SECTIONAL TRANSACTIONS.— K. 421 



SECTION K.— BOTANY. 



Thursday, September 2. 



Presidential Address by Prof. E. J. Salisbury, F.R.S., on The modern 

 study of plants iti relation to education (lo.o). 



Sir Arthur W. Hill, K.C.M.G., F.R.S.— The Botanic Garden, 

 Buitenzorg, Java (11.5). 



Prof. Dr. A. J. Kluyver. — On the luminescence of bacteria (11. 15). 



A report on some results obtained by a biophysical research group, under 

 the direction of Ornstein and Kluyver, in investigations on the luminescence 

 of bacteria. The aim of the work is to get a general insight into the factors 

 which determine the emission of visible light by luminous cells. In the 

 first place careful quantitative determinations of the energy distribution over 

 the various wavelengths were made. The results led to the conclusion 

 that to all probability the spectrum emitted may be reduced to two sym- 

 metrically broadened fundamental frequencies. A study of the spectra of 

 two different chemoluminescent reactions, proceeding in an aqueous 

 medium, yielded analogous results, partly the same frequencies being 

 encountered. Moreover an analysis of the fluorescence spectrum of flavin 

 showed that this spectrum may be considered as one symmetrically 

 broadened fundamental frequency, this being one of the fundamental 

 frequencies present in all bioluminescence spectra studied. This result 

 offers an indication that flavin, a compound of quite general occurrence in 

 living cells, may in some way be connected with the light emission. 



Secondly, experiments were made in which the influence of various 

 poisons both on oxygen consumption and on light emission was studied. 

 By adding suitable quantities of cyanide to the medium, a region was found 

 in which the light emission is linearly dependent on the oxygen consumption, 

 thus giving definite proof that, in agreement with a widely spread assumption, 

 oxygen indeed takes part in the process which ultimately is responsible for 

 the light emission. 



Also this result points to the co-operation of flavin, as a component of 

 the yellow respiratory enzyme, in the light emitting reaction. 



Dr. M. J. SiRKS. — Plasmatic inheritance (11.45). 



By the very impressive character of Morgan's theory of genes as localised 

 in the chromosomes, the majority of geneticists have been led to confine their 

 attention to the role of the genes, while the plasm is entirely neglected. 

 Those geneticists forget that the genes as such can show their action in the 

 phenotype only by means of the plasm instrumentality. A number of 

 cases have been observed in which the plasm plays a role as a counterpart 

 to the genes. These results may be grouped as follows : 



(i) an afterworking by the nature of the eggplasm whereby in the embryo 

 characters are fixed before the newly constructed genotype of the fertilised 

 nucleus can show its influence (Correns, Matthiola ; Boycott, Limnaea) ; 



(2) an entirely independent action of the plasm in the production of 

 characters without any influence of the genotype (chlorophyll ; Wettstein, 

 mosses ; Schlosser, osmotic values) ; 



