November 3, 1923] 



NATURE 



675 



and N. Bezssonoff : The influence of the sugar con- 

 centration of the media on the activity of nitrogen 

 fixing bacteria. Both for the development of the 

 aerobic baciUi in a non-nitrogenous medium and for 

 the fixation of nitrogen in those possessing this 

 property, low sugar concentrations of the order of 

 I in 1000 are more advantageous than those usually 

 employed. — M. Lemoigne : The butyleneglycolhc 

 fermentation of calcium lactate by bacteria of the 

 B. subtilis group. The formation of 2-3-butylene- 

 glycol and acetylmethylcarbinol by the action of 

 bacteria of the B. subtilis group on calcium lactate 

 has been proved. The action is slow and difficult 

 to detect. — H. Barthelemy : The action of water, 

 common salt, sodium bromide, and calcium chloride 

 on the spermatozoids of Rana fusca and Biifo 

 vulgaris. — A. Weber : Does the rupture of the 

 branchial operculum at the moment of metamorphosis 

 of Batrachians demonstrate the transmission of an 

 acquired character ? 



Vienna. 



Academy of Science, July 12. — R. Wettstein, 

 president, in the chair. — Fritz Fruchtl : A contribu- 

 tion to the knowledge of the qualitative and quanti- 

 tative distribution of Copepoda in the Plankton of the 

 North Adriatic and of their ectoparasites. The use 

 of graphic representation in distribution-maps. — 

 Gerhard Kirsch and Hans Pettersson : On the 

 destruction of atoms by a-particles. A study of the 

 H -particles produced when atoms are destroyed by 

 swift a-particles. The ranges of the atomic frag- 

 ments (H-particlcs) are 18 cm. for beryllium, 12 cm. 

 for silicon, 13 cm. for magnesium in air. The ratio 

 between the H-particles produced and the number of 

 a-particles employed is about lo"* for beryllium, 

 6xio"* for silicon and magnesium. — J. Hepperger : 

 On the heliocentric velocity of meteors. Theoretical 

 representation of the relative numbers of the frequency 

 of meteors. Assuming the heliocentric velocity of 

 the meteors to amount to 74 km. per second, the 

 number of meteors per hour ascertained by observa- 

 tion may be made to agree witli the relative numbers. 

 — Julius Zellner : Contributions to comparative 

 phytochemistry. Chemical analysis of the leaves and 

 flowers of Knautia sylvatica. — Konstantia Piiringer : 

 Chemical analysis of the leaves and flowers of Cham- 

 (snerion angustifolittm. Quantitative determinations 

 show agreement in constitution for leaves and 

 flowers.— Chaja Feinberg, Johann Herrmann, I^o- 

 poldine Rogelsperger, and Julius Zellner : Chemical 

 analysis of the bark of Acer campesire, Corylus 

 Avellana, and Alnus incana. — Josef Einleger, 

 Jolanthe Fischer, and Julius Zellner : Chemistry' 

 of heterotrophic Phanerogam ia. Loranthus was 

 chemically analysed for the first time. Elements 

 have been found in Viscum not previously recog- 

 nised. — Hans Przibram (i) : A critique of the trans- 

 plantation experiments made by R, G. Harrison. 

 The rudiments of the anterior limbs of axolotl 

 embryos, if excised and implanted in the same or 

 neighbouring situations upside down (with dorsal 

 and ventral surfaces reversed), develop into extremi- 

 ties which have the symmetry of limbs belonging to 

 the opposite side of the body. These experiments 

 do not prove a change of the upper side of the rudi- 

 ment into an under side by the influence of the body 

 ;i.s a whole. It is an inversion of the polarity of the 

 extremities, which grow proximally instead of distally. 

 The inversely tran.splantcd rudiment is impeded m 

 the original direction of its growth by the adjacent 

 l)arts of the body. (2) The causes of animal colour- 

 ing. The presence of " dopa " (3, 4-dioxyphcnyl- 



NO. 2818, VOL. I 12] 



alanin) in the cocoons of night-butterflies and saw- 

 flies causes spontaneous formation of melanine when 

 water is admitted. Wliile in the case of day-butter- 

 flies the sensitiveness to light of the tyrosinase- 

 ferment plays a part in the adaptation to the bright- 

 ness of the background, the adaptation of the night- 

 butterflies is caused by the degree of moisture. The 

 cocoons acquire a dark colouring on a moist, dark 

 background. — Alfred Ehrenpreis (i) : Curvature of the 

 neck of the larva when the animal pole of the ovum 

 of Triton alpestris, Laur., has been punctured. By 

 puncturing the animal pole of fertilised, but still un- 

 segmentated, ova of Triton alpestris, Laur., Przi- 

 bram 's hypothesis has been confirmed that the 

 prospective signification of the animal half of the 

 ovum is in tlie formation of dorsal parts of the 

 embryo. An animal developed so far as to form a 

 larva, after puncture had its head bent dorsally at 

 almost a right angle, owing to a deep indentation 

 in the neck due to the puncture. (2) Transplantation 

 of the sperm of full-grown Urodelaj. Successful 

 transplantation of the whole sperm of Triton Cristatus, 

 Laur., by the autophorous method of Przibram. 

 The transplanted spermatozoa were in good condition 

 even four months after the operation ; their functions 

 were normal. The formation of the spermatophore 

 was completed in eighteen days. — August Jellinek 

 and Theodor Koppanyi : Mental capacity of rats 

 with an injured brain. Kinaesthetic and optical 

 experiments in training rats, the cortex of the cere- 

 brum of which had been destroyed by thermo- 

 cautery, proved that the associative memory of the 

 rats is to a very large extent independent of the cortex 

 of the cerebrum. — Sato Kunio and Leonore Brecher : 

 The causes of animal colouring. In vertebrates it is 

 probably the tyrosine in the teguments and dermal 

 coverings that supplies the chromogen. " Dopa," 

 as the element of pigment formation, could not be 

 found in fish, birds, and mammalia. — Leonore 

 Brecher and Ferdinand Winkler : The agreement of 

 positive and negative " dopa "-reactions both in 

 frozen sections and extracts. Frozen sections of rats' 

 eyes, of the scalp of dark-haired men, of the chrysalis 

 of Vanessa urticcB, and the cocoon Bombix mori did 

 not show any " dopa " reaction ; " dopa " was found, 

 however, both in frozen sections of the cocoons of 

 Saturnia pavonia and Erigaster lanestris and in their 

 extracts. — Walter Finkler : (i) Reflex action to 

 absence of moisture of the marsh toad, Bombinator 

 igneus, Laur. On dry, clayey soil the toad remains 

 stationary ; the hind-legs only make an irregular 

 alternating movement, which is a reflex action, 

 probably in order to save itself from drying up and 

 to get to the deeper, moister layers of earth. On 

 dry ground the toads also lose the reflex of turning 

 round. (2) The influence of external factors on the 

 colour of the iris of marsh toads, Bombinator igneus, 

 I^ur. The golden colour of the iris of animals kept 

 on moist ground or moss does not change. The iris 

 of toads kept in aquaria becomes whitish when they 

 are illuminated by a mirror from below ; the iris 

 acquires a green metallic lustre when the animal is 

 kept on dry ground. Wlien no light is admitted the 

 iris does not change its colour. (3) Experimental 

 variation of the colour of the skin of toads, Bom- 

 binator igneus, Laur., and Bombinator pachypus, Br. 

 If the upland toad is kept on dry clay, light green 

 spots appear on its back, resembling those of the 

 marsh toad. Grey marsh toads turn green on moist 

 clay ; when kept in water and illuminated from 

 beneath, a golden colouring with a metallic lustre 

 appears on the two parotids, reminding one of the 

 bronze metallic lustre of the ground-colour found in 

 upland toads. 



