206 THE COCKROACH 



wrought by time be so carefully and completely studied as 

 here ; none other has furnished more important evidence con- 

 cerning the phylogeny of Insects. Even the oldest known air- 

 breathing animal has been claimed (though I think erroneously) 

 as a Cockroach ; yet, however that may be, it is certain that in 

 the most ancient deposits which have yielded any abundance of 

 Insect remains, the Coal Measures, they so far outnumber all 

 other types of Insects, that this period, as far as its hexapodal 

 fauna is concerned, may fairly be called the Age of Cockroaches. 

 And though the subsequent periods show an ever-diminishing 

 percentage of this family when compared with the total syn- 

 chronous Insect fauna, yet the existing species are counted by 

 hundreds, and the fecundity of some, attested by every house- 

 wife, may be looked upon as a sufficient explanation of the 

 persistence of this antique type. The Cockroach is, therefore, 

 a very aristocrat among Insects. 



Our knowledge of its, past is derived almost entirely from its 

 wings ; perhaps because these organs are the farthest removed 

 from the nourishing fluids of the body, which on death become 

 one of the agents, or at least the media, of putrefaction and 

 consequent obliteration. At all events, whatever the cause, 

 these chitinous membranes, with their network of supporting 

 rods, and even not infrequently with the minutest reticulation 

 of the membrane itself, are preserved with extraordinary fidelity, 

 and in such abundance that, by comparison with similar parts 

 in existing forms, we may reach some general conclusions 

 concerning the life of the past of no little interest. 



The first thing that would strike an observer, looking at the 

 ancient Cockroaches, would be their general resemblance to the 

 living. Excepting for their usually larger size,* were we to 

 have the oldest known Cockroaches in our kitchens to-day, the 

 householder would take no special note of them unless, indeed, 

 the transparency of their wings (shortly to be mentioned) were 

 to give them a somewhat peculiar aspect. There would be the 

 same rounded pronotal shield, the same overlapping wings, 

 coursed bv branching: veins, the same smooth curves and oval 



*/ cj 



flattened form of the whole creature, and doubtless also the 



* Yet noiie were so large as our largest living forms ; their average size was very 

 nearly that of Pcriplaneta americana. 



