i:. K. (iUKKN 101 



Diaspis bomlucaUii usually (lisii])pt'ar entirely wlien mounted in balsam. 

 The peculiar form of the Tachardia insect is best shown (and ligured) 

 at this stage. 



It should also be noted whether the bodies contain well developed 

 ova or embryos. The presence of such will settle conclusively the stage 

 of the insect, in doubtful cases. 



On the following day the specimens should be transferred to clean 

 water, when the remaining contents of the body may be easily removed 

 by manipulation with tine needles, assisted by the mounted snipe feathers. 

 If the body is not already ruptured, a small opening should be made at 

 one point, through which the liquid contents may be gently worked 

 out. Small aggregations of wax, fatty globules, or partially solid matter 

 may be removed by inserting a fine point through the artificial aperture. 



The specimens are next transferred to and washed in 70 % alcohol 

 for a few minutes. They are now mounted temporarily on a glass 

 slide in a drop of dilute glycerine, under a glass cover slip, for preliminary 

 examination. After which, a few drops of fuchsin solution are run in 

 with a pipette, and the slide is put by for another 24 hours. 



Then add a few drops of picric acid solution and leave for five or 

 ten minutes, to fix the stain. 



Remove the cover glass ; flood the slide with alcohol, to redissolve 

 the partially crystallised picric acid, and transfer the objects to a bath 

 of 70 % alcohol, where the glycerine and superfluous stain can be washed 

 out, together wdth any small fragments of the body contents that may 

 have been overlooked during the earlier process. Such omissions can 

 now be readily detected, as they will have absorbed a deeper stain. 



AVhen the removal of the stain has proceeded to the right point, 

 the objects may be w^ashed in absolute alcohol, preparatory to their 

 removal to a bath of oil of cloves, though I have not found any ill effect 

 following upon their direct transference from 70 % alcohol. They may 

 be allowed to remain in the oil for about 10 minutes, after w^hich they are 

 finally mounted in Canada balsam. 



If the same receptacles and media are used on subsequent occasion 

 great care must be taken that every specimen has been removed. Con- 

 fusion and erroneous determinations have occasionally arisen through 

 the accidental inclusion in the finished mount of one or more specimens 

 inadvertently left over from a previous operation. 



After arranging the objects neatly in the centre of the slide, 1 place 

 a sufficienc)' of balsam on the underside of the cover glass and lower it 

 gently uii to the specimens. I used, at first, to find that the balsam, 



