CHAPTER 3 

 POISONOUS FUNGI AND OTHER SPORE-BEARING PLANTS 



This chapter will deal with the poisonous character of the lower plants, 

 those which form spores instead of true seeds. The bacteria, such as 

 the organisms which produce anthrax and glanders, are not included, 

 because the study of their pathogenicity is elaborated in various works 

 on bacteriology and they are considered as a special phase of medical 

 research requiring an elaborate technique. There are a number of fungi, 

 such as corn smut, Ustilago Ze&, reputed to be poisonous to stock, but such 

 belief needs confirmation. The following fungi have been studied thor- 

 oughly and there can be no doubt^as to their poisonous action. 



Ergot (Cla-viceps purpurea). The ergot fungus is found on rye both in 

 America and Europe, where during wet, warm weather it may be extremely 

 prevalent. It gains entrance to the host at the base of the young ovary 

 penetrating the ovary wall and gradually replacing the tissues of the rye 

 ovary. This is accompanied by an enlargement of the ovary, which at 

 its upper end presents a somewhat spongy character. This is due to the 

 outgrowth of the mycelium in the form of twisted strands, the marginal 

 hyphae of which acting as conidiophores abstrict off conidiospores. This 

 early stage was known as the Sphacelia stage. Later, as the time for the 

 maturing of the healthy grains arrives the diseased ovaries will be found 

 to be replaced by bluish-black, horn-like bodies which project conspicuously 

 from between the glumes of the rye spikelet. The rye ovary is replaced 

 by a hard body with blackish surface and white interior known as the 

 sclerotium. The ergot spurs, or sclerotia, perennate as such until the 

 following spring, when they send up one or several outgrowths, or stroma, 

 with a knob-like end of a yellowish-brown color. In the hyphal tissue, 

 which comprises the knob-like portion of the stroma, flask-shaped peri- 

 thecia are formed with short necks and slightly protruding ostioles. The 

 asci contained in these perithecia are elongated and contain eight needle- 

 shaped ascospores, which measure 60 to 70^ in length, and issue from the 

 tip of the ascus by a small opening. These ascospores bud off condio- 



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