ABSTRACTS                                        419

A further contribution to the proposal of a new classification of Trypanosomes.
I. JOCONO. (The J. of Trop. Med. and Hyg. (1938), 41, 53-57, with 14 figs.)

IN this article the author has brought forward further evidence in support of his
previous publication [Jocono, 1935. Annali di Med. Nav. e Coloniale, i, fasc. 1-11 ]
in which it was proposed that the genus Trypanosoma should, provisionally, be repre-
sented by Trypanosoma rotatorium of frog, while the other haemoflagellates of man and
animal should be regrouped under the genus Castellanella. Development of T. rota-
torium has been observed in vitro and a new medium has been suggested which consists
of the following ingredients:—

Under aseptic conditions 0.01 c.c. of blood from the ascellar vein of frog was
aspirated by means of Pasteur pipette and mixed with 0.1 c.c. of the culture medium
placed previously on a clean slide and covered with a coverslip. Both the slide and
coverslip should be sterilized with dry heat at 180°C. Edges of the cover glass are
then sealed with melted hard paraffin. In this medium phenomenon of lysis occurred
after three days and the process of development showed no further modification in
shape or size, contrary to what occurred in vivo [Jocono, 1935, ibid]. Dividing
forms were seen by the author at frequent intervals and it was found a parasite divided
into two or, at most into four elements. Daughter individuals thus formed gradually
elongate and ultimately develop flagellum and rudimentary undulating membrane.
The author has also dealt somewhat in detail, with the difference in regard to the
protoplasm, nucleus, and kinetonucleus and basal body as observed in the genera
Trypanosoma and Castellanella, respectively. On the basis of these observations two
genera are defined as follows :—

"(1) Genus Trypanosoma Gruby, 1843, Haemoflagellates belonging to the family
Trypanosomidae and characterised in the mature form by an oval or globular shape.
(The transverse diameter being only slightly smaller than the longitudinal diameter),
a centrally placed nucleus which is small in proportion to the diameter of the parasite
and with diffuse chromatin; the parasite with few vacuoles and lacking a basal
granule, characterised principally by the location of the kinetonucleus near and behind
the nucleus. "

"(2) Genus Castellanella Chalmers, 1918, emend. Jocono, 1935. Haemoflagella-
tes of the family Trypanosomidae and in the mature form are typically elongate (the
length being considerably greater than the width) with granular or homogenous cyto-
plasm and with a granular nucleus which is large in proportion to the diameter of the
parasite and located centrally or placed at the aflagellar extremity ". [H. N. R.]