BEETLES. 255 



tion. I take an ordinary glass 5;lide, find the centre, and then fix 

 on to it, by means of Canada balsam, an india-rubber ring, ^-in. 

 diameter, ^-in. deep, and ^'^-in. thick. Rings of any required 

 size or depth may be used. Filling the enclosed space with the 

 water and weed to be examined until the surface of the water is 

 slightly convex above the plane of the upper surface of the ring, 

 I then place a cover-glass of the requisite size on the top, and the 

 trough is ready for examination. Capillary cohesion holds the 

 cover-slip perfectly tight, so that the trough may be turned upside 

 down without spilling the contents. 



The advantages I claim for this little trough are : — ist, its 

 cheapness ; 2nd, the facility and rapidity with which it can be 

 made. Moreover, by choosing various sized rings, troughs of any 

 depth and size can be made, and such a trough may be readily 

 used at the pond-side for rapid examination of small portions of 

 the material collected. Lastly, it is less cumbrous than the glass 

 trough and more useful in my experience. The rings I have 

 chiefly used are such as one gets from certain mineral-water 

 bottles ; the dimensions given are those of a ring labelled 

 " Matlock Mineral Water Co." 



Beetles. 



The long imprisonment of beetles within furniture is 

 treated of in the last report issued by the New York State 

 Museum of Natural History. It is suggested that when such cases 

 occur, the conditions may bring about a legarthic state in which 

 respiration and accompanying phenomena are almost entirely 

 suspended through the complete exclusion of air by the rubbing, 

 oiling, and varnishing, or other polishing the furniture has under- 

 gone. This instance of the imprisonment of a beetle is cited, 

 says The Illustrated American: — In 1786, a son of Gen. Israel 

 Putman, residing at Williamstown, Mass., had a table made from 

 one of his apple trees. Many years afterwards, the gnawing of an 

 insect was heard in the leaves of the table, which noise continued 

 for a year or two, when a large, long-horned b;etle made its exit 

 therefrom. Subsequently the same noise was heard again, and a 

 second insect, and afterwards a third, all of the same kind, issued 

 from this table-leaf; the first one coming out twenty, and the last 

 one twenty-eight years after the tree was cut down. 



