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DIRECTIONS FOR COLLECTING AND PRESERVING 

 MARINE ALGiE. 



By W. a. Setchell. 



The marine algse, or seaweeds, grow either between tide-inarks or 

 below theui. In the latter case they may grow just below low-water 

 uiark, or in deeper water down to a depth of a number of fathoms. 

 The best times for collecting, then, are when the tide is low, since 

 at that time a certain zone, called, for convenience' sake, the litoral 

 zone, is bare of water, and the algse growing in it may be gathered 

 from the rocks and pebbles on which they are growing; and also 

 those growing in the zone immediately below the litoral zone, which 

 is called the sublitoral zone, may be reached by wading. The lower 

 part of the sublitoral zone, however, lies too far below the surface of 

 the water to be reached by wading, as do also those deeper waters 

 of what is called the elitoral zone. The algae inhabiting these zones 

 exclusively must either 1)6 sought for with the dredge or else the 

 collector must wait until they are detached in some way or other 

 from their places of growth, and floated ashore. The times most 

 advantageous for collecting, then, are as follows: — 



1. From the Litoral Zone. — Tiie collecting place should be 

 reached from one to three hours before the time for the occurrence 

 of extreme low water, in order that the collector may follow the tide 

 as it ebbs, /. e., as it goes down. B}-^ doing so, two advantages are 

 obtained: in the first place, the period available for collecting is 

 the longest possible, as well as the safest on some coasts ; and in the 

 second place, there is less danger of being suriounded by the tide, or 

 of being overwhelmed by the incoming waves and either drenched 

 or even carried off one's feet and takeJi out to sea by an especially 

 strong undertow. The exact time of encli low as well as each high 

 tide during the year may be learned from the " Tide Tables " pub- 

 lished by the U. S. Coast and Geodetic Survey ivnd for sale at all 

 custom-houses and agents for charts and other aids for navigation. 

 The tables give the times foi- all places of any consequence along 

 both coasts of the United States. 



2. From the Sublitoral Zone. — The upper part of the sub- 

 litoral zone may be reached by wading at low water, as mentioned 



