and Laboratory Methods. 2379 



show all that is necessary for the study of that sex of the species to which it 

 may chance to belong. 



When pinning, care should be taken to so locate and pass the pin as to hold 

 solidly the insect, and at the same time not interfere in studying it afterwards. 

 In the Saltatoria, or jumping forms, a correct method is to insert the pin near 

 the back edge of the pronotum, a little to one side of the middle, and directing 

 it to the rear, letting it pass downward through the mesothorax, thereby tightly 

 fastening together the two sections of the body. (See Fig. 4, a.) In the other 

 forms {^Blattoidea, Mautoidea and F/iasmoidea) the pin should be inserted back of 

 the pronotum and through the middle of the body, taking care to select a solid 

 portion for this purpose, without running the pin through the basal portion 

 of any of the legs. 



In pinning these insects directly from the cyanide bottle they can be arranged 

 so as to fit closely in the box. This is done by sticking the pins into the lining 

 so as to allow the tips of the insects' bodies to nearly rest on the bottom of the 

 box or cork lining. The next and following rows can then partly overlap the 

 ones just preceding. This method of pinning also allows the hind legs to rest 

 upon the bottom of the box and keeps them from jarring loose, as well as put- 

 ting them in place for the future. 



LIMITATION OF THE ORDER ORTHOPTERA. 



This order, as now restricted, is made up of six super-families, as follows: 

 Blattoidea, Phasmoidea, Mantoidea, Acridioidea, Lacustoidea, and Grylloidea. 

 The members of the first are known popularly as " cockroaches ; " of the second, 

 as "walking-sticks," "spectres," "leaf-insects," etc.; of the third, as " mantides," 

 " praying insects," " rear-horses," etc.; of the fourth, as " locusts," or " short- 

 horned grasshoppers ; " of the fifth, as " long-horned grasshoppers," " katydids," 

 " stone-crickets," " camel-crickets," etc.; and of the sixth, as " crickets," " tree- 

 crickets," " mole crickets," etc. All of these forms are directly interesting to 

 the economic entomologist on account of their food habits, while many of them 

 are intensely so on account of their mimicking forms which show striking 

 resemblances to portions of various vegetable organisms. 



Lawrence Bruner. 



The following description of a simple and inexpensive apparatus for collect- 

 ing atmospheric dust may be of some interest to bacteriologists and amateur 

 microscopists : The apparatus consists essentially of a wire, the middle portion 

 of which is coiled into a spiral to fit over and turn on a vertical support. One 

 end of the wire is bent so as to hold a strip of glass, and the other end is bent 

 so as to clamp a piece of cardboard, serving the purpose of keeping the plane 

 of the glass at right angles to the direction of the wind. The support comprises 

 a tenpenny nail driven into a block of lead. Soldered upon the head of the 

 driven nail is the head of a second nail. The heads thus placed in juxtaposition 

 serve as a shoulder upon which the coil of wire rests. 



The glass plate is smeared with glycerine upon which the dust adheres. 

 The apparatus can be set in any convenient place where the wind blows, and 

 the plate examined from time to time. — Sci. Am. 



