DISTRIBUTION BY MAN. 109 



The investigation and the subsequent inspection based 

 thereon revealed tlie important fact that the most dangerous 

 traffic was that going only a short distance from the centre 

 of the infested district. A large proportion of this did 

 not even go out of the district, and nearly all the re- 

 mainder went but little farther. The proof of this is ample. 

 The most dangerous traffic is the steady and constant traffic 

 back and forth between the same points which, by its regu- 

 larity, makes possible the occasional transportation of cater- 

 pillars to the same locality. This regular traffic includes the 

 trips of market-gardeners, farmers, milkmen, swill-takers 

 and others living in the outer towns of the infested district 

 or in the towns next beyond, who go daily or weekly in and 

 out of the heart of the infested district or through it to 

 Boston and return. Nearly all of the foregoing classes of 

 people live comparatively near the heart of the infested dis- 

 trict. None of them live very far away. In a word, in 

 proportion as the distance from the heart of the infested dis- 

 trict increased, the regularity and frequency of traffic to and 

 fro decreased, and in the same ratio the danger of moth 

 transportations and consequent possible establishment of new 

 colonies diminished. The work of four years has proved 

 that new colonies at a distance from the infested centre 

 have owed their origin and rise, not to a single transportation 

 of the moth but to various cases of the sort which have 

 been made possible by steady communication over the road 

 between two points. Even pleasure driving, when con- 

 stant and frequent between an infested locality and one out- 

 side, has been responsible for the establishment of a new 

 colony. 



In the study of traffic and driving of all sorts over the 

 road, the question of routes became of the utmost impor- 

 tance. The vast aggregate amount of wheeling by its very 

 existence caused the roadsides of all main highways and the 

 neighborhoods of hotels, village stores, blacksmith shops 

 and watering troughs to become more or less exposed, the 

 danger, of course, decreasing as the distance increased from 

 the infested district. There were two reasons for this : 

 first, the great bulk of all wheeling, miscellaneous as well 

 as regular, did not go to a great distance ; second, the ma- 



