November 9, 1917] 



SCIENCE 



465 



emerging from cocoons in the fur material first 

 studied in June and July, 1913. These were 

 caught and placed in pairs for breeding pur- 

 poses in jelly tumblers which were easily cov- 

 ered. The females were almost invariably 

 larger than the males and much less active. 

 Breeding began usually immediately after 

 emergence from the cocoons. The males were 

 active in pursuit, fluttering and running about 

 the female and bringing the flexible abdomen 

 forward until it pointed anteriorly. During 

 copulation the moths rested with bodies in op- 

 posed directions. The abdomen of the female 

 was always large and distended with eggs even 

 before copulation. 



Egg-laying began within twenty-four hours 

 after breeding. Single females were found to 

 lay from thirty to one hundred and sixty eggs, 

 but the latter number was very exceptional 

 and by only one unusually large moth. The 

 usual number was between forty and fifty. The 

 egg-laying might be completed in one day or it 

 might continue two or three weeks. The fe- 

 male died when the eggs were all laid. The 

 males might live and continue active and 

 breeding for two or three weeks. Twenty-three 

 days was the longest period observed. The 

 eggs were carefully placed among the threads 

 of the cloths and fastened by some glutinous 

 material so that they did not readily shake off. 

 If the cloth had a ravelled edge, the female 

 would generally place most of the eggs deep 

 among the loose threads. 



To receive the eggs, small pieces of woolen 

 cloth were generally used. When cotton cloth 

 was tried experimentally, the moths did not 

 differentiate, but laid on cotton stocking ma- 

 terial and also on silk. 



For incubation and brooding, Petri dishes 

 were used and the egg-covered cloths were 

 placed one in each dish. Hatching began in 

 seven days, the larvse emerging as millimeter- 

 long translucent-white active caterpillars. 

 These began to feed immediately and were then 

 colored according to the color of the cloth 

 used. Experiments were tried with felts of 

 several colors and as a result larvse could be 

 obtained with a median streak of red, blue, 

 green, et al. The dyes passed through the ali- 



mentary canal apparently unchanged, and it 

 was always possible to determine by the excreta 

 what material had been fed upon when there 

 were cloths of different colors. 



The larvse behaved differently in the matter 

 of case making. Some began immediately to 

 spin a webbing case or sometimes a passage 

 several times the length of the body in which 

 they would live for a longer or shorter length 

 of time. Woven into this " silk " tunnel were 

 usually fibers from the material from which 

 they were feeding. In the case of fur, the re- 

 sulting case would often have the appearance 

 of a bur with the hairs woven crossways and 

 forming a case sometimes much thicker than 

 long. On cloth, the case was made of shorter 

 fibers closely attached to the cloth, thus dis- 

 tinguishing it from the cases formed by Tinea 

 which are carried about. When a Tineola larva 

 wished to change its feeding place it would 

 either continue its gallery, sometimes for sev- 

 eral inches, or would leave it entirely and build 

 another when a satisfactory place was reached. 

 As the larvae grew to mature size, the feeding 

 case was enlarged and changed to form the 

 cocoon. 



Other larvsB seemed to spend their time 

 " grazing " about without ever forming more 

 than small patches of silk if any. 'Ro conclu- 

 sion was dravsTi as to the probable explanation 

 of the difference. It might be that the quieter 

 kind were eventually to form the female moths, 

 and necessarily had less energy to spend in 

 roaming. If this is true, it establishes another 

 instance of the application of Kipling's law, 

 for the larvae which remained in cases do much 

 more damage than the roaming kind. Moth 

 holes usually appear as round holes, or as 

 dumbbell-shaped slits. The latter are made by 

 the feeding of a stationary larva, the straight 

 slit part being cut out underneath the case, the 

 enlarged ends being at either opening of the 

 case. The single holes are merely the feeding 

 places at the ends of a case without the con- 

 necting split. These stationary larvse also use 

 much more cloth in order to make their 

 cases. Of course both types enter cases at the 

 end before i)assing into the pupa stage. 



The larval stage may be completed in about 



