Maskell. — On Coccididae. 5 



Canada balsam dissolved in benzine. Put it away again to 

 dry (any length of time required), and except the final cleaning 

 and ornamenting of the slide it is complete, and the specimen 

 ought to show every organ necessary for examination with 

 full clearness. 



The foregoing process may at first sight seem to be long 

 and complicated. It is not so in reality. I have frequently 

 gone through the whole (except, of course, the final dryings) 

 in a quarter of an hour, and mounted several specimens in an 

 afternoon. The two things which must not be neglected, at 

 the risk of entirely spoiling the specimen, are — first, carefully 

 avoid touching the insect with a needle or a brush, as far as is 

 possible, all through the process, at least until it has been 

 well hardened by the alcohol : secondly, take every care that 

 all the potash is washed out and that all the alcohol has 

 evaporated before the balsam is run in. Mr. Eaithby has 

 sent me some very fine specimens which, in addition to the 

 above treatment, he has stained with carmine. I have not 

 practised any staining. 



It must be noted that the foregoing applies only to the 

 female insects. The males of most species are so small and 

 so delicate that it is best to mount them untouched. I have 

 many specimens quite sufficiently clear which have simply 

 been first placed in position in a drop of alcohol, covered with 

 thin glass, left to soak in alcohol for some time, and when dry 

 had the balsam run in as usual. I have even treated in this 

 way large males such as Leachia or Icerya : successfully 

 enough for purposes of study, but of course not " show " 

 slides. The larvae, again, will not require the potash. But 

 the adult females in almost all cases will require the process 

 just given. 



It will usually be found advisable to mount, in addition to 

 the slides showing the entire insect, various portions — antennae, 

 or feet, or spiracles, &c., separately dissected. When it is con- 

 sidered that a Coccid which attains a length of ^in. is almost 

 a monster, one of lin. a large one, and one of xV^- probably 

 above the average, the necessity for clear microscopic prepara- 

 tions for any thorough study will be apparent. 



It will perhaps have been observed that in this and in all 

 my former papers I have continued to speak of the grouped 

 organs noticeable in the abdominal segment of the Diaspidmge 

 as " spinnerets." The word has been so used by writers on 

 Coceids for a long time. Targioni-Tozzetti, in his elaborate 

 essay on the anatomy of Coceids (" Studii sulle Coccineglie," 

 1867), speaks of them as "fihere agglomerate." Signoret terms 

 them "groupes de fiheres agglomerees." Other authors have 

 used similar phrases. Mr. Morgan (Ent. Mo. Mag., Jan., 

 1889, p. 190) draws attention to the fact that these groups are 



