December 23, 1920] 



NATURE 



551 



diversity in many cases of chemical reactions in 

 closely related forms. 



Dr. F. F. Blackman contributed a paper on "The 

 Biochemistry of Carbohydrate Production in Plants 

 from the Point of View of Systematic Relationship," 

 in which the distribution of the primary products of 

 the photo-reduction of CO, in different groups of 

 plants was traced, pentoses being the basis of the 

 succulent habit, and the diversity of the condensation 

 products, saccharose, starch, and inulin, was con- 

 sidered in relation to species and families. Emphasis 

 was laid upon Reichert's work on the individuality 

 of the starch-grains of every species of plant, and of 

 its bearing on the chemical specificity of protoplasms. 

 Prof. G. H. Nuttall followed with a paper entitled 

 ■' Precipitin Reactions as a Means of Determining 

 Systematic Relationships in .\nimals and Plants," in 

 which it was pointed out that both animal and vege- 

 table albumins retain certain chemical properties 

 which persist, while the animal or plant to which they 

 belong undergoes a phylogenetic morphological 

 change, and that qualitative precipitin tests carried 

 out with different albumins give a measure of the 

 degree of relationship existing between forms that 

 have descended from a common stock. The contribu- 

 tion of Mr. J. Rarrroft (president of Section I) cor- 

 nlated the properties of the oxygen-carrying power 

 of blood, essentially the properties of hicmoglobin, 

 with the functions and habits of the animal in ques- 

 tion rather than with its phylogeny, comparing in 

 particular the oxyh.-rmoglobin equilibrium of fishes 

 living in different habitats. 



The semi-pooular lecture which has become a 

 feature of the Botanv Section was delivered this year 

 bv Prof. Chamberlain, who came from Chicago to 

 do so at the invitation of the committee. His eye- 

 witness account of his adventurous acquaintance with 

 the Cvcads of the world delighted the audience no 

 less than the beautiful lantern-slides which accom- 

 panied it. 



.Amongst other descriptive accounts of vegetation 

 may be mentioned that of Prof. Chodat on some 

 ;ispects of plant ecology and biology in Paraguay ; 

 that of Mr. Kingdon Ward on the distribution of 

 floras in south-east .Asia as affected by the Burma- 

 ^■unnan Ranges ; that of .Mr. Patton on the vegeta- 

 tion of Beinn Laiogh ; and, lastly, a lantern demon- 

 stration of the Eastern Canadian Rocky Mountains 

 bv Prof. F. J. Lewis. Vegetation and soil surveys 

 formi-d the subject of the joint meeting between 

 the .Sections of Holanv and .Agriculture, presided over 

 bv Prof. Keeble, president of the latter Section. 

 Mr. G. W. Robmson dealt with the soil types of 

 .North Wales as revealed in the soil survey of recent 

 years, and Mr. G. A. Fisher with soil acidity. Mr. 

 Robinson suggested that, while uniformity in 

 .sampling and analytical methods should be secured, 

 the classification of soils must depend on local condi- 

 tions. In extreme humid conditions it would appear 

 that differences due to geological factors tend to be 

 obliterated. I-arge numoers of soil samples should 

 I'd, anil the types worked out from actual 

 .ns; correlation with geology may follow 

 .iinru.iriis. The soil survey gives informntljn 

 as to ont of the factors affecting plant-growth and, 

 ultimately, agriculture in a particular area. The 

 survey in its widest sense should take cognisance of 

 ;ill the other factors, including climate and soil-water 

 conditions. The vegetation survey give* th« results 

 of the operation of all these factors. 



Miss Wortham gave an account of the results of 

 her survey of Anglesey and North Carnarvonshire, 

 with special rrfi-rrnre to the grass-Iands, and showed 

 that the plant-formation* are closely related with the 



NO. 2669, VOL. 106] 



geological structure of the district. She traced the 

 origin of grass-lands from upland moor, from wood- 

 land, and from the degeneration of lowland moor. 



The botanical part of the discussion centred 

 especially round types of grass-land, their importance 

 in Wales and in general in agriculture, the possibility 

 of fixing on some standard, symbols of colours for 

 ecological mapping, and the correlation of the various 

 surveys. Prof. Stapledon, after discussing Festuca 

 agrostis pastures in detail, laid stress on the need for 

 a colour scheme which would allow of the representa- 

 tion of transition types. He also took up the question 

 of the difficulties of the representation of arable, and 

 suggested the possibility of using the weed flora in 

 this connection. lastly. Prof. Stapledon emphasised 

 the immediate importance of hastening on the primary 

 vegetation survey. As a result of the discussion, in 

 which Sir Daniel Hall, Mr. T. J. Jenkin, Dr. E. N. 

 Thomas, Mr. Morrison, and others took part, it 

 became obvious that there existed a great need for 

 co-operation among workers and more codification of 

 observations. Steps were initiated with the view of 

 bringing about this end. 

 _ The subject of geotropism, which has received con- 

 siderable attention during the last few years, was 

 considered on the Wedne.sday afternoon, when Dr. 

 Harold Wager gave a paper on the geotropism of 

 foliage leaves and their possible dia-gcotropism. In 

 a contribution entitled "Further Evidence for the 

 Differentiation in Hvdrion Concentration in Stem and 

 in Root as the Explanation of Positive and Negative 

 Geotropism," Prof. Small, in collaboration with Miss 

 Rea. further developed his theorv of the CO, balance 

 as the cause of this differentiation in behaviour. 



The only contribution to fossil botany was furnished 

 bv a paper by Mrs. Clement Reid on the history of 

 the West European Pliocene flora as deciphered by 

 the study of fossil seeds, in which, by the critical 

 comparison of percentages which were then plotted 

 as a curve, she demonstrated very clearly that seeds 

 may be used to determine species and with strong 

 probability for zoning purposes. Since Mrs. Reid's 

 conclusions agree with those furnished by ^imal 

 palaeontology for known ages, they can be used for 

 one unknown. The deductions from the curve based 

 on the numerical study of plant species also agree 

 with, and therefore support, many conclusions arrived 

 at by stratifraphiral and other evidence. 



The president expressed special interest in a paper 

 by Miss Blackburn on anomalies in microspore 

 formation in Rosa and its possible connection with 

 hvbridity in the genus. The normal process had been 

 examined in three species. .Abnormalities were 

 described in ten forms, two of which were known to 

 be hybrids. The results suggested the possibility of 

 determining the genetic constitution of forms by 

 an examination of cytological phenomena. 



Probably the most outstanding contribution of 

 original work was supplie<l by Prof. Lloyd Williams, 

 who fave a detailed account of his researches Info 

 the life-history of the I^Tminariace.T, which demon- 

 strated the existence of alternation of generations 

 throughout the group. 



Great interest was expressed in the progress 

 reported by Mr. Martineau on the growth of pit- 

 mound plantations in the Midlands, and a resolution 

 was proposed bv .Sir Daniel Morris, seronde<l by Prof. 

 Henrv. and passed unanimously, urging State sup. 

 port for similar experiments in other parts of the 

 country. 



Notwithstanding the short time .md crowded pro- 

 gramme, the botanists were able to see something of 

 the vegetation of the neighbourhood on their ex|>odifions 

 to the very beautiful country surrounding Cardiff. 



