32 



Malignant Tertian. I. The rings of this species 

 are the smallest, one-sixth to one-seventh the diameter 

 of a red cell. Instead of being ring-like they may 

 stretch across the cell (bacilliform), or be applied to 

 the margin of the cell (Plate I). Pigment is generally 

 absent, at least in the tropics. It must, however, be 

 admitted that it is difficult to be certain of the species 



Fig. ys. The three species of Malarial Parasites (stained) 



of a single isolated ring. 2. The largest stage in the 

 blood is characteristically egg-shaped, one-third to 

 one-fourth the red cell. These forms occur (in 

 regular charts) when the temperature is low. If, on 

 the contrary, the "temperature is still high, and large 

 forms are found, they are probably simple tertian or 

 quartan. 3. The infected red cell shews occasionally 



