Entomological Xotes. 311 



is really known. To throw a little light on this question, we copy 

 a very practical address delivered by Prof. TV. S. Farlow, before 

 the Massachusetts Board of Agriculture. 



What is meant by a fungus? Fungi are plants of a very low 

 organization, which are never of a grass green color, and which 

 are not capable of absorbing inorganic matter, and converting it 

 into nourishment for themselves, but must take directly from other 

 plants or animals the organic matter which has already been 

 formed out of the inorganic materials contained in the soil or air. 

 All plants which are capable of changing inorganic into organic 

 material contain a quantity of green coloring matter known as 

 chlorophyl, which is not found in fungi. Fungi are, in the strict 

 sense, parasites, and not being able of themselves to assimilate the 

 inorganic materials about them, must appropriate it from other 

 plants and animals as best they can ; consequently any plant 

 which has a fungus growing upon it must not only manufacture 

 food enough for itself out of the surrounding earth and air, but 

 enough also to support the fungus. If enough cannot be provided 

 for both, it is the plant which must suffer, and not the fungus, 

 which helps itself without ceremony to any organic materials 

 which it wants. The more the fungus grows the worse for the 

 plant on which it is growing. Fortunately for the world the dif- 

 ferent species of fungi do not all require the same substance for 

 their support. Some do not grow upon living animals or vege- 

 tables, but only on dead substances, and are useful, inasmuch as 

 they hasten the decomposition of bodies which would otherwise 

 slowly putrify. The fungi which live on dead, inert matter, are 

 called " saprophytes," from a Greek word meaning rotten. Of 

 course, none of the fungi of this class are the source of disease in 

 fruit trees. Other fungi grow upon living plants and animals, 

 and produce many serious diseases. Of the fungi which grow 

 upon living plants, the greater part of them are limited in their 

 range, and do not grow indifferently upon any plant, but either 

 upon a particular species or on several species which are botanic- 

 ally nearly related. The reason for this selection cf plants upon 

 which to prey is probably that different chemical substances are 

 necessary to the existence of the different species of fungi, and 



