68 MISSOURI STATE HORTICULTURAL SOCIETY. 



Many of them are so delicate and of such minute proportions that 

 the highest powers of the microscope are necessary for studying their 

 structure and classification. 



One form of these parasitic plants are known as hacteria' They 

 are the lowest of all vegetable organisms, and are the sole cause of 

 putrefaction, the name given to the decomposition of nitrogenous sub- 

 stances, which takes place whenever they are exposed to the atmos- 

 phere. The germs are found everywhere in the air, and under proper 

 conditions they increase rapidly by division. 



The so-called fungi are one stage higher in the vegetable kingdom. 

 They are divided into four classes, of which we may take as types re- 

 spectively (1) moulds, (2) smuts and mildews, (3) mushrooms and puff- 

 balls, and (4) truffles and ergots. 



All fungi are very rapidly reproduced generally by means of spores 

 which are the result of the breaking up of sporangia, or mother cells. 



Sometime the process of reproduction is very complex, as in the 

 case of Puccinia the mildew of cereals. The so-called resting spores 

 winter on the stems of grasses, and in the spring produce filaments,, 

 which enter the leaves of the bererry, and there develop the fungus, 

 known as ^Ecidium berberidis. This in turn produces spores which 

 enter the stomata on the leaves of grasses, and produce in them, and 

 in them only, the mycelium of Puccinia. 



We may safely say that all plants are liable to the attack of veg- 

 etable parasites. When temperature and moisture are favorable to 

 fungoid development, and they rarely escape if they have been weak- 

 ened in any way. Once seated in their host, they will interrupt its 

 normal growth, and perhaps, cause death. 



It is impossible to control the weather, and the only thing tfiat 

 can be done is to take such measures as will promote a healthy 

 growth. 



In order to secure this, the soil for any crop should be in proper 

 condition, both physically and chemically ; neither too wet, nor toa 

 dry ; properly underdrained and with a. correct exposure. 



The soil, too, should contain a sufficient amount of soluble plant 

 food to properly nourish the plant, and should be frequently stirred to- 

 prevent evaporation. 



The seeds or plants used should be of selected stock and perfectly 

 healthy. They should be planted at such distances as will enable them 

 to obtain all the sun and air necessary for their proper development. 

 If anyone follows these directions, and a blight of any kind destroys 

 his crop, he can feel that he has done all in his power to enable it tO' 

 withstand such an attack. 



