CORN SMUTS AND THEIR PROPAGATION 139 



definite bodies of well-marked origin. The same cannot be 

 said of the cell or "spore" from which the basidium, jointed 

 or unjointed, of the Basidiomycetes arises. As the apex is the 

 only part in the basidium with a free surface in the compact 

 hymenial layer of the Basidiomycetes, I do not think too much 

 stress should be laid on the apical origin of the basidiospores in 

 the comparison with the apical origin of the sporidia in the 

 Tillctia promycelium. The affinities of the rusts and smuts 

 are admitted, and I am, I realise, in a heterodox position in 

 suggesting caution before accepting the view of similar affinities 

 with the mushrooms, etc. 



The next advance in our knowledge of the smuts after the 

 Tulasne work was made by Kiihn, the director of a large estate 

 in Silesia. Kiihn attacked them from a practical point of view, 

 and though he protests he writes as a practical man, he shows a 

 thoroughly scientific knowledge of his subject, and in his book, 

 Die Krankheitcn der Kulturgewcichse, published in 1848, he makes 

 many valuable contributions to knowledge. He convinced 

 himself and his neighbours that by treating the seed before 

 sowing with such a fungicide as copper sulphate the loss from 

 smut could be reduced to a minimum. 



He gave himself a great deal of trouble in trying to ascertain 

 at what stage in the corn plant's life-history the smut spore 

 attacked it, and was finally rewarded by the discovery that it is 

 the seedling (he thought the seedling only) that is attacked, and 

 that, when the corn plant has passed the seedling stage, the 

 mature cuticularised and hardened tissues of the corn plant are 

 proof against penetration by the smut spore. This fundamental 

 point, of the greatest practical importance, is indicated in a few 

 lines only in the book mentioned. The discoveries of Tulasne 

 brothers and of Kiihn gave an apparently satisfactory and 

 complete account of the life-history of the smut fungus, when 

 Brefeld in 1878 turned his attention to the group. He began by 

 testing the germination in water of as many different kinds of 

 smut spores as he could get, and was struck by the fact that 

 while some spores {e.g. those of Indian corn smut) do not sprout 

 at all in water, the spores of other forms germinate, giving 

 secondary spores or conidia, which, however, show very feeble 

 power of any further growth. On the one hand, the smut 

 disease was world-wide and very abundantly represented 

 wherever a corn crop was grown ; on the other hand, the 



