246 THE NORTHERN MICROSCOPIST. 
of mole, and longitudinal section of jaw of cat, both showing teeth zz sit#, Aus- 
tralian zoophytes, mounted as opaque and transparent objects, selected speci- 
mens of Foraminifera from Ireland, injected animal tissues and stained wood 
sections. 
MANCHESTER SCIENCE ASSOCIATION.—At the meeting held in 
the Memorial Hall, Albert Square, Tuesday, August 23rd, the President 
occupying the chair, Mr. E. Napper, F.C.S. read an interesting paper on 
Yeast (Torula cerevisize), in which he stated that ‘‘In Literary culture the 
student is dependent on books; in Scientific study on the other hand he should 
study nature,—get his facts first hand, then know them thoroughly and 
precisely.” If in this spirit we approach the study of this, one of the most 
simple forms of life, we may become acquainted with some of the fundamental 
phenomena of life. The ancients failed to understand many of the facts of 
nature which are easy tous; not from a want of intellectual power, but because 
of the imperfection of their instruments. Yet they might have learnt that 
yeast was a brown fluid, that it had the power of exciting fermentation in sub- 
stances containing sugar, viz., wine, wort, etc. The sugar in solution being 
resolved into alcohol, and carbonic acid; and they might have performed many 
experiments to show that this power may be destroyed by exposing it to a high 
temperature, that the particles are diffused through the air. 
Let us now see what the microscope will tell us. It was first used by 
Leenwenhoek. He found a number of globular bodies floating in the liquid ; 
he did not know what they were, but was struck by their regular arrangement. 
Later, Caignard de la Tour found that these bodies had a definite form, and 
were associated in various ways. Size, from 2 to 7-1000 in., average I-3000 in. 
Shape, well defined cell or vesicle, containing a nucleus and some granules. The 
cell is termed the sac and the contents of the sac, protoplasm; by treating with 
Magenta or Iodine the protoplasm is stained, but the sac is of. Caustic 
alkalies dissolve the protoplasm, but not the sac. Dilute Sulph. Acid, the 
ae is dissolved, but not the protoplasm ; their chemical constituents therefore 
iffer, 
The Torula lives, and is a plant. Between plants and animals it is difficult 
to draw a line; but in the Torula the protoplasm is contained in a cellulose sac, 
which is characteristic of plants. The power of manufacturing Protein com- 
pounds out of simple substances is characteristic of plants. Animals consume 
Protein and destroy it. Plants are generally green, the Torula is colourless, it 
gives off C Oz and absorbs O, requires no sunlight to aid its development. The 
ee three characters belong to Fungi, therefore the Yeast-plant is considered a 
ungus. 
A number of slides were shown, descriptive of the above-mentioned charac- 
ters, and Mr. Napper remarked that it surprised him, that the young micros- 
copist did not devote some of his earlier hours in examining more of these 
easily obtainable, and deeply instructive lessons from nature. 
ROCHDALE AND WHITWORTH MICROSCOPICAL SOCIETY.— 
On Thursday, August 11th, the members of this Society had their usual Micro- 
hunting Excursion, the weather proving unpropitious ; only a limited number 
put in an appearance. 
The party took train to Park Bridge Station, near Ashton, whence (under 
the guidance of Mr. W. Burton) they wended their way to Fairbottom, the 
termination of a branch of the Hollinwood Canal, near which some pools 
notorious to microscopists in the district were visited. Subsequently, they went 
along the Canal side to Daisy Nook, and afterwards to the Hollinwood Canal 
where some very good finds were made. This is a favourite spot for Plumatella 
repens, Melicerta ringens, Hydra fusca, and Spongilla fluviatilis. 
