together b ; the lower side c consists of irregular cells, loosely 

 packed, having air spaces between them. Communicating with 

 the air spaces are little openings in the epidermis, called breath- 

 ing pores or stomata, one of which is shown at e. In the left half 

 of the section the cells are represented filled with the chlorophyU 

 bodies which contain the green coloring matter. Running among 

 the cells are seen the threads or mycelium of the fungus which 

 causes the blight ; and growing from the breathing pores the 

 branching spore stalks bearing the spores. 



Fig. I. 



Treatment. — If it can be avoided, potatoes which are known 

 to be diseased or which have been grown in a field attacked by . 

 the blight should not be used for seed. However, a remedy has 

 been found which if used in season seems to be very efficient in . 

 checking or preventing the disease. This remedy is the Bordeaux 



