G. H. F. Nuttall 
105 
Ill nature, the tick will probably be able to complete its life cycle in 
a year but it may well run into two years in our climate. Taking 
average figures from the data recorded above, the cycle may be completed 
in 163 daysb but the developmental period may of course be much 
prolonged: 
Time required 
in days 
From the time egg is laid to emergence of larva ... 38 
Larva hardens ... ... ... ... 7 
Larva stays on host ... ... ... ... 6 
Metamorphosis: Larva to Nymph... ... ... 14 
Nymph hardens ... ... ... ... 7 
Nymph stays on host ... ... ... ... 7 
Metamorphosis: Nymiih to Adult... ... 15 
Adult hardens ... ... ... ... 7 
Adult ( ? ) stays on host ... ... ... 14 
Gorged ? having dropped off host, begins to lay after ... 10 
From the time egg is laid to emergence of larva ... 38 
163 days 
HYALOMMA AEGYPTIUM. 
The only observations upon the biology of this common species 
appear to be those of Lounsbur.y (1900, p. 27 ; 1900, p. 44; 1904, p. 30) 
who reports that it attacks all farm animals in South Africa, doing most 
harm to sheep and goats and also troubling ostriches. Lounsbury’s 
observations, as he himself states, are but fragmentary. He concluded 
that it is a three-host tick. He records the following observations: 
Both the larvae and nymphs leave the host to moult. Larvae 
remain upon the host for 3-|-4-|- days. Males predominate on 
animals and remain a long time upon them. Females begin to 
oviposit 14 days after leaving the host (in February'^) and the 
eggs are more resistant to dryness than those of A. hehraeum and 
B. decoloratus. The time required for metamorphosis from egg to 
larva varies ; in four observations which are cited the times required 
were 37, 57, 63 and 79 days respectively; the longest period 
observed was six months. 
The following observations were made by me in Cambridge, chiefly 
upon the progeny of four replete females (Lot 1305 a) which were 
1 Stockman gives a theoretically shortest cycle, but through an error in omitting to 
complete the cycle his period is too short. 
" Southern hemisphere. 
