A FOREIGN INVASION OF ENGLAND 297 



ing attention was Mr. Knock enabled to discover 

 the true use and meaning of the so-called " anchor- 

 process." It is really not an anchor, but a sort of 

 hooked foot or lever, by whose aid the apparently 

 dormant grub turns himself bodily over within his 

 own hardened skin, now become too large for his 

 shrunken body. 



Discoveries like these are Lard to make ; yet 

 they bring little return in money or glory. But it 

 is only by such patient and careful investigation that 

 a way can be discovered to get rid of pests which 

 cost civilisation many hundreds of thousands, nay, 

 many millions, annually. 



The grub in the turning stage is thus by no 

 means what he looks a dormant creature ; on 

 the contrary, he is a gymnast of no small skill and 

 activity. The muscular contortions by which he 

 seeks to free himself of discomfort when disturbed 

 by man show that he possesses great power of 

 contraction, and that he can exercise a consider- 

 able force of leverage. 



After the grub has succeeded in putting itself in 

 position for assuming the winged stage, and emerg- 

 ing from its home head upward, it begins next to 

 grow into a true pupa, or chrysalis. It is in the 

 pupa, of course, that all winged insects acquire 

 their wings and become definitely male or female, 

 and this stage is, therefore, one of the most im- 

 portant. As soon as the grub begins to reach it, 

 he swells once more and grows quite tight inside 

 his larval skin, which is stretched so much that it 

 seems to be bursting. At last, as he wriggles and 



