Conditions 41 



culty and remove few of them. The water-fowl 

 appear and may be the cause of the introduction 

 of the kind of fish they come to catch. It is not 

 at all improbable that fish-eggs stick to their legs 

 and are thus transported from one place to another. 

 Extensive construction work, as a rule, is per- 

 formed by contract. Each of the contractor's su- 

 perintendents is responsible for one particular 

 phase of the work and his entire time and attention 

 are devoted to it. The foreman on the dump must 

 unload his cars and return them within a minimum 

 of time, the tracks must be moved with equal 

 rapidity. If a culvert is to be elongated and no 

 pipe is available, some makeshift is used and prob- 

 ably no attention is given to grade when the pipe 

 is laid. The work is performed in record time, or 

 possibly a record is broken, and the cost of the 

 work for that day, week, or month is reduced an 

 appreciable amount. Probably such saving and 

 efficiency are properly rewarded, and the increased 

 salary or bonus acts as a spur to even more rapid 

 work. The makeshift culvert is soon covered up 

 and does not show. If it collapses some time after- 

 wards, the cause of the collapse is unknown. A 

 lagoon is formed at the back of the dam. Unless 

 the entire valley is filled, the artificial mosquito- 

 producing area created is permanent, and when 



