CHAPTER XII. 



BRISTLE-TAILS AND SPRING-TAILS. 



THE Thysanura, as the Poduras and their allies, the Lepismas, 

 are called, have been generally neglected by entomologists, and 

 but few naturalists have paid special attention to them.* Of all 

 those microscopists who have examined Podura scales as test 

 objects, we wonder how many really know what a Podura is? 



In preparing the following account I have been under constant 

 indebtedness to the admirable and exhaustive papers of Sir John 

 Lubbock, in the.London "Linnaean Transactions" (vols. 23, 26 

 and 27). Entomologists will be glad to learn that he is shortly 

 going to press with a volume on the Poduras, which, in distinc- 

 tion from the Lepismas, to which he restricts the term Thysa- 

 nura, he calls Collembola, in allusion to the sucker-like tubercle 

 situated on the under side of the body, which no other insects 

 are known to possess. 



The group of Bristle-tails, as we would dub the Lepismas in 

 distinction from the Spring-tails, we will first consider. They 

 are abundant in the Middle States under stones and leaves in 

 forests, and northward are common in damp houses, while one 



*Nicolet, in the "Annales de laSociete Entomologique de France" (tome v, 1847), 

 has given us the most comprehensive ssay on the group, though Latreille had 

 previously published an important essay, "De 1'Organization Exterieure de3 Thy- 

 sanoures" in the "Nouvelles Annales du Museum d'Histoire Naturelle, Paris, 

 1832," which I have not seen. Gervais has also given a useful account of them iu 

 the third volume of "Apteres " of Roret's Suite a Buffon, published in 1844. 



The Abbe Bourlet, Templeton, Westwood, and Haliday have published important 

 papers on the Thysanura; and Meinert, a Danish naturalist, and Olfers, a German 

 anatomist, have published important papers on the anatomy of the group. In this 

 country Say and Fitch have described less than a dozen species, and the writer has 

 described two American species of Campodea, C. Americana, our common form, 

 and C. Cookei, discovered by Mr. C. Cooke in Mammoth Cave, while Humbert has 

 described in a French scientific journal a species of Japyx (J. Saussurii) from 

 Mexico. 



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