brooks, Associate on biology atJohns Hopkius university.
Published by
John Murphy and co., Baltimore,
ing and the female the perpetuating
factor in the evolution of species." Mr. Brooks offers no more convincing argu-
ments in support of his views than the
evidence from sexual characters, and
while the illustrations drawn from ento- mology are probably the best that could
be selected, it has seemed to the writer that it might not be uninteresting to
note the application of the theory to the genera and species of as little known
and little studied an order as that of
orthoptera. In presenting this evi-
dence I shall collocate it with the five propositions formulated by Mr. Brooks.
I. "In most animals of separate
sexes, the males of allied species differ



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PSYCHE.
[August-December 1839.
Ì
more than the females from the ances-
tral type."
In the first place, assuming that the
larvae and pupae are more like the an-
cestral forms than the imago, the females show less divergence from this form than the males in being more frequently ap-
terous or abortive winged. When the
wings are fully developed they are as a
rule smaller relatively if not absolutely in the female, and there is perhaps no
notable exception to this rule. The fe-
males also approach more nearly to the
ancestral type in the frequently less de- veloped antennae.
Throughout the order it is very gen-
erally true that the coloration is brighter and more contrasting in the male. In
Pezotettix viridu/us the male is bright
pea green (in living specimens) with
black pleural stripes while in the female the color is nearly uniformly dull
brown. In the *wings of most oedi-
-fiodae the transverse black or fuliginous band is more extended in the male as
are also the similarly colored spots in
the usually transparent apex. In the
same family the fuscous spots and bands
of the elytra are not infrequently much
deeper in color in the male. The ge-
nus Acridiunz offers some exception to
this rule of coloration since, while on
the whole the males are more brilliantly colored, certain species have the elytra as well as the head and pronoturn obso-
letely spotted or unicolored in the male, and obsoletely or distinctly spotted in
the female, the latter being much more
variable in this respect. This apparent
departure from the rule may possibly be
explained by the females retaining
longer a larval or ancestral character.
Unfortunately I have no knowledge of
the larvae of these species to help me
in deciding this point. But in the al-
lied genus ~ela'n?$lus it is certain that the larvae are in many species much
more spotted and streaked than the
images. In man./idae generally the
males have the elytra distinctly more
membranous than the females. Since
the elytra are, in orthoptera generally, protective in color and form as well as
in structure, it might be expected that
the only carnivorous family needing this protection least would be the first to out- grow it and it is quite in accord with
Mr. Brooks's theory of heredity to find
the males of mantidae leading the fe-
males in this change. In the genus
Melano$/a.s the males show in the club-
shaped abdomen a marked departure
from the usual subcylindrical or taper-
ing- form of this part which is common
in the saltatorial division of the order: The males of this genus and its allies
Pezotettix and Acridium exhibit a pe-
culiar development of the anal cerci
which tire generally of the simplest and most regular form in this family.
Finally the much more attenuate forms
of the males of phasmidae certainly
show them to be in advance of the
stouter females in their divergence from the typical orthopterous form.
3.
"'Those organs that are confined
to males or are of more importance or
are more perfectly developed in them
than in the females are much more
likely to give rise to hereditary modifi-



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August-December ISS~.] PSYCHE. 271
cations than parts which are confined to or are more perfectly developed in fe-
males. "
On this point it will be sufficient to
call to mind that the organ which is al- most entirely restricted to the males of locustidae, g'ryllidae, and acdidae is
the musical apparatus. I11 acrididae
this apparatus is too little specialized to repay examination. In locustidae and
gr~,/Zidae there is little evidence to be found of an unmistakable character, but
the last mentioned family has one genus
Oemthus and the first mentioned two
genera Conocephalus and Orchelimuvz
which throw some light on the subject.
Concerning' Oecanifzus I may say
that the three most common species
are nivens, De Gees, an/yustifiennis,
Fitch, and fasciatus Fitch. These
species are usually considered to be
mere varieties, and although T am sktis- fed that the distinctions of form and
habits and to a less degree of color en- title them to rank as species, their
very distinct "songs" leave scarcely any room for doubt. Of course this differ-
ence in the character of striclulation is accompanied by a certain, though not
conspicuous, difference in the structure of the stridulating apparatus, and by its tending to vxy in structure and use,
it aids greatly in establishing two spe- cies. In Conoccphalus and Orchelimum
the evidence is similar. The species for the most part are very similar and the
most certain means of distinguishing
them is in their song's.
3.
b''l'hat a part which is confined to
or is most developed in males is more
likely than a similar female part to
vary."
This principle is well illustrated in
the anal cerci of the males of Melano-
@us, Pezotettix, and A cridium.
This part which has been before
remarked in the females is simple and
constant in form, in the males is ex-
tremely variable in size and shape, so
that in the two genera first mentioned,
at least, it furnishes the best. specific characters for distinguishing the species. In these genera also the males furnish
good specific characters in the form of
the last ventral segment, while in the
female this part is very constant in form. 4. "That males are, as a rule - more
variable than females."
Much of the evidence already given
bears upon this point - and I will con-
tent myself with a very few more
examples.
The males of two species of Tri-y-
lus, T, apicalis Say and T. terminalis
Uhler have the anterior tibiae furnished with a very remarkable appendage.
l'he tibiae are divided into two forks
nearly at right angles to each other.
That fork which occupies the usual posi- tion of the tibiae ends in two strong
spines. From its base the true tibia
extends backward parallel with the
thigh, with which it forms a raptorial
apparatus. This brand ends in a strong
curved claw - and a very diminutive
tarsus which is placed at right angles
to the tibiae. In these species the
males are further distinguished from the females by the swollen pronotum.
In the genera Centko$hilus and




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2 72 PSYCHE. [August-December 1889.
tideo&yZZa the males are very generally
distinguished by the larger and more
numerous spines on the lower margin
of the posterior femora.
5. 6hThat the male leads and the
female follows in the evolution of new
races."
Little remains to be said on this point
since nearly all that has gone before
shows already that in orthoptera male
characters lead in the recognition if not in the evolution of new species. No
student of orthoptera will question the
statement that were it not for the varia- tion of the cerci and the last ventral
segments of the males of Melanoplus
and Pezotettix it would not be possible
to recognize nearly so many species in
these genera as are now known to exist.
It is also indisputable that in Me7anoplzi.s especially in several instances, it is
practically impossible to distinguish
with certainty between the femnles of
closely allied species. Examples are
not wanting of cases in which the males
differ so greatly from the females, that they have been placed when first de-
scribed in different genera. The male
of Chloealtis c01zs$ersa Hart-. , differs so much from the female that Mr. Scudder
in his ignorance of their relationship was quite justified in describing the male
as Stenobothrus me!aw/)leurus. The
males of SyrbuZa admirabilis Uhler
are of two forms ; the green one, which
is very rare, resembles the female in
coloration but differs in structural
characters, and especially in the clavute antennae. The dark form, in addition
to the structural features which are very similar to those of the green form, is so very different in coloring that it was for a long time widely separated from the
female, and as genera are now made, the
sexes may be considered generically dis- tinct.
It will be seen that orthoptera
furnish strong, if not striking, corrobora- tive evidence of the truth of Mr.Brooks's theory of heredity. While I do not
pretend, in this hasty review, to have
exhausted the illustrations that might be furnished by the species and families
represented in the United States I have
not found any controvertive evidence
except the considerable variation in the length and shape of the ovipositor of
Xi$kidium, that of the closely allied
genus Orchelimum being quite constant,
and the less marked variation in the
length of the same organ in Conacepha.
lus, Thyremotus and Gryllus.




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