A. C. Coles 
‘37 
passed over as lymphocytes unless the particles of pigment were detected, 
but even these may be masked by the deep staining of the parasite. 
Chromatinoid granules are occasionally seen in the macroganietes 
but the}^ are much larger and more generally found in the microgameto- 
cytes. 
Prolonged search was made in more than 36 films but no definite 
signs of segmentation were found, except the fact that in some few reil 
stained parasites, four or five large chromatin granules were found, but 
even in these the pigment was scattered and not collected in the 
centre. 
As to the frequency with which these haemamoebae were detected, 
I should think that in a perfectly spread film 1.5 to 20 parasites might 
be found, and almost invariably these were free and showed no evidence 
of the red corpuscle. My experience in this particular bat was that the 
smaller the parasite the rarer they were. 
Films made from the bone marrow, spleen, and lung were examined 
and one or two parasites detected in the two latter organs but they 
differed in no way from those found in the peripheral and heart blood. 
From the small amount of literature at my disposal, I find that 
Dionisi^ has described three types of parasites found in bats : 
1. Polychromophilus vielanipherus from the blood of Miniopterus 
screihersii which shows polychrome staining with Romanowsky. 
2. Polycliromophilus muriims from blood of Vespertilo murinus 
which also shows polychrome staining and contains pigment. 
3. Achromaticus vesperuginis from the blood of Vesper ago noctula 
which contains no pigment and which according to Minchin appears from 
recent investigations of Yakimoff and others to be a true piroplasni. 
The form I have found and described in the Pipistrelle apparently 
, belongs to Polychromophilus, as it contains pigment, but the red blood 
corpuscles show no sign of polychromatophilous degeneration. 
Achromaticus vesperuginis in the Pipistrelle. 
Unpigmented parasites situated in the red blood corpuscles were 
found in 7 out of 20 Pipistrelles examined, but were not detected in the 
blood of three Noctules or two long-eared bats {Plecotus cmritus). The 
degree of infection varied considerably. In two the infection was heavy 
and in one case as many as 15 to 20 parasites were found in the field of 
jV inch objective with compensating ocular 6. In this case they were 
’ See Liihe. 
