8 FUNGOID PESTS OP CULTIVATED PLANTS. 



as in animal diseases an accurate diagnosis must precede treatment. 

 Such being the case, it is important to consider what means can be 

 employed to diffuse the necessary information amongst cultivators, so as 

 to enable them to determine the general character of the disease. This 

 does not imply the specific identification of the fungus, which would be 

 the work of an expert, but the general characteristics only, and especially 

 whether the disease is caused by an endophyte or an epiphyte ; after 

 this, presuming it to be an endophyte, whether it is related to the rot- 

 moulds, the forms of anthracnose, as represented by species of Glceo- 

 sporium, or to the "rusts" or Uredines. The cultivator in possession of 

 the power to determine thus much for himself might easily learn what 

 remedies have been most successful in similar cases, and apply them 

 systematically with some hopes of success. 



Another important question cannot summarily be dismissed without 

 consideration, and that is whether, and to what extent, heredity has to do 

 with the dissemination of plant diseases. It is admitted that in the 

 animal world certain diseases are hereditary. Can it be possible also that 

 amongst plants there is any evidence to be found of the transmission of 

 disease through the seeds to a succeeding generation ? On this point we 

 have a few authenticated facts to submit, and then we have done. 



The first instance is a record of 1885 by W. G. Smith, where he states, 

 as the result of his examination of Oat grains, that not only the mycelium 

 but the resting spores of Corn mildew sometimes do exist within the 

 grains of Corn when the Corn is planted ; that the fungus spores germinate 

 at the same time as the grain ; and that the disease can be and potentially 

 is hereditary.* 



There can be no doubt that some of these diseases are hereditary 

 and can be transmitted through the seeds. A writer t says : " We had 

 about 1,000 very fine plants (Sweet Williams) for blossoming next year, 

 all raised from seed last summer, and in the autumn we noticed a few 

 patches of the fungus (Puccinia Dianihi) and used Gishurst's compound 

 and sulphur mixed with it as a solution, applying it with a syringe. We 

 thought we had destroyed it, but find that all the plants that are not 

 dead are dying piecemeal, and there is not one that has escaped. We 

 cannot grow one of these seeds from Japan ; immediately they are up in 

 the seed-pans, under glass, they are attacked and destroyed." This view 

 is also confirmed by a subsequent writer.^: 



Upwards of thirty years ago a friend sent us specimens of infected 

 Celery leaves, asking for the name of the pest, which was Puccinia 

 Apii ; at the same time he stated that he had two separate stocks of 

 Celery plants, and although both were in the same garden, only one 

 stock was attacked by the parasite. The seed which produced the 

 infected plants was given to him by a person who had informed him 

 Bince that all his plants were similarly affected. The seed from which 

 the other plants were raised had been derived from another source, and 

 not a pustule of the brand could be detected on the leaves ; and yet they 

 had been transplanted and were growing in rows side by side. The 

 conclusion is that the germs of the parasite were present in the seed 



* Gard. Chron., Aug. 22, 1885. 

 f Gard. Chron., Jan. 12, 1884, p. 57. J Gard. Chron., Jan. 26, 1884, p. 120. 



