AND DISTRIBCTE INSECT VARIETY. 33 



music and its modulations adapted to syllables fixed by intona- 

 tions of the human voice. If the insect should, on the other 

 hand, be reared from the larva or ova on a potted plant, or in 

 the breedinij;"-cafye, or be foi'ced under artificial conditions as a 

 variety, invaluable reference will be afforded by attaching a label 

 indicating- its food plant, locaUty, and date of emergence, which 

 will hereafter greatly tend to fix its identity. To fully record 

 its metamorphosis, with its acquirement of lines and eyes, its 

 changes of colour, and new members, a series of observations, 

 accompanied with sketches, are required at each casting of the 

 integument. Caterpillar skins may likewise be preserved by 

 intlation, a method that has led to good results. 



It is needless to say dissections of insects when freshly killed 

 are easily made by means of a cameVs-hair brush; to remove 

 scales, a pair of nail scissors and a pocket lens are necessary. 

 To examine the digestive organs it may be necessary to immerse 

 the subject in water ; and to examine the air-tubes, the insect 

 may be cut open along the back, the skin pinned out, and the 

 preparation set to dry. Even the delicate nervous system may 

 be worked out to some extent by placing the insect pi-eviously 

 in alcohol for a night. But different operators have doubtless 

 different methods. The various structures are also capable 

 of being prepared and mounted in the usual fashion for the 

 microscope, but greater results will be obtained of their 

 relations by using this instrument subservieDtly for the purpose 

 ot drawing up diagrams. Micro-photography would here be 

 invaluable could it be only adapted to reproduce the delicate 

 tissues and organs which are generally poorly rendered by 

 drawings made under the camera lucida. 



The present volume, exhibiting the scope and bearing of such 

 occupations, may therefore find some recommendation, both as 

 regards a novelty of arrangement and as regards such original 

 matter incorporated ; and the latter will, it is believed, be found 

 to considerably extend the special illustration of such works as 

 Dr. Darwin's " Descent of Man,"-' Kirby and Spence's " Intro- 

 duction,''' or Rennie's " Miscellanies." The concluding chapter 

 on the variation of species will afford some information on a 

 favourite topic with butterfly fanciers, and is in a measure an 

 attempt to epitomise the labours of insect collectors and classifiers. 



