154 MICEOSCOPIC PtJNQl. 



leaves soon after the fungus makes its appear- 

 ance. 



At the period when this little volume was origi- 

 nally written and published^ the oogonia or resting- 

 spores of the potato mould had not been dis- 

 oovered. It is true that Montague had found 

 similar bodies which he called Artotrogus, but he 

 had no knowledge, and apparently no suspicion, of 

 their functions or relationship. Very recently, 

 however, similar bodies were again found in 

 diseased potato-leaves by Mr. Worthington Smith, 

 and these were, after much investigation and 

 careful manipulation, declared by him to be the 

 oospores of the potato disease. At this period, and 

 before any more complete information had been 

 obtained as to the ultimate development of these 

 resting -spores, some of the material containing 

 them was forwarded to Professor De Bary for his 

 opinion. After some little lapse of time, De Bary's 

 report made its appearance in the Journal of the 

 Eoyal Agricultural Society, and in this he distinctly 

 repudiates the bodies in question being the resting- 

 spores of the potato disease, and rather dis- 

 courteously taunted Mr. Smith with ignorance of 

 the subject which he had undertaken. It was then 

 too late to carry the examination further until the 

 next season ; this, however, soon arrived, and again 

 Mr. Worthington Smith resumed his work with the 



