xxvi PROCEEDINGS OF THE ROYAL HORTICULTURAL SOCIETY. 



Scientific Committee, February 24, 1903. 

 Dr, M. T. Masters, F.R.S., in the Chair, and fourteen members present. 



Chrysanthemum diseased. — Mr. Michael reported on specimens sent 

 that there were only one or two aphides, but sections showed abundance 

 of eel worms, which had caused the injury. 



Cypripedium Fairieanum Hybrids. — With reference to the fact that 

 hybrids of this plant refuse to cross with each other, Mr. J. Douglas, 

 Y.M.H., sent the following communication : — u Some remarks were 

 made at a recent meeting on crossing Cypripediums, and a mis- 

 understanding arose thereupon. It was stated as a fact, and so far as 

 I am aware the statement is correct, that hybrids of C. Fairieanum will 

 not cross with each other. C. Fairieanum is so scarce a plant in Britain 

 that with the exception of a small plant in the collection of the President 

 of the Royal Horticultural Society I am not aware of any other. Con- 

 sequently hybridists are anxious .to obtain seedlings with as much of the 

 character of this scarce variety as possible. They have made many attempts 

 by recrossing the C. Fairieanum hybrids in existence, but have always 

 failed, although other hybrid Cypripediums will cross with C. Fairieanum. 

 For instance, G. cenanthum superbum crossed with C. Fairieanum 

 produced a very scarce and beautiful variety, 1 Baron Schroder ' ; C. vexil- 

 larium was obtained by crossing C. barbatum with C. Fairieanum, and 

 this hybrid on being crossed with C. bellatulum produced C. bellatulo- 

 vexillarium, but C. vexillarium was the pollen parent. The object of 

 bringing this matter before the Committee is to ascertain why it is 

 that, if other hybrid Cypripediums will cross with each other, C. vexil- 

 larium will not cross with C. 'Niobe,' or why C. 'Juno' will not cross 

 with C. Arthurianum, or any other of the numerous ways in which the 

 G. Fairieanum hybrids may be crossed with each other. The pollen is 

 potent enough if used on other species of Cypripediums." 



Parasite on Daphne Mezereum. — Dr. Cooke sent the following report : 

 " The mould on twigs of Daphne Mezereum, brought by Mr. Holmes on 

 January 13, consists of dense tufts of Polyactis with coloured hypha? and 

 elliptical spores, probably Polyactis cana. In each instance there 

 appears to have been a wound in the bark, upon which the mould 

 became established, but originally it was saprophytic in its habits. Like 

 others of the genus, it may become parasitic, but in this instance there is 

 no indication of its having injured the plant whilst sound, but to have 

 attached itself to wounds already existent." 



Alcohol from Sawdust. — Mr. A. Rickmann wrote to inquire for in- 

 formation as to the probable cause of the difference in the behaviour of 

 Pine and Oak wood sawdust in Europe and in America. The process of 

 the manufacture of alcohol from it being identical, the result was that 

 10 per cent, less of alcohol was obtained in the United States than at 

 Aix-la-Chiipelle. The names of the trees of which the wood was employed 

 were not mentioned, but the Committee agreed with Mr. Rickmann's 

 ii.L'.L'fstion. thai "tin American wood must be in it- component parts 

 different from wood grown in Europe, in a similar manner as American 



