104 



DOMESTIC BOTANY. 



swell into a substance very distinct from that of the grain, 

 being solid and of a fatty nature, generally in the form of 

 a spur, sometimes an inch or more in length. This is common 

 to rye, whence the name " spurred" rye. In its earliest stage 

 the surface of the spur is covered with mildew of a chalky- 

 white colour, which moisture readily removes; hence the 

 spurs (ergot of shops) are of a black colour, the mildew fila- 

 ments being the oidium or true plant. The spur is very 

 poisonous, and in Germany and other parts of Europe, where 

 rye-bread is extensively used, it causes those who eat it to 

 be afflicted with incurable gangrenous diseases. This led to 

 the interference of Government to test the purity of rye be- 

 fore being ground. Ergot being common to grasses on w^hich 

 sheep and cattle browse, it is supposed to be the cause of dis- 

 eases to them. Although it is of such a poisonous nature, it 

 is a most valuable medicine. 



Moulds consist of different species of Mucor and Penicil- 

 lium. They are similar to mildews in their ravages, but 

 more evident, being larger, and are often seen with their 

 fructification on stalks like pin-heads growing on jellies, 

 bread, cheese, &c. Yeast is the result of a species of 

 Mucor ^ or Penicillium, as is also the vinegar plant, which 

 is brought into existence by a combination of sugar, treacle, 

 and flour. Racodium cellare is a curious filamentous 

 fungus growing in wine-cellars, covering the walls and casks 

 with a substance like felt. A mildew fungus attacks the 

 corks of wine bottles, also the wine itself, making it what is 

 called ropy." Grease mould [Mucorini phy corny ces) has 

 the appearance of a filamentous conferva, and grows abun- 

 dantly on oily walls, also on grease, destroying all fatty 

 matter, and often causing great losses to the merchant. Poly- 

 actis vulgaris is a filamentous spiderweb-like mould, appear- 

 ing suddenly in a single night, and spreading rapidly over 

 moist surfaces. It is a great pest to gardeners, as it destroys 

 low plants in propagating and store-pits. 



Fungi do not confine their attacks to dead substances, but 

 are known to grow on living animals, of which there are 



