32 BOOK-NOTES, IfEWS, ETC. 



pp. 321-3, by Mr. Wilmott, to whom specimens were sent by Mr. J. 

 E. Arnett, from North Pembrokeshire, on its discovery: a further 

 note will be found on p. 23 of this number. The other, Ajiicja 

 genevensis, was discovered by Miss Fry on the Berkshire downs 

 in May, 1918, where it is limited to a small area but appears 

 undoubtedly native. 



At the same meeting Prof. R. C. McLean made a communication 

 entitled " Sex and Soma." The author enlarged upon the recently- 

 discovered phase of multinucleosis in the developing soma cell of 

 higher plants. The genetic interest of the phenomenon has not 

 received sufficient consideration, and the present paper was designed 

 to direct attention to the possibilities involved. The author main- 

 tained, in opposition to Arber and Beer, that there is evidence of 

 nuclear reunions taking place in the multinuclear cells, and he 

 characterized these fusions as modified sexual conjugates consequent 

 upon the long series of vegetable divisions in the lineage of a soma 

 cell, and necessary to avoid the degeneration which experiment shows 

 to be attendant upon prolonged vegetative propagation. The develop- 

 ment of the plant body may thus be regarded as embracing two 

 phases of stimulus : firstly, the normal sex stimulus which initiates 

 the period of maximum cell proliferation, and, secondly, this somatic 

 nuclear union, initiating the period of maximum differentiation. 

 Tissue differentiation, it was suggested, ma}^ be associated with 

 some process of segregation subsequent to this nuclear fusion. The 

 separation of sex characters in the development of monoecious 

 organisms was pointed to as evidence of the existence of such segre- 

 gation during development. It was finally suggested that germinal 

 modifications as well as somatic segregations may be derived from a 

 mechanism of nuclear fractionization and subsequent partial reunion 

 in somatic cells. 



The post of Sherardian Professor of Botan}^ at Oxford, vacant by 

 the retirement of Dr. S. H. Vines, has been filled by the appointment 

 of Dr. Frederick William Keeble, F.R.S., of whose botanical career 

 some account was given in the Times of December 20. Dr. Keeble 

 has edited the Gardeners' Chronicle since 1908, and has contributed 

 reviews to our own pages. 



The Report for 1918 of the Botanical Exchange Club includes 

 what is evidently a useful monograph of the British Batrachia, by 

 Mr. W. H. Pearsall, and a supplement to the Flora of Berkshire 

 compiled by its author, Dr. G. C. Druce. 



The Journal of the Boyal Horticultural Society (xlv. pt. 1 : 

 October) contains an account by Dr. Daydon Jackson of Pritzel's 

 Index and of the forthcoming" new edition, which was referred to last 

 year in this Journal (p. 104). 



The Rev. W. Wilks has retired from the secretarj^ship of the 

 Royal Horticultural Society— a position which he has occupied with 

 conspicuous success since 1888. He is succeeded by Mr. W. R. 

 Dvkes, whose fine work on The Genus Iris was noticed m this 

 Jo\irnal for 1913, p. 103. 



