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Psyche 6:216-219, 1891.

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216 PSYCHE. [February 1892.
swarms just as some years ago I saw
Harma caenis in the Ogov6 region.
They seemed to come from nowhere in
particular, they flew in no order, no
two even keeping company. Some-
times only a dozen were visible, at
other times hundreds seemed to fill the
air. They flew a little E. of N. E.
This has no particular significance,
however, as this is the general direction of the coast here. Even upon the beach
the migratory movement was easily ob-
served, and as far as I went back, (about half a mile) the air seemed full of the
flies. None were returning, and all
flew as if they had a definite purpose in view. A native remarked it, and ven-
tured, in calling my attention to the
movement to add 'Sometimes they fly
so, and sometimes they fly in the oppo-
site direction.' " . . .
"1 am utterly at a loss to account for
the phenomenon. The explanation
which I suggested for the migration of
Harma caenis, which
this exactly re-
sembles, will not apply here. That
took place near the end of the dry sea-
son and was toward the approaching
rains.
But here the rains are frequent
now, and if these flies are seeking any- thing to northward it must be dry
weather."
CHRYSOPSYCHE MIRIFICA Butler.
I have received from Mr. Good sev-
eral specimens of this exceedingly beau- tiful bombycid, and also a specimen of
the cocoon, which is very tough and
dark chocolate hrown in color and
studded all over as are many of the
cocoons of the African Bombycidae
with minute spines, which are derived
from the epidermis of the caterpillar.
The figure upon Plate 5 will serve
better than a description to give an idea of the form of the cocoon.
EXPLANATION OF PLATE 5.
Fig. I. Chrysalis of Saturnia arnobia
Westw.
Fig. 2. Chrysalis of Idiomorphus vala
Ploetz. (lateral view).
Fig. 3. Chrysalis of Idiomorphus vala
Ploetz. (dorsal aspect).
Fig. 4. Larva of Harma caenis Drury.
Fig. 5. Chrysalis of "
Fig. 6. Cocoon of Chrysopsyche miri-
fica Butler.
CONCERNING THE "BLOOD-TISSUE" OF THE 1NSECTA.-I. BY WILLIAM MORTON WHEELER, WORCESTER,
MASS.
Hitherto
little attention has been de-
lature and nervous system, and even on
voted to the study of the blood, fat-body, the alimentary tract and its various sub- and allied structures in insects. We
divisions, but few serious attempts have have extensive monographs on the eyes
been made to fill the gaps in our knowl- and other sense-organs, on the muscu-
edge of the physiologically highly im-




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[February 1892. PSYCHE. 217
portant tissue, so intimately concerned
with the nutrition of the organs. Of
these attempts two, however, are wor-
thy of special attention - one by Wie-
lowiejski,l who approaches the subject
from the anatomical side, and another
by Graber,2 who contributes some valu-
able observations of an embryological
nature.
Wielowiejski includes under the term
blutgewebe (blood-tissue) the follow-
ing structures :
I. The blood corpuscles ;
2. the fat-body proper ;
3. the pericardial fat-body ;
4. the oenocytes, of which he
distinguishes three varieties in
some insects.
To this list I would add :
5. The garland-shaped cord of
Muscid larvae ; and
6. a peculiar organ, which I may
call the suboesophageal body,
and which I have found in the
embryos and young larvae of
Blatta and Xiphidium.
Wielowiejski is careful not to main-
tain a common origin for all the com-
ponents of his 6'blutgewebe" but
comprises them under a common head-
ing on purely physiological grounds, as
he expressly states. They are blood-
tissue to the extent "dass sie alle von
dem sie umgebenden medium gewisse
stoffe aufnehmen, zeitweise aufspeich-
--
I Ueber das blutgewebe der insecten. Zeitschr. f. wiss. zool., 43. bd. p. 512-536. 1886.
2 Ueber die embryonale adage des blut- und fett- gewebes der insekten. Biol. centralbl., XI bd. nos. 3 u. 8. p. 212-224. 1891.
ern resp. verarbeiten und irgend
welche umsatzprodukte an dasselbe
zuruckgeben und dadurch auf die in
den hauptgeweben des organismus
vor sich gehenden assimilations und
desassimilationsprocesse einen einfluss
ausuben ."
Graber is less cautious and does not
hesitate to conclude that the different
tissues constituting Wielowiejski's blut- gewebe are genetically related. Stated
very biiefly these are the conclusions at which he arrives.
I. The oenocytes are derived
from the ectoderm ;
2. They are metamorphosed into
the fat-body ;
3. The blood-corpuscles arise
from the fat-body (and also
from the oenocytes ?) .
Eryo the fat-body and the blood are
ectodermal structures ! Certainly a re-
markable conclusion and one which an
even more intrepid investigator might
hesitate to advance in these days when
we are so accustomed to derive the
blood-corpuscles and connective tissue
from the middle germ-layer. While
my own conclusions differ radically
from Graber's, so far as the origin of
the fat-body is concerned, I cheerfully
confess that his interesting paper was
the means of calling my attention to this much neglected subject.
Even the earlier entomotomists were
familiar with certain huge cells associ- ated with the fat-body. By some they
were supposed to assist in respiration
since they were often found attached to
the fine tracheal ramifications. Graber




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218 PSYCHE. [February 1892.
called them1 "eingesprengte zellen" and
regarded them as unicellular glands. It
was Wielowiejski who first fully de-
scribed them and named them oenocy-
tes from their wine-yellow color. He
pointed out that these oenocytes are not infrequently the largest cells in the
body, excepting the ova, that they are
arranged in metameric clusters in the
trachigerous abdominal segments and
that they are more or less intimately
associated with the blood and fat-body.
In some cases they occur in the poste-
rior thoracic region. Most frequently
pleural in position they may occasion-
ally extend over the sternal region.
The separate cells of the clusters are
usually distinctly isolated and inde-
pendent of one another, but in rare
instances they may fuse in pairs or to
form smaller clusters. The tough and
resistent cytoplasmic wall is round or
oval and often drawn out into a few
pseudopodia-like outgrowths by means
of which the cells are suspended to the
tracheal ramifications or to one another. The cytoplasm, which is very abun-
dant, is full of yellowish granules and is sometimes radially striated towards its
periphery. The large spherical or oval
nucleus contains a densely wound and
delicate chromatic filament. .An idea
of the appearance of these cells may be
obtained from Fig. I, which represents
a cluster of oenocytes from a nearly
mature Phryganeid larva. This speci-
men does not show the pseudopodia-
like outgrowths.
I Ueber den propulsatorischen apparat der insecten. Archiv f. mikr. anat,, 9. bd. p. 129-196. 1873.
To Graber is due the credit of first
pointing out the identity of the oeno-
cyte-clusters with certain metameric
cell-masses mentioned by embryolo-
gists. Tichomiroff and Korotneft de-
scribed segmental masses of cells origi- nating from the ectoderm near the stig-
mata and just pleurad to the nerve-cord. Tichomiroff at first regarded these cells as a kind of fat-body but finally con-
cluded that they represented an organ
suigeneris which he called the "gland-
like body." Korotneff regarded the
migrant ectoderm-cells in Gryllotalpa
as mesenchymatous, and if I understand
him correctly, as giving rise to the fat- body.
I fully agree with Graber that the
embryonic cells described by the two
Russian embryologists are identical
with the oenocytes of Wielowiejski.
Graber is also correct in referring to the same category certain huge cells de-
scribed by me in D~ryphora.~ They
originate from the ectoderm as I have
since been able to ascertain.
Graber describes the oenocyte clus-
ters in Stenobothrus as delaminated
from the ectoderm. In Hydrophilus he
claims that they originate in connection with a distinct pair of metastigmatic
invaginations. It appears to have es-
caped his notice that these invaginations 2 The embryonic development of the silk-worm (Bombyxmori). Publ. labor. 2001. mus. Moscow., vol. I. 1882. (Russian.)
3 Die embryologie der Gryllotalpa. Zeitschr. f. wiss. zool., 41- bd. 1885.
4 The embryology of Blatta germanica and Dory- phora decemlineata. Journ. rnorph., vol. 3, no. 2. p. 291-374. 18%-




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February 1892.1 PSnxLE?. 21 9
were first seen by Patten in Aci1ius.l
They are also present, as I have been
able to make out, in Blatta, Xiphidium
and Dytiscus. With the proper methods
Graber would also probably have found
them in Stenobothrus. This second
pair of segmental invaginations, which
Fatten took to represent a second pair
of tracheal ingrowths, are supposed by
Graber to be the formative centers of
the oenocyte clusters. He admits, how-
ever, that a delamination of the area
surrounding each pit contributes largely to their formation.
My own observa-
tions lead me to believe that the invagi- nations are very weak and transient and
that they contribute very few, if any
elements to the clusters; most of the
oenocytes originating by delamination
and immigration from a considerable
area just caudad to the stigmata. In
Lepidoptera this area is more extensive
than it is in the Orthoptera.
In nearly mature Xiphidium embryos
the oenocyte clusters may be seen shin-
ing through the hypodermis much as I
have represented them in Fig. 2. They
form eight bands running along the
pleural wall just back of and alternating with the stigmata.
Now Graber maintains that the fat-
body, at least in part, arises from these oenocyte clusters. But a section through a young Blatta embryo (Fig. 3) shows
most conclusively that this is not the
case. At o may be seen the oenocytes,
still forming a part of the ectoderm v
from which they have differentiated,
I On the origin of Vertebrates from Arachnids. Quart. journ. micr. sci., vol. 31, pt. iii, new ser. p. 317- 378. 1890.
while the fat-body e is simply a thick-
ened portion of the inner coelomic wall. The thickening is largely due to an ac-
cumulation of fat-vacuoles in the cyto-
plasm of the mesoderm-cells. Were
Graber correct in his assumption we
ought either to find no adipose tissue in the embryo outside of the eight trachiger- ous abdominal segments or be able
to show that the oenocytes migrate into
the head, thorax and terminal abdom-
inal segments and there form the fat-
body - since fat- tissue is developed in all these regions of the body. But al-
though some of the oenocytes do later
on migrate into the metathorax and
perhaps even into the mesothorax, they
never occur in the head. Moreover.,
long before any migration takes place,
thickenings of the coelomic wall, sim-
ilar to that in the figure, are found giv- ing rise to the fat-body in the thorax,
gnathitic segments and also in the ter-
minal segments of the abdomen. Fur-
thermore, the oenocytes, so far as I have been able to observe, are always per-
fectly distinct from the fat-body, never contain fat-vacuoles, and never divide
after they are once differentiated from
the ectoderm during embryonic life.
Their number is therefore subject to no
increase during the growth of the ani-
mal. They are, as Tichomiroff claimed,
a series of organs suigeneyis. Although
they certainly resemble the blood-cor-
puscles in some insects, they are always much larger and seem not to be amoe-
boid. They are never seen constricting,
or exhibiting any appearance of giving
rise to the blood-cells. It follows then



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220 pSRXU3. 5 [February 1892.
that the fat-body is not derived from the oenocytes, that it is not of ectodermal
but of mesodermal origin as claimed by
the majority of authors, and that there
is no evidence for the origin of the blood from the oenocytes.
It is interesting to note that only the
winged orders of Hexapoda, the Ptery-
gota, seem to possess oenocytes. I could find no traces of these peculiar cells in Lefisma saccharina, Cawz$odea fra-
yilis (young and adult) and Anurida
maritima, insects which may be taken
t
to represent the three families of the
Apterygota. If oenocytes exist at all
in this subdivision of the Hexapoda,
they are probably confined to the
embryo or to the forms most closely
allied to the Orthoptera - like Machilis. I believe that oenocytes do not occur
in the Myriopoda. In the just-born
young of Scolopendra com@Zana/a from
the Galapagos I find no traces of them
and so far as I am aware they have not
been described by any of the investi-
gators of Myriopod anatomy.
DESCRIPTION OF A SARCOPHAGA BRED FROM HELIX. BY C. H.
TYLER TOWNSEND, LAS CRUCES, N. MEX.
I have recently received from Mr. H.
A. Surface, of the Ohio experiment
station, a small Sarcophagid which he
bred from Helix thyroides Say, while
engaged on his catalogue of shells of
Franklin County, published in Bulletin
2, volume I, technical series, of that
station.
Mr. Surface accompanies the speci-
men with the following note : "The
snail was placed in a tight bottle Au-
gust 25, in Warren County, Ohio, and
during the first part of September the
pupae were seen. From September 27
to 30 five or six mature flies came
forth."
The fly proves to be a small species
of Sarcophaga. After considerable
time spent in looking over descriptions
of North American species, I feel justi- fied in considering it new.
Sarcojhaga helicis n. sp.
$ .
Eyes brown, bare ; front, sides of face and cheeks silvery or cinereous, sometimes with a brassy reflection; frontal vitta dark brown or blackish, about one-third width of front, the front being about one-third width of head ; frontal bristles descending a little be- low base of antennae; the two vertical bris- tles strongest, directed backward, next three bristles also directed backward, rest more or less forward; two orbital bristles directed forward; a strong anterior pair of ocellar bristles directed forward and outward ; sides of face with a few bristles in a row on lower portion next orbital margin; cheeks about one-fourth eye-height, sparsely hairy with a row of bristles on lower border; facial de- pression more or less silvery, epistoma
rather prominent; facial ridges bare except two or three bristly hairs next vibrissae, the latter decussate and inserted on the oral margin; antennae a little shorter than face, black, second joint slightly elongate with a long bristle on front border, third joint



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