24 



be given as follows : For a distance of four miles on either side 

 of the mouth of the pass there Avas a deposit of soft mud after 

 each period when the water was high. The layer of sediment 

 was thickest near the jetties and scarcely perceptible at the 

 limits mentioned above. The distance oft' shore of the line of 

 separation between the muddy and the clear water varied very 

 much, sometimes as much as a half-mile difference being noted 

 in the course of a single day. Usually the line of separation 

 was about two miles beyond the jetties, but at times it was more 

 than a mile beyond this point. 



The deposit of sediment on the beach usually Avashed away 

 rapidly, except where it was above the usual high tide level, so 

 that within four or five daj^s after a heavy deposit the beach 

 would be clean until the time when another exceptionally high 

 tide caused a fresh deposit to be laid down. 



That the disappearance of the shells put down in the gulf 

 was due to their being covered up by sediment, and not the re- 

 sult of the settling of the shells because of their weight, was 

 maintained by Dr. Kellogg. As proof of this statement he cites 

 the behavior of a bed of the same sort of small shells put down 

 on the soft mud near the laboratory wharf at the time when 

 the gulf plants were made. This bed was not nearly as thick as 

 the one in the gulf, and yet after a year and a half from the 

 time of its deposition the limits of this bed are clearly defined 

 and the shells above the mud. While the construction of these 

 beds was in progress, a number of barrels of adult oysters were 

 thrown overboard a little way above the laboratory wharf, on a 

 very soft bottom, without any previous application of hardening 

 agents. Practically, all of these oysters were above the mud at 

 the time of their examination in March of this year, and yet a 

 pole could be thrust into the mud beside the bed for a distance 

 of six feet. 



These facts support Dr. Kellogg 's contention that his plants 

 did not settle in the soft mud, and besides, are of value in that 

 ttey show how easily a bottom apparently useless for growing 

 oysters may be brought into a condition such that it will afford 

 ample support for a bed of oysters. 



