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Mr. Maya and myself have noticed the following characteristics in well-stained preparations: The parasite presents a protoplasmic ground which stains hardly, if at all, and exhibits two nuclei and a flagellum. The first nucleus is tolerably large and sometimes blurred; it occupies the half, or more exactly the anterior third. The second nucleus, which stains more or less intensely, is much smaller. These two nuclei are often very close together. The flagellum starts from one extremity of the parasite and is situated on the same side as the centrosome, but the staining does not establish whether it starts from the centrosome or not.

By means of improved staining we have since ascertained that the flagellum does start from the centrosome. It may here be observed that the situation of the flagellum is inversely that found in pathogenic trypanosomes. that the undulating membrane existed, but in a rudimentary state, in certain speci- It appeared to us mens; more often it is non-existent, as is the rule in the herpetomonas-like forms.

The posterior extremity is sometimes curled up, as if spiralled down upon itself, and often tapering.

somes.

The dimensions of the parasite, flagellum included, are very variable and are being studied. In its entirety the parasite appears smaller than the surra trypano- This flagellate measures on an average 185 long by 16 in breadth, without reckoning the flagellum which measures 10 (mean of 10 mensurations).

The smaller forms met with do not exceed 14 long, 15 μ broad, with a 6μ flagellum. The divisional forms, which are more stubby, give :—

146 length

3.3

Д

breadth

103, flagellum

Mean of three mensurations.

The mensurations were carried out by Mr. Maya by the ocular micrometer pro- cess, and, for the sake of greater accuracy, were compared by means of the objective micrometer; length of tube set at 160 millimetres-No. 6 compensating ocular with Zeiss' spectro-objective lens of 20 m.m. large nucleus or macronucleus, of a small nucleus, micronucleus or centrosome and The presence of a protoplasmic body of a of a flagellum, enables one to liken our parasite to trypanosomes, or better still to the herpetomonas-like forms. These herpetomonas-forms in trypanosomes, repro- duced by cultures, represent the immature forms. Moreover, the parasite divides

itself longitudinally, but it is necessary that it be further studied for the purpose of comparing it with the already numerously-known specimens. This bipartition is accompanied by enlargement of the protoplasma and of the two nuclei, as in the species already referred to. For the present we will call it "Trypanosoma Davidi," from the name of the one of us who first saw it (end of April, 1909) at La Malmaison. Since that time I have again met with the same parasite, or at least a parasite very akin to it, in a variety of another of the Euphorbiacea, the "Euphorbia thymifolia' or Rougette, which is scattered all over the Island and is as well known as the pre- ceding species in popular medicine. same characteristics as the former one, but its divisional forms are larger.

In fact, this parasite presents generally the

I have been able to stain some parasites of the size of a small mononuclear leucocyte, exhibiting in the interior of the sphere a large and a small nucleus devoid of flagellum. This new type offers a great likeness to, and may be mistaken for, an isolated Leishman-Donovan body, were it not for the situation of the centrosome, which is different.

Our investigations have proceeded no further.

Distribution of “Trypanosoma Davidi" in Mauritius.

We have found at the Réduit Laboratory parasites in 70 specimens (or a pro- portion of 341 per cent.) out of 205 plants of the genus Euphorbia pilulifera, gathered in parts of the Island remote from each other, viz. :—ˆ

At St. Pierre (La Malmaison), Réduit, Rose Hill, Beau Bassin, Port Louis (railway station and garden of the Museum), and at Black River (Lamivoie).

The

The proportion in the Euphorbia thymifolia is slightly less: 33 per cent. first parasite-bearing plant was met with at Curepipe.

Certain plants of the Jean Robert" species contain very few and others numberless parasites, while others again contain none at all.

Mr. Maya has made this peculiar observation, that a branch of the same plant may be parasitically affected while the neighbouring branch may be quite free from parasites; similarly, upon sectional division of a stem at a given point, a drop of

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kuipibumih TLC.O. 885

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