550 REPORT—1905. 
tract of country, has been found to be associated with Amblyomma hebreum. The 
tick becomes infected with the undiscovered organism of the disease in one stage 
of its life-cycle, and communicates it at a later stage. To some extent infection is 
dependent on temperature, since the tick fails to convey the disease if it has not 
been subjected to a requisite degree of warmth during or subsequent to the transi- 
tion from one stage to the other. Infection may be transmitted from one kind of 
the animal subject to it to any of the other kirds. Sheep of the Persian breed 
take the disease mildly, but the virulence of the infection does not appear to be 
modified by passing through them. The incubation period averages several days 
longer when the infecting ticks are applied to the leg than when applied to the 
abdomen ; but the transmission of the infection is supposed to take place within 
twenty-four hours after the ticks attach, Infection has resulted through the bite 
of a single tick. Animals which recover soon lose the capacity to infect ticks, but 
it appears that their immunity is only relative, and it is therefore suspected that 
they may be a medium of continuing the infection. The progeny of the transmitting 
tick appears innocuous. Canine piroplasmosis has been found associated with 
Hemaphysalis leachi. The infection may be derived from sick or recovered 
animals, It appears to be transmitted only by adult ticks which are the progeny 
of females off infective animals. In other words, the infection passes through the 
egg stage of the tick and remains latent during the larval and nymphal feedings. 
Most. of the experiments in connection with bovine piroplasmosis have failed to 
afford conclusive results for reasons not yet fathomed. The only perfectly satis- 
factory case induced under observation by ticks was one due to larval progeny of 
Boophilus australis females off a recently recovered animal. 2B. decoloratus is 
press to be the common transmitter of the disease. African coast fever has 
een found to be communicated by ticks in a manner analogous to heart-water, 
that is, by nymphs or adults which in the previous stage fed on a sick animal, 
Five species of the sub-genus Eurhipicephalus, appendiculatus, nitens (?), evertst, 
stmus, and capensis, have heen found implicated. No infection has been derived 
from recovered animals, and none has resulted from the application of the progeny 
of females of any species of tick off sick animals. The duration of the fever 
period averaged twelve and a half days in the cases produced; so there appears 
apn abundance of time for laryee and nymphs of the various species of Hurhipi- 
cephalus to hecome infected. 
Colonel Bruce thanked Mr. Lounsbury and Dr. Hutcheon for their papers ; 
the latter had laid the foundation of all their knowledge of South African 
stock diseases, and Mr, Lounsbury’s work on ticks was of the most brilliant 
character. The value of such work could not be over-estimated by those in 
authority or by the owners of stock, for horse-sickness had killed 78,000 horses 
in a single year. 
Sir Watrer Henry Hurcnrinson also expressed his thanks to Mr. Hutcheon 
and Mr. Lounsbury for their papers. He believed that the farmers were becoming 
alive to the importance of ticks as carriers of disease ; they had, however, to combat 
enormous difficulties, notably, that bucks, hares, &c., were infested by this tick, as 
well as cattle, and therefore it was almost impossible for the farmers to clean- 
their farms. 
Mr. Rozgertson said that osteoporosis in equines was first recognised in 1880 
by Professor Varnel. It made its appearance at Port Elizabeth among race- 
horses ; and as most of those affected were progenies of the same sire, it was sup- 
posed to be due to hereditary predisposition, Serious outbreaks occurred at 
Wynberg amongst the Argentine horses during the recent war, and also at Kim- 
berley, Johannesburg, and elsewhere. The disease was spreading so fast that it 
bid fair to become one of the scourges of South Africa; nor was it confined to any 
particular breed of horse. : 
The disease had been compared to osteo-malacia, but in his opinion was abso- 
lutely distinct from it. It was in no way due to insufficient phosphates in the 
food, and was in his belief an infectious disease, and he was not without hope of 
introducing remedial measures by inoculation. 
