100 
Biology of Ixodidae 
they were maintained in corked bottles and glass dishes in an unheated 
outhouse, moulds being avoided by keeping the ticks somewhat drier 
than under natural conditions. The results of his raising experiments 
are fully referred to and incorporated in the following pages, the author’s 
name being given in all cases where he is cited. Stockman’s records 
were somewhat confused and it was not always easy to extract the 
desired information from them. 
Seasonal occurrence on hosts. The specimens which have reached 
us have been adults collected in April. According to Stockman, in 
Kent and Devon, engorged females are found on sheep in April-June, 
in October and occasionally at other times of the year; engorged 
nymphs were found in May and August. Judging from observations at 
the Alperton laboratory on material collected at various times in the 
field, the ticks not being incubated during metamorphosis, Stockman 
concludes that larvae which feed and moult up to May, nymphs which 
feed and moult up to July, and adult females which feed and oviposit 
up to August, are all derived from eggs hatched the previous year. 
The larvae which hatch out, feed, and moirlt from July onwards, the 
nymphs which feed and moult from August onwards, and the adults 
which feed from October onwards are presumably all derived from eggs 
of the same year. All eggs laid in February, May and June hatched in 
July and August. Stockman believes that in nature the different 
stages emerge and feed as follows : the larvae do so chiefly in July and 
August, the nymphs in August-October, the females in October- 
November, but all stages may hibernate (fed or unfed) and appear on 
hosts in the spring. The females oviposit mainly in the spring. 
Starting with eggs laid in the spring, the ticks, according to Stockman, 
probably pass the next winter as gorged nymphs, and feed as adults in 
April-May of the following year, the cycle presumably lasting about 
290 days. 
Further observations made in the field appear to me required before 
definite conclusions can be arrived at; until such observations are made 
Stockman’s hypothesis, based almost purely on laboratory experience, 
can scarcely be accepted. 
Conclusions from the follotving protocolvegav^m^ the time H. punctata 
remains upon the host: 
Larvae placed upon a hedgehog in June-August, the host being 
maintained at 16-17° C., remain 3-11 days upon the host, the majority 
dropping off gorged after 4-7 days. In November-December, the 
temperature being 10-12° C., they remain upon tlie host 7-21 days. 
