MYRIAPODS. 



Section Pauropoda. 



31 



The little creature which alone composes this section can be 

 brought neither into the ranks of the Chilognaths nor into those 

 of the Chilopods j and there seems no help for it but to make a 

 separate section to receive it. It certainly is a very insignificant 

 object to be entitled to so much honour. It is a semitransparent 

 little animal, only the twentieth of an inch in length, and with 

 much more of the appearance of the Thysanura (among whom 

 and in whose haunts it lives) than of a Myriapod ; and only one 

 species of it seems yet to have been found. Sir John Lubbock, 

 to whose researches we owe our knowledge of the creature at all, 

 indeed describes two species, and gives, as the only character that 

 he could find, some difference in the antenna. He thinks that he 

 has found both sexes in one of his species ; at least, in some that 

 had organs, which he was unable to trace in all, he found sperma- 

 tozoa, and these consequently must have been males, although it 

 does not absolutely follow that the rest were not. If he is right in 

 this, the present will be the first case that we can call to mind of 

 the antennae differing materially in species of the same genus. 

 It is a very common thing for them to differ in the sexes of the 

 same species \ but the generic character, as a rule, subsists 

 through all the species of the same genus. This tiny and solitary 

 species, although it looks so like the Thysanura, cannot go with 

 them ; for although it has only six feet in the earlier stage of its 

 life, it ends by having eighteen (9 pairs). Now, as Mr. Wood, the 

 American myriapodist, has well put it, when a spider, an insect, a 

 Thysanura, or a Crustacean, leaves the egg, its body has its maxi- 

 mum number of segments, and development takes place by the 

 coalescence and disappearance of some of these. The embryonic 

 Myriapod, on the contrary, has its minimum number of segments, 

 and develops by their increase ; so that while the adult insect has 

 generally fewer, never more segments than the young, the adult 

 Myriapod may have eight times as many, and never fewer than 



