390 ALDO CASTELLANI AND ARTHUR WILLEY. 
When the blood is examined in the fresh condition, the 
crescent-shaped or reniform body of the endoglobular parasite 
presents a clear pole, one granular pole and a clear but sharply 
defined central tract, which in stained preparations proves to 
contain the nucleus. 
Frequently the clear pole is directed towards the displaced 
nucleus of the blood-corpuscle, but there is no constant 
orientation. . 
The granular pole is the growing end of the organism, 
which becomes bent round upon itself in the manner 
characteristic of the genus Hemogregarina. 
The doubling of the parasite usually takes place by a very 
narrow bend, but occasionally a wider bight is produced. 
Young stages before the bending also came under our 
observation both in fresh and in stained preparations, and 
we have seen a double infection of a corpuscle, though this 
appears to be rare. 
The nucleus consists of a more or less diffuse aggregation 
of chromatin or cyanophil granules which sometimes extend 
to the recurved limb of the parasite. The length of the bent 
organism is 0°01 mm. (10). In one corpuscle the parasite 
had unbent itself and appeared asa long “vermicule,” the 
corpuscle being enlarged and somewhat distorted. 
In a hanging-drop prepared from the blood of a specimen 
which had been killed some hours previously we have once 
only observed a motile parasite free in the blood-plasma. It 
resembled the one which was found uurolled in the corpuscle. 
The movements consisted of slow revolutions in the direction 
of the arc of the parasite and also of movements of flexion. 
The granular pole was directed forwards, while the other pole 
remained more or less fixed and appeared to be adhesive. 
Finally, the parasite was attracted by an irresistible chemo- 
taxis to a neighbouring phagocyte, by which it was gradually 
absorbed. 
It may be noted here that we have hitherto not succeeded 
in finding any parasite in the blood of the herbivorous land 
tortoise of Ceylon, ''estudo elegans. 
