[9] THE PRESERVATION OF MARINE ANIMALS HOVEY. 



in the bottom. The wax bottom is for the purpose of holding the wooden 

 pins used in straightening out worms while they are hardening. Pins 

 of orange or other hard wood are preferable to those of metal, because 

 the fixing fluids attack metals. A convenient size for such a tray is 

 60 by 6 by 6 cm. (24 by 2^ by 2^ inches) with about 1 cm. (one-half 

 inch) of wax in the bottom. 



For the transfer of objects from one receptacle to another spatulas 

 are largely used. These are made preferably of horn, because that 

 material is not attacked by the reagents in use. They range in size 

 from mm. (one-fourth inch) to 10 cm. (4 inches) in width, and are of a 

 convenient length, say 17.5 to 20 cm. (7 or 8 inches). 



A pair of soft iron forceps 30 cm. (12 inches) long is very convenient 

 for taking objects out of deep receptacles. Iron is both cheaper and 

 just as good as brass for that purpose. Small forceps, wire cutters, 

 syringes, and so on are used at times. 



The apparatus for narcotizing certain Actinians is constructed as fol- 

 lows: The nose of a pair of bellows is provided with a metallic bowl 

 which fits over the metal bowl of a tobacco pipe. The latter is pro- 

 vided with a peg which fits into a slot in the bowl on the bellows and 

 fastens the two together. The tube of the tobacco pipe is continued 

 with a piece of flexible rubber tubing which terminates in a U-shaped 

 piece of glass tubing, the distal end of which has been drawn out to a 

 point. With this apparatus one can easily force vsmoke into a receptacle. 



REAGENTS. 



Alcohol. — Without doubt the most indispensable liquid is alcohol. 

 For the preparation and preservation of delicate, trans])arent animals 

 it is necessary to use puriiied spirit which has been filtered and diluted 

 with distilled water. For coarser animals ordinary alcohol may be 

 used, if desired, even that which has been obtained by redistilling 

 what has once been used being available, care being exercised to see 

 that acids and alkalies have been neutralized. The station always has 

 on hand a quantity of alcohol of 70 per cent strength, which is what 

 is ordinarily used for preserving animals, that of 90 per cent being 

 used only in special cases. By mixing the alcohol and water somewhat 

 in advance of actual need one avoids the innumerable bubbles of air 

 which form on the surface of an animal when immersed in freshly 

 diluted alcohol. Soft or gelatinous animals must be allowed to remain 

 from two to six hours in alcohol of 35 to 50 per cent, according to their 

 consistency, and then be transferred to that of 60 per cent, and after- 

 wards to that of 70 per cent. If the preparations are too delicate to 

 bear handling, the transfer may be made by pouring off the liquid and 

 adding the proper amount of alcohol to make a 35 per cent solution, 

 continuing the process until the standard strength is attained. When 

 necessary to avoid disturbing the animal at all a siphon may be used 

 in effecting the transfer. Frequently it is necessary to change the 

 alcohol after a few days, on account of discoloration. Some forms are 



