5 



(one rarely finds them at a depth greater than ten feet), the dredge and 

 line is essential. The best dredge for all purposes is the one recom- 

 mended by Prof. Nordstedt, made as follows : 



A disk of lead about three inches in diam- 

 eter and three-fourths of an inch thick, has im- 

 bedded in its circumference a row of hooks, 

 about ten in number; through the centre of this 

 disk is passed an iron rod, which projects about 

 three inches below the disk and about nine 

 inches above ; to the ring in the upper end, to- 

 ward which the points of the hooks are directed, 

 a cord is attached. The dredge weighs about 

 two and a half pounds and catches all sorts of 

 "weeds" growing on the bottom. 



Messrs. Flynn & Doyle, carriage makers, at Bantam Falls, 

 Conn., have made these dredges for me at a cost of four dollars 

 each. 



The dissection of these plants is perfectly simple. The delicate 

 species are placed in water till their normal form is restored (if they 

 have been dried), and a portion is put in a " cell " on a glass slide and 

 examined under a two-inch objective; sometimes, but rarely, a higher 

 power is needed for determining fine points, such as the structure of 

 the cortex. 



Should the species be incrusted with lime a piece should be 

 placed in a little strong vinegar till the lime is completely dissolved, 

 then washed in pure water and examined. 



Specimens foul with mud must be cleaned in water, with a camel's 

 hair brush ; but this is liable to detach the globules of fruit, and is 

 only occasionally to be resorted to. Should it be desirable to preserve 

 bits for future reference, they are best mounted in glycerine jelly, in 

 " cells " deep enough to avoid crushing, and shallow enough to per- 

 mit free examination (flattened brass curtain rings make excellent 

 cells). When the jelly has dried at the edges turn on a ring of white 

 zinc cement. 



THE writer has prepared a few sets of Exsiccatae for distribution to 

 Herbaria and persons interested in the study of Characese. The num- 

 ber of sets has necessarily been limited, for very few besides himself 

 have contributed plants, and it has been judged best not to offer them 

 for sale. The plan has been to offer a part (containing ten species or 

 varieties), to any one who would contribute about 100 specimens of 



