182 EXPERIMENT STATION RECORD. [Vol. 4:! 



Siven also illustrate in one or two oases the phenomenon of disappearano 

 and reappearance of the complement deviatinj; bodies. 



On the specificity of IJabesia iiiinor, J. I\I. (^Hevedo iRei\ Roc. Med. Ve 

 [Buenos ylfre.s], J, {1919), No. 6, pp. 170-175, fl(js. 3; aha. in Vet. Rev., 4 (1920), 

 No. 1, p. 113). — The author maintains that B. minor is the causative agent of 

 " tristeza." 



Clinical and anatonio-pathological aspects of American trypanosomiasis, 

 C. Chagas (Netv Orleans Med. and Surg. Jour., 72 (1920), No. 11, pp. 630-660, 

 fiff. 1). — In this translation by L. Ambrose of an article which appeared in 

 1916* and 'a translator's note, a summary is given of the present status of 

 knowledge of Chagas' disease in Brazil due to Trypanosoma cruzi, which is I 

 transmitted by (ConorJiinus) Triatoma megistus. 



A tick-resistant condition in cattle, T. H. Johnston and M. J. Bancroft 

 (Proc. Roy. Soe. Qtiecnsland, 30 (1918), pp. 219-317, figs. 3).— The data here 

 presented have been summarized by the authors as follows : 



" The cattle tick in Queensland may cause tick fever and tick worry. There 

 exists a degree of resistance to tick fever, and this is largely influenced by 

 individual idiosyncrasy, age, sex, and general health of the animal as well as ; 

 by food and other conditions. Tick worry is at present a more serious com 

 plaint than tick fever in Queensland. It is apparently due, at least in part, to ' 

 the injection of a toxin by the tick. Many cattle become habituated to tick 

 infestation and this, in individual cases at least, leads to some degree of re- 

 sistance. Such resistance is probably due to the formation of anti-tick poison 

 bodies by the blood of the animal. 



" Tick-resistant cattle are known from a number of Queensland localities. 

 Asiatic breeds are tick resistant. Of the various breeds commonly met with 

 in this State, Jerseys appear to be less affected than others by ticks. Tick 

 resistance seems to be influenced by food only in so far as the latter affects 

 the general health of the animal. The effect of the application of arsenical 

 solutions to resistant cattle has not been satisfactorily determined. Perhaps 

 the use of arsenical solutions prevents the realization of such resistance. Tick 

 resistance persists, pi'ovided the resistant animal's health be maintained. 

 The temperature of resistant animals appears to be normal. There is good 

 reason to conclude that the resistant tendency is hereditarily transmissible. 



" Although there is considerable positive evidence of the transmissibility of 

 resistance by vaccination, we have not succeeded in proving it. In many 

 cases the condition has been acquired naturally. AYe think that habituation 

 is a step toward resistance, which seems to us to be a physiological reaction 

 to the introduction of a tick toxin. The comparatively few ticks which mature 

 on resistant cattle appear to have their fertility, as a rule, somewhat im- 

 paired. 



" Associated with tick resistance in many animals is an exudation of a' 

 lymph-like substance on the skin. This condition is quite distinct from the 

 typical tick sore, though it is apparently a response to tick attack." 



A 3-page list of the literature cited is included. 



The bacteriology of the reproductive organs of the cow and its relation 

 to that of the meconium of the calf, W. Giltnee and S. G. Bandeen (Jour. 

 Amer. Vet. Med. Assoc., 57 (1920), No. 1, pp. Ji6-57). — This is a report of ex- 

 tensive studies of the bacterial flora of the uterus and vagina of cattle, con- 

 ducted at the IMichigan Experiment Station. The authors' summary of the 

 work and the conclusions drawn are as follows : 



" In this series of 12 pairs of cases of fetus and dam, bacteria were isolated 

 from the uterus in 11 cases and from the meconium in 9 cases. Since the 



iPreusa Med. Argentina, lOlG, III, pp. 12.5-127, 137, 138, 153-158. 



