CHAPTER III 

 ROACHES AND OTHER ANCIENT INSECTS 



We used to speak quite confidently of time as something 

 definite, measurable by the clock, and ot a year or a cen- 

 tury as specific quantities of duration. In this present age 

 ot relativity, however, we do not feel so certain about these 

 things. Geologists calculate in years the probable age of 

 the earth, and the length of time that has elapsed since 

 certain events took place upon it, but their figures mean 

 only that the earth has gone around the sun approximately 

 so many times during the interval. ! In biology it signifies 

 nothing that one animal has been on the earth for a million 

 years, and another for a hundred million, for the unit of 

 evolution is not a year, but a generation. If one animal, 

 such as most insects, has from one to many generations 

 every year, and another, such as man, has only four or five 

 in a century, it is evident that the first, by evolutionary 

 reckoning, will be vastly older than the second, even 

 though the two have made the same number of trips with 

 the earth around the sun. An insect that antedates man 

 by several hundred million years, therefore, is ancient 

 indeed. 



The roach scarcely needs an introduction, being quite 

 well known to all classes of society in every inhabited part 

 of the world. That he has long been established in human 

 communities is shown by the fact that the various nations 

 have bestowed different names upon him. His common 

 English name ot "cockroach" is said to come from the 

 Spanish, cucaracha. The Germans call him, rather dis- 

 respectfully, kuchenschabe, which signifies "kitchen 



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