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®n flDountino :BectIe6 anb otber 3u5cct6 



without prcci^urc* 



By Robert Gillo. 



BEING desirous of obtaining as much knowledge as possible 

 of die structure of Beetles, and more especially of their 

 mouth-organs, I thought I could not do better than pre- 

 pare some of them as transparent objects for the microscope ; for 

 although a dissection, in which you may examine each part sepa- 

 rately, is undoubtedly best, still it is of considerable advantage to 

 be able to see the various organs /// situ. I therefore set to work 

 and prepared some by the usual process — viz., mounting in balsam 

 with pressure — but soon found that this method was most unsatis- 

 factory, for although all the organs were visible under the micro- 

 scope, the relative position of each and the form of the whole was 

 altogether altered by pressure. To attain the end I had in view, 

 I experimented in various ways, and after several failures finally 

 adopted a process by which I have prepared a large number of 

 insects. Some of my friends who have seen these objects have 

 asked me to publish an account of the process. I willingly do so, 

 but with much diffidence, since there is really nothing new about 

 it. I consider that the plan I adopt is a selection and combina- 

 tion of methods and dodges known to all microscopic mounters. 



Let us suppose that the object to be mounted is an ordinary 

 Ground-Beetle, perhaps half-an-inch long. The first thing to be 

 done is to steep it in Liquor Potassce (full strength), and for this 

 purpose I use a test-tube. When the solution becomes dark- 

 coloured, it must be poured away and fresh added. After being 

 in this for ten days or a fortnight, the insect must be transferred 

 to water in a tea-saucer (distilled or soft water should be used), 

 and whilst holding it steady with a cameFs-hair brush, gently 

 squeeze the body with another, giving the brush at the same time 

 a kind of rolling motion, thus driving the contents of the abdo- 

 men towards the anus, from which it will presently be discharged. 

 The beetle should now be removed to clean water, and left for an 

 hour or so, when the squeezing process with the two brushes must 



VOL. IV. M 



