OBSKRVAXrONS. 



253 



A New mode of Preserving Slugs. — 

 Most of the readers of " The Nat- 

 uraUst/' at least that portion of them 

 who study conchology, have, doubt- 

 less, at some time or other wished 

 that tliey could find some mode of 

 satisfactorily preserving the various 

 beautiful molluscs, familiarly called 

 slugs, which form the genera Limax, 

 Arion, Doris, ffiolis, and others. 

 Some time ago I made some experi- 

 ments with a view of attaining this 

 desirable end. After trying spirit 

 of various strengths, glycerine, pure 

 and watered, creosote, and various 

 other solutions, I hit, accidentally, on 

 the following process which answers 

 the purpose admirably. — Make a 

 cold saturated solution of the Bi- 

 chloride of ]\Iercury (corrosive subli- 

 mate,) put it into a deep wide mouthed 

 bottle. Then take the slug you 

 wish to preserve and let it crawl on 

 a long slip of card. When the ten- 

 tacles are fully extended plunge it 

 suddenly into the Bichloride Solu- 

 tion ; in a few minutes it will die 

 witli the tentacles fully extended in 

 the most life-like manner ; so much 

 so indeed that if taken out of the 

 fluid it would be difficult to say 

 whether it be alive or dead. The 

 slugs thus prepared should not be 

 mounted in spirit, as it is apt to 

 contract and discolour them. A 

 mixture of one-and-a-half parts of 

 water and one part of glycerine I 



find to be the best mounting fluid ; 

 it preserves the colour beautifully, 

 and its antisepctic qualities arc 

 unexceptional. A good sized test 

 tube answers better than a bottle 

 for putting them up, as it admits 

 of closer examination of the animal. 

 The only drawback to this process 

 is, that unless the solution is of 

 sufficient strength, and unless the 

 tentacles are extruded when the 

 animal is immersed, it generally 

 but not invariably fails. Some 

 slugs aj^pear to be more susceptible 

 to the action of the fluid than 

 others, and it generally answers 

 better with full grown than with 

 young specimens. But, if success- 

 ful, the specimens are as satisfac- 

 tory as could be desired ; and even 

 if unsuccessful, they are a great deal 

 better than those preserved in spirit : 

 for although the tentacles may not 

 be completely extruded they are 

 always more or less so. — T. G. P. 



Field-Days ^'EAR Scarborough. 

 No. III. 

 Oct. 6th, 1804.— Our third field- 

 day was in Harwood Dale. Wo 

 ascended the course of the Jugger 

 beyond Ravens' Ghyll, till we came 

 nearly to the verge of Fylingdales 

 Moor. This tract is on the Lower 

 Oolite, but there are many indica- 

 tions of the Cleveland ironstone, 

 especially near to Ravens' GhylL 



