242 
The London Botanical Society. 
generations is only 5%, and the probably error of a standard 
deviation (based on 1000 observations) is approximately 2%. 
So far as they have gone then, Professor Jobannsen’s results do 
not seem in any way to contradict but rather to support the 
hypothesis of continuous variation. The results of succeeding 
generations will be awaited with a good deal of curiosity, if, as is to be 
hoped, the breeding of the “ pure lines ” is continued in such a way 
as to enable the above view as to the gradual approach towards the 
behaviour of an ordinary race to be tested ; whether the view be 
confirmed or disproved it is equally desirable to have the experi¬ 
mental evidence. 
Professor Johannsen’s work is certainly one of the most 
important contributions to the theory of heredity of recent 
years, and his results should be studied and judged in the original 
by all who are interested in the subject. The mode of treatment is 
novel, and the study of “pure lines” a thoroughly sound procedure 
well calculated to elucidate the nature of intraracial heredity. One 
may add that the refreshing width of sympathy and sobriety of the 
author’s style contribute not inconsiderably to the pleasure of the 
reader. 
THE LONDON BOTANICAL SOCIETY. 
1 1HE November Meeting of this Society was held on Friday, 
November 20th, Mr. Percival being in the Chair. 
Mrs. Scott exhibited the cinematograph camera which she/uses 
in taking successive photographs of moving parts of plants, and 
explained her method of work. It was found that the ordinary 
cinematograph camera with a continuous series of films was un¬ 
suitable for the purpose. The type used had a large circular 
sensitive plate on which the photographs were taken in a spiral 
series. The greatest difficulty is the different exposures necessi¬ 
tated by the variations in the lighting of the object, since the series 
has to be spread over a considerable time. Another difficulty is 
keeping the object in the field, especially in the case of a growing 
shoot. That these and the numerous other technical difficulties 
met with had been to a large extent overcome was proved by the 
specimens of her work which Mrs. Scott shewed on the screen. 
Among the best of these was the series shewing the opening of the 
flowers of Spannannia africana . 
