USTILAGO MAIDIS. 113 



material is taken out and the remaining fine powder examined, we 

 find, besides the great quantities of spores, specimens showing the 

 minute structure from almost every part of the corn, and even of 

 many of the neighboring plants. 



Scale t-lOOOth of an inch. 



Pig. 5. Commercial Ustilago Maidis. x 250. 



In fig. 5 we have a representation of the fine powder as it is 

 sold in the drug stores. There are found in this powder many 

 things that do not belong to Ustilago Maidis. The characteristic 

 spores (a) are found in great quantities everywhere. The long 

 slender hairs seen at c are the minute hairs found on the surface of 

 corn leaves, and which give the roughness to the leaf ; they are 

 commonly present in the powder. At b is seen a fragment of the 

 woody part of corn, or more properly speaking, a cross section of a 

 vascular bundle. At d we see a stellate hair which is quite charac- 

 teristic of some of the weeds growing along the road-side and in 

 the fields. Very frequently we find the spores of other parasites 

 mixed with the ergot, such as rust from wheat, onion smut, blight 

 on fruit trees, etc. 



