M icroscopes are particularly important in mycology where critical identification may rely on exa... more M icroscopes are particularly important in mycology where critical identification may rely on examination of microscopic parts like spores, cystidia and asci. This is the first of two articles covering a range of topics in microscopy from the viewpoint of the amateur field mycologist. Choosing a microscope There are two basic types of microscope: • compound (or slide) microscopes • stereo (or dissecting) microscopes Compound microscopes (Fig. 1) A compound microscope (usually just "a microscope") is absolutely essential for the serious mycologist. Compound microscopes offer both high magnification and, more importantly, high resolution (i.e. ensuring that more detail is visible). They are designed for working with a transparent subject mounted on a microscope slide, although with a little ingenuity, you can use top lighting to examine or photograph opaque objects. Although modern compound microscopes are generally binocular (having two eyepieces), the same image goes to each eye so the image appears strictly two-dimensional. So called 'trinocular' microscopes allow the image to be viewed by a camera as well as by two human eyes. Stereo microscopes (Fig. 2) Stereo microscopes offer lower magnification than compound microscopes but also lower resolution. They are usually used with top-lighting to examine opaque subjects by reflected light. Some can also light from below for transparent subjects. They have a good working distance between the lower surface of the objective lenses and the subject, thus providing easy access to the subject, and, unlike compound microscopes, the image is presented the right way up so they are
M ost Entoloma species are quite a challenge to identify to species level. It was perhaps easier ... more M ost Entoloma species are quite a challenge to identify to species level. It was perhaps easier when this large 'super genus' was divided into a number of smaller genera but the current wisdom is to combine them all in the one genus, with a number of subgenera. These two yellowish brown, smooth to velvetycapped species with greyish yellow stipes are comparatively distinctive and would formerly have been placed in the genus Leptonia, now subgenus Leptonia. Species in that subgenus are characterised by usually slender, collybioid stature, i.e. like the genus Collybia (now Gymnopus), with rounded, weakly or not hygrophanous caps which are radially fibrillose or squamulose with an often more or less depressed or umbilicate centre. The two species differ in spore size and the dark gill-edge of E. xanthochroum. This latter is also said to have a slightly darker-coloured cap but the difference is subtle, along with rather yellower gills when young and more abundant cheilocystidia.
M icroscopes are particularly important in mycology where critical identification may rely on exa... more M icroscopes are particularly important in mycology where critical identification may rely on examination of microscopic parts like spores, cystidia and asci. This is the first of two articles covering a range of topics in microscopy from the viewpoint of the amateur field mycologist. Choosing a microscope There are two basic types of microscope: • compound (or slide) microscopes • stereo (or dissecting) microscopes Compound microscopes (Fig. 1) A compound microscope (usually just "a microscope") is absolutely essential for the serious mycologist. Compound microscopes offer both high magnification and, more importantly, high resolution (i.e. ensuring that more detail is visible). They are designed for working with a transparent subject mounted on a microscope slide, although with a little ingenuity, you can use top lighting to examine or photograph opaque objects. Although modern compound microscopes are generally binocular (having two eyepieces), the same image goes to each eye so the image appears strictly two-dimensional. So called 'trinocular' microscopes allow the image to be viewed by a camera as well as by two human eyes. Stereo microscopes (Fig. 2) Stereo microscopes offer lower magnification than compound microscopes but also lower resolution. They are usually used with top-lighting to examine opaque subjects by reflected light. Some can also light from below for transparent subjects. They have a good working distance between the lower surface of the objective lenses and the subject, thus providing easy access to the subject, and, unlike compound microscopes, the image is presented the right way up so they are
M ost Entoloma species are quite a challenge to identify to species level. It was perhaps easier ... more M ost Entoloma species are quite a challenge to identify to species level. It was perhaps easier when this large 'super genus' was divided into a number of smaller genera but the current wisdom is to combine them all in the one genus, with a number of subgenera. These two yellowish brown, smooth to velvetycapped species with greyish yellow stipes are comparatively distinctive and would formerly have been placed in the genus Leptonia, now subgenus Leptonia. Species in that subgenus are characterised by usually slender, collybioid stature, i.e. like the genus Collybia (now Gymnopus), with rounded, weakly or not hygrophanous caps which are radially fibrillose or squamulose with an often more or less depressed or umbilicate centre. The two species differ in spore size and the dark gill-edge of E. xanthochroum. This latter is also said to have a slightly darker-coloured cap but the difference is subtle, along with rather yellower gills when young and more abundant cheilocystidia.
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