SILVER-FISH OR FISH-MOTH 



INSECTS 



For certain distinctive characteristics of insects see p. 32 

 and the sections on anatomy in the Introduction. 



THE MOST PRIMITIVE INSECTS 



These were, not long ago, all put in a single order: 

 Aptera, or "wingless." They are now divided into four 

 classes, including Thysanura and Collembola, and seven 

 orders ; but the user of this book is not apt to notice more 

 than one or two species. 



Two hundred and fifty-odd years ago 

 Tnvsanura 



Hooke wrote concerning the Silver-fish 

 or Fish-moth: "It is a small Silver-shining Worm or 

 Moth, which I found much conversant among Books and 

 Papers, and is supposed to be that which corrodes and 

 eats holes through leaves and covers; it appears to the 

 naked eye a small glittering Pearl-colored Moth, which, 

 upon the removal of Books and Papers in the Summer, is 

 often observed very nimbly to scud, and pack away to 

 some lurking cranney, where it may the better protect 

 itself from any appearing dangers. Its head appears big 

 and blunt and its body tapers from it towards the tail 

 smaller and smaller, being shaped almost like a carrot." 

 If such a creature is eating your wall paper, starched 

 curtains or clothing, photographs or other belongings, 

 your sorrow may be mitigated by your interest in seeing 

 the most primitive insect you are likely to observe without 

 special effort. Insects of this and related classes never 

 have and never have had wings; they just grow up, from 

 new-born to adult, with scarcely as much change as occurs 

 in the growth of a dog. The species just mentioned is 

 Lepisma saccharina (Plate VIII). It is a "moth" only 

 because it eats furnishings and clothing. A related species 

 (domestica) is abundant in some bake shops and old 

 kitchens, running about even in hot places, whence its 

 Old English name: Fire-brat. 



39 



