1120 EXPERIMENT STATION RECORD. 



In a second exjx'rinu'nt, 9 out nf 12 nililiits I'cHistcd infcctiMU. The author con- 

 fludes, tlierefore, that it is possil)l(' lo indducc an acti\i' ininiiiiiily in a majority of 

 cases by inoculation with the nncleoj>rotei<l containcil in antiirax hacilli. 



The bactericidal power of plasma-free blood, plasma, and serum of 

 normal pigeons and those -which have been immunized against anthrax, 8. 

 Si'AXOAHo [CriitU. liakl. n. I'm-., 1. M.t., <>ri<j., JO {J904), X<>. I, j>]>. <VJ-r//).— The 

 author descril)es his method for ol)taining what lie denominates pure ])lood, or l)lood 

 free from plasma. Such material and also tlie plasma and serum were tested for the 

 purpose of determining their bactericidal action. The plasma and serum were 

 found to possess no demonstraljle bactericidal power, while this power in pure blood 

 ■was very conspicuous. The difference between the blood of the normal and iniiiiu- 

 nized j>igeons consists simply in the intensity of the bactericidal power, being much 

 greater in the latter. A large quantity of bacilli in pure or jtlasma-free V)lood may be 

 completely destroyed witliin a })eriod of 2 or 3 hours. 



Transmission of African coast fever, C. P. Lounsbury (At/r. Jour. Cape Good 

 Hope, 24 {1904), iV'o. 4, PP- 4'^8-43^2, ids. 3). — According to the investigations thus 

 far made on the etiology of African coast fever it appears that tlie 1)rown tick (A7(t- 

 picephalu.^ appendiculatus) is the chief and perhaps the only natural means of trans- 

 mitting this disease to cattle. 



The brown tick is widely distributed in South Africa. Notes are given on the 

 habits and life history of the tick with especial reference to the relationship between 

 its habits and the transmission of the disease. The brown tick is found chiefly on 

 cattle, but may also infest horses, asses, mules, sheep, goats, dogs, and cats. It was 

 first shown in November, 1902, that this tick was concerned in the transmission of 

 African coast fever, and subsequent experiments have confirmed the results obtained 

 at that time. 



The most effectual means of controlling the brown tick has been found in repeated 

 dipping in arsenical dips. This process may take place every 2 weeks during the 

 warn^ season, and is effective in destroying other species of ticks as well as the one 

 under consideration. 



Rhodesian redwater or African coast fever, R. Koch {Agr. Jour. Cape Good 

 Hope, 24 [1904), No. 5, pp. 549-560). — This constitutes the author's fourth report on 

 the subject of African coast fever. Many of the experiments reported in previous 

 articles have been repeated and results obtained which are believed to be reliable. 



The general results of the author's investigations indicate that African coast fever 

 is a cattle disease due to a specific blood parasite distinct from that of Texas fever. 

 The 2 diseases, however, jnay exist simultaneously in the same animal and, under 

 such circumstances, hemoglobinuria is observed. The disease did not originate in 

 Rhodesia, but was introduced from the eastern coast. It is not transmissible 

 directly, but only through the agency of ticks. The mortality is very high, usually 

 about 90 per cent. Recovered animals are immune to subsequent attacks, but retain 

 small numbers of the parasites in their blood. Such animals aie therefore capable 

 of transmitting the disease to other animals through the agency of ticks. 



The disease can not be reproduced by means of single injections of virulent blootl. 

 Repeated injections, however, at intervals of 2 weeks produce a mild infection, which 

 after a period of 4 or 5 months results in a permanent immunity. In obtaining blood 

 for inoculation purposes care should be exercised that it does not contain organisms 

 of other diseases. Notes are also given on other means of prevention, especially 

 dipping for the destruction of ticks. 



Heart-water inoculation experiments, D. Hutcheox {Agr. Jour. Cape Good 

 Hope, 24 {1904), Xo. 4, pp. 433-442). — Elxperiments had already indicated the pos- 

 sibility of immunizing goats to heart-water by means of intravenous injections of 

 the blood of recovered animals. The animals which had just l)een immunized were 

 exposed to natural infection with virulent heart-water, and were also inoculated 



