Method of Mounting Heads of Insects ivithout Pressure. 143 



should be secured, at right angles to each other, into the corner of 

 which the small mounting block will fit and be kept in position 

 by a short length of spring, fig. 4. 



I propose to deal with the mounting of a wasp's head, which 

 is in many ways more difficult to set out than a bee's, as the palpi 

 are troublesome and will curl up if they can. 



The small mounting block being in position on the dissecting 

 table, the head is placed on it, antennse-side down, and is kept in 

 position by two of the headless pins placed one on either side 

 close behind the mandibles, fig. 5-\ 



Mr. Enock took a rather larger pin, and pushing it through a 

 small piece of thin card, placed it just behind the head, so that 

 tlie card pressed flat upon the head.^ 



Personally I dispensed with this card as I found it un- 

 necessary. 



With a pin in the forceps open the left hand mandible and 

 push the pin into the cork.^ 



Do the same with the other mandible, being careful, having 

 regard to the beauty of the mount, not to straddle the mandibles 

 too wide open. 



With the loop of the bent " cork pin " gently draw out the 

 tongue as far as it will go, and keep it protruded by pressing into 

 the mounting block the second or stouter pin.* 



Next lay out the palpi, preventing them from curling up by 

 placing pins crossed where necessary.^ 



Finally place the straight " cork pin " across the tongue to 

 prevent its rising up during the hardening process.^ 



The head is now finished. 



For the hardening process I had a large round bottle made, 

 about 5 in. in diameter, and 2 in. up to the shoulder, with an 

 opening 2 in. or 2^ in. in diameter, into which fitted a ground 

 .stopper. This bottle was tilled with sufficient methylated spirit 

 to completely cover the mount, say, for safety, to a depth of 1 in. 



An ordinary common pin is stuck into one corner of the 

 small mounting block, which is now removed from the dissecting 

 table, and, by means of this pin, lowered into the spirit. Its glass 

 bottom will cause the block to sink. 



Colonel Freeman has suggested, and I think it well worth con- 

 sideration, that in order to avoid the possible shrinkage and 

 twisting of parts, it might be well to use two strengths of spirit 

 solution, the first of half strength, in which the mount might 

 stand for (say) three days, 'and the second of full strength, into 

 which the mount might then be transferred, to stand for a week. 



During the hardening, especially in the earlier stages, the 

 mount should be fi:equently examined to see that there is no 

 curling, or displacement of parts, and to remedy this if necessary. 



When satisfied that the head is perfectly set lift the mounting 



