‘*APERTURES AND AMPLIFICATION.” 319 

that real progress had been made by those members who had applied them- 
selves to the difficulties of preparation of objects, and it is satisfactory to note 
that a senior division has been arranged for teaching the various modes of dis- 
section, the preparation of animal and vegetable tissues, staining, and the use 
of the microtome, 
Mr. Stanley exhibited a good collection of mosses and hepatics, and also a 
selection of sections of animal tissues ; Mr, Lean algze and lycopodiacez insect 
and vegetable dissections; Mr. Fleming volvox globator, mounted in osmic 
acid; Mr. Mestayer micro-fungi; Mr. Chaffers foraminifera, recent and fossil ; 
Mr. Brauer marine algz from the Isle of Man, and zoophytes from the Channel 
Islands and St. Anne’s-on-the-Sea. Other exhibits by the members generally 
were there in plenty. A special feature of the meeting was the illustration of 
the various processes in connection with the preparation and mounting of 
objects. This was practically shown at the various tables by Messrs. Lofthouse, 
Miles, Furnivel, Stanley, Hay, Graham, Chaffers, and Hall. These gentlemen 
successively showed the mounting of an object, from the centering of the slide 
and making the cell to the embedding of the object in its medium and finishing 
it off with its plain or ornamental ring of coloured varnish. Mr. Hay, of the 
Salford Royal Hospital, was eagerly watched in cutting sections, both by the 
ordinary method and by the use of the combined freezing microtome, lately in- 
troduced by Mr. H. P. Aylward. 
MANCHESTER CRYPTOGAMIC SOCIETY.-—Monday, Sept. 18th, 
Captain Cunliffe in the chair. Several of the members had made recent 
excursions to the Breadalbane mountains, and exhibited some of the rarities 
brought home. 
Mr. Ashton showed specimens of Zimmza, Orthotrichum Ludwigti, and 
Hypnum Oakesit. 
Captain Cunliffe specimens of Orthothecium rufescens in fruit ; Dicranella 
squarrosa and Stylostegium cespiticium. All the parties had found the beauti- 
ful Hypnum crista-castrensis fruiting more abundantly than had hitherto been 
seen, and Mr. Ashton brought a number of specimens for distribution amongst 
the members. 
Mr. W. Horsfall contributed freshly gathered specimens of Cryphea hetero- 
malla from Tenby. 
Mr. H. Boswell, of Oxford, sent specimens of a Sphagnum new to Britain, 
which hitherto had only been found in America, and known there as Sphagnum 
Torreyanum (Sull). He had discovered it this summer at Whitchurch, Salop. 
Mr. Boswell also sent specimens of Sphagnum intermedium var pulchrum (one 
of the prettiest of the bog mosses) from the same locality, and Tortula princeps 
from Blair Athol. 
Mr. T. Rogers exhibited several frondose hepatics from Southport, the 
Pallavicinia Hibernice, being remarkable for its strongly pungent odour when 
dry. 
“APERTURES AND AMPLIFICATION.” 
To THE EpITOR OF THE NORTHERN MICROSCOPIST. 
Sir, 
I have read Mr. J. H, Jenning’s remarks in yonr last publication, and accept 
them as the conscientious opinions of a gentleman with whom however I must beg to differ. 
Mr, W. Stanley, another correspondent, in his eagerness to bear testimony to the service- 
ableness of the Davis Aperture Shutter, gives a forcible illustration of the value and useful- 
ness of low apertures, and, per contra, of the want of merit and utility in objectives of 
