36 



work is concerned. The integuments of the body are generally 

 very deficient in chitin, and become hopelessly transparent when 

 treated with an alkali, whilst the male palpus, the form of which 

 is of paramount importance in the identification of species, is 

 almost invariably distorted by any attempt at clearing. Apart 

 from alkaline treatment, any pressure of the cover-glass must be 

 regarded as fatal. It is very necessary to preserve the mounted 

 dissection in as nearly as possible the same condition as the un- 

 mounted object. It often happens that one possesses a solitary 

 example of a rare and obscure spider, and may have occasion to 

 compare it, time after time, with specimens more recently cap- 

 tured, or received from correspondents. This means, under 

 ordinary conditions, the removal of the specimen from its tube 

 of spirit, with much consequent damage to legs and spines. The 

 mounting of such a specimen, or of some important portion of it, 

 upon the orthodox 3 by 1 slip is clearly an advantage, provided 

 that (1) it can be so mounted as not to disturb the relative 

 position of its component parts or alter their form ; and (2) that 

 it can be mounted permanently, or, if not, that it can be expected 

 to keep in good condition for a reasonably long period, and 

 further, that it can, should the mount deteriorate, be remounted 

 without more trouble or risk than that involved in the original 

 process. The procedure is as follows. The spider, when caught, 

 is killed by immersion in whisky. Mr. Smith said that some one 

 will probably ask, "Why not brandy?" There was no reason, 

 except that when he commenced the work there happened to be 

 a bottle of whisky in the house, and he " purloined " sufiicient 

 for his first experiments. Finding these successful, he continued 

 to use it. If a preserved spider is to be dealt with, the palpus 

 is removed and soaked in whisky for an hour or so, presuming 

 that the specimen has been suitably preserved in methylated 

 spirit. Material used consists of glass slips with ^-in. circular 

 excavated cells and some tin cells of |-in. diameter and various 

 thicknesses, with cover-glass to match. The cells should be 

 ground perfectly flat upon each side. This is easily accomplished 

 by glueing a sheet of emery-cloth upon a smooth board, and rub- 

 bing the cell upon it by means of a large cork or flat piece of 

 indiarubber. The slips must be scrupulously clean. If at all 

 greasy, a little liquor potassae will be found useful. The follow- 

 ing reagents, which should be brought to exactly the proper 



