166 MICEOSCOI'IC FUNGI. 



power, as a drop of water is let fall at tte edge of 

 the cover and insinuates itself, by capillary attrac- 

 tion, between the two plates of glass. So soon as 

 it touches the moniliform threads, the disunion 

 commences, and- almost before they are enveloped 

 in the fluid, two spherules will scarce remain at- 

 tached to each other. This delicate little mould 

 on the grass leaf at one time bore the name of 

 OidAwm monilioides. It is now regarded only as a 

 condition of another minute fangus, to which at- 

 tention will shortly be directed. 



The vine disease, so fearfully destructive on the 

 Continent, and not altogether unknown in this 

 country, is another of these incomplete fungi. 

 From an individual who at the time of its first 

 discovery in the south of England took consider- 

 able interest in the subject, it was called Oidmrni 

 Tuckeri, which name it continued to bear, both 

 here and abroad, until, with many others, probably 

 nearly all of the same genus, it was found to be 

 only a barren state of what is called by mycologists 

 an Erysiphe. The real discoverer of -this mildew 

 was undoubtedly the Rev. M. J. Berkeley, who has 

 successfully devoted a long life to the study of 

 these minute organisms, through evil and through 

 good report, and when that study was beset with 

 more difficulties, and received less encouragement 

 than at present. If, towards the autumn, we should 

 again collect some whitened, mouldy, or mildewed 

 grass-leaves, similar in appearance to those men- 



