Rockweed {Fucm Sp.) 



Material. — Eockweed is to be found almost every- 

 where along the coast, attached to the surface of rocks, 

 timbers, shells, etc., or carried along by the currents or 

 cast ashore. It can be sent on a several days' journey 

 inland and arrive in good condition, if care be taken to 

 pack it in a close wooden or tin box. On arrival it should 

 be placed in real or artificial sea water, if a prolonged 

 study is to be made. Otherwise, it may be kept in good 

 condition if laid in a cold, damp place. It should not, 

 however, be moistened directly with fresh water. In 

 many towns it is possible to get good material from res- 

 taurant keepers and fish-dealers, who receive the rock- 

 weed as packing around lobsters, crabs, etc. For the 

 study of structure, alcoholic is better than fresh material. 

 The plants may be put directly into alcohol, beginning 

 with fifty per cent, and passing through the various 

 grades, leaving the specimens from twelve hours to a day 

 in each grade ; or, they may be placed for two to four 

 hours in a mixture consisting of one part of a saturated 

 solution of picric acid in sea water to four parts of sea 

 water; then, after washing for about fifteen minutes 

 in sea water to remove the excess of the acid, passed 

 through the different grades of alcohol. 



Additional requisites consist of the compound micro- 

 scope, hand-lens, fine forceps, scalpel, razor, watch-glass, 

 pipette, glycerine, sulphuric acid, Schulze's solution, 

 glacial acetic acid, and pith. 



