COCKROACHES 5 



menageries ; but a third species, P. germanica^ 

 sometimes gets established. Mercifully, P. 

 germanica does not seem to spread. Neither 

 P. germanica nor P. americana seem to make 

 much headway against P. orientalis, which 

 appears to be predominant over both these 

 other species. 



P. germanica is probably most methodical, 

 very thorough, very brave, very faithful — 

 but rather lacking in the power of under- 

 standing the point of view of others. If it 

 has any association with its specific name, it 

 illustrates the most striking example in the 

 world's history of the divorce of wisdom from 

 learning. ' O Lord ! give us understanding,' 

 should be the prayer of P. germanica. 



Miall and Denny tell us that from the first 

 introduction of P. orientalis into England 

 it took two centuries before it spread far 

 beyond London. In 1790 Gilbert White 

 speaks of it as ' an unusual insect, which he 

 had never observed in his house till lately,' 

 and, indeed, at the present moment many 

 English villages are still blissfully ignorant 

 of this particular nuisance. 



As Fig. 2 shows, the cockroach is a some- 

 what slackly put together insect. One might 

 almost call it rather slatternly and loose- 

 jointed — and the latter it certainly is. Its 

 head moves freely on the thorax, and the 



