282 INTRODUCTION TO CRYPTOGAM IC BOTANY. 



287. The identity of ergot with Cordyceps has been called 

 in question by Cesati, because two species of Cordyceps occur 

 occasionally on the same kind of ergot. Mr. Currey has lately 

 forwarded to me specimens of 0. purpurea, on the ergot of the 

 common reed, which usually produces C. microcepihela. But it 

 is very possible that the same grass may be ergoted by more 

 than one Cordyceps ; and even should a single ergot be found 

 to produce two species of Cordyceps at once, it is possible that 

 the sporidia of the two species may have concurred iu its pro- 

 duction. 



288. A volume might be written on the different forms of 

 Sphmrice, their peculiarities, and their fruit ; but our limits 

 and object require brevity. The point in view is merely to give 

 general notions, which may afterwards be applied in practice. 



289. It has been stated that the peculiar character oi Asco- 

 inycetes depends upon the presence of asci containing sporidia, 

 but it is quite certain that in many cases perithecia occur 

 containing naked spores totally different in form from the 

 sporidia, though sometimes closely resembling them. In some 

 cases, again, spores are formed immediately beneath the cuticle 

 of the matrix without any perithecia, which may either 

 differ entirely from those of the ascigerous plant provided with 

 a perithecium, or may closely resemble them, as in Sphceria 

 inquinans (Fig. 65, c), where the one is distinguished from 

 the other merely by the presence of an appendage at either 

 extremity. 



290. This dualism has given rise to the formation of nume- 

 rous genera ; and in point of fact, under our present state of 

 knowledge, it is impossible to say whether such genera as 

 Sphwropsis, Diplodia, Sepitoria, &c., are ever autonomous. On 

 the same twig perithecia occur perfectly alike, though totally 

 different as regards fruit, and which it is impossible to distin- 

 guish without microscopic examination. One of the best 

 examples is, perhaps, Sp. mutila, with its numerous allies, all 

 of which at times produce naked spores as well as asci. At 

 present, 1 am by no means inclined to give up the whole mass 

 of sporophorous Sphoerim as mere secondary forms of fruit, 

 the ascigerous form being that which is normal. Besides 



