Gr. H. F. Nuttall and G. S. Graham-Smith 255 
haemoglobin. When the blood was kept at room temperature they 
persisted longer. In blood kept in the ice box the parasites after 
12 days appeared as distinct as in fresh blood, but in most cases had 
become spherical, and were situated at the edges of the infected blood 
corpuscles. Very exceptionally free parasites were encountered. Some 
of the corpuscles which contained parasites did not stain in the vicinity 
of the parasite, so that the latter appeared surrounded by a colourless 
zone. Theiler suggested that this zone might be due to the destruction 
of the haemoglobin by some excretion product of the parasite. 
Although he transplanted the parasites into fresh serum he was unable 
to observe any multiplication such as Lignieres states he observed in 
the case of P. bovis. He regarded the parasites which stained well 
after 12 days in vitro as alive. 
Bowhill (1905, p. 2) mixed infected horse blood with potassium 
citrate in a flask and kept it at room temperature. After 24 hours 
many circular and oval extra-corpuscular parasites arranged in irregular 
masses were seen. Stained by the Romauowsky method the chromatin 
and protoplasm stained red and blue respectively. On adding fresh 
serum to infected blood and keeping the latter at room temperature, at 
29° C. or at 40° C. he was unable to detect any multiplication of the 
parasites, although on one or two occasions he observed amoeboid 
movement. 
Theileria parva (= Piroplasma parvum). 
We have elsewhere (ix., 1908, p. 516) stated our reasons for excluding 
this parasite from the genus Piroplasma, but since it belongs to an 
allied genus it is desirable to consider the cultivation experiments of 
Miyajima (1907, p. 84). 
This observer, working in Japan, states that he tried to cultivate 
the parasite in blood agar, sodium citrate (acid and alkaline), beef 
extract, peptone water, calf-serum, normal saline solution, and common 
broth, to which media he added infected blood. He obtained positive 
results when he added Theileria blood to ordinary broth in the proportion 
of 1—5 to 1—10 and maintained the cultures at 20—30° C. 1 
“ The development of the parasites in a successful culture takes 
place in the following manner: on the first day no motile form is seen; 
1 Miyajima states incidentally that he was able to cultivate Tr. lewisi under similar 
conditions. Although we have tried to cultivate this parasite on several occasions 
according to Miyajima’s method we have not succeeded in doing so. 
