50 
further larval change. When full-fed it presses itself gradually 
out of the opening at the top of the warble, which at first sight 
looks much too small for the operation ; but the orifice can be 
squeezed somewhat larger, and the maggot is compressible, and is 
further helped by its roughened skin and by its ringed shape, which 
prevent it slipping back into its former hole. 
The larval exit from the warble has long been recorded as taking 
place early in the morning between six and seven o’clock. But 
speaking more generally, in the case of some observations made 
by Mr. A. C. C. Martyn (previously referred to, p. 41), he found 
that the full-grown maggot squeezed itself out of the warble 
in the morning, or at some time between six o’clock in the even¬ 
ing and 8 a.m. the following day. This point he ascertained in 
the course of his experiments in rearing the chrysalis; in these 
he found the maggots leaving the warble stuck fast, or trapped, 
as the case might be, on bird-lime, or in the little bags fixed 
for them to drop into, in the morning, but never in the middle of 
the day. 
In the case of eighteen specimens watched by Mr. Martyn, the 
chrysalis stage lasted about twenty-five days ; but, to ascertain the 
effect of colcl on rate of development, four chrysalids were put by 
themselves at a much lower temperature. These developed into 
flies (scientifically speaking, the pupae developed into the imago- 
state) in an average of thirty-six days (that is, took eleven days 
longer in development than the others), and the flies were not such 
fine specimens, nor so large or well marked as the others. 
The ordinary duration of the pupal condition is given in German 
observations by Dr. E. L. Tasclienberg as being twenty-six to 
thirty days. 
When the maggot has fallen to the ground it creeps to some shelter, 
as under a stone or a clod, or (it is stated) goes down two or three 
inches into the ground, or otherwise shelters itself for the chrysalis 
change. In my own observations I have found that the maggot 
(though legless) could drag itself along at a rate on a smooth sur¬ 
face of three times its own length in two minutes. 
For appearance in chrysalis state, see figure at p. 39. The 
external observable change consists in the coat of the maggot 
hardening and turning to a dark brown or blackish colour, other¬ 
wise the maggot and chrysalis much resemble each other. 
Within this hardened skin the fly forms, as shown at figure 6, 
p. 39, and it takes flight, to commence a new series of trouble and 
mischief; but, so far as we know, regularly preferring to select for 
