322 Sir Joseph Banks 



the millers allowed that it was the best sample brought io 

 inarket. Barlcv was in some places considerably spotted ; 

 but as the w hole of the stem ot' that grain is naturally en- 

 veloped in the hose or basis of the leaf, the fungus can in 

 no case gain admittance to the straw j it is however to be 

 observed" that barley rises from the flail lighter this year 

 than was expected from the appearance ot the crop when 

 gathered in. 



'I'hough diligent enquiry was made during the last 

 autumn, no information of importance relative to the origin 

 or the progress of the bliglu could be obtained : this is not 

 to be wondered at ; for, as no one of the persons applied to 

 had anv knowledge of the real cause of the malady, none 

 of them could direct tlieir curiosity in a proper channek 

 Now that its nature and cause have been explained, we 

 may reasonably expect that a few years will produce an 

 interesting collection of facts and observations, and we 

 may hope that some progress will be made towards the 

 very desirable attainment of either a preventive or a cure. 



it seems probable that the leaf is first infected in the 

 spring:, or early in the sunmier, before the corn shoots up 

 into straw, and that the fungus is then of an orange co- 

 lour*; after the straw has become yellow, the fungus 

 assumes a deep chocolate brown : each individual is so 

 snuiU that every pore on a straw will produce from 20 to 

 40 funci, as may be seen in the plates, and every one ot 

 these will no doubt produce at least 100 seeds : if then one 

 of these seeds tillows out into the number of plants that 

 appear at the bottom of a pore in Plate V and VI. fig. 1, 2. 

 how incalculaldy large must the increase be ! A few diseased 

 plants scattered over a field nmst verv speedily infect a whole 

 neighbourhood ; for the seeds of fimgi are not much heavier 

 than air, as every one who has trod upon a ripe pufl'-ball 

 must have observed, by seeing the dust, among which is its 

 ^eed, rise up and float on before him. 



How long it is before this fungus arrives at puberty, and 

 scatters its seeds in the wind, can only be guessed at by 

 the analogy of others ; probably the period of a generation 

 is short, possibly not more than a week in a hot season : if 

 so, how freq-iently in the latter end of the summer must 



• The able Tcssier, in liis Traite des maladies des Grains, tells us, that in 

 France this disease first shows itself in minute spots of a diity white colour 

 on the leaves and stems, which spots extend themselves by degrees, and in 

 time changp to yellow, and throw otTa dry orange-coloured powder, pp. 201 . 

 y-lO. — /IdUtliiii.al luitc uf the Author. 



