26 Ornithodorus savignyi 
of the female from 775 to 358 days, i.e. by 45 per cent.; an increase of 7 ° C. 
(from 30° C.) reduces the period required for the production of third stage 
nymphs by 2 b per cent. At 30° C., the mean minimum periods required for 
metamorphosis are 60 days for males and 73 days for females (cf. 0. moubata , 
06 days for males and 45 days for females). Reproduction was inhibited at 
37° C. 
4. Moisture is an unfavourable factor, decreasing the vitality of the 
individual at each stage of growth. 
o. Changes in external anatomy undergone during development are 
similar to those already described for 0. moubata. 
Fig. 3. Ornithodorus savignyi, outlines of cribriform plates of spiracles: (a) to (/) of 1st to 6th 
stage nymphs; ( h) and ( i ) of males from 3rd and 5th stage nymphs; (j) and ( k ) of females 
from 4th and 6th stage nymphs. (N. C. del.) 
REFERENCES. 
Cunliffe, N. (1921). Some observations on the biology and structure of Ornithodorus 
moubata, Murray. Parasitology, xm. 327-347. 
Drake-Brockman, R. E. (1915). Some notes on the Bionomics of Ornithodorus savignyi in 
British Somaliland. Bull. Entom. Research, London, vi. 195-196. 
Fletcher, T. B. (1919). Report of Agric. Research Inst. Pusa, 1915-16, 78-84. 
Howlett, F. M. (1916). Ibid. 1914-15, 74-77. 
Nuttall, G. H. F. and Warburton, C. (1908). Ticks, a monograph of the Ixodoidea, Pt. i. 
Cambridge. 
