BROWN-TAILED MOTH. 677 



species, nor even to the same genus. The experiment which we 

 tried was, to confine two broods of different species to the same 

 branch, by placing it in a glass of water to prevent their escape. 

 The caterpillars which we experimented upon were several 

 broods of the brown-taU moth (Porthesia aurifiua) and the 

 lackey (Clisiocampa neustria). These we found to work with as 

 much industry and harmony in constmcting their common tent 

 as if they had been at liberty in their native trees ; and when 

 the lackeys encountered the brown-tails they manifested no 

 alarm nor uneasiness, but passed over the backs of one another 

 a,s if they had made only a portion of the branch. 



" In none of their operations did they seem to be subject to 

 any discipline, each individual appearing to work in perfecting 

 the structure from individual instinct, in the same manner as 

 was remarked by M. Huber in the case of the hive bees. In 

 making such experiments, it is obvious that the species of cater- 

 pillars experimented with must feed upon the same sort of 

 plant." 



One remark ought to be made on this interesting narrative. 

 The author lays some stress on the fact that the two insects 

 belonged not only to different species, but to different genera. It 

 must, however, be remembered that although the distinction of 

 insects into species is easy enough, their grouping into genera is 

 quite arbitraiy, depending entirely on the classifier. linnajus, for 

 example, divided aU the butterflies into two genera, while the 

 modern classification admits some thirty genera. While, there- 

 fore, we may lay every stress on the species, we need not trouble 

 ourselves much about the genus. 



The two moths mentioned in this history are very different iji 

 appearance, and the larvae are still more unlike. They have, 

 however, this point of similarity, that they construct large 

 dwellings upon branches, spinning them of silk, and making 

 them large enough to contain a whole brood at once. The 

 Lackey moths are so called on account of the bright colours of 

 the caterpillars, which are striped and decorated like modern 

 footmen. Some species, however, derive the name from a different 

 source. 



When the mother insect lays her eggs, she deposits them on a 

 small branch or twig, disposing them in a ring that completely en- 

 circles the twig, as a bracelet surrounds a lady's wrist. Wlien she 



r p 



