THE YOUNG NATUBALIST. 



33 



T. Mangel — This slug differs from the last species in being dark brown, 

 and in having its shell larger and more cylindrical. 



One final word as to the preservation of slugs. They should be killed by 

 drowning, and their mucus removed by careful rubbing with a cloth. They 

 may then be transferred to glass tubes filled with some preservative medium. 

 Several media for this purpose have been recommended. I used formerly a 

 weak solution of chloride of zinc ; but turpentine, or a mixture of equal parts 

 of glycerine and methylated spirit may be used in the absence of this. Mr. 

 "Woodward employs a solution of calcium chloride, made by dissolving white 

 marble in hydrochloric acid until all effervescence ceases, and a saturated 

 solution is obtained. But by far the most preferable method — and it is the 

 one I always pursue now — was described by M. Dubreuil in an article entitled 

 "Procede pour la preparation des Limaciens," which appeared in "La Jour- 

 nal de Conchologie," for 1864, p. 243-245. The animal is first killed and 

 washed in pure water, to which, after the lapse of six or eight hours, some 

 salt is added. A slit is then made along the left side, and the animal 

 skinned. Thus by means of two more longitudinal slits three preparations 

 can be made — one to show the back, one the foot, and the third the right 

 side with the pulmonary orifice. These are then glued on cardboard, varnish- 

 ed with white shellac varnish to which a little corrosive sublimate has been 

 added, and duly labelled with the scientifiic name — and when requisite the 

 varietal name in addition — of the species, locality, and date of capture. 



ACHETA DOMESTICUS (The House Cricket.) 



By J. HILLMAN. 



Of all the insects which inhabit our domestic sphere, perhaps none is so 

 well known as the house cricket (Acheta domesticus.) Although its life 

 history is less known than that of most insects, passing as it does most of 

 its time in secretive places, and seldom appearing until the lights of the house- 

 hold have been extinguished. As soon as darkness reigns supreme, then 

 begins in earnest the revels of these musical and frolicsome pests, flying, 

 jumping, and running in all directions, in search of food, or on amatory 

 visits intent. Now is the time for the naturalist to make his observations, 

 and scientific enquiry into the habits and life history of this interesting and 

 curious creature. Proceed quietly to the fire-place, and then what a sight 

 one beholds, crickets of all sizes from the day-old baby to the full-grown 

 male of about six months, for that seems to be the period of their existence. 

 About Eebruary, or at the latest the second week in March, the female de- 



