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POPULAR SCIENCE REVIEW. 
family; they form beautiful objects under the microscope, but 
present merely black or coloured blotches to the naked eve. 
The Blue Mould of cheese is a popular member of this family ; 
and the Potato Blight ( Peronospora Destructor) is the most de- 
tested. It seems to spread through the whole plant, stem, 
leaves, and tubers. It consumes the starch, filling up the cells 
with its poisonous spawn. The mould familiar to us on jams, 
etc., is nearly allied to this. The spores of these plants are of 
amazing lightness, and float in the air in myriads, germinating 
when they find a suitable matrix. The Vinegar Plant has nume- 
rous barren threads which grow into a tangled mass. The Yeast 
Plant belongs to this group. Arising, like other Fungi, from 
spawn in the first instance, yet its spores multiply with such 
exceeding rapidity that it does not depend on the spawn for 
propagation : a simple cell placed in a congenial position buds 
in the course of an hour, and thus chains of cells are formed. 
These dried constitute the “ German yeast.” Hogg informs us 
that ringworm and another allied diseases are, produced by a 
plant of this order ; he also appears to be of opinion that such 
microscopic Fungi had a share in causing the cholera, great 
quantities having been detected in the air at the time when it 
raged. The mildew, so destructive to silk, gloves, etc., is of 
this group ; another is found eating into the glass of our mir- 
rors ; and there is even one species which infests the chemical 
solution used in electrotyping. Some members of this group 
are able to bear any climate, from the heat of the Tropics to the 
cold of the Poles. 
In the Sporidiferous group there are but two great families. 
The first, Ascomycetes, is characterised by the important dis- 
tinction of the spores being enclosed in bags, or asci; the 
second, Physomycetes, are merely moulds. 
Many members of the first group, the Evellacei, equal in 
stature and interest the aristocratic Agarics. The Morchella 
esculenta, or common morel, is much prized in Yorkshire, as 
giving excellent flavour to gravies, and no good housekeeper is 
without a string of them suspended in her store-room. Here 
the hymenium is in honeycomb cells on the upper surface of 
the cone ; the stem is white and the head brown ; they are 
found on field borders in May and June. So highly did the 
Germans appreciate its excellence, that they used to burn down 
a portion of forest every year, because the wood ashes secured 
a crop of morel ; this custom was stopped by an edict of state. 
The Helvellce have an even hymenium, drooping over the stem ; 
there is an edible species, but I do not know its recommen- 
dations. 
The M-itrula paludosa, with its white stem as thick as a 
goose-quill, and its orange club-shaped head, is a pretty orna- 
