NOTES AND MEMORANDA. 177 



1845, under the name of ArtotroguSy might be this second 

 form of fruit. 



In 1861 De Bary published an investigation of the potato 

 disease, in which he described for the fii'st time the mode 

 in Avhich the filaments of the germinating spores penetrate 

 the potato plant. About the same time he also announced 

 that the sporidia (whicli had been first detected by Montague) 

 of the Peronospora were ciliated — were, in fact, zoospores. 

 Prevost, however, had discovered zoospores in the nearly 

 related genius Cystopus in 1807. 



In 1863 De Bary published an elaborate memoir ' On 

 Parasitic Fungi,' in which tlie history of the Peronosporecs 

 was carefully investigated. No one, however, has succeeded 

 in detecting the sexual mode of reproduction of the species 

 which infests the potato, and it remains to be seen whether 

 Professor de Bary will obtain under the auspices of the Iloyal 

 Agricultural Society the information on this important point 

 which lias hitherto eluded him. While all botanists will 

 look forward with interest to Professor de Bary's report, it 

 seems almost a matter for regret that the Society did not 

 endeavour simultaneously to enlist the aid of some English 

 niicroscopists in the investigation. It Avould, perhaps, have 

 been possible for the Council to request the botanical adviser 

 of the Society, who would necessarily be versed in '' the fungi- 

 of our farm crops," to report upon the subject, and to 

 associate with himself some of the not undistinguished crypto- 

 gamic botanists of this country, with a view of organizing 

 during the present year a systematic plan of investigation of 

 the resting stage of this terrible parasite. 



Mounting in Balsam. — Mr. W. H. Walmsley's success in 

 mounting objects gives great value to his practical suggestion 

 contributed to Science Gossip. He regrets that beginners 

 should be confronted Avith spring clips, spirit lamps, and 

 over-heated balsam, when balsam, dried to the point of 

 brittleness and then dissolved to the consistency of rich 

 cream in chemically pure benzole, would obviate the neces- 

 sity for such annoyances. He frees the specimen from 

 moisture by dryings or preferably by passing successively 

 through weak and absolute alcohol, treats it with oil of 

 cloves Avhich is more desirable than turpentine because 

 more readily miscible with balsam, and not calculated to 

 harden the specimens even if they are left in it for a long 

 time, transfers it to the slide, and arranges it with needles, 

 places a drop of the balsam solution on it and applies the 

 glass cover in the usual manner. In a few days the mount 

 will be sufficiently hardened to be handled with safety, espe- 



