30 



from them. 4th. Taking them out of the spirits of wine I immerse them in 

 spirits of turpentime, in which I allow them to remain until symptoms of 

 transparency set in. 5th. If the insect is a pretty thick one, I take a slide to 

 which a glass ring has been cemented to serve as a cell ; I then put the insect 

 in the cell with as little turpentine adhering to it as possible, after that I take 

 on the point of a very big needle a lump of very stiff and thick Canada balsam, 

 and with the help of a similar needle I drop it on the insect. If the first lump 

 is not sufficient to fill the cell to overflowing, I take another, and when the 

 balsam is heaped up beyond the level or rather the rim of the cell, I hold the 

 slide for a second or two over a spirit lamp, and when the balsam softens a 

 little, I put a thin cover over it, but do not press it close down upon the glass 

 ring. I leave it tilted on one side for the escape of air bubbles, which are very 

 numerous when thick balsam is used. I then put the slide away, and do not 

 operate upon it again until all the air bubbles have disappeared, when I subject 

 the thin covering glass to slight pressure, which can be nicely done with the 

 assistance of Smith's mounting machine. Sometimes a lot of balsam is pressed 

 out of the cell in this way, which can be easily removed." 



The President remarked upon the difficulties attendant upon the mounting of 

 insects whole, owing to the breaking of their bodies. Another difficulty was that 

 of getting rid of the air and moisture of the insect. A third difficulty was the 

 tilting of the cover, which would produce refraction. A cell would obviate this 

 if not over-filled. 



The Secretary explained that Mr. Green referred to the tilting of the whole 

 slide to expel air bubbles. The tilting of the cover in the slides presented to 

 the Club might have occurred during transit to England, but the viscid state ot 

 the balsam rendered it nearly impossible to correct this. It was very difficult 

 to account for the fact of the fatty matter being so thoroughly got rid of. The 

 climate probably had much to do with this, but the amount of fat varied greatly 

 in different specimens. 



In the absence of a paper Mr. Ingpen made some remarks upon a gathering 

 of Volvox globafor collected on the 1st of January last in two bottles, one quite 

 clean, the other with the admixture of a little conferva. Each bottle contained 

 about 100 specimens. They were placed in an east window, and at the end of 

 the month shewed no diminution in numbers. On the 9th of February the 

 water in the bottle containing conferva froze slightly — not at the top, but in 

 thin plates stretching obliquely across the middle of the bottle. Next day all 

 the Volvox in this bottle had assumed the winter state, while those in the other, 

 which had not frozen, remained unchanged. The latter continued to develop 

 till about the middle of March, from which time they gradually diminished in 

 number, the last disappearing on the 8th of April. Shortly after which the 

 water became turbid and dried up. No specimens in the winter stage were 

 found in this bottle, but they continued in that which was frozen till the middle 

 of April, when that bottle also began to dry up, no water having been added to 

 either. At the end of February Closterium lunula made its appearance in great 

 numbers in both bottles, giving place, a few days afterwards, to a much 

 smaller variety, apparently produced from sporangia, and not subsequently in- 

 creasing by fission. In the middle of April water was added, after which 

 conferva greatly increased in the bottle which had been frozen. On the 1st of 

 June no Volvox in any stage was found in either bottle. The points considered 

 worthy of note were— the continuance of Volvox in a small quantity (3oZ.) of 

 water, for three months, and the rapid transition to the winter state upon the 

 occurrence of a slight frost. 



