HOW TO KNOW THE SEAWEEDS 



The sheet or card bearing the spread specimen may be placed 

 directly on a dry felt in the press and covered either with a piece 

 of cloth or a piece of waxed paper. Cloth will serve best for drying 



coarse, succulent specimens, while 

 the waxed paper will prove more 

 satisfactory for smaller forms and 

 especially very lubricous or muci- 

 laginous ones. Very coarse speci- 

 mens need not be spread on pa- 

 per at all, but arranged between 

 cloths in the press. After drying 

 they may be mounted on the her- 

 barium sheets by means of straps. 

 Each specimen sheet should bear 

 the collection number assigned to 

 the particular species in the field 

 note book. 



When the spreading has been 

 completed and the last felt drier 

 has been placed over a specimen, 

 the press should be strapped up 

 with the application of consider- 

 able pressure. It is necessary to 

 prevent the specimens from shrink- 

 ing or curling during the drying 

 process and to accomplish the dry- 

 ing in the shortest possible time. 

 This may best be done by frequent 

 changing of the driers, — at least 

 once a day. The specimens should not be subjected to heat, as by plac- 

 ing the press in an oven, but, rather, dehydrated by frequent replacement 

 of the wet driers with warm, dry ones. In changing the driers the first 

 wet one on top should be removed and a dry one placed over the speci- 

 men, then, by insertion of one hand beneath the next lower wet felt 

 while the other is placed on top, the whole layer may be Hfted and 

 turned upside down without disturbing the specimens or the cloth or 

 waxed paper covering them. If this process is repeated quickly for 

 each sheet and the pressure promptly reapplied in the press, good 

 specimens will result in which a large proportion will adhere to the 

 paper satisfactorily by means of their own mucilage. Drying will usu- 

 ally take from two days for delicate specimens to a week for coarse 

 ones. It will usually be more quickly and satisfactorily accomplished 

 after kilhng the specimens in formaHn than otherwise. Care must be 

 taken to be sure the drying is complete before removal of specimens 

 from the press, for otherwise shrinkage of the specimen and conse- 

 quent wrinkhng and curling of the paper backing will result. 



A Finished Herbarum Sheet. 



12 



