300 THE ENTOMOLOGIST. 



or Societies combined ; and surely the subject is important 

 enough for them to do so at once ! In the first place this societj^ 

 or combination should adopt a range of standard sizes of pins, 

 each size properly numbered. These should in future be known 

 to the world as " The British Entomological Society's Standard 

 Pins and Pin-numbers." Each size should be of a standard 

 length, and be made from wire of a strictly defined wire-gauge. 

 (Standard wire-gauges ah'eady exist.) This would corapel pin 

 manufacturers to come into line, and produce entomological pins 

 for British use which would be the same from all makers, quality 

 perhaps excepted. Next let the Entomological Society decide 

 whether a specimen looks best stuck at the bottom of a pin 

 resting on the paper, stuck at the top as if on a stilt, or mid- 

 way, looking something like respectable, and hitting the happy 

 medium. Uniformity would undoubtedly be best obtained by 

 fixing the centre of the pin for the centre of the insect, as every 

 eye can fix this point best, by reason of there having to be the 

 same length of pin on the under as on the upper side ; besides 

 which you avoid extremes, and secure the important advantages 

 which have been referred to respecting mites and air-circulation. 

 Let the Society recognize the centre of the pin as its standard 

 of height, and then go a step further, and adopt one or other of 

 its own standard pins for every named species on the British 

 list (giving two numbers where necessary by reason of the male 

 and female varying greatly in size), have the number of pin to 

 be used printed by the side of the name on the exchange lists, 

 and the greater part of the difficulty would be solved. Every 

 lepidopterist would thenceforward work to the exchange list, 

 which would show him at a glance the standard number of pin 

 he must use for each insect. Even if one had to pin hosts of 

 captures one could not immediately identify, there would be no 

 difficulty, as we should instinctively know by comparison which 

 size of pin to use. I think five, or at most six, sizes of pins 

 would meet all requirements for the Macro- and Micro-Lepi- 

 doptera put together. One should, in adopting or fixing the 

 wire-gauge for the smaller sizes, err, if err at all, on the side of 

 strength. 



The mechanical and engineering world adopted years ago the 

 Whitworth standards, which detail the number of threads per 

 inch for different sizes of bolts, screws, nuts, &c. ; also steam, 

 gas, and water tubing. The adoption of these standards revo- 

 lutionized those trades, bringing perfect order out of chaos and 

 confusion. There are standards of thickness for copper, tin, 

 zinc, and other sheets ; also standards of thickness and weight 

 for lead, glass, &c. 



The Eoyal Microscopical Society has its own standard screw 

 for objectives and other fittings, to which all English makers 

 conform, and by means of which all Enghsh-made objectives are 



