GENERAL INFORMATION 15 



4. Abnormal llowering — ^where the attacked part 

 flowers at a different time from the rest of the plant, 

 e.g. "witches' broom" on the cherry tree. 



5. Suppression of part of the reproductive organs, 

 e.g. Ustilago (smut) on Lychnis dioica (campion). 



6. Premature development of buds, e.g. a 

 diseased potato usually develops the buds earlier 

 than the healthy ones, and the same phenomenon 

 is seen in the ''witches' broom" on the elder. 



7. Contortions of the most varied nature, e.g. 

 Cystoptts candidus on Capsella Inu'sa pastoris (shep- 

 herd's purse). 



8. Discoloration of the parts affected — most 

 fungi. 



9. Formation of different colours, e.g. Rki.zoctoma, 

 violet on roots, and Fitsarium (species), rose-pink 

 on potatoes. 



10. Cell wall and cell contents changed by means 

 of ferments, e.g. wall and starch grains in a diseased 

 potato. 



Others might be given, but these will suffice to 

 convey to the mind of the reader the great changers 

 which are brought about. 



Influence of Host on Parasite. — While parasites 

 are able to bring about such contortions, etc., in 

 plants, these in turn are not without their effect on 

 the attacking party. Certain fungi are only capable 

 of existing on plants of a particular genus ; others 

 again on a single species, while some can only 



