The Prince George's enquirer and southern Maryland advertiser. (Upper Marlborough, Md.) 1882-1925, 1899-05-05

Witch lii' l'iiiNit'N tNl@I tN'iuS!NtIN
in the blood.
This is an interesting and seductive
hypothesis. II We pursue it further
we arc Immediately confronted with
the question: How may the parasite
enter the mosquito and how may the
mosquito Introduce it into the human
being? There are many possibilities
in this connection. Let us consider
what occurs in somr other parasitic
Diseases In Texas fever it is not the
adult tick which transfers the para
sites from one animal to the other.
The adult tick feeds upon the parasites
which infect the blood the parasites,
living in some form within the tick,
are transmitted to its descendants, and
it is only upon being bitten by one Of
new brood of ticks that infection is
acquired Another way in which in
sects may assist in transferring the
disease is shown by the behavior of the
mosquito and the tilaria sanguinis
hominis. This nematode has been
shown by Mason to enter and live
within the muscles of the mosquito.
The mosquito dying, often iniects wa
ter which. if ingcsted by human beings.
conveys the contagion.
Manson some years ago advanced
the idea that the mosquito might form
an intermediate host for the maiarial
parasite as well as for the lilaria, and
that if mosquitoes were to bite in
fected individuals the organisms might
continue to live in some form within
the body of the insect. and being set
free upon its death, contaminatc drink
ing water.
Beyond the fact that the develop
ment of flagellate bodies has been noted
in blood contained within the stomach
of the mosquito, and that Ross i'll India
has noted. in several instances, curious
pigmented bodies in the stomach wall
of some insects which had been tt.!
upon the blood of infected individuals.
no confirmation of this hypothesis has
as vet been obtained from the eXami-
Of I,,,,,, J1nnl
Recently, however, observers have
turned their attention toward the par
asites in the blood of birds Birds
are subject to infection with several
varieties of organisms which are very
closly analogous to the malarial para
stiles of men, and inasmuch as expert
ments of various sorts, impossible with
the human being, may be readily car
ried out with birds, this field particu-
larly hopeful one for investigation.
Two years ago two Of our students,
Mr.. Opic and Mr.. MacCallum, made
some interesting studies upon the blood
Of birds, confirming the observations of
several other foreign students, and
noting certain further, as yet, unde-
scribed features in the avain para
sites. And last summer Dir. MacCal-
lum was fortunate enough to discover
what is partial proof at least of Man
sons hypothesis with regard to the fla
CELIA. While studying certain va
riety of parasite in birds blood he
noted that whenever tlagellation oc-
cured some of the lilaments, breaking
loose from the mother body, rushed
across the field to other full-grown
parasites, parasites which DR.. Opie
had previously noted were apparently
incapable of flagellation. Single fla
CELIA might be seen to penetrate these
full-grown forms Only one hagellum
ever succeeded in entering, though
sometimes bodies of this nature might
be seen surrounded by three or four
filaments which would butt their heads
against them and, apparently, endeavor
il every way to force an entry. Short
ly afterwards the body which had been
penetrated changed its shape into Il
long pointed element, the pigment
gathering at one end; it then became
motile, advancing steadily across the
field, destroying with its sharp point
any red corpusclcs which were in its
way These elements had previously
been described by Danilevsky under
the name of 'pseudo-vcrmicules' This
remarkable process which has been
repeatedly observed can, from analogy,
scarcely be other than an act OF fertilI-
zation. The discovery may be said to
have definitely shown that the tlagella
are not degenerate bodies. The further
fate of the pseudo-vermiculcs MacCa,-
lum was, however, unable to discover.
He is inclined to suspect that they
may be forms capable of development
under other conditions than those Of
fered in the body of the bird. There
are numerous analo5ies in natural
history which ten | to support this
view
Within the last year, Ross in India
has carried out some excessively inter
esting studies which bear directly upon
the manner of infection. Ross noted
that the process of tlagellation might
occur in avain parasites as well rs in
those of human beings within the
stomach Of the mosquito. Further
more, he noticed, when working with
Il peculiar variety of the mosquito fed
upon birds infected with the protcosoma