84 GELATINOUS, CRUSTACEOUS, AND STONE-LIKE ALG.E. 



stone ; here a stout hammer and two good steel chisels are 

 requisite — one of the latter being broad and flat, the other 

 pointed. The former serves to break off a piece of rock 

 of the required size, when the plant grows on an angle, or 

 at least where there is a good bearing for the instrument ; 

 when, on the other hand, the surface is smooth, and 

 offers no point of resistance, the narrow-pointed chisel 

 comes into play to punch out a notch, on which one side 

 of the broad chisel may rest, while a smart blow of the 

 hammer is given. Of course, the thinner the stony bed of 

 the Alga is, the better, as then it may be deposited among 

 the leaves of the herbarium ; whereas if it be too thick it 

 must be kept in a separate drawer or cabinet. Let me 

 here warn the young botanist to fold the sections of rock 

 or bark each in its own piece of paper, before placing 

 them in his pocket or bag, to prevent the specimens from 

 being rolled and rubbed together : unless this precaution 

 be taken, the adherent Alga is certain to be much injured, 

 if not entirely destroyed. If the stones, on being brought 

 home, are found to be sufficiently thin and flat, they may 

 be gummed on stiff strong paper ; and so with the pieces 

 of bark. Should they be too large and rough, they may 

 be put away on the shelf or in the drawer of a cabinet, 

 such as is used for mineralogical collections. 



Vegetable parasites like Coleochgete may be dried and 

 put away in paper bags ; or, if it is thought worth while to 

 take so much trouble, may be stripped from their bed, and 

 either dried upon glass or mounted in Hantzsch's fluid. 



Some of the foregoing species are encrusted with lime. 

 These must be immersed in dilute muriatic acid, in 

 order to get rid of the lime, before they can be properly 

 examined. The operator must recollect not to lay on the 

 cover until the bubbles of carbonic acid have ceased to 

 rise ; otherwise they will collect under the glass, and the 

 experiment will come to nothing. 



With regard to the species of Chroolepus, it is as well to 

 mention that its filaments lose their characteristic yellow 



