22 ~=PROCEEDINGS OF THE ROYAL SOCIETY OF QUEENSLAND. 
In this paper the term “‘ prepupa ”’ is applied to cover the 
maggot from the time of wandering away from the meat till 
it has begun to form a puparium, when further movement 
becomes impossible. There is reason to suppose, however, 
that some larvee remain in the meat for one, two, or even more 
days after having become fully fed, thus extending their 
calculated feeding period and diminishing the recorded prepupal 
period. A case in point may be mentioned relating to a batch 
of Sarcophaga beta J. & T., that was bred by us and given special 
attention. Four days after deposition all the maggots were 
fully grown ;, nothing was left of their short food supply but 
slime, and five of the fifteen specimens left it to pupate, the 
others remaining in the slime. The next day three further 
specimens migrated, while the balance remained for eight more 
days before leaving and during the whole of this period scarcely 
moved their position and did not increase in size. Ifin the table 
given later in-this paper, four days be allowed as the feeding 
‘period and the balance of the figures above this number be 
added to the prepupal period, then the latter would vary from 
4 to 12 days, whilst the pupal period would vary not more than 
one day either side of the 14 days, this being a comparatively 
constant period, so that given the date of deposition and the 
date of emergence, the dates of other periods should be readily 
estimated with a reasonable degree of accuracy. Although 
this appears to apply to the spring and summer time, it does 
not hold good for the winter, when Sarcophaga pup vary 
widely in their pupal period. We wish to emphasise the wide 
variation in the length of individual life-cycles, such being 
probably due mainly, if not entirely, to the varying time the 
insect takes to pass through the prepupal condition. 
The climbing abilities of blowfly maggots are great, and 
many prepupe will escape if special precautions be not taken. 
In three of the larger series we used a metal receptacle with an 
inwardly curved lip. and without cracks or crevices. When 
sifted out from this the larvee were then placed in a glass jar 
with a wide open mouth and with a shoulder sufficiently wide 
to again form an inwardly curved obstacle against the maggots’ 
climbing powers. Once the insect has become sufficiently far 
advanced in its prepupal condition (7.e. after not less than 
three days) further precautions against escape are unnecessary, 
provided the maggots are not subjected to damp, which may 
again induce them to wander, if pupation has not actually 
