1(3 
Variation in Ticks 
Fig. 3 conveys a clearer impression than bare measurements of the 
remarkable difference in size of the extreme individuals in the series 
comprising Lot No. C. 309. 
REFERENCES. 
Aragao, H. de B. (1911). Notas sobre ixodidas brazileiros. Mem. do Inst. Oswaldo 
Cruz, ni. 145-146. 
- (1912). Contribui^ao para a sistematica e biolojia dos ixodidas. Ibid., iv. 
114-117. 
CuNLiFFE, N. (1913). The variability of Rhipicephalus pulchellus (Gerstacker, 1873). 
Parasitology, vi. 204-216. 
- (1914). Rhipicephalus sanguineus-, variation in size and structure due to 
nutrition. Ibid., vi. 372-378. 
Nuttall, G. H. F. (1913). Rhipicephalus appendiculatus: variation in size and 
structure due to nutrition. Ibid., vi. 195-203. 
Warbubtok, C. (1912). Notes on the genus Rhipicephalus, with the description 
of new species, etc. Ibid., v._3. 
