1 Ava., 1901.] QUEENSLAND AGRICULTURAL JOURNAL. 253 
IT have often obtained no result, not even arise in temperature, after a 
sub-cutaneous injection of 1 cc. of blood, whilst 10 ¢.c. by intra-venous 
injection, produced an outbreak of malaria. 
At the same time, positive results may be obtained with very small doses. 
‘Thus, I have caused disease of a virulent type, and have occasionally killed an 
‘animal with 3, ¢c.c., and even with 53, ¢.c. 
The blood retains its virulence for a variable period, according to the stage 
of the disease: It may retain it sometimes for six, eight or ten days at the 
temperature of the laboratory. In other cases, twenty-four hours after 
withdrawal, it may be injected into a receptive beast without effect. The 
surrounding temperature is not of itself sufficient to account for this variability. 
In fact, if the blood of several diseased animals be taken at the same moment, 
and if all are placed under identical conditions, a very great difference may 
be observed in their virulence. 
At this time of writing I have inoculated 127 cattle, amongst which I had 
‘an uninterrupted series of 42, and of these, 32 died, or say, 76 per cent. Such 
a large number of experiments enabled me to reproduce almost all the clinical 
forms of the natural disease. 
By successive intra-venous injections of 10 c.c. of blood, I have obtained, 
in a given time, a virus which was certain death four or five days after 
inoculation, and often some hours after the appearance of the first characteristic 
symptoms of the disease.* 
J have distinguished, in the natural malaria and especially in the experi- 
mental, a typical form in which the symptoms and the lesions coincide with 
the infection of the infiltrated blood and the change in the blood; also, an 
atypical form in which the examination of the blood often shows no evidence 
of the gravity of the disease, nor even sometimes of the nature of the infection. 
TYPICAL FORMS. 
1.—VIRULENT DISEASE TERMINATING QUICKLY IN DEATH. 
(Pratz XII.) 
Bullock No. 108, Cross-bred Durham.—Age, 18 months. 
On June Ist, 1899, I inject into the vein of this animal 12 ¢.c. of very virulent 
blood. The temperature at the moment of inoculation is 39° C. 
June 2.—Temperature 39°7 C.; the general condition is good. I find nothing 
in the corpuscles, the number of which amounts to 8,200,000 per m.m.c. 
June 3.—Temp. 39°6 C.; the appetite is very good; there is nothing to denote 
any infection whatever; yet it is easy to find hematozoa in the corpuscles, which now 
number 6,100,000 per ¢.¢.m. 
June 4.—Temp. 40° C. The animal still feeds, but with less appetite than on the 
previous evening; it appears much depressed, yet, at the same time, shows great 
energy when roused to excitement; the excrements are semi-fluid, greenish, and 
exhale a fetid odour; when exposed to the air they assume a characteristic rusty 
appearance. ‘The urme has a yellow tinge, and contains a little albumen. The 
respiration and pulsations are slightly accelerated. Hiematozoa are easily detected in 
the corpuscles, the numberof the latter having fallen to 1,350,000 per m.m.c. The 
serum has a distinct pink colour. At 9 p.m. the urine is slightly rose-coloured. 
June 5.—Vemp. 41°5 C. The animal is now at once seen to be ill; it takes no 
food; the respirations rise tc 75 and the pulsations to 100 per minute. The urine is 
deep red, and contains a great deal of albumen. The blood is very clear; the serum 
is decidedly red. ’ 
I can only count 56,420 red corpuscles per m.m.c. An enormous number of 
endo-globular, piriform parasites is found in the blood of the jugular; 30 to 40 per 
cent. of the corpuscles are infected ; some of them have lost their colouring matter, 
and only present a very faint outline; there are Prroplasmu in perfect freedom in 
the serum. 
June 6.—The sick animal is in a bad way; its breathing is spasmodic, pulsations, 
115 per minute. Temperature, 3791 C. Appetite, none; dribbles freely; eyes, 
haggard; staggering gait; the muzzle and nostrils very pale. ‘The urine is 
* Unfortunately, in consequence of the enhanced price of experimental cattle, the series 
“was necessarily broken. 
