98 OP THE MARINE ALG^E. 



very fact of the Alga and the paper on which it lies 

 differing widely in their powers of absorption and evapora- 

 tion is alone sufficient to cause the former to separate from 

 its support during the process of drying. To meet this 

 difficulty it must be submitted to a press, and left there 

 until all the moisture is withdrawn. As was mentioned 

 tinder the head of the Filamentous Algae, there is nothing 

 so good for the purpose as smooth white absorptive blotting 

 paper. Let the preparation, already partially dried, be 

 laid on half-a-dozen sheets, and let a piece of stearine paper' 

 be placed over it, adapted as nearly as can be to the size of 

 the object. Next to the stearine comes another layer of 

 blotting paper, then a specimen, and so on, until a pile is 

 formed of a manageable size, according to the discretion of 

 the operator. The whole is then to be placed between 

 smooth boards and weighted with three or four bricks, as 

 previously described at p. 68. Nothing more is to be done 

 for some six or seven hours, when the damp blotting paper 

 should be removed and a fresh supply inserted between the 

 boards. The oftener, in fact, a change is made in the 

 absorptive material, the better ; as it tends to preserve 

 both the colouring of the specimen and the clean white 

 appearance of the paper on which it lies. 



When changing the drying paper, the best plan is to 

 turn the whole pile upside down, so as to get at the lowest 

 examples first — the stearine paper, of course, now lying 

 below the plants. Carefully remove the first layer of damp 

 sheets, taking care not to lift with them the piece of white 

 paper attached to the specimen. Lay the latter on a fresh 

 stratum of blotting paper, and so proceed with each speci- 

 men, loading the whole, as before, with bricks. After the 

 lapse of some hours the process must be repeated ; in a 

 word, the operator will find that his preparations are not 

 merely neater, but also more true to nature, the oftener he 

 gives himself the slight trouble required in replacing the 

 drying material. In proportion as the moisture is got rid 

 of, the latter must be reduced in quantity, until a single 



