92 Chapter III. 



The buildings of animals either serve to shelter 

 the individual, or else they are places for breeding 

 and rearing the young. To the former class belong 

 the tunnels excavated in the earth by the serpulas, the 

 envelopes made of various substances by the moth- 

 caterpillars and the larvae of the may-flies, as also 

 the different casings constructed by the larvae of 

 insects, particularly of many butterfly-caterpillars 

 before their metamorphosis. To the latter class 

 belong the regular nest constructions of animals. The 

 most primitive specimens are found with the parasitic 

 Nemertine worms. 1 In several orders of insects, 

 especially among the Hymenoptera 2 and the beetles, 

 we meet with instances of ingenious and manifold 

 development of the same art. Here we find the most 

 various forms of nests, and made of all kinds of 

 material. Those elegant little domes of mortar, the 

 wasps of the genus Eumenes have built for their 

 offspring. Those breeding burrows, lined with red 

 poppy blossoms, have been excavated by the so-called 

 rose-bee (Megachile). Those graceful funnels and 

 barrels of leaves have been rolled into shape for their 

 young by weevils (Rhynchites, Apoderus, Atteldbus). 

 And that boat adorned with streamers has been spun 

 by the great water-beetle (Hydrophilus piceus), as a 

 receptacle for its eggs. Among fishes nest building is 

 rare. We find examples of it, in the stickleback ( Gas- 

 terosteus aculeatus), and in other fishes provided with 

 spines. On the other hand, birds are unsurpassed in 

 the art of nest building as regards variety, both of 



!) See "Naturforscher," 1886, 19th year, No. 50, p. 494. 

 2 ) See especially J. H. Fabre, "Souvenirs Entomologiques," who 

 has described these buildings with admirable skill. 



