DISEASES OF WHEAT. 157 



entirely preserved and connected together, but without any traces of amylum. This latter 

 is scarcely ever developed in diseased seed, but in place of it are formed clear globular cells 

 of the same size (fig. 7) , which we instantly distinguish as the young grains of brand. 

 These by form are oily-grained contents (fig. 7) , which increases with the advancing 

 growth of the same (fig. 8) ; and their cellular skin, previously clear as glass, and white, 

 becomes brownish colored. In the later growth we find the entire cells of brand (fig. 9) 

 filled with little oil-drops ; and the cellular wall is of pale violet color, but it is still smooth. 

 These cells, natural historians call the spores or seeds of the fungi which constitute the 

 brand ; and in the advancing growth the cellular skin, which is the seed skin of the spore, 

 gradually becomes dark colored and covered with fine warts, while at the same time the 

 little oil-drops visibly increase in the space of the spore-skin, and finally flow into a com- 

 pact yet scarcely discernible body (fig. 10) . 



But if we thoroughly examine the ripe spores of brand, and we happen to obtain good 

 sections of the same — a problem extremely difficult on account of the minuteness of the 

 body to be cut, and only to be secured by chance — then we see that the spore-skin (figs. 

 11, 12, t, t) of the brand-spore forms a dark colored single membrane uneven on the 

 outer surface, which encloses in its hollow space a second transparent cell (figs. 11, 12, 

 13, u, u, u) , which forms the second or inner spore-skin ; but in the space of the second 

 spore-skin we find a waxy, curved body (figs. 11, 13, v, v), which is called the kernel of 

 the spore, and which, in spores not yet fully ripe, appears to be surrounded with little drops 

 of oil. The spores, compared to other of the different kinds of brand, are large, and their 

 linear diameter is from 0"000700 to 0'000730 ( TT V^) of a Paris inch. The spores dis- 

 tinguish this species of brand from all others which habitate wheat, and their specific gravity 

 is greater than that of water : they sink therefore in water, and hence the seed which is 

 affected by brand may be cleaned with running water, as it is thus also clear that well 

 washed seed suffers less from the brand. But the seed must be thoroughly washed before 

 sowing, in order that the spores of the brand, which may still be in the furrow of the seed 

 and among the chaff-hairs of the head, may be removed. 



Here is not the place to quote all the various opinions of the husbandmen and natural 

 historians respecting the existence and propagation of the brand in the various kinds of 

 grain generally. The conviction and view of every individual is so peculiar a matter, 

 which rests on such different grounds of representation and positive induction, that oppo- 

 sition to even the crudest ideas (and so-called experience), according to my multifarious 

 observation, is only injurious. 



Yet I may be allowed to maintain here as preliminary, that the view which regards the 

 brand merely as a stage of disease, or a disease analogous to the organic diseases of the 

 animals, must indeed be false. I can only compare the parasitic formations which belong 

 to the class of fungi or mushrooms, to the phthiriasis or the louse disease, and in this case 

 no spontaneous generation is supposed. We have one of the most decisive proofs in the 

 case of a majority of exotic plants which are evidently produced from seed, and no parasites 

 (especially eutophytes) have been imported from their native country; while in our glass- 



