EXPLANATION OF PLATES 
All the illustrations accompanying this paper, except where it is 
otherwise stated, are drawn to a magnification of 2,000 diameters. 
No camera lucida was employed ; the dimensions were obtained by 
measurement. A Zeiss 2mm. apochromatic i'40 aperture objective, 
with an 8 or 18 eyepiece, was regularly used. 
Plate XX 
Figs. 1 to 28, except 27. are “Young Forms” 
As a rule, ectoplasm, endoplasm and nuclear material can be 
distinguished in each of these parasites; occasionally it is difficult to 
do so (fig. 24). The arrangement of the parasites and the host-cell 
are well seen in figs. 1, 25, 28. The constant presence of a clearer 
area about the chromatic material is to be noted in these parasites. 
F'fT- i- Chromatic mass with linear extension possibly antecedent to 
nuclear division, as in fig. 3. 
Fig. 2 Shows nucleus with vacuole containing indistinct granules. 
3 - Nuclear material divided into a small and a larger chromatin 
mass connected by a line ; possibly stage succeeding fig- 1 
Figs. 4, 5 and 9. Chromatin divided into a larger mass and a smaller 
granular one, placed in a vacuole. Note the vacuole in 
these parasites is frequently pink-staining. 
Figs. 6 and 7. — Forms similar to 2 and 5 in very small parasites. 
Fig. 8. Very small parasite showing a line. 
Fig. 10. Chromatin divided into two equal masses. 
Figs. 11 and 12. Are squashed and somewhat degenerated parasites. 
They are useful in that they show distinctly the presence 
of definite structure in the nuclear material. 
