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Diaphragm for Microscope.—I find the diaphragm of which I have sent a model of the working part, a very good one, as it is very easily and cheaply made, and the aperture can be increased or decreased to any degree, still keeping the same shape; and by moving to one slide lower than the other, the light can be directed to either side of the field of view, which is sometimes useful; though I don't think a much better one can be used than the common kind, only made to slide up and down.

Fig. 1 represents the diaphragm with the notched places working freely one over the other.

Fig. 2, the two plates a and b removed. In proportion as the inner angles of these plates approximate or recede from each other, the orifice is diminished or increased, having the quadrilateral form indicated in fig. 1.—E. T. Scott.

Fish Mounds.—At the Dublin Microscopical Club, Mr. Archer recently showed specimens of Aphanomyces stellatus, one of the curious moulds allied to that described and figured at page 134, and at the same time pronounced his own opinion in favour of regarding them as Fungi, and not Algæ, as some have supposed.

Faces in the Eye.—Hooke counted 7,000 in the eye of the house-fly; Leeuwenhoek more than 12,000 in that of a dragon-fly; and Geoffrey cites a calculation, according to which there are 34,650 of such facets in the eye of a butterfly.

Improved Clip.—In the Microscopical Journal, Dr. Maddox describes and figures a new spring clip for holding the thin glass cover in place during the drying of the cement, &c. (fig. a). It appears

to me to have one drawback, viz., it cannot be moved longitudinally along the slide; so that if your object is not exactly in the centre of the length of the slide, the pressure cannot be properly applied. To overcome this difficulty I would suggest a slight modification in the shape of the lower portion, which forms the spring (fig. b). This trifling alteration in the form will give the clip above a quarter of an inch of longitudinal motion.—C. A.

The Quekett Microscopical Club.—At a General meeting called for the organization of this Club, held at St. Martin's Schools, Charing Cross, on the 7th of July, the following resolutions were adopted:—

That this association be called "The Quekett Microscopical Club."

That its ordinary meetings be held on the first Friday in each month, at eight o'clock in the evening.

That the terms of subscription be ten shillings per annum, payable in advance, on the 1st of July in each year.

That the business of the Club be conducted by the following officers, to be elected from the members:—A President, two Vice-Presidents, a Committee of twelve (four of whom shall form a quorum), a Treasurer, and a Secretary.

That the Provisional Committee continue to conduct the business of the Club until the above officers are elected.

That the next meeting be held on the first Friday in August, at the same place and hour, for the election of members, officers, and other business.

Several gentlemen joined the Club, and others willing to do so previous to the next meeting may pay their subscription to Mr. Hardwicke (Treasurer pro tem.), 192, Piccadilly.