BY T. HARVEY JOHNSTON AND M. J. BANCROFT. 311 



Little whitish sores containing pus are also formed 

 in response to tick irritation. Thick, whitish scurf may 

 also be formed from the same cause, notably at the butt of 

 the tail and in the ears. 



With regard to the appearance of an exudate on Clover 

 and Tinkerbell, Pound (R.S.C., 1915, p. 20), stated that 

 such vesicles as did occur on them, Avere the result, purely 

 And simply of tick irritation. On arrival at Yeerongpilly 

 in December, 1912, and again during the stalling experi- 

 ments of June-July, 1914. these cows are reported to have 

 been covered with sores of a vesicular and pustular character 

 (Pound. 1914, p. 110). Further on, however, in the same 

 report he mentioned that bacteriological examination was 

 made of " the serous exudate." Several kinds of ordinary 

 skin bacteria were found ; while such pyogenic cocci as 

 •alhus and auretts were observed in the pustides, but no other 

 organisms were detected that could be regarded as fatal 

 to the cattle tick. Pound (R.8.C., 1915, p. 20), also stated 

 that no such vesicles occurred when the animals were kept 

 on non-infested country. 



Smears of blood and exudate taken from a number of 

 resistant animals during the period 1915-1918, failed (on 

 •examination by us) to reveal the presence of any organisms 

 other than those which one might expect to find as a result 

 of contamination. 



Cultures were made of some exudate sent down in 

 capillary tubes. These were submitted to Dr. Bradle}^, 

 Microbiologist to the Health Department, Brisbane, Avho 

 reported as follows : — " The plate culture submitted shewed 

 several types of colonies. The types of these were such as 

 usually occur from air or Avater contamination. None 

 resembled known pathogenic organisms, except a few which 

 may have been varieties of Staphylococci (commonl}" found 

 in the skin of men and animals). Many of the colonies 

 were apparently dead as no growth occurred on sub-culture 

 of the smaller types. Gram stained film shewed gram 

 positive cocci and gram positive bacilli." 



Cultures made in agar slopes were incubated at 37 

 degrees C. for several days ; several shewed a groAvth of 

 mould but no organisms other than those noted above were 

 •detected. 



