A SECOND PLAGUE OF TICKS IN RENT. 
483 
tures, on shrubs and trees, as well as on horses, cattle, and 
birds, and especially on young pheasants. There seems no 
reason to doubt that the two tick-plagues are connected with 
each other, and that during the interval which has elapsed 
the parasites have been enormously increasing in number, 
and greatly extending the area of their presence. At the time 
of the first visitation we placed several of the larger specimens, 
which had been received from Mr. C. Morgan, veterinary sur¬ 
geon, Nonington, near Wingham, in a box, chiefly to deter¬ 
mine the length of time the parasites would survive without 
food. On examining the box, on June 9th, 1869, the females 
were found to have expelled large quantities of ova, of a deep 
brown colour, and agglutinated together in masses, nearly 
equal in size to the ticks themselves. Some of the ova were 
collected into small glass tubes, and kept warm, day and 
night; others, similarly secured, were only subjected to arti¬ 
ficial warmth during the day, and others, again, left without 
any application of heat in the box. 
On June 25th the hatching process commenced in the 
lot kept constantly warm, and went regularly on up to 
July 2nd, when it was completed. In lot 2, subjected to 
warmth during the day only, the hatching process was de¬ 
layed for more than a w r eek; but when begun it went on 
without interruption, and was finished in about the same 
space of time as in lot 1. In lot 3—those left in the box— 
a still greater difference in the period of incubation was 
observed. Daily examinations, subsequently to the hatching 
of the two other lots, showed that the developing process was 
gradually going on; but it was not until July 26th—forty- 
seven days from the expulsion of the ova by the parent ticks 
—that any young ticks made their escape from the ova. 
On June 28th some of the young ticks hatched on the 
25th were placed in the upper part of the head of a pony, on 
the back of a cow, on the top of the shoulders of a lamb and a 
dog, on the heads of three sheep, and also on the head of a 
cat. None of these, however, could afterwards he found, 
notwithstanding a most diligent research was made for them. 
On June 30th others of the same hatch were placed on the 
inner part of the ears, and on the back of a white rabbit, for 
the subsequent better finding of them. Two days afterwards 
a few of those placed in the ears were observed to be very 
slightly attached to the skin, but the others had wandered 
away, and could not he found. On the same day some of 
the young ticks were put into the ears of two white mice, 
but these also could not afterwards be found. 
Besides these experiments, in order to determine how long 
