ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 733 



SO as completely to cover it, noticing that the legs are not displaced, 

 for if they are right during this part of the process, they will 

 naturally assume the same position in the final stage of the mounting. 

 After several hours, or next day, change the spirit for fresh, and 

 again, after several hours, pass the insect into ether, but as this is 

 such a volatile fluid, it should be used in a test-tube tightly corked. 

 There need be no anxiety about the position of the legs in this stage, 

 as they have been already stiffened by the spirit, and if displaced 

 now will spring back again into their original position. After soak- 

 ing some hours in ether, pass into turpentine, in which it may be 

 allowed to remain any length of time." 



Directions for mounting in a cell with balsam in benzole follow, 

 and for cementing, and it is pointed out that among other advantages 

 insects thus mounted polarize brilliantly, probably owing to the action 

 of the bleaching solution on the different tissues. 



Mounting the Proboscis of the Blow-fly in Biniodide of Mer- 

 cury. — Mr. H. Sharp describes his method as follows : — ^The appa- 

 ratus necessary consists of two pieces cut from a glass slip, 1 in. by 

 1^ in., a weak spring clip, and a wide-mouthed bottle containing 

 methylated spirit. 



Kill the fly by dropping it into boiling water, cut off the head, 

 place it on one of the pieces of glass, and squeeze it with the finger 

 imtil the tongue protrudes and the lobes expand. Then gently nip it 

 with the other piece of glass, and put on a weak clip to hold it in 

 position. Place the whole in the methylated spirit, and leave it there 

 for an hour or more. On releasing the proboscis from the glasses the 

 lobes will remain expanded ; cut off the proboscis and place it in spirit 

 till all the air is removed. Then put it in water for half-an-hour, 

 and then in weak solution of biniodide of mercury (half water and half 

 saturated solution) for two or three hours ; then in the full strength 

 solution for 12 hours. 



When the proboscis is put in the weak mercury solution the 

 lobes will most likely curl up, to prevent which place it on a slide 

 when taken from the water, and put on a cover with a weak clip to 

 hold it in position, and then run the weak solution of mercury under 

 the cover. Do the same when transferring from the weak to the full 

 strength solution. 



Mount in a shellac cell, and use shellac for securing the cover. 



Mr. Sharp finds it safe to use for the final mounting a solution of 

 the biniodide of mercury slightly weaker than saturation, as if of 

 full strength crystals will develope in very cold weather. 



Preparing Luciola italica.* — To investigate the scat of oxida- 

 tion which produces the light. Dr. C. Emery kills the living animal 

 in a solution of osmic acid, which stains the luminous plates of tho 

 still living and light-developing animals brown. The parts which 

 are to bo further examined are macerated for a long time in water, 

 the development of fungi in which is prevented by the addition of 



• ZeitHchr. f. Wits. Zuol., xl. (18S1) iip. 338-51. 



