84 Biology 



Nevertheless, they may feed more rapidly after fairly long starvation, 

 if they are in good condition. On the other hand, they appear to have 

 some difficulty, possibly a mechanical one, in feeding on mammals. 

 Thus of 7 hungry specimens placed on a rat, 4 fed for 2 hours and 3 for 

 4| hours, and 1, placed on a mouse (having starved 3 months), fed 

 for 5\ hours. A meal of blood does not always appear to agree 

 with them. We do not know upon what this depends. Thus 

 Lounsbury (1903) saw an adult turn black and die soon after having 

 sucked his blood, and Donitz (1907, p. 28) saw larvae which had fed on 

 white mice die rapidly after they had abandoned the host. Donitz 

 supposes that the death of his larvae may have been due to the blood 

 of the mouse being toxic for the tick, but he brings no proof in support 

 of the hypothesis. 



Note relating to oviposition and hatching of larvae. 



From the foregoing, oviposition appears to last 7 to 9 days, and 

 larvae hatch out in 11 — 13 days, when the eggs are kept at 24° C. 

 The period when oviposition takes place after feeding was 6 — 8 days in 

 four cases, 18 — 42 days in four cases. Retarded oviposition may be 

 due to fertilization not having taken place. 



Longevity (unfed): Lounsbury observed unfed adults to survive in 

 captivity for a little over 2 years. He believes that under natural con- 

 ditions both larvae and nymphs can survive unfed for long periods. 

 Laboulbene (1881, and Laboulbene and Megnin, 1882, p. 337) observed 

 the survival of unfed specimens (from Persia) for over 3 years. Robertson 

 (1905, p. 561) kept'adults unfed in pill-boxes for 2 years and 3 months, 

 nymphs survived 2 months without food. Borrel and Marchoux (1905, 

 p. 362) kept adults and nymphs alive for a year unfed and in a dry 

 place. 



Resistance to immersion in fluids: they may, in our experience, 

 survive for over an hour in spirit. In von Loder's letter to Oken (1818, 



