82 



Where possible add the early stages preserved. It adds vastly 

 to the interest and value. With mimics, where possible, show the 

 supposed model with which it is associated. 



Put the labels of your families, sub-families and genera at 

 the head of the row, the specific names at the bottom, keep one 

 label to the first series for the synonyms, the other series of that 

 species need only be labelled with the name having priority. 



Small explanatory labels showing the points on which sections 

 of genera are formed are of great utility to others utilizing the 

 collection, and help one to keep the value of the sections in mind. 



At the bottom of the row it is an excellent plan to give the 

 numbers of any microscopic preparations you may have made 

 written on a card and pinned in. It enables you to get out the 

 slides referring to that insect readily to illustrate a discussion or 

 elucidate a point, or for any of your own purposes. 



Do not follow every whim of classification, adopt a good 

 general scheme, e.g., Sir G. F. Hampson's, and stick to it for a 

 long period, noting in your loose-leaf records reasons for doubting 

 its entire correctness and other people's views. 



Microscopic Preparations. 



A separate catalogue in the same order as the Synonymic 

 list is useful to have by you, each slide being given a serial number. 



For general utility in mounting preparations of insects 

 Canada balsam seems to me best. Gum Styrax is not bad, but is 

 useless in deep cells; for larvae and ova Farrant's medium is very 

 good. As to stains. I have been fairly successful with acid 

 carminic and gentian violet, less so with methylene blue. (See 

 Note B). 



I label both ends of my slide, one end serial number of slide, 

 the name of insect, catalogue number of insect and date. The 

 other end mounting medium, stain used, date of finishing prepara- 

 tion and, lastly, special points of interest. 



There is much room for research as to the best mode of 

 preserving the delicate tests of lepidopterous ova, since I have 

 not seen a satisfactory preparation yet. The tests slowly dis- 

 integrate in all the media so far tried. I have not tried parolein. 



The embryonic stages of lepidopterous larvae are insufficiently 

 studied, and open a field for an energetic worker where much 

 good work may be done. 



Note B. — Since the above was read T have had an opportunity of discussing preparations 

 of wings to show neuration with J. Hartley Durrant, Esq., a gentleman of great experience, 

 one of the foremost of microlepidopterists. He teUs me that after many years unstained pre- 

 parations of the wings of lepidoptera became invisible in Canada balsam owing to the 

 penetration of the balsam into the fabric. He recommends the following method : Soak your 

 wing in absolute alcohol, and whilst it is still in the alcohol brush the scales off gently with a 

 sable brush. Take the wings, put tbem on your slide, put on your cover glass, fill with 

 absolute alcohol, bind the cover glass down with strong gummed paper, the centre of which 

 has been cut out to a circle smaller than the cover glass to show the wing through. The 

 alcohol will evaporate leaving the wing easily visible. Slides so prepared keep well, and the 

 other pair of unstripped wings can be mounted at the other end of the slide as a check to 

 identity of the mount. If necessary the legs, palpi, etc., can be treated in the same way. Mr. 

 Dnrrant showed me numbers of his preparations, and whilst they are not as pretty as Balsam 

 mounts their utility is certainly greater and they show no deterioration after years of use. 



