1920] VETERINARY MEDICINE. 77 



The isolation of and search for anai)lasnia by the inoculation of the 

 sheep or goat with suspected blood, J. Ligni£res {Bui. Soc. Path. Exot., 12 

 {1919), No. 10, pp. 774-779). — The iuoculation of sheep and goats with Piro- 

 plasma Hgeminum and P. argentmum produces no effect upon them and these 

 organisms can not be recovered from their blood. The injection of the slieep 

 or goat with blood containing both piroplasma and anaplasma is only positive 

 for anaplasma. If in one to two months after inoculation 5 to 10 cc. of blood 

 from sheep or goats is injected into a susceptible bovine intravenously or sub- 

 cutaneously a pure anaplasmosis is produced. Injection of the sheep or goat 

 with blood suspected of containing anaplasma and then injecting their blood 

 into bovines is a simple and easy means of isolating the anaplasma. This 

 method will greatly facilitate the pre;)aration of an epidemiological chart in 

 any region where anaplasmosis may exist. 



The vaccination of bovines against anaplasmosis, J. LiGNiftRES {Bui. Soc. 

 Path. Exot, 12 {1919), No. 10, pp. 7C5-77// ) .— The author finds that Anaplasma 

 argentinum becomes attenuated if inoculated into sheep and goats, and that the 

 blood of such animals provides a vaccine for bovines against the more serious 

 forms of anaplasmosis to which they are subject. The attenuation of A. 

 argentimim is in proportion to the duration of its presence in the sheep or goat. 

 It was found that, by the selection of those strains that are least virulent at 

 first and passing them successively and at long intervals through the sheep or 

 goat, such fixity in the attenuation of the virus is obtained that it may be 

 employed to immunize with almost no danger. Since 1916 several hundred 

 animals intended for breeding purposes have been vaccinated in this way with 

 excellent results. 



Arrow grass. — A new stock-poisoning plant (Triglochin maritima) , C. E. 

 Fleming, jV. F. Peterson et al. {Nevada St a. Bui. 98 {1920), pp. 21, figs. 10).— 

 Recent experiments conducted by the station show that xmder certain condi- 

 tions the grasslike plant commonly known as arrow grass is poisonous to both 

 sheep and cattle. This plant looks like the common grasses, and often grows 

 among them in wet soils, especially where the soil contains alkali. It contains 

 an luiknown substance which is sometimes broken up in the stomach of the 

 animal, liberating hydrocyanic acid gas. 



"Animals fatally poisoned by arrow grass breathe very rapidly at first; 

 tliey tremble, breathe through the mouth, walk around stiffly, have spasms, 

 and go down in convulsions. Later they breathe more slowly and with in- 

 creasing difficulty, spasms continuing at intervals until death, which occurs in 

 from half an hour to three hours. An animal must eat a large dose at one 

 time in order to be poisoned. Small doses eaten at frequent intervals or 

 moderate quantities eaten daily have no harmful effects. Arrow grass cut and 

 dried in hay is far more dangerous and deadly than the green plant. When 

 tlie body of any animal dead of arrow grass poisoning is cut up there is 

 little indication of the cause of death. There is usually some congestion of 

 llie lungs and of the fourth stomach, but neither condition is characteristic of 

 this plant alone. Because of the nature of the poison and because death fol- 

 lows poisoning so promptly, there is little hope of finding methods of treating 

 and curing animals seriously poisoned by arrow grass. Places where arrow 

 .crrass grows very thickly should be fenced off. Considerable effort should be 

 made to jirevent arrow grass from being cut, dried, and put up in hay." 



Astragalus tetrapterus, a new poisonous plant of Utah and Nevada, C. D. 

 Marsh and A. B. Clawson {U. S. Dept. Agr., Dept. Circ. 81 {1920), pp. 6, figs. 

 2). — Requests received in the late sunnner of 1916 for the investigation of 

 losses of cattle on a range near Newcastle, Utah, led to the preliminary investi- 



