No. 4.] CRANBERRY GROWING. 263 



reinforce where necessary. The covered or trunk flume is 

 favored by some growers of experience, and it is to be said in 

 favor of this type that, when built of w^ood, it will not rot out 

 as quickly as the open flume. When built of concrete and 

 properly constructed, the open flume appears to the writer to 

 be preferable. The open flume should be connected with the 

 soil beneath and with the diking on its sides by means of plank 

 spiling, and if the head of water to be held is very great, and 

 the soil underneath the flume is soft and sandy, it is best to 

 use more than one line of spiling. In the writer's opinion it is 

 better to have the flume built so that the water may be handled 

 from the top rather than from the bottom. It will usually be 

 found profitable to employ a man of considerable experience in 

 flume building. 



The Form and Size of the Bog. 

 It is the general experience that, other things being equal, 

 bogs of small area give much better returns than do those of 

 large area. This is due to a variety of circumstances. Long 

 and narrow bogs are more profitable after a certain point in 

 size is reached than are bogs of compact form. In the first 

 place, with large bogs of compact form, the expenses connected 

 with the care of the bog and the harvesting of the crops are 

 disproportionately large, particularly because it takes so much 

 more time to wheel sand out to the center of the bog and to 

 bring the berries to the upland from the center. Then, too, all 

 the operations connected with harvesting and with the general 

 care of the bog call for much more tramping over, and con- 

 sequent injury to, the vines on such large blocky bogs. But 

 perhaps more potent than these circumstances leading to the 

 diminished success of the large bog is the fact that the flowed 

 bog fire worm (blackhead cranberry worm) is far more prevalent 

 and destructive, other things being equal, on such bogs. This 

 is due to the fact that the winter flowage favors the insect by 

 driving off from the bog most of its natural enemies such as 

 spiders and parasites, while the water at the same time protects 

 its eggs from unfavorable and severe winter weather conditions. 

 The natural enemies of the insect are, of course, much slower 

 in reaching the middle portion of a large compact bog in 



