G. H. F. Nuttall and H. B. Fantham 
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(fig. 21) two chromatin masses appear to be separating, the interspace 
staining faintly pink. Comma-shaped or club-shaped parasites (figs. 5, 6) 
are very common. In these the chromatin mass is terminal and the 
protoplasm usually stains uniformly blue. Straight or slightly curved 
bacilliform parasites (figs. 13—1(1, 26, 27) are also seen, which closely 
approximate to the foregoing. In the earlier stages of the disease 
(figs. 5, 6, 7) such parasites may show relatively large chromatin masses 
and in some cases (figs. 8, 25) have a drum-stick appearance. At times 
the chromatin mass shows a slight constriction (fig. 28), suggesting 
commencing nuclear division. When two bacilliform parasites chance 
to lie cross-wise (figs. 29, 40, 41, 43), as occasionally happens, they may 
present the appearance of true cross-forms. Bacilliform parasites increase 
in numbers during the course of the disease. Pyriform parasites (fig. 4) 
are neither numerous nor typical of T. parva. Intermediate forms 
between pyriforms and ovoids (figs. 23, 24, 36, 42) are often encountered. 
These and the pyriforms probably belong in the same category as do 
parasites from which a single pseudopodium-like process (figs. 11,12) is 
protruding. Judging from observations on the living parasites ( Parasi¬ 
tology , vol. ii. p. 334) the movements of such forms are slow. In the 
parasite depicted in fig. 12 the chromatin mass is curved dumb-bell shaped. 
Forms apparently undergoing division into two :—We have already 
referred to appearances observed in the chromatin masses of rounded, 
ovoid, bacilliform and amoeboid parasites which suggest that these 
may be undergoing nuclear division. In some parasites two distinct 
masses of chromatin are observable lying at opposite poles of the 
parasite. This is clearly seen in some oval (fig. 32) and bacilliform 
parasites (fig. 27). In most bacilliforms showing two distal masses of 
chromatin, the rod-shaped body of the parasite is bent at an angle (figs. 17, 
18, 19, 20, 30, 39, 44) midway along its length. We have frequently 
observed such parasites alive; they present a curved dumb-bell-shaped 
appearance ( Parasitology , vol. II. p. 336, Diagram 3), but we have not as 
yet been able to see them divide. The appearances seen in the stained 
parasites suggest that they are dividing forms. In one case (fig. 19) a 
small mass or strand of chromatin was observed at the bend. As will 
be seen by reference to the plate, some of these “ bent ” forms are very 
much larger than others. Bent dumb-bell-shaped masses of chromatin 
may be observed in minute pear-shaped parasites (fig. 35) as well as in 
large ones (figs. 12, 34, 42). If these appearances observed in the 
chromatin denote division, then we must conclude that both large and 
small parasites may undergo nuclear division in a similar manner. 
8—2 
