14 NATURALISTS' ASSISTANT. 



In putting in alcohol the abdominal walls should be opened 

 so that the spirit may the more readily enter and thus ensure 

 the preservation of the viscera, some parts of which are very 

 important even from a systematic standpoint. 



Fishes in alcohol do not present a very interesting or 

 attractive appearance on the shelves of a museum, and only 

 the ichthyologist is able to decide on the identity of alcoholic 

 and fresh specimens. Many attempts have been made to 

 preserve fish dry but the majority of methods employed do 

 not produce very satisfactory results. The best process 

 known to the writer is that invented by Dr. H. E. Davidson, 

 who has not only described his method but has also given 

 chances to witness the operation which is as follows : 



The necessary materials are thin pieces of soft wood about 

 one- eighth of an inch in thickness ; square sticks measuring 

 from three-fourths of an inch upwards ; plaster of paris 

 glycerine, tissue paper, pins, and double pointed carpet tacks- 



The outline of the fish without the fins is marked on 

 two pieces of board which are held together by pieces of the 

 square sticks tacked across the ends, and then the portion 

 corresponding to the body is cut away so that we have two 

 strips of wood one following the dorsal and the other the 

 ventral contour of the fish. The fish is then placed in this 

 opening and the various fins are extended and fixed in 

 position with pins, the board in the meantime being supported 

 so that one side of the fish can freely extend through the 

 opening in the joined boards. Strips of tissue paper wet 

 with glycerine are then laid smoothly over the fish and next 

 a coating of plaster is poured over the same side. When 



