332 On BligTit. 



reason that Mr. Errington found that burying his celery- 

 roots only made the mildew spread more rapidly. The only 

 cure for this fungus seems to be that adopted by Mr. Knight 

 with his pear trees, viz., taking them up, washing the roots 

 quite clean from every particle of soil, and then replanting 

 them in quite a different part of his grounds. 



Red plants are said to be more liable to mildew than any 

 other. Red is, indeed, supposed by some, always to indicate 

 a morbid action, as it shows that the plant is unable to absorb 

 carbonic acid gas from the .atmosphere, which is necessary to 

 its perfect health ; at all events, it is a proof of disease when 

 leaves, or any other parts of a plant, not naturally red, assume 

 that colour. Other experiments have been made for curing, 

 or at least preventing the spread of, the internal mildew ; and 

 Mr. Bauer has found that steeping grains of corn in lime- 

 water will produce the desired effect. There appears no 

 cure for mildew in the roots, but by cutting a deep trench 

 round the infected plants, and cutting off all communication 

 between them and the rest of the field. I regret to have 

 been unable to submit these notes to Professor Lindley : but, if 

 they should contain any thing very erroneous, I will correct 

 it in my introduction to his succeeding lecture on climate. — 

 J. W. L. 



The young gardener will find it worth his while to follow up these remarks 

 by a perusal of the enumeration of the genera and species of British funguses 

 in the HorLus Britamiicus, and EncyclopcBdia of Plants, where, besides 

 their names, some information is supplied on their habits. In relation to 

 the above remarks, it is a question, the answer to which would interest. 

 Are all the individual plants of any one species of any genus, to which 

 species a certain species of fungus is peculiar, soil equally eligible, whatever 

 be their condition of health, for the seeds of that fungus to germinate in 

 or upon, and for the plants arising from these seeds to thrive in or upon, 

 and be nourished by ? This question is asked in consonance with a view 

 entertained by a thinking friend of ours, who opines that disease, previously 

 to the arrival of the seeds of the fungus, must predispose and prepare the 

 leaves, or other parts, of a plant, as eligible soil for them to germinate in ; 

 and that, consequently, parasitic fungi are never the forerunners, but ever 

 the followers, of disease ; and, therefore, that, although the seeds of parasitic 

 fungi are, doubtless, dispersed indiscriminately, and fall on the surfaces of 

 vegetables indiscriminately too, they only germinate in and upon those 

 which disease had previously rendered a fit soil for them. — J, £). 



Art. XIX. Additional Facts on the Fungus (^cidium cancellatum 

 Sowevhy) parasitic on the Leaves and Fruit of the Pear Trees in 

 the Garden at Buscot Park, By Mr. John Merrick. 



Sir, 

 Relatively to the fungus which has been so injurious 

 to my pear trees, and so very grievous to my master, 



