M. DRAPER, A LIVE BOX FOR THE OBSERVATION OF INSECTS. 313 



A LIVE BOX FOR THE OBSERVATION OF INSECTS 



AND SIMILAR OBJECTS. 



By B. M. Draper. 



{Read December 23rd, 1 ( J13.) 



This live box, which was worked out for me by Mr. Angus, 

 displays satisfactorily, with superstage illumination, under the 

 lowest powers, large creatures such as house-flies. It is not 

 meant for pond-life. 



It is of the simplest description, being really nothing but a 

 transparent chamber of the shape and size of a small pill-box. 

 The body is made of a short piecs of glass tube of any size de- 

 sired, say, one-third of an inch deep by two-thirds in diameter ; 

 this is cemented to a 3 X 1-inch slip. The lid, which is loose, 

 is a circular plate of glass of rather larger diameter than the 

 body. In the lid, near its circumference, and at equal distances 

 from each other, are fixed three short pins, projecting downwards, 

 so as to clasp the outside of the body and thus keep the lid in 

 position. The little collars by which the pins are fixed in the 

 lid rest on the rim of the box, so as to prevent the lid itself 

 from touching. The crack thus left gives enough ventilation. 

 The depth of the box can be varied by means of a false bottom, 

 preferably opaque. 



This box serves well for the exhibition of a fly in the act of 

 feeding. If a little syrup is put on the inside of the lid of the 

 box, the sucking surface of the proboscis may be seen in action. 



DARK-GROUND ILLUMINATION WITH THE GREEN- 

 HOUGH BINOCULAR. 



By B. M. Draper. 



{Bead December 23rd, 1913.) 



The Greenhough pattern of binocular consists, as is well known, 

 of two separate microscopes, one for each eye, with paired 

 objectives of very low power. Like other binoculars, it is 

 particularly well suited for use with dark-ground illumination, 

 and a good way of getting the dark ground with its higher 

 powers is to put a stop behind the condenser. 



