BLATTODEA. G9 



Cockroaches will eat almost anything even their 

 own. dead bodies, or at any rate those of their com- 

 panions--^!^ Miall says, " cucumber disagrees with 

 them horribly." As regards insecticides there seems 



/ o 



to be some conflict of opinions, but apparently phos- 

 phorus-paste may sometimes be claimed as successful. 

 It must, however, be borne in mind that the cockroach 

 has its place in nature. It is an effective scavenger 

 and so far must be looked upon as a useful insect, and 

 no doubt would be so regarded could we but conquer 

 our rooted dislike to it, and the cockroach get rid of 

 its unpleasant odour. Cockroaches are lovers of 

 warmth and are really numerous only in tropical 

 regions. British cockroaches, too, lack the beautiful 

 colours sometimes found in foreign species.* 



In the Silurian sandstone of Calvados in France, 

 the late M. Brogniart found a fossil which he con- 

 sidered to be part of an elytron of a cockroach, and 

 named it Palasoblattina douvillei. Brauer, however, 

 thinks it more probably belongs to an insect like the 

 mole-cricket, while Sharp inclines to the opinion that 

 it does not belong to the Insecta at all. If there were 

 no doubt concerning the identification, this fragment 

 would represent the oldest insect known. 



It is in the Carboniferous period of Palaeozoic times 

 that cockroaches first appear with certainty upon the 

 scene or rather, that evidences of them first appear, 

 which is probably a very different matter. The Coal- 

 measures of Great Britain, Belgium, and Germany, 

 and the Coal-measures and Millstone Grit of America, 

 have supplied a great number of cockroaches, which 

 group of insects appears to have been more numer- 

 ously represented and more generally distributed than 

 any other at this period, which in fact has been called 

 the " Age of Cockroaches." The Permian period has 

 produced only a few insects, though amongst them are 



* For " stridulation " in the genus Nauphseta see ' A Naturalist in Borneo/ 

 p. 141. 



