CHAPTER XXVIII. 



WILSON'S VARIETY OF CLAVICEPS ON ERGOT. 



Claviceps purpurea, Tul., var. Wilsoni, W.Sm. 



No account of ergot would be complete without a descrip- 

 tion of a curious form of the germinating ergot of floating 

 sweet grass, Glyceria fluitans, RBr., observed by our friend 

 Mr. A. Stephen Wilson near Aberdeen. 



Glyceria Jluitans, E.Br., is common in wet and muddy 

 places and in stagnant pools and slow-running streams ; 

 and, in our opinion, the peculiar variety of Claviceps named 

 Wilsoni entirely owes its origin to its peculiar environ- 

 ment, so different as it is from the environment of wheat, 

 rye, and other cereals, and many grasses. Mr. A. S. 

 Wilson, in July last, obligingly forwarded us a consider- 

 able number of germinated ergots of Glyceria fluitans, 

 R.Br., on which the new and curious variety of Claviceps 

 was growing, and from these examples the following notes 

 and illustrations have been prepared. 



Mr. Wilson detected these growths in July 1882 after 

 a very wet spring and early summer. In July 1883 they 

 were less common, and were intermixed with the normal 

 purple form of the Glaviceps described in Chapter XXVII. 

 Sometimes the purple form as well as the new white or 

 yellowish one was growing from the same ergot. 



Four germinated ergots carrying Glaviceps purpurea, 

 Tul., var. Wilsoni, W.Sm., are engraved, natural size, at 

 Fig. 107. This illustration may be compared with Fig. 

 100, where the normal form is illustrated, natural size. 



Two germinated ergots are enlarged five diameters at 

 Fig. 108, for comparison with Fig. 101, A, where the 



