304 NATURAL HISTORY OF OtTR SHORES 



or watch-glass in which the examination is to be made 

 or into preservative, as desired. It is a good plan to select 

 and preserve right off the more valuable and the more 

 delicate things. 



The Cydippes and larger Medusids can be lifted out with 

 a cup-shaped salt spoon attached to a handle, and these 

 put into the ordinary formalin solution. (Sea-water is 

 better than ordinary tap water for this.) The formalin 

 should be ten per cent, of the whole. 



When selection ^ has been made replace the cork and 

 strainer, and pour off three-fourths of the water, so as to 

 concentrate the animals ; then pour in a few drops of the 

 osmic acid solution (p. 318). All the animals will fall 

 to the bottom instantaneously. They should be left so for 

 half-an-hour, then washed in fresh water, and transferred 

 to a suitable bottle with dilute (twenty-five per cent.) 

 spirit until next day, when they can be gradually changed 

 into stronger grades, and finally into seventy-five per cent. 

 The bottle is then well stoppered, and labelled with date 

 and locality for future work. 



Preserving specimens. The essentials for this should all 

 be at hand before work is commenced or, in fact, any 

 collecting is done. They are not numerous : 



A few shallow dishes stone-ware photographic dishes, 

 " J plate " and " J plate," are excellent. 



Some wide-mouthed glass jars, preferably the ordinary 

 cylindrical museum jars, with either a ground-glass stopper 

 or a ground flat rim for covering with a glass disc ; but 

 ordinary jam jars will do pro tern. 



Some glass tubes, of from four to nine inches in length, 

 and good corks to fit. 



Some sheets of mica. 



A " luting " substance, for sealing down preparations to 

 avoid the evaporation of the spirit or other preservative 

 fluid. Gold size is usually employed, but a better mixture 



