
1905. | Infe History of ‘Trypanosoma balbianii. 371 
deserve to be regarded, provisionally at any rate, as being of female character, 
although the intermediate stages between them and the female gamete have 
not been obtained. In the indications it affords of the existence of indifferent 
and female forms, Z7rypanosoma balbiani resembles Trypanosoma noctuce 
described by Schaudinn.* 
The question of the relationships of Zrypanosoma balbiani with other 
Trypanosomes will be discussed in the complete paper. It is here only neces- 
sary to point out that Z7rypanosoma balbianii is by far the most primitive of 
all Trypanosomes known. In many points it realises the “ Urhwmoflagellat” 
imagined by Schaudinn as the ancestor of the Trypanosomide, though upon 
the whole it is of yet more simple structure. It is interesting also to note 
that in the distribution of its nuclear material through the cell in the form 
of a long spiral thread, Trypanosoma balbianw presents a condition not tar 
removed from those bacteria which possess a nucleus in form of small masses 
of chromatin scattered through the protoplasm of the cell. 
Longitudinal Division is the normal method of multiplication for both 
female and indifferent forms. Division is begun by the undulating membrane 
dividing into two longitudinally, the body following suit. The body does not, 
however, divide completely, the spht which forms not extending quite up to 
one extremity. It thus happens that the two halves; after separating from 
one another through an angle of 180°, remain attached at the ends, producing 
the appearance of a Trypanosome twice the length of an ordinary individual, 
which, after a period of considerable activity—the two halves endeavouring to 
wriggle apart—divides into two. A transverse division is thus simulated in 
the last stage of the process of longitudinal division. The nuclear band mean- 
while undergoes a series of remarkable changes, whereby its division into two 
equal parts is effected. The homogeneous band resolves itself into a spirally- 
wound thread, along which the remainder of the chromatic nuclear substance 
is arranged in small masses placed at more or less regular intervals 
(fig. 2,2). The spiral thread, with its masses of chromatin, next condenses 
to form a straight homogeneous rod, which breaks up into segments (fig. 2; 
3, 4). These segments again divide into a number of small dumb-bell 
shaped rods (fig. 2, 5), which, by transverse division, give rise to a number 
of approximately spherical nuclear masses, the chromosomes (fig. 2, 6). 
Each chromosome finally divides into two (fig. 2, 7), in a plane containing 
the long axis of the Trypanosome, a double row of chromosomes extending 
through the whole length of the creature being thus produced. The longitudinal 
split takes place down the middle of this double row, an equal division of 
* Schaudinn, “Generations- und Wirtswechsel bei Trypanosoma und Spirochaete ” 
(Vorl Mitteil), ‘ Arbeit a. d. Kaiserlichen Gesundheitsamt,’ vol. 20, 1904. 
