300 Genus Ixodes 



females. I have found these ticks attached in similar situations on 

 deer and roe-deer. On dogs they occur frequently about the head 

 and neck. They attach themselves to guinea-pigs and rabbits inside 

 and outside the ears and upon the eyelids and in other situations. 

 Incidentally, I may mention that I have for several years utilized 

 hedgehogs for raising experiments with very good results, since the 

 bristles protect the ticks against injury from the host. 



The time required for Metamorphosis. 



Hatching of the eggs. A variable period of time elapses between 

 oviposition and the hatching out of the eggs. According to Chabrier 

 (1807, p. 366), the larvae issue from the egg after 2-3 weeks, but more 

 recent observers record a longer period : 



Larvae emerge after : 

 about 6 weeks (Kossel, Schiitz, Weber and Miessner, 1903, p. 40). 

 „ 7 „ from 17. vi. to 4. vin. (Bertkau, 1881, p. 148). 

 „ 8 „ „ 25. v. to 19. vii. at 65° F. (Wheler, xn. 1899). 

 „ 22 „ „ 4. v. to 12. x. (Meek and Smith, cited by Wheler). 

 „ 36 „ „ ix. to vi. (Ashworth, 1909, p. 133). 



As first noted by Gene (1844), the hexapod larva, when it issues from 

 the egg, is almost transparent. It subsequently grows darker as the 

 chitin hardens. Having exhausted its reserve food-supply, derived from 

 the yolk of the egg, it attacks a host and sucks blood, abandoning the 

 host when replete. 



Gorged larvae metamorphose into nymphs after a period which may 

 be considerably prolonged by low temperature. 



Nymph* emerge after : 



(in summer) 1 month (Kossel, Schiitz, Weber and Miessner, 1903, p. 40). 

 (in winter) 5 months ( „ „ „ „ „ „ „ ). 



( „ ) 3 „ (in a room ; Nuttall, 1905, v. supra). 



As in the case of the larvae, the nymphs darken and harden for 

 some days after they emerge from the larval skin. They in turn attack 

 a host and abandon it when replete. 



Gorged nymphs metamorphose into adults after a period which like- 

 wise varies according to temperature : 



Adults emerge after : 



(in summer) 2 months (Kossel, Schiitz, Weber and Miessner, 1903, pp. 40, 43). 



( „ ) 2$ „ : 29. v. to 19. vn. (Wheler, xn. 1899). 



(in winter) 7 „ (Kossel, Schiitz, Weber and Miessner, 1903, p. 43). 



(kept cool) 12 „ ; 14, vin. 1899 to 4. vm. 1900 (Wheler, 1902), 



