18 



NATURAL HISTORY. 



travelling collector, and judging from Dr. Fritz Miiller's article on the dwellings of tin; Trichoptera 

 of the neighbourhood of Santa Catharina, in Southern Brazil, we may fairly assume that 

 when the Caddis-flies of tropical countries have been better studied, the present apparent prepon- 

 derance of the species of temperate climates will at any rate be considerably diminished. The 

 insects are found about water, generally resting upon the leaves of plants or upon the trunks of 

 trees and palings. Some of them are tolerably active in the day-time, whilst others move about 



only in the evening 

 and night. The females 

 deposit their eggs upon 

 plants growing in or 

 close to the water, or 

 upon stones similarly 

 situated. The eggs are 

 enclosed together in 

 a gelatinous mass, 

 formed by the secre- 

 tion from a pair of 

 large glands connected 

 with the oviduct. 



We have already 

 noticed the resemblance 

 of the perfect insects 

 to Moths, and the 

 larvae also present a 

 similarity to the cater- 

 pillars of many Lepi- 

 doptera. They are 

 elongated, more or less 

 cylindrical, soft-bodied 

 creatures, having only 

 the head, the segments 

 of the thorax, or some 

 of them, and the six 

 thoracic legs horny ; 

 and the segments of 

 the abdomen, from the 

 second onward, are 

 usually amply pro- 

 vided with branchial 

 filaments, two or 

 three of which spring 

 from a point on each 



side of the segments on the dorsal or ventral surface. To protect this soft body the larva makes 

 himself a little habitation, which is composed of the most various materials by different species. 

 Fragments of wood and leaves, short lengths of reeds, and other hollow stems, small stones and 

 grains of sand, little shells, often with their owners still living in them, and sometimes even the 

 cases of other smaller Caddises are made use of; but each species usually employs the same 

 materials, or, at any rate, the same class of materials in the construction of its dwellings. These 

 materials, whatever they may be, are held together by means of silky threads produced by glands 

 which have their opening in the labiuni of the larva. The cases are often at first tapering ; but in 

 most instances the larva prefers a cylindrical dwelling, and after a time removes the slender posterior 

 end and uses the materials, along with others, to add to the length of the case at the wider end. 

 The cases are open at both ends, and in some instances the larva appears to turn round in his 



THE METAMORPHOSIS OF THE CADDIS PLIES, LTMNOPHILU8 FLAVICORNIS, L. LUNATUS, 

 AND L. RHOMBICUS. 



