18 BRITISH INSECTS 



even longer than the cerci, and very mobile, while the 

 legs move with extraordinary rapidity ; so that, despite 

 its skulking habits, Lepisma is wonderfully alert and 

 agile, and on the smallest alarm scuttles nimbly to 

 some place of hiding. A very similar species, but 

 with a more pronounced taste for the good things of 

 life, frequents especially London warehouses and 

 bakeries, where it is known as the " fire brat," or 

 " baker's brat." Science calls it Thermobia furnorum. 

 A third, nearly white, species 1 is fairly common 

 among dead leaves and garden mould ; while a fourth 

 species, 2 which looks like a large brown Lepisma, 

 abounds among heaps of loose stones at some spots 

 on the coast. 



All the above-cited species, which, with their near 

 relatives, make up the bristle-tailed section (or sub- 

 order Thysanura) of the Aptera, have ten abdominal 

 segments, some of which carry pairs of small " limbs"; 

 though whether these are used to assist locomotion is 

 not definitely known. A second section (sub-order 

 Collembola) includes the quaint little insects known 

 as " spring-tails." They are usually much more 

 compactly built than their bristle-tailed allies, with 

 only six evident abdominal segments ; but the most 

 characteristic feature in many species is a forked 

 appendage, lying beneath the body and actuated by 

 muscles, by means of which the creature is able to 

 hurl itself into the air whence the popular name. 

 Spring-tails of various species are very common in 

 decaying vegetable matter, on herbage by the road- 

 side, and on the banks of ponds. Other kinds disport 

 themselves upon the surface of water, both fresh and 

 salt, and are able to sustain long periods of submersion. 

 Campodta staphylinus. 2 Machilis maritima. 



