Jury 27, 1899] 
are Teixeira’s ‘‘Corso de Analyse infinitesimal: Rudio’s Verhand- 
lungen der ersten internationalen Mathematiker-Kongresses in 
Ziirich,”’ vom 9 bis 11 August, 1897; Klein’s lectures on the 
mathematical theory of the top; Moritz Cantor’s ‘‘ Politische 
Arithmetik oder die Arithmetik der taglichen Lebens” ; and 
Virgilii and Garibaldi’s ‘‘ Introduzione alla Economia Mate- 
matica.”—Prof. J. Pierpont gives a short note on elliptic 
functions, which discusses the simplest and most natural way of 
presenting the theory.—Notes, new publications as usual, and 
the index follow. 
SOCIETIES AND ACADEMIES. 
Lonpon. 
Royal Society, June 15.—‘‘A Preliminary Note on the 
Morphology and Distribution of the Organism found in the 
Tsetse Fly Disease.” By H. G. Plimmer and J. Rose 
Bradford, F.R.S., Professor Superintendent of the Brown Insti- 
tution. (From the Laboratory of the Brown Institution. ) 
These observations are the result of an inquiry entrusted to 
us by the Tsetse Fly Committee of the Royal Society, at a 
meeting of the Committee on March 16, 1899. 
The material for our investigations was obtained in the first 
place from a dog and a rat, inoculated with the blood of a dog 
suffering from the disease, by Mr. H. E. Durham, at Cambridge. 
The organism found in the Tsetse Fly disease was discovered 
by Major Bruce, R.A.M.C., F.R.S., and was classed by him 
as a Trypanosoma. These belong to the order Flagellata, and, 
according to Biitschli, to the sub-group Monadina. 
We will, in the first place, describe the adult form of the 
organism, such as is met with most frequently in the blood of a 
susceptible animal affected with the disease. 
A. Description of the Adult Form of the Trypanosoma. 
In freshly drawn blood examined as a hanging drop, or as a 
very thin layer in a cell, the adult form of the Trypanosoma 
ean be easily studied. The latter method is the better, as the 
organism can be better seen and more accurately examined, in 
the thin, uniform layer of fluid than in the rounded drop. The 
easiest method of examining the blood in this way is to make, 
with a red-hot platinum loop and a small piece of paraffin, a 
thin ring of paraffin on an ordinary glass slide ; the drop of blood 
is placed in the centre of the ring and a cover-glass placed on it, 
the thin layer of paraffin preventing pressure. Ifit be desired to 
keep the blood for continuous examination, it should be drawn 
into a graduated Pasteur pipette, and one-tenth part of a 5 per 
cent. solution of sodium citrate should be drawn up after it, 
then the blood and citrate solution should be carefully mixed in 
the bulb ; the tube should then be sealed up, and drops can be 
taken from it as desired. 
Under ordinary conditions of illumination the Trypanosoma, 
as seen in the blood, appears to consist of a uniform, homo- 
geneous mass of protoplasm, of worm-like form, with at one end 
a thick, stiff extremity, and at the other a long, wavy flagellum. 
It is generally in active motion, and this is seen to be caused by 
the rapid lashing movement of the flagellum, and by the rapid 
contractions and relaxations of the mass of protoplasm forming 
the body, and by the movements of an undulating membrane 
which is attached to one surface of the body, and which appears 
to undulate synchronously with the contractions of the proto- 
plasmic body. This membrane is, excepting at the free edge, 
very transparent, and can be seen much better in citrated blood 
which has been thickened by the addition of a small drop of 1 
per cent. gelatine solution, when its contour and attachments 
can be much better made out, owing to the slower rate of vibra- 
tion effected by the thickened medium. 
The general shape of the Trypanosoma, when rendered 
quiescent by this means, but not killed, is that of a long oval, 
with one end blunt and the other continued into the flagellum ; 
the membrane is then seen to be attached to one side of the 
body ; it begins a little in front of the blunt end of the organism, 
and is continued at the end into the flagellum. 
But with better illumination, such as a very oblique pencil of 
rays, or, better still, with monochromatic light (green or blue), 
the protoplasm is seen not to be homogeneous. The organism 
appears then as a highly refractive body, and near the middle, or 
between it and the flagellate end, is seen a large dark body much 
more refractive than the rest of the protoplasm; this is the 
macronucleus. Near the thick, stiff end of the body a tiny still 
NO. 1552, VOL. 60] 
NATURE 
309 
more refractive body (with monochromatic light nearly black) is 
seen, which is the micronucleus. The addition of a drop of 5 
per cent. acetic acid makes both of these bodies much more dis- 
tinct. At the stiff end of the Trypanosoma, in varying relation 
to the micronucleus, is seen a vacuole. There is no suggestion 
of a mouth or of any organs, but the protoplasm with the most 
careful illumination appears not to be uniform, which suggests 
an alveolar structure, as described by Biitschli, With the 
ordinary simple stains (hematoxylin, fuchsin, methylene-blue, 
thionin) the differentiation is not much better than can be 
observed by careful illumination of living unstained organisms, 
as these stains are with these, and similar organisms, too diffuse 
to be of any service. Acting on a method which Ehrlich 
originated in 1889, and which Romanowsky modified in 1891, 
and which has still been further elaborated by Ziemann in 1898, 
we have used a mixture of methylene-blue and erythrosin, which 
has enabled us to follow the different stages of the Trypanosoma 
with certainty. This method depends on the fact that when a 
basic and an acid stain are mixed together in certain proportions, 
a third neutral body is formed, which has a specific colour re- 
action with chromatin. By the use of this method we have been 
able to trace the various stages of the organism in the blood and 
organs of the affected animals, which is not possible with the 
ordinary stains, these being useless for many of the forms to be 
presently described. With this method the macronucleus of the 
Trypanosoma is stained a clear, transparent, crimson lake, the 
micronucleus a deep red, and the protoplasm a delicate blue ; 
these reactions are constant throughout all the stages of its life- 
history. 
The protoplasm of the adult Trypanosoma does not stain, 
uniformly, as does that of some of the other forms, but there 
are parts faintly stained and parts unstained, which is again in 
favour of the alveolar structure mentioned above. The vacuole 
is quite distinct as a clear round space when the organism is. 
stained by this method. 
The macronucleus is generally of an oval or elongated shape, 
and it may be either uniform in colour, or in the form of fine 
threads ; this latter is seen especially in those forms which show 
other signs of division. The micronucleus is seen as an 
intensely stained round dot, or as a short rod, this latter form 
again being seen in those forms which show other signs of 
approaching division. With the highest powers (1°5, 
apochromatic objective and 18 compensating eyepiece of 
Zeiss) we have not been able to make out any special structural 
characters in this body. The flagellum is not stained by this 
method, but if the preparation has been well fixed, it is easily 
visible ; the vibratile membrane also is unstained, and can be 
generally better studied in specimens stained by simple stains, 
preferably thionin. 
As regards the movements of the organism, in preparations 
where no pressure is exercised, they can be seen moving either 
with the flagellum or with the blunt end in front; but we think 
that the commoner mode of progression is with the flagellum 
forward. 
The size and length of the body varies very much with the 
period of the disease at which the blood is examined and with 
the kind of animal. The largest forms we have seen have been 
in rats’ blood, just after death, and the smallest in rabbits’ 
blood, early in the disease. 
B. Déstribution of the Trypanosoma. 
(1) Lx the Body of Normal Animals. 
(a) Zn the Blood.—We have found the flagellate form in the 
greatest numbers in the blood of the mouse, towards the end 
of the disease. In the rat also they occur in great numbers, 
and in both these animals they can be found in the blood on 
the fourth or fifth day. In the dog large numbers can be seen 
in the blood from the sixth day. In the cat they are fewer in 
number in the same lapse of time than in any of the animals 
before mentioned. 
The rabbit seems to be the most refractory animal of any we- 
have as yet used, and the Trypanosoma are found in the blood 
in small numbers only, and at very uncertain intervals. 
(6) In the Lymphatic Glands.—In the superficial glands 
nearest to the point of inoculation-the flagellate organism can 
be found earliest. In the rat the Trypanosoma can be found 
in the nearest superficial gland in twenty-four hours after in- 
oculation. We have not found that generalisation of the or- 
ganism in the lymphatic glands occurs until nearly the end of 
the disease, when the organism is present in very large numbers 
