THE PRESERVATION OF MARINE OBJECTS 75 



part of a museum collection, it will be necessary to transfer it to a 

 fresh solution after a time, and a second, and even further changes 

 may be necessary before the object ceases to discolour the fluid or 

 render it turbid. 



Considerable difficulty will sometimes be found in the attempts 

 to preserve a soft-bodied animal in its natural attitude. Thus, 

 when a sea anemone is removed from its native element, it 

 generally withdraws its tentacles, and, contracting the upper part 

 of its cylindrical body, entirely conceals these appendages, together 

 with the mouth they surround ; and a mollusc similarly treated 

 will generally pull itself together within its shell, leaving little or 

 no trace of the li ving body inhabiting the lifeless case. Then, if 

 these animals are transferred to any fluid other than sea water, or 

 placed anywhere under unnatural conditions, they usually remain 

 in their closed or unexpanded form. Thus, almost every attempt 

 to kill them for preservation deprives them of just the characteristics 

 they should retain as museum specimens. 



Some such animals may be dealt with satisfactorily as follows : 

 Transfer them to a vessel of fresh sea water, and leave them 

 perfectly undisturbed until they assume the desired form or 

 attitude. Then add a solution of corrosive sublimate very gradu- 

 allya drop or two at intervals of some minutes. In this way the 

 bodies of anemones may be obtained ready for preservation with 

 expanded tentacles, tube-secreting worms with their heads and 

 slender processes protruding from their limy or sandy cases, 

 molluscs with their ' feet ' or their mantles and gills protruding 

 from their shells, and barnacles with their plume-like appendages 

 projecting beyond the opening of their conical shells. 



The specimens thus prepared may be placed at first in very 

 dilute spirit, and then, after a time, finally stored in a stronger 

 solution of spirit in water ; or they may be transferred to one of 

 the other preservative solutions previously mentioned. 



All specimens permanently preserved in fluid for a museum 

 should be placed in jars, bottles, or tubes of suitable size, each vessel 

 containing, as a rule, only one. Where expense is no object, stop- 

 pered jars made expressly for biological and anatomical specimens 

 may be used for all but the smallest objects ; or, failing this, ordinary 

 wide-mouthed bottles of white glass, fitted with good corks or glass 

 stoppers. 



For very small specimens nothing is more suitable than glass 

 tubes, but it must be remembered that wherever corks are used, 



