'a new accessory for dissection work. 



By Chaeles S. Banks. 



{From the Entomological Section, Biological Lahoratoiy, Bureau of Science, 

 Manila, P. I.) 



In the course of my studies in insect anatomy, I have had occasioji to 

 use a small, easily made piece of apparatus with such excellent results 

 that I believe it to be worth noting, especiallj' as I have never seen 

 mention of a similar accessory. 



This apparatus is especially adapted for such delicate work as that of 

 differentiating the parts of the alimentary canal and the reproductive 

 organs in small, adult insects such as Bomhyx mori Linn., and it also 

 serves admirably for all kinds of larvaj and for larger adult insects; 

 Arachnida, Lumbricidas, Cestodea, Nematodea and Myriapoda, as well 

 as for small vertebrates, the dissection of which could be performed in 

 normal salt solution, or other similar liquid. 



The apparatus is really nothing more than the classical jjin of our 

 school days, fashioned on slightly different lines from that A^'ell-l^nown 

 weapon of offense and defense, and is made from brass or nickel insect 

 pins No. 3 or No. -5. I have used two styles of this pin, one in which 

 the ba.se forms two sides of an c(|uilateral triangle, the other in which 

 the triangular, base is comiilete. (See Plate I, a and h.) A bend is 

 made .5 to 10 millimeters from the point so as to form an angle of 60° ; 

 the other bends are made so that when completed the point comes over 

 the center of the triangular base. The only advantage in using style 

 rt is that the base is larger and somewhat greater stability is thereby 

 secured. 



The subject to be dissected is cut open, laid in normal salt solution 

 in the dissecting j^an with paraftine in the bottom, and the flaps of in- 

 tegument are stretched open and fastened with ordinary pins. 



"With a number of the bent pins at hand, l.ying loose upon the paraffine, 

 one may begin tearing away any part desired, the trachea probably first 

 demanding attention. As each part is freed, a bent pin is seized by the 

 forceps and its pdint hooked under a loop of the tissue. The bent pin 

 is then gently pulled away as far as possible and set down upon its base 

 on the paraffine. As other parts are dissected, successive bent pins are 



ncoO£? A ioi 



