THE LAWS OF PROTOPLASM I3I 



grown flower. The width ol a flower and its 

 stalk is frequently from three to five times greater 

 than that of a normal blossom and stalk. When 

 these conditions were first studied, they were in- 

 terpreted as normal variations; but further ob- 

 servations indicated that the soil was too rich and 

 that these plants had been overeating of the good 

 things in a dandelion's life with the result that ab- 

 normal giant flowers were produced. No one so 

 far as I know has attempted to work out the exact 

 chemical stimulus that is responsible for this ex- 

 cessive growth, but the writer is inclined to think 

 that we may say that these dandelions with ab- 

 normal flowers are diseased. Every spring in 

 New York state there blossoms an early flower, 

 the spring-beauty (Claytonia Virginica) and fre- 

 quently brownish blotches are found on the leaves. 

 As the blotches spread the leaf curls up, and, if 

 several leaves are attacked, the dainty flowers 

 wither before the seeds have ripened. The 

 blotches are due to the growth of one of the leaf 

 moulds, the hyphae of which have penetrated into 

 the mesophyll of the leaf. Here they absorb the 

 nourishment which should go to the leaf. If the 

 mould is successful, its reproductive elements ripen 

 and spread to other plants. If the spring-beauty 

 is successful in resisting the attack, the seeds ma- 

 ture. The spring-beauty having these brown 



