STUDIES OF SPORE-PLANTS 261 



the liquids over plants in fine mist so as to touch all parts. A 

 mixture of lime and copper sulphate, called Bordeaux mixture 

 because discovered in about 1885 by scientists who tried 

 to check the mildew which was destroying the vineyards 

 near Bordeaux in France, has proved an important remedy for 

 most fungous diseases which are on the surface of plants, 

 and is extensively used by growers of fruits, potatoes, many 

 vegetables, and ornamental plants. 



Since insects may attack the same plants, an insecticide 

 (insect-killer) is often mixed with the fungicide. For ex- 

 ample, Bordeaux mixture (for the potato blight and rot) and 

 Paris green or other poisonous compounds of arsenic (for kill- 

 ing the potato-beetles) may be mixed. Likewise, Bordeaux 

 mixture (for apple scabs, rots, and blights of either the fruit 

 or the leaves) and arsenical poisons (for the larvae of codling 

 moth, which makes wormy apples) are commonly sprayed as 

 a mixed liquid. 



For information concerning the proper solutions and times 

 for spraying a particular crop in order to get best results 

 write to the agricultural departments either at Washington 

 or at a state experiment station and apply for the latest 

 pamphlets on sprays for plant diseases. Also every spring 

 the best agricultural newspapers review the latest methods 

 for preventing plant diseases. 



Water-molds. Some aquatic molds live on dead animals 

 and plants in water ; and some of them are very destructive 

 parasites on living fishes. The fluffy white masses often 

 seen around dead insects in water and on fish in aquaria are 

 examples. The spores lodge on the skin of fishes, germinate, 

 and some hyphse penetrate the tissues of the fish so that 

 nutriment is absorbed from the blood and lymph. It has 

 been found that brief immersion of trout and other fishes 

 in sea-water will check the growth of the fungus. 



Fungi and Diseases. Some of the fungi allied to common 

 molds may produce diseases in man and domesticated 



