760 REPORT UNITED STATES GEOLOGICAL SURVEY. 



rotten cabbage-stalks in the beginning of Marcb I fonnd the lulus pilo- 

 sris among the roots ; they were then of a large size, and had, as well as 

 I could ascertain, one hundred and fifty-six feet, being thirty-nine pairs 

 on each side. At the end of the same month lulus londinensis was de- 

 tected at the roots of wheat; they were at that time an inch long, and 

 lulus imlcliellus was observed with them; these I buried at the roots of 

 some potatoes and wheat, which I dug up in x\ugust, when the former 

 were completely decayed, but the latter were not in the least injured; 

 and I could not detect any of the snake-millepedes. I received some 

 roots of the scarlet-bean from Ullswater, in Westmoreland, which were 

 eaten through and through by the lulus imlcliellus and Polyclesmus com- 

 planatus, which were still sticking in the holes formed by them in the 

 cotyledons, and the party who transmitted them stated that thousands 

 of those species infested his garden, destroying the pease and kidney- 

 beans also. Near Nantwich, in Cheshire, the lulus latestriatus was in 

 countless myriads in January, 1844, destroying the potted plants in the 

 green-houses by eating the rind just at or under the surface of the soil ; 

 and cauliflowers and cabbage-plants shared the same fate in the gar- 

 den. Nearly at that period of the year the luhis loiulhiensis was doing 

 great injury to the early potato-crops near Chester. My friend, Mr. W. . 

 W. Saunders, who is too able a naturalist to be deceived, has ascertained 

 that the iuli are very destructive in his garden at Wadsworth, where 

 they devoured the young shoots of the heart's-ease just below the surface. 

 I have more than once observed the snake-millepedes nud polydesmi in 

 •September infesting the roots of onions which had been attacked by the 

 maggots of a fly ; and the polydesmus injures the carrot-crops by eating 

 various labyrinths in the roots. The iuli are also found in pears, apples, 

 etc., but I believe not in sound fruit. A few similar proofs the reader 

 will have observed appended to the descriptions of the various species. 

 These animals are also found in considerable numbers under the loose 

 bark of decaying trees, in company with wood-lice, earwigs, etc.; also 

 among the moss which clothes the base and holes in the trunk and 

 stumps of trees, and likewise under stones in humid situations. 



In his " Entomologie horticole," Boisduval tells us that lulus sahulosas 

 Linn., " sometimes enters pots, gnaws the plants at the necks of the root, 

 and, like the sowbugs, makes it die of feebleness." Blanniulus guttulatus 

 " is usually found under the straw in strawberry-beds; it introduces itself 

 into the fruit at the time of maturity, devours the pulp, and remains 

 coiled up in the interior like a small snake. The hole by which it 

 penetrates is not always very large; thus it often happens that straw- 

 berries are picked which undoubtedly contain iuli. We only know it 

 when eating them by their cracking between our teeth. This small myria- 

 pod prefers the larger species of strawberrj-, but the small ones which 

 grow on Fragasia vesca are not exempt ; we have very often found them 

 in autumn in the variety called des quatre saisows." The mostauthcn- 

 tative writer on the subject of the food of the millepedes is Prof. F. 

 Plateau, of Gaud, Belgium, from whose " Researches sur les Ph6nomenes 

 de la Digestion et sur la Structure de I'Appareil digestif chez les Myri- 

 apodes de Belgique," Belgium, 1870, we quote as follows: "It is com- 

 monly understood tluit the iuli live on vegetable matters; but the 

 notion is general, vague, and I have found nothing exact in the works 

 devoted to this group of animals. This leads me to state with some 

 detail what I have myself observed. I do not believe that any inlus 

 feeds naturally on green leaves like a caterpillar. One of our smallest 

 species, the Blaniulus gutiulatus {Gervais, lulus fragariarum of Lamarch), 

 eats strawberries in spring-time. Before and after the season of straw- 



