242 MISSOTRI STATE HORTICULTURAL SOCIETY. 



like threads a number of small black globular bodies which appear to 

 the naked eye as mere specks. These small globular bodies, called 

 sporocarps^ contain one or more sacks, and these sacks contain the re- 

 productive bodies that live through the winter and germinate the fol- 

 lowing spring; consequently they are commonly known as winter 

 spores. 



The life history, then, of the members of of this order, is about as 

 follows : 



The old leaves containing the ripe sporccarps fall to the ground 

 and the following summer they decay and the sjyorocarps containing 

 the reproductive bodies are set free. Under the proper conditions the 

 reproductive bodies germinate, and ultimately give rise to the white 

 threads or mycelia^ from which in time arises the conidla or summer 

 spores already described. 



We have then this important difTerence between the two mildews 

 Peronospora Viticola and Uticinula- spiralis), that attacks the foliage 

 of the grape which will enable anyone to distinguish one from the 

 other. Pero7iospora Viticola appears in the spots on the under surface 

 of the leaf, while TJncinula s])iralis covers the upper surface of the leaf 

 with a dirty white coating. 



The members of the last order {ErysiphacecB) are exceedingly 

 common. Erysiphe lamprocarpa occurs on the verbena, and also on 

 various plants belonging to the sunflower family. 



Podosphera Kunzi occurs on the plum. Erysiplie Martii often 

 attacks the cultivated pea, doing it great injury. 



REMEDIES. 



There are many preparations when applied to plants infested with 

 insects, either kills the insects outright or drives the intruders away. 

 And as soon as the cause of the trouble is removed, the plants usually 

 recover. In dealing with the fungi, however, it is somewhat different, 

 as in most cases the plant body of the fungus is internal. That is, it is 

 in the tissue of the plant infested. 



It is almost impossible to destroy the fungus protected in this man- 

 ner by the tissue of the host plant. It must be remembered that this 

 work is yet in its infancy, and that little or nothing has been done to- 

 ward testing the effect of difl'erent preparations on fungoid growths. 



There is yet another wide field for work and experiment, viz. : It 

 is a well-known fact that animals (man included) in perfect health are 

 less liable to disease than those that have had their vigor impaired by 

 some cause or causes. This is also true of plants, consequently what- 

 ever has a tendency to impair the vigor of a plant, subjects it to the 



