20 THE COCCIDAE 



to one hundred ec. of water. This should be followed by acidulated 

 water or alcohol. 



The following formula for Gage's Saurefuchsin contains 

 considerable hydrochloric acid in order to reduce any cautsic potash 

 there may be left in the specimens : 



Saurefuchsin 0.5 gr. 



Hydrochloric acid, 10 per cent 25.0 cc. 



Distilled water 300.0 cc. 



The excess of stain should be removed by washing with 

 distilled water. The use of acidulated water will sharpen the color 

 of the stain. The longer the specimen has to remain in the caustic 

 potash beyond a certain time, the more difficult it will be to stain. 



A stronger solution, one gram of Saurefuchsin to the same 

 amount of water and hydrochloric acid, will be found advan- 

 tageous. This is particularly true in staining individuals with a 

 very thin cuticle and in staining specimens of Eriococcinae from 

 which the anal ring is to be dissected and mounted separately 

 under a cover. 



Dehydration. The removal of the water from the specimens, 

 if they are to be mounted in a resinous media, as Canada balsam, 

 is known as dehydration. The water must be removed because the 

 balsam and water are not miscible. If a nonresinous mounting 

 media is used, as glycerin jelly, dehydration is unnecessary. If 

 the specimens are to be cleared in a clearer containing carbolic 

 acid, the dehydration can be done in commercial or 95 per cent 

 alcohol, otherwise absolute or 98 per cent alcohol should be used. 

 The dehydration is best done in a vial or watch-glass. The speci- 

 mens should remain in the alcohol for at least fifteen minutes. 

 If a complete dehydration is not accomplished, the specimens 

 become cloudy or foggy, have a whitish aqueous bubbly appearance, 

 a short time after they are placed in the balsam. Time will be 

 saved by allowing the specimens to remain in the alcohol for a 

 sufficient length of time to insure a complete dehydration. If the 

 specimens become cloudy, remove the cover-glass and return the 

 specimens to the clearer and then give them a thorough dehy- 

 dration. They should then be returned to the clearer and mounted 

 in balsam again. The same alcohol should not be used too long, 

 renew the supply from time to time. 



Clearing. The placing of the specimens in a solution that is 

 miscible not only with alcohol but with the resinous mounting 

 media is known as clearing. It can be done in a watch-glass or a 



