REPORT ON MOSQUITOES. 75 



in alcohol or carbolic acid upon a slide. This is most easily ac- 

 complished by adjusting the part to be examined upon a slide, 

 laying the cover slip upon it and allowing the alcohol or acid to 

 run under. The carbolic acid has the advantage of not evaporat- 

 ing as rapidly as the alcohol, which has to be renewed every few 

 minutes, and of clearing the specimen to some extent, when left 

 in it for a sufficient length of time. 



The vrings are best examined dry and are so mounted. This 

 is accomplished by making a ring of asphaltum with a turn table, 

 or in any other way upon a slide, then placing a single wing or 

 pair of wings within it and, before the asphaltum is dry, placing 

 the cover slip upon it. A small camel's hair brush will be found 

 most useful in making the ring. The cover slip should not be 

 placed upon the ring while it is too moist, otherwise the asphaltum 

 will be drawn under it and will spoil the mount. Other objects 

 to be preserved dry mav be treated in the same way. 



In mounting the legs the same method is employed which is 

 used in making nearlv all our insect mounts. The specimen is 

 placed in alcohol long enough to harden and dehydrate it. It 

 is then passed through carbolic acid for a longer or shorter time 

 and mounted in pure balsam or' balsam dissolved in xylol. This 

 can be accomplished with the object on a single slide, by simply 

 drawing off one liquid with a bit of blotting paper and replacing 

 it with another liquid. If the balsam is a little thick, its running 

 under the cover slip may be facilitated by heating the slide 

 sightly, but care should be taken that it is not heated to such an 

 extent as to shrivel the specimen. 



It is sometimes necessarv to clear a specimen more than can 

 be done with acid and this can be accomplished by first placing it 

 for a few hours, if necessary, in liquor potassa. If this is done 

 the specimen should be thoroughly washed with water before 

 running it througli the alcohol and carbolic acid. This clearing 

 will not be necessary in mounting the legs of Culcidcc, but may 

 be found useful in the case of the head and genitalia. The latter 

 do not stand the treatment of running through ordinary alcohol 

 and acid into balsam, but good results have been obtained by 

 mounting them in balsam dissolved in chloroform. If this is 

 done the specimen, after being in alcohol, should be thoroughly 

 dehydrated and hardened by passing it through absolute alcohol. 

 It should then be passed through chloroform and finally mounted 

 in chloroform balsam. If the specimen is sufficiently hardened, 

 little or no contraction will take place except perhaps in the 

 terminal joints of the antennae which, however, do not appear 

 to be in any way characteristic. If the specimen is thoroughly 

 dehydrated, passing it through chloroform may be omitted. 



