INJURIOUS AND OTHER FUNGI. 43 



nature, and means of propagation of the black knot, it is for the 

 fruit growers to profit by their instruction and use their best endea- 

 vors to destroy this pest. It is now peculiar to America, and any 

 means of introducing it into other countries should be carefully 

 avoided. 



In concluding this general and very incomplete account of fungi, 

 perhaps it will not be more than justice to give a notice of some of 

 these parasitic plants which pre}^ upon living animals. 



Who has not seen house-flies in autumn, crawling slowly upon 

 the wall with their bodies covered with a white powder, making 

 them appear as if they had paid a visit to the flour barrel ; or, later 

 still, found them fastened in death to the wall or window-pane? 

 The struggle between the animal and vegetable has been won by the 

 latter, which in turn must also perish when the substance of the fly 

 is all destroj'ed. The tender and v&luable silk-worm has long been 

 subject to epidemics, by which large quantities have perished, caus- 

 ing such fluctuations in the price of silk that the trade in this pro- 

 duct has frequently been threatened with a panic. The fungus, 

 which is commonly called muscardine, begins its growth within the 

 bod}^ of the insect, soon to increase in size and burst through the 

 skin, thus producing death. 



One of the most curious of these insect infesting or carnivorous 

 fungi grows upon or from the head of the larva of a certain species 

 of moth. It is an amusing sight to see the heavily burdened larva 

 bearing erect upon the front of its body a vegetable growth, often 

 three or four times its own length, the signal of distress as it must 

 be, telling plainly the slow but inevitable approach of death. 



Thus we have seen that the members of this peculiar group of 

 plants which has received the name of fungi, are all parasites, and 

 from their very nature do not increase the amount of organic matter 

 in the world, but on the other hand, are powerful reducing agents, 

 seizing upon that which is highly organized, and aiding rapidly in 

 its reduction to a more simple state. 



Though fungi furnish delicious articles of food, it is in the light 

 of then- power to hasten decomposition that we see their great im- 

 portance in the world ; aiding in the cycle of life by facilitating 

 decay. Sometimes they encroach upon our fields of growing grains 

 and fruits and do us serious damage ; but even here the moralist 

 would say there is a lesson of appreciation and care for our crops, 

 which only the school of sad experience is able to teach. 



