G. H. F. Nuttall and G. S. Graham-Smith 247 
of degeneration. The majority of the intracorpuscular forms soon became 
rounded, but a few of the pyriform ones retained their shape for many 
days. Occasionally large numbers of rounded parasites were found 
within leucocytes. (See Plate XIII, fig. 3, Journ. of Hygiene, Yol. vi. 
1906.) 
In some cases the red blood corpuscles retained their normal shape 
up to 35 days. 
E. Eleven experiments were made with blood agar in the hope of 
obtaining cultivation forms. The blood agar was made by mixing equal 
parts of defibrinated rabbit’s blood with melted agar at 55° C. and was 
prepared one hour before use. Small quantities of fresh defibrinated 
heart’s blood of dogs dead of the disease were placed in the tubes, 
which were cultivated at various temperatures. Examinations made at 
various times revealed only a few degenerated parasites. 
F. Defibrinated dog’s blood added to various quantities of 2°/o 
sodium citrate solution was kept under the same conditions and 
examined in the same way as in experiment D. Seven experiments 
were made, the times of the examinations varying between 28 hours 
and 72 days. Even after 28 hours the majority of free forms and 
intracorpuscular parasites had become rounded. After this time very 
few free parasites were seen. In one experiment a few forms with well 
marked slender radiating processes like those described later (p. 252) 
were seen. In some cases the red blood corpuscles were found well 
preserved up to 53 days. 
G. Five similar experiments were made by adding defibrinated 
blood to slightly acid 2°/ 0 sodium citrate solution with the same results. 
H. In three experiments defibrinated blood was added to 4°/ 0 
sodium citrate solution and the cultures examined at various times 
between 13 hours and 23 days. With very few exceptions both the 
intracorpuscular and free parasites were found to be rounded. Many of 
the red blood corpuscles retained their shape up to the 23rd day. 
I. Two experiments with normal saline solution containing 4°/ 0 
sodium citrate gave similar results. 
J. In six experiments defibrinated blood was added to 25°/o potas¬ 
sium oxalate solution and specimens were examined between 36 hours 
and 62 days. The same changes were noted as in experiment F. In 
some cases the red blood corpuscles retained their normal shapes up 
to 60 days. 
K. Six experiments with slightly acid potassium oxalate solution 
gave the same results. 
