432 
Biology of Ixodiflae 
The fertilized female becomes replete in 8-10 days; she is then slate- 
coloured and weighs on an average, when fully gorged, 0-35 g. Unfer¬ 
tilized females may stay for several weeks upon the host remaining about 
a third gorged. 
Time required for met amorqihosis. 
Egg to larva: the larvae emerge some weeks after the eggs are laid 
and they are capable of living for a long time unfed. 
Larva to nymph: nymphs emerge 17 days after they abandon the 
host as gorged larvae, when maintained at 25-30° C. From 64 gorged 
larvae found upon a hedgehog, 64 nymphs emerged. 
Eymph to adidt: adults emerge after 22 days at 25° C. From 4 
gorged nymphs found on a stag at Chantilly there emerged 4 S after 
two months; from 15 gorged nymphs found on a hedgehog there emerged 
15 adults. Certain incompletely gorged nymphs undergo metamorphosis 
to adults very slowly and they often die before it is completed. H. 
concinna differs in this respect from certain species of ticks, for instance 
Amblyomma cajennense (as seen by Aragao, 1912, p. 96), Rhipiceqyhalus 
ajjpefidicidatus and R. sanguineus (Nuttall, 1913, p. 195; Cunliffe, 1914, 
p. 372), Dermacentor reticulatus (as seen by Brumpt), wherein imperfectly 
gorged nymphs were found to give rise to small adults. 
Oviposition. 
At a temperature of 18° C., oviposition occurs in about the second 
week. The eggs are larger than those of Ixodes ricinus, they are dark 
salmon-coloured. Each female usually lays upwards of 1000 eggs. 
Season. 
From the accompanying table relating to Brumpt’s observations on 
the seasonal occurrence of H. concinna (and H. inermis) in France, it 
will be seen that all stages were encountered on deer in February-April 
and October, none were found in January and September, 1912, and 
none were encountered in November-December of 1912 and 1913. 
All stages were most numerous in March and April, usually few or none 
being encountered later. Observations for the 4 months May-August 
are lacking. In one instance (April, 1912) the number of (Js greatly 
exceeded that of the $s encountered on one host. On two hedgehogs 
examined at Chantilly (27. vi. 1911 and 6. vi. 1912) he found immature 
stages only: 15 nymphs, 64 larvae and 19 nymphs, 174 larvae 
respectively. 
