The Beneficial and Injurious Influences of Fungi. 191 



but in France and Italy other species are more esteemed, as 

 a visit to the markets testifies. In many places an inspector 

 of Fungi examines and gives certificates for the sale of Fungi 

 brought to the market and condemns that of a doubtful nature. 



Ergot of Rye Claviceps purpurea (of which I shall later on 

 have to mention as a pest), holds a place in the Materia Medica 

 on account of its active principles and is employed as a vaso- 

 constrictor in uterine haemorrhage. 



The Giant Puff ball, Lycoperdon covista, is still used in our 

 country places as a styptic. Even a century ago, important 

 surgical operations were performed under its influence as an 

 anodyne and styptic. 



The mycelium of Chlorosplenium aeruginosum stains wood 

 a rich blue-green colour and the wood thus coloured was 

 much used formerly for many ornamental purposes. 



Cheese ripening is due to fermentation caused by bacteria, 

 and the blue mottled colouring and flavour to the mould 

 Penicillium glaucum which develops readily in the spaces of 

 unpressed cheese like Stilton, Wensleydale and Gorgonzola, 

 whilst in pressed cheeses of a more homogeneous nature like 

 Cheddar and Cheshire, the spores of the fungus are unable to 

 mature owing to lack of air and oxygen which the intertices 

 of the former cheeses provide. 



Brewing and Wine and Cyder making are dependent on 

 Yeast, Saccharomyces cerevisice, for the conversion of the sugar 

 in the wort into alcohol, emitting during the process C0 2 

 (carbonic acid gas). 



It is found that the terminal rootlets of some plants are 

 are invested with fungus hyphae forming root caps which do 

 not appear to be detrimental to the host but are in some 

 cases actually necessary to the existence of the plant. This 

 partnership or cohabitation has been termed symbiosis, and 

 the organs performing the symbiosis of root and fungus have 

 been named mycorhiza or fungus-roots which seem to perform 

 the functions of root hairs. 



Symbiosis is known to occur in several Orders and Genera 

 of plants, viz., Cupuliferae, Salicaceae, Abietineae, etc., certain 

 of the Orchideae and some of the Ferns and Lycopods. These 

 fungus-roots are found where much humus exists in the soil 

 and are absent from the roots of plants growing in poor soil 

 with small humus content. The fungus is able to utilise the 

 organic material of the humus and convey it directly in some 

 form to the plant. Although the case is still sub judice, it is 

 possible that these fungus-nurses contribute more to the sus- 

 tenance of the higher plants, including the cereals and forest 

 trees, than has hitherto been supposed. 



It is known to farmers that the Leguminosae (Peas, Beans, 

 Vetches, Clover, etc.) in conjunction with certain species of 



1917 June 1. 



