Ixviii PROCEEDINGS OF THE ROYAL HORTICULTURAL SOCIETY. 



photographs of plants on a large sensitive plate at frequent intervals, so 

 that the photographs could be shown continuously on a screen by means 

 of a cinematograph, and thus illustrate the nature and extent of the move- 

 ments performed by the different parts of plants. 



Potato Scab and Bhizocto7iia." — Mr. Gussow referred to the potatoes 

 covered with a violet web of fungal hyphae belonging to the fungus 

 Bhizoctonia shown before the Scientific Committee on October 24, 1905, 

 and reported upon at the meeting on November 7, 1905. See Journ. 

 E.H.S. xxxi. pp. Ixxxviii and Ixxxix, and said that he had been con- 

 ducting experiments, which showed that this fungus produces the well- 

 known scab disease on potatoes. See report in "Journal, Royal 

 Agricultural Society," vol. Ixvi. (1905), pp. 173-177, with figures. He 

 referred to some independent investigations upon the same fungus, carried 

 out by Mr. F. M. Rolfs, of the Colorado Agricultural College, whose 

 careful observations are published in "U.S.A. Experimental Station, 

 Colorado," Bulletins 70 and 91. These observations seem hitherto 

 to have escaped notice in this country. Mr. Rolfs has carried on his 

 observations during three years, and has placed it beyond doubt that the 

 fungus known as Bhizoctonia violacea is the cause of the potato scab in 

 America. He has also cleared up the mystery of the " sterile mycelial 

 fungus," as this has been called, by finding the fruiting stage, which 

 proves it to belong to the Hymenomycetes, and to agree with the fungus 

 called Corticium vagum. Dr. E. A. Burt calls it var. solajii of that 

 fungus. Thus a very interesting fact has been arrived at, and, although 

 Mr. Gussow is well aware of the numerous other fungi to which the scab 

 disease has been attributed, he considers there is no doubt that the real 

 cause has now been finally ascertained. It is interesting, said Mr. 

 Gussow, to observe that Mr. Rolfs succeeded in 203 cases out of 225 in 

 producing the disease from the basidiospores and the sclerotia of the 

 Corticium, and he finds that dipping the seed potatoes into a weak 

 solution of corrosive sublimate (1 oz. to 10 gallons of water) efficiently 

 checks the injury : a fact of great importance. 



Galls on Sjmice a7id Yew. — Galls on spruce and yew were shown by 

 Mr. Hooper. 



Fruits of Leucadendro7i. — Dr. Masters showed some fruits of the 

 silver tree, Leucadendron argenteum. The flowers are unisexual. The 

 abortive stamens in the female flowers are covered with long silky white 

 hairs, and are united at the base around the wiry style from which the 

 fruit depends, the style being prevented from passing through the hole 

 where the staminal lobes are joined by the button-like stigma. Thus the 

 whole forms a parachute apparatus by means of which the dispersal of 

 the fruit is assisted. 



Double Spathe in Anthurium. — Herr Froebel, of Zurich, sent a 

 specimen of the inflorescence of AntJmrium Scherzerianum in which the 

 spathe was doubled, the second and smaller spathe being separated from 

 the lower by an internode of about ^ in. The second spathe had not yet 

 expanded. 



Sporting in Calceolaria. — Mr. Shea drew attention to a curious 

 herbaceous Calceolaria shown by Mr. Riley, of Oakfield, Walton-on- 

 Thames, one side of which bore yellow flowers, while the greater part — 



