March 9^ 19 16] 



NATURE 



51 



I supplements and confirms the author's previous de- 

 \ scription of the skull of a Dicynodon {Phil Tratis., 

 B., vol. cciv., 1913). — W. L. Balls: Analyses of agri- 

 cultural yield. Part iii. — The influence of natural 

 environmental factors upon the yield of Egyptian 

 cotton. A discussion is given of all existing' data for 

 the behaviour of the Egyptian cotton crop under the 

 . conditions of field cultivation during five years as 

 analysed by the author's method of plant-development 

 : curves. The term pre -determination is given to the 

 fact that a fluctuation may be due to causes acting at 

 some date long prior to its visible appearance. Thus 

 •' daily fluctuations in rate of flowering are due to 

 environmental conditions existing a month beforehand. 

 Many other reactions of crop to environment are in- 

 , explicable unless allowance is made for pre-determina- 

 tion. It is shown that there is no factor of " season " 

 as such. The action of such factors as weather and 

 i climate, soil-water and soil-fertility, are differentiated 

 and traced in the various curves. The predominant 

 ! influence of an autumnal rise of water-table in deter- 

 ] mining yield of crop is indicated, and the sensitivity 

 of the plant to root-asphyxiation is shown. A dis- 

 ; cussion of the function of the root-system, and of the 

 i importance of the factors operating through it, is made 

 i possible by the nature of the data. The factor of 

 ; varietal constitution is shown to be of relatively in- 

 ; significant importance, as compared with environ- 

 ■ mental factors, in determining vield of crop. The 

 : results of these three analyses show that vield of crop 

 : can be studied physiologicallv as vield of an average 

 i plant by statistical records of development, and these 

 can be satisfactorily interpreted in terms of the limit- 

 1 ing factors of environment, reacting upon inherited 

 1 genetic properties of plant, provided that the pheno- 

 I menon of predetermination is taken into account. — 

 A. J. Ewart : The function of chlorophyll, carotin, and 

 xanthophyll. In the assimilation of carbon dioxide 

 chlorophyll acts as a light energising enzyme. It 

 takes direct part in the cycle of chemical changes which 

 j have xanthophyll as an intermediate product, and 

 glucose, levulose, formaldehyde, and oxygen as end 

 i products. Most of the sugar is formed directly and 

 not through the medium of formaldehyde. A large 

 part of the energy represented by this sugar is absorbed 

 during the reconstruction of the chlorophyll molecule. 

 Apart from its protective function, carotin seems to 

 be especially important as providing, during its photo- 

 oxidation, the massive hydrocarbon combination in the 

 phytyl radicle of chlorophyll, the addition of which is 

 necessary to convert the dicarboxylic glaucophyllin into 

 . the tricarboxylic chlorophyll. Carotin and xanthophyll 

 ! are mutually transformable by the aid of metallic oxy- 

 • dases and reductases respectively. Oxidation in dark- 

 I ness is not necessarily the same as that taking place in 

 light. An emulsion of carotin in light in the presence 

 of copper sulphate and salt develops reducing sugar 

 and formaldehyde, whereas in darkness, although 

 slowly oxidised, no sugar or formaldehyde is produced. 

 The oxidation of chlorophyll, carotin, and xanthophyll 

 ; is more rapid at high temperatures than at low ones. 

 I Zoological Society, February 22.— Dr. A. Smith 

 Woodward, vice-president, in the chair. — B. F. 

 ' Cnmmings : Report on a collection of Anoplura and 

 Mallophaga obtained from animals in the society's 

 : gardens. The author dealt with the structure and 

 dev^elopment of the various species, and gave descrip- 

 I tions of three new forms.— Dr. P. Chalmers Mitcliell : 

 t Further observations on the intestinal tract of 

 mammals. 



Cambridge. 

 Philosophical Society, February 21.— Prof. Newall, 

 president, in the chair. — Dr. Do'ncaster : Some gynan- 

 dromorphic specimens of Abraxas grossttJariata. In 

 NO. 2419, VOL. 97] 



1915 two specimens of A. grossulariata were bred 

 which showed a mixture of male and female charr 

 acters. Both were from matings of grossulariata 

 female by lacticolor male. The specimen which was 

 predominantly male was lacticolor, although only 

 grossulariata males are expected from this mating, 

 and the predominantly female specimen was grossu- 

 lariata, where lacticolor females are expected. Reason 

 was given for supposing that previously reported ex- 

 ceptions to sex-limited transmission may have been to 

 some extent gynandromorphic. — L. Harrison : A pre- 

 liminary account of the structure of the mouth-parts 

 in the body-louse. The stomatodaeum of Pediculus 

 comprises a buccal cavity, pumping-pharynx, pharynx, 

 and oesophagus. Upon the floor of the buccal cavity 

 opens a long diverticulum, containing two piercing 

 stylets and a chitinous salivary duct. A hitherto un- 

 described structure, the buccal tube, formed of two 

 apposable half-tubes rising from the floor of the buccal 

 cavity at its junction with the pumping-pharynx, car- 

 ries blood to the latter. It is suggested that this buccal 

 tube and the whole of the piercing apparatus are 

 derived by modification of the Mallophagan hypo- 

 pharynx, and that the Anoplura have no close affinity 

 with the Rhynchota. — E. H. Neville : The field and the 

 cordon of a plane set of points. 



Paris. 

 Academy of Sciences, February 21. — MM. Ed. Perrier 

 and d'Ansonval in the chair. — L. Maquenne : The pre- 

 sence of reducing substances in commercial sugars 

 other than invert-sugar. It is shown that known 

 quantities of invert-sugar added to pure cane-sugar 

 can be accurately determined by the methods described 

 by the author in previous communications, working 

 either at 65° C. or 100° C. On the other hand, com- 

 mercial sugars, both crude and refined, show appre- 

 ciable differences in the invert-sugar obtained irom 

 analysis at these two temperatures, and this is held 

 to be due to the presence of other reducing substances. 

 — Pierre Duhem : The electrodynamics of dielectric 

 media. — A. Khintchine : An extension of Den joy's in- 

 tegral. — Ed. Sarasin and Th. Tommasina : Study of the 

 Volta effect by induced radio-activity : proof of two 

 new facts. It is established that, either in the case 

 of electrodes separated by air containing emanations 

 and the radiations of induced radio-activity, or in 

 that where the electrodes (of different metals) are in 

 direct contact, but in contact also with induced radio- 

 activities and always under the influence of an electro- 

 static charge, there is a production of current. The 

 radio-active medium in these experiments behaves 

 sunilarly to the electrol)rte of a battery. — ^Thadee 

 Peczalski : The law of integral radiation and the yield 

 of light of metals at high temperatures. The law of 

 integral radiation of tantalum is found by experiment 

 to be E='t1^"-. Graphite sensibly follows Stefan's 

 law ; and its emissive power corresponds to that of 

 a black body. — C. Benedicks : A new thermo-electric 

 method for the study of the allotropy of iron and 

 other metals. The wire under examination is moved 

 at a constant velocity (i-6 mm. per second) through a 

 small electric furnace maintained at a constant known 

 temperature, and measurements made of the electro- 

 motive forces developed. Iron shows clearly the point 

 A,, but no discontinuity was found for the point A.. — 

 Leon Berard and Auguste Lumiere : Retarded tetanus. 

 Commenting on a recent note on this subject by M. P. 

 Bazy, the authors have noticed cases of tetanus de- 

 veloping 84, 90, and 102 days after the wound. It is 

 recommended that a fresh dose of antitetanus serum 

 should be administered every time a surgical operation 

 is made, as such an operation may provoke the libera- 

 tion of septic products latent in the suspected wounds. 



