676 MANUAL OF NATURAL HISTORY. 



the outer edge of the mouth, and which we have here 



figured. Inside the mouth 



- ._ of the bottle is a rim of 



^gjf cork about an inch in 

 depth, and an eighth of 

 an inch in thickness, into 

 which is inserted a stout, 

 solid, plug - shaped glass 

 stopper, the top of which 

 is flattened and made of 

 exactly the same diameter 

 as the neck of the bottle. This, when put well in, is 

 kept tight by means of the cork-rim, yet not so much 

 as to prevent its being easily extracted. When full 

 they may be covered over with moistened bladder, 

 or better, by putting on a slip of thin sheet Vulcan- 

 ized India-rubber, which is made to adhere by the 

 previous application of a little " Caoutchouc-varnish" 

 along the edges, and further secured by a piece of 

 twine. Bottles of this construction could, be made 

 with the mouths of any convenient size, and would 

 form excellent travelling companions. 



1 6. A quantity of twine, some thread, and & pocket 

 measuring-tape. 



17. One or two pairs of scissors. 



18. When it is intended to transmit living plants 

 Ward's plant-cases, which are simply miniature 

 green-houses, must be procured. 



General Directions for Dry Specimens. 

 1. Selection of Specimens, &c. — Whenever it is pos- 



