CHAPTEK VII. 



MODE OF DISSECTING [NSE( IS. 



The External Anatomy. — For this purpose alcoholic 

 specimens are necessary, the chief drawback being that the 



hoi causes the musch o contract thai the joint 



the palpi and other appendages may be retracted : specimens 

 killcil with cyanide of potassium and then placed in alcohol 

 may prevent contraction. With a lens mounted in a 

 holder, bo that both hands ran be used, the student can, 

 with a pair of fine forceps and a needle mounted in a handle, 

 remove the appendages of the mouth, the antenna? and 

 and with a pair of fine s< cutoff the wings. For ex- 



amining microscopically the ends of the antenna? and palpi 

 to discover the externa] parts of the . the ap- 



pendages should be carefully cleaned and then soaked in 

 eau de Jav* 7< . or in dilute liquor potassa?, in order to render 

 the parts transparent. It should be borne in mind that the 

 liquor potassse dissolves the mi nerves, etc., lea 



only the external integument. The head with its app< 



gments of the thorax, and the abdomen may in 



• insects be dissected, the parts poisoned with com 

 sublimate and gummed to a caid, in the manner repr< 

 1>\ Fig. 1. Dried beetles and ether insert- nun be reli 

 bj being placed overnight en w-t sand, or placed in warm 

 water, in alcohol, or in glycerine. Main 

 Buch as Lepidoptera, should be denuded with 

 hairbrush: thisof course is necessary in exan 



Of Lepidoptera. 



The Internal Anatomy.— The d : - the internal 



organs of insects is exceedingly difficult and nice work, 

 quiring delicacy of manipulation and untiring pati< 



