1^6 NOTJES AND MEMORANDA. 



ppse to all miscroscopists, by enabling them to label all slides 

 at once -with the minimum expenditure of time and trouble. 



I tried, but without success, to discover where a sand-blast 

 for etching glass was to be found in operation; for this 

 would obviously be the most simple means of roughening the 

 ends of the slides. Frederick J. Hicks. 



The Potato Disease. — From a statement in the * Agricultural 

 Gazette' (February 7th, 1874, p. 185), a sura of £100 

 appears to have been granted to assist Professor de Bary, 

 of Strasburg, in the investigation of the life-history of the 

 potato-fungus [Peronospora infestans). In the next number 

 an explanation was published (p. 210) from Mr. Jenkins, 

 the Secretary of the Society, of the grounds which had induced 

 the Council to take this step. It is as follows : 



"The scientific aspect of the potato disease also received 

 the careful attention of the judges of the essays, and in their 

 report to the Council they expressed their regret that no 

 essayist appeared to be acquainted with the most recent 

 discoveries in that field of inquiry. They therefore recom- 

 mended the Council to grant a sum of money for the pur- 

 pose of inducing a competent mycologist to undertake a 

 special investigation into the life-history of the potato- 

 fungus. The Council have adopted tliis course also; and it 

 is most gratifying to be able to announce that Professor de 

 Bary, of Strasburg, the highest living authority on the fungi 

 of our farm crops, and especially on the potato-fungus, has 

 undertaken this important investigation." 



It may be interesting to recapitulate the present state of our 

 knowledge of the Peronospora. It was first described by 

 Montague in 1845. In the following year Berkeley pub- 

 lished a paper in the 'Journal of the Horticultural Society,' 

 in which he gave the drawings which Montague communicated 

 to him for the purpose, in addition to those of himself and 

 Broome. At that time Berkeley in this country and Morren in 

 Belgium stood alone against the whole weight of eminent 

 botanical authority, in regarding the Pcronosp>ora as the cause, 

 and not the effect, of the potato disease. This paper established 

 the general habit of the fungus, and also described its 

 asexual spores. 



In 1854 Tulasne published in the ' Comptes Rendus' his 

 discovery of the oospores or resting spores resulting from the 

 sexual reproduction of the Peronosporecp.. Down to the 

 present day, however, this has never been verified in the case 

 of Pcronospora infestans, although Berkeley, as long ago as 

 1857, suggested that a fungus described by Montague in 



