106 PROCEEDINGS OF THE SOCIETY. 



that it received the full force of a stream of water falling about 2 feet. 

 It proved to be new, and was described as G. Scourfieldii. 



Mr. Scourfield then called attention to three specimens of the new 

 species which he was exhibiting. 



Under one microscope was a mounted specimen of a free growth 

 of this alga, which took place in a Petri dish, in which some little 

 pieces of the lime-incrusted specimen were placed. 



Under another microscope could be seen an edge view of a piece of 

 the incrusted alga, showing that it grew somewhat spasmodically. A 

 layer of intense growth, represented by the amount of chlorophyll 

 in the algal threads, was succeeded by a layer of carbonate of lime 

 without so much chlorophyll in the threads penetrating it ; then,, 

 again, there was more chlorophyll in the threads, and so on, causing 

 a banded appearance. He did not think the alternating bands re- 

 ])resented long seasonal periods, but there was evidently some periodic 

 difference in the intensity of growth of the alga and the deposit of 

 lime. The incrusted specimen was not now of the vivid green it wa& 

 when first collected ; at that time it looked like a piece of polished 

 malachite. 



Under a third microscope a decalcified section of the incrusted 

 specimen was shown. 



Mr. Paulson asked how long Mr. Scourfield had had the alga grow- 

 ing in a free state. He assumed that it was growing in water con- 

 taining no great proportion of lime, and it would be interesting to know 

 whether any difference had been noticed in the growth, or whether the 

 piece now being shown was exactly like the plant as he got it when 

 dissolving the lime away. 



Mr. Scourfield replied that he thought there might be slight dif- 

 ferences between the decalcified specimen and that grown freely. The 

 latter had been growing for a month or so, and in water containing a 

 good deal of lime, in ordinary tap-water in fact. 



The Meeting accorded a vote of thanks to Professor West for hi& 

 paper. 



Prof. W. Bateson, M.A. F.R.S., then gave an address on " Cytology 

 and Genetics," in which he said that attempts to find regularity in the 

 distribution of chromosome numbers had generally been unsuccessful ; 

 but called attention to the recent work of Winge, who, by preparing a 

 graph of these numbers in plants, had shown that simple multiples of 

 two and three occur with special frequency, while prime numbers are 

 rare and exceptional. A survey was given of the phenomena of linkage 

 between genetic factors as demonstrated in breeding experiments, with 

 a discussion of Morgan's suggestion that this linkage is due to a linear 

 arrangement of the linked factors in the same chromosome. Whether 

 the proposition in its entirety was established or not might be doubtful, 

 but the factors certainly behaved as if arranged in lines, and, a& 

 represented by the theory, a great diversity of genetic and cytological 

 observations relating to the heredity of sex and other characters assumed 

 an orderly form. 



