132 MAN, THE ANIMAL 



blotches on Its leaves is diseased. The mould that 

 is living at the expense of the spring-beauty is 

 termed a parasite. 



Now consider the adult honey bees in this 

 country which suffer from two diseases — paralysis 

 and dysentery. Dysentery in one form is in- 

 fectious and due to the presence of a protozoan in 

 the mid-gut region of the intestinal canal. This 

 portion of the intestine in diseased bees, which die 

 of a virulent form of dysentery, is found to be 

 milk-white and completely filled with spores. 

 These protozoan spores are present in the excre- 

 ment, on the frames and walls of the hive. 



But the most serious losses to the bee-keepers 

 come from a disease which occurs in the larvte and 

 is known as the American foul brood. "The 

 brood affected with this disease is usually capped 

 before It dies. The color of the dead brood 

 presents In general various shades of brown. 

 The marked ropiness of the decaying remains of 

 the dead larvae Is probably the most characteristic 

 and well-known feature of the disease." Here 

 in these insects exist diseases that follow a regular 

 sequence, as in higher animals and plants. The 

 course In American foul brood is due to a specific 

 germ which can now be properly prevented. 1 



The two specific illustrations just described | 

 demonstrate that a definite plant or animal is ' 



