xcii PROCEEDINGS OF THE ROYAL HORTICULTURAL SOCIETY. 



B. Ugandea by Mr. R. A. Rolfe. At first sight it reminds one of 

 Hahenaria, with its long spurs and peculiarly shaped flower. 



The colour is light green except upon the column, which is white ; 

 and Mr. Brown tells us that practically the whole flower is pure white 

 in its native habitat. It was found growing with plants such as one 

 usually assigns to the cactus house, and probably the plants in this 

 country have been grown under too moist conditions, which may cause 

 a slight variation in colour. Until recently the genus Bonatea was only 

 represented by B. speciosa, a native of South Africa. It is not often 

 seen in flower, and has the reputation of being a bad grower ; but 

 B. Ugandece promises to be a stronger plant. At present it is exceedingly 

 rare : the only living specimens known in this country are two plants in 

 the rich collection at Kew, and a few tubers that are in the possession 

 of Mr. Brown. 



On the motion of Mr. C. T. Druery, seconded by Mr. Bennett-Poe, it 

 was unanimously awarded a Botanical Certificate. 



Plant Diseases. — Specimens of diseased violets from Exeter and 

 Northwich, and celery from Colyton, were received, and will be reported 

 upon at the next meeting. 



Scientific Committee, Xovembee 20, 1906. 

 Dr. M. T. Masters, F.E.S., in the Chair, and fifteen members present. 



Spotting in Apples. — Mr. Giissow said : — " The apples brought before 

 the Committee on October 23 by Mr. Worsley showed externally a number 

 of depressed spots. "When cut, discoloration s of the tissues correspond- 

 ing with the external pits were noticeable ; also a number of brownish spots 

 distributed all over the cut surface. To the naked eye the appearance of 

 the spots was spongy. The taste of the apple was distinctly bitter. This 

 injury renders the sale of the apples impossible. The cause of the spots 

 finds an explanation as follows : The injury is most prevalent in dry 

 seasons, and confines itself generally to fruits with softish flesh. Those 

 of a firm, hard flesh rarely show these spots. ^Yhen in dry seasons the 

 flow of organic materials necessary for the full development of the fruits 

 is interrupted, several groups of cells will remain poor in reserve food, and 

 much sooner become exhausted. This exhaustion manifests itself by a 

 brownish discoloration of the tissues. The beginning of this injury 

 evidently takes place in the early stages of the developing fruit. One 

 generally finds the cell tissues, when viewing them under the microscope, 

 of a corky nature, and filled with small colonies of starch granules, whilst 

 in the healthy tissues the starch has been already transformed into sugar. 

 The brown tissues are frequently torn. The explanation of this is simple. 

 During the growth the normal tissues only develop, and when normally 

 expanding, the injured cells, which on account of their dry and corky cell 

 walls have become inflexible, are torn. The manifestation of life is stopped 

 in these cells, and the change of the starch granules into sugar cannot 

 take place. The remedy for this injury is a supply of water, to be repeated 

 at intervals during the dry season. It has been found that when nitro- 

 genous manure had been applied the apples showed more signs of injury 



