SECALE CORNUTUM. 



743 



gradually throw out little white heads. These increase in size, w^hilst 

 the outer layers of the neighbouring tissue gi-adually lose their firmness 

 and become soft and rather granular, at the same time that the cells, of 

 which they are made up, become empty and extended. In the interior 

 of the ergot, the cells retain their oil drops unaltered. The heads 

 assume a greyish -yellow colour, changing to purple, and finally after 

 some weeks stretch themselves towards the light on slender shining 

 stalks of a pale violet colour. The stalks often attain an inch in length, 

 with a thickness of about | a line. They consist of thin, parallel, 

 closely felted cell-threads, devoid of fat oil. Ergot is susceptible of this 

 further development only so long as it is fresh, that is to say, at most 

 until the next flowering time of rye. Within this period however, even 

 fragments are capable of development. There are sometimes also pro- 

 duced colourless threads of mould which belong to other fungi, as 

 Verticillium cylindrosporum Corda, and which frequently overgrow 

 the Claviceps} 



At the point where the stalk joins the spherical or somewhat flattened 

 head, the latter is depressed and surrounds the stalk with an annular 

 border. After a short time there appear on the surface of the head, 

 which is 1^ of an inch in diameter, a number of brownish warts, in 

 which are the openings of minute cavities, the conceptacula or 

 jyeHthecia. On transverse section, they appear arranged radially round 

 the circumference of the head. In each cavnty are a large number of 

 delicate sacs, only 3-5 mkm. thick, and about 100 mkm. long, the thecce 

 or asci, each containing, as is usual in fungi, 8 spores. These are simple 

 thread-shaped cells, fi[lled with a homogeneous solid mass. 



The thicker ends of the spore-sacs {asci) open while still within the 

 perithecium ; the spores issue united in a bundle, and are emitted from 

 the aperture of the perithecium. In consequence of their somewhat 

 glutinous consistence, they remain united even after their extrusion, and 

 form white silky flocks ; their number in the 20 or 30 heads sometimes 

 produced from a single ergot, often exceeds a million. The heads them- 

 selves die in two or three weeks after they have begun to make their 

 appearance. They represent the true fructification of the fungus. This 

 state of the plant appears to have been first noticed in 1801 by 

 Schumacher, who called it Sphceria; it was subsequently known as 

 Gordiceps, Gordyliceps, Kentrosporium, etc., until Tulasne proved it to 

 be the final stage of development of ergot. 



The three difierent forms of this structure, namely, the mycelium, 

 the ergot, and the fruit-bearing heads, are therefore merely successive 

 states of one and the same biennial fungus, which have been appropri- 

 ately united by Tulasne under the name of Claviceps purjourea. The 

 middle stage forms the sclerotium, which occurs in a large number of 

 the most various fungi, and is a special state of rest of these plants. 

 The direct proof that the mycelium is produced from spores of the fruit- 



^ Ergot of rye collected by myself in 

 August, placed upon earth in a garden-pot 

 and left in the open air unprotected through 

 the winter, began to develop the Claviceps 

 on the 20th March, and on another occasion 

 on the 20th April, at which date some sowed 

 in February also began to start. Sharp 

 frost appears to retard the vegetation; thus. 



after the cold winter of 1869-70, Claviceps, 

 even in the greenhouse, did not make its 

 appearance before the 11th May. The 

 earliest instance of fully developed ergots 

 which I ever observed, occurred on the 11 th 

 of June; more frequently they are seen only 

 in the beginning of July. — F. A. F. 



