MOULTS OF THE Maggot. 



iK 



its growth that the spiracles were developed to their angularly kidney- 

 shaped form, and the maggot assumed the compressed oval shape in 

 which it is best known. It was still white, but opaque, and with the 

 segments well-marked; and the early part of its work being done, and 

 the warble-passage open, it has no occasion now to bore its way, and ceases 

 to he furnished with a form fitted for x>erJ'oration. 



Other alterations of a very practical bearing also take place at this 

 time, or follow on this most important of the moults. The skin of 



Fig. 9. 



Fig. 11. 



Fig. 9. — Muscles within skin of maggot, much magnified. Fig. 10 — Pricldes of 

 maggots, much magnified. Fig. 11. — Full-grown maggot, magnified. 



the maggot becomes furnished within with a powerful coat of muscles, 

 extending over it like basket-work, which give it a power of contraction 

 and expansion. Externally in this stage the skin of the maggot is 

 furnished with a much larger amount of prickles arranged in more 

 numerous bands, than are noticeable in the previous stages. The 

 prickles are now strong enough to cause an unpleasant sensation 

 when the maggot crosses the hand, and to play an important part in 

 its locomotive powers in its cell, and in the effect on the tissues caused 

 thereby. The visceral contents are now thick, and obviously formed 

 of the filthy matter which is caused by the perpetual irritation of the 

 suction of the mouth-end of the maggot at the bottom of the sac. It 

 is also now furnished with a small curved caudal aperture, placed 

 nearly between the spiracles (see fig. 8, p. 8) from which some slight 

 amount of discharge of contents can take place. 



Fig. 11 shows the maggot about four times the natural size, in its 

 fully developed state, with the tips of the pair of spiracles indicated in 

 the centre of the tail-end. It is, as is well-known, when full-fed, and 

 for much of its previous life, of a bluntly oval somewhat compressed 

 shape, of various shades of colour, from whitish to deep grey or 

 brownish, and marked with cross-bands, which, under the magnifier, 

 are seen to be formed (as figured above) of minute prickles, 



