C. A. Hoare 
321 
As regards the mutual relationship between all the forms described above, 
we can, of course, only make such suppositions as are based on cycles of 
development already studied. 
The forms of tyfe 1 (Figs. 9, 10, 11) doubtless represent the young stages 
of the parasite just beginning its cycle of development. Probably they are 
merozoites and pass through a certain period of free life, in the course of which 
they penetrate into the erythrocytes for a short time (sometimes pictures are 
seen in which only the middle portion of the parasite lies in the blood corpuscle, 
whilst its ends are free), as was stated by Stebbins (1905), Dobell (1910), 
Neresheimer (1909), and others. This stage is probably succeeded by an 
intracorpuscular stage, during which the parasites grow and bend over, 
adapting themselves to the limited space within the erythrocyte (Figs. 12, 13). 
In this period there appear in the protoplasm of the parasite the characteristic 
granules of volutin. 
The volutin probably represents reserve material formed in the protoplasm 
and used up for the formation of nuclear substances during the maturation 
of the nucleus in the period of multiplication. The appearance of volutin in 
the protoplasm indicates the beginning of the processes of reproduction 
(Reichenow, 1910; Doflein, 1916). 
Taking into consideration the circumstances stated above, we may suppose 
that the forms described as tyfe 2 (Figs. 12, 13) represent adult, ripe tropho¬ 
zoites. The form represented in Fig. 14 probably shows the stage at which 
one of the limbs of the body is retracted. Such a process usually precedes 
the formation of the schizont (Reichenow, 1910). 
The forms of tyfe 3 are encountered in the films in predominant and very 
large numbers. It is to be supposed that after complete reduction of the 
“tail” the form just described (Fig. 14) passes to this stage (Fig. 15); as is 
also confirmed by the resemblance in the appearance of their nuclei (the 
structure of the latter is hardly discernible in these stages). 
The succeeding stages of development evidently take place in the internal 
organs. 
The forms represented in Figs. 17 and 18 are encountered only in single 
cases. It is possible that they represent the intermediate stages between the 
initial (Fig. 15) and final stages of the process of schizogony. 
In the forms of tyfe 4 (Figs. 17 and 18) a gradual increase in the size of 
the cell, and a swelling of the nucleus, are visible. 
Of course, all the considerations set forth here are hypothetical, as it is 
impossible to form a definite judgment regarding the successive phases of a 
complex cycle of development based on separate forms from several blood 
films. 
As has been mentioned, some of our forms resemble, in general features, 
the parasites described by Dutton, Todd, and Tobey, MacFie, Stebbins, 
Stevenson, and Shortt. This likeness is, however, always limited to some 
single stage, whereas the other forms differ sharply from our parasites. More- 
