390 Lecture on the Parasitic Fungi of the British Farm. 



The structure in a very young stage is 

 thread-like, but all traces of mycelium 

 soon disappear, and nothing remains 

 but a mass of minute spores (Fig. 11). 

 The whole was drawn by Mr. Leonard 

 from the specimen this day exhibited to 

 the audience. In addition to the ruin 

 of the grass, this fungus is most per- 

 nicious. According to Leveille, the 

 immense quantity of black dust result- 

 ing from it in the hay-fields in France, 

 produces disastrous consequences on 

 the haymakers, such as violent pains 

 and swelling in the head and face, with 

 a great irritation over the entire sys- 

 tem. A like account was given of these 

 peculiar maladies by Michel, in 1845, 

 which he compared to the well-known 

 effects of ergot, on which singular abor- 

 tion of the seeds of corn and grasses I do 

 not enlarge here, because though accom- 

 panied by a fungus called ergotetia, it 

 cannot be called one. Botanists term 

 it ergotetia abortifaciens, or ergot, fungus, 

 rendering the seed an abortion ; but the 

 only argument they adduce in favour of 

 its producing ergot is, that it constantly 

 attends it. But it is clear that because 

 two things are coincident it does not 

 follow that they are cause and effect, 

 while the best examination does not 

 warrant such an inference in this in- 

 stance. I will only remark that it is 

 more common than is supposed, and I 

 am persuaded that cattle in ill -drained 

 localities, where it always abounds, 

 derive serious injury from it, and that 

 it is the unsuspected cause of many 

 disorders both in them and human 

 beings. 



Another ustilago, named typhoides, damages the stems of 

 reed, swelling and distorting them, and rendering them almost 

 useless for thatching. 



The only remedy for such a disease in a grass-field seems to 

 be breaking it up, and substituting for it a crop not subject to its 

 ravages. 



Fig. 11. Ustilago Hypodytes. 



1. Represents the stem covered with 

 the black spores. 



2. Shows a portion magnified. 



3. Shows the spores under 

 power of the microscope. 



high 



