P. P. Shorygin, V. A. Petukhov, L. G. Stoliarova. The mutual influence of atomic groups in molecules containing heavy atoms and π-bond systems . . . 441

GENETICS

V. K. Shumnyi. The experimental production of tetraploid Zea mays . . . 445

V. K. Shcherbakov. Variation in morphological characters in plants against the background of polyploidy . . . 449

MICROBIOLOGY

E. N. Kondratieva, L. N. Petrova, E. P. Fedenko. Absorption of organic compounds by Chloropseudomonas ethylicum, as dependent on the presence of hydrogen sulphide and carbon dioxide . . . 453

BIOPHYSICS

S. Iu. Gol’dat. The effect of products of water radiolysis on the viability and variation of spores . . . 457

F. F. Litvin, V. A. Sineshchekov, A. A. Krasnovskii. Long-wave types of chlorophyll in photosynthesizing organisms and aggregate structures . . . 460

O. Iu. Orlov, E. M. Maximova. On the role of intra-cone light-filters. The mechanism of colour vision in the lizard and the turtle . . . 463

BIOCHEMISTRY

Z. S. Kagan, G. Choishner, V. L. Kretovich. The biosynthesis of valine and isoleucine from their keto- and dioxyanalogues in phanerogamous parasitic plants . . . 467

A. I. Oparin, K. B. Serebrovskaia, N. V. Vasilieva, T. O. Balaevskaia. Formation of coacervates from polypeptides and polynucleotides . . . 471

V. V. Iurkevich. The role of cell starvation in the induction of enzymes . . . 473

PLANT PHYSIOLOGY

N. I. Volodarskii, V. G. Potselueva. The effect of gibberellin and day-length on the development of Dipsacus fillonum . . . 476

PHYSIOLOGY

M. G. Pshennikova, V. P. Godin. Variations in sodium equilibrium in rats subjected to experimental heart lesions . . . 480

EMBRYOLOGY

N. A. Samoshkina. On the liability of rat embryos to injury when acted upon by external agents during the pre-implantation period of development . . . 484

ERRATUM

In V. P. Zarovnyi’s article “On the representation of the transition function of a machine by associative operations,” published in DAN, vol. 150, no. 2, 1963, the following corrections should be made.

On p. 246, line 15, where it reads “by \(m\)-semigroups and \(p\)-machines,” it should read “by \(m\)-semigroups and \(p\)-machines.”

On p. 246, line 1 from the bottom, where it reads

\[ \overline{A}=\mathfrak{A}\cap\mathfrak{X}, \]

it should read

\[ \overline{A}=\mathfrak{A}\cup\mathfrak{X}. \]

On p. 247, line 3, where it reads \(\varphi^{1}\), it should read \(\varphi^{-1}\).

On p. 247, line 4, where it reads \(\varphi^{-2}\), it should read \(\varphi^{-1}\).

T-04924. Signed for printing 14/I–64. Print run 4950 copies. Order no. 2901. Paper format 70×108 1/16. Printing sheets 21.70 + 2 inserts. Paper sheets 7⅜. Publisher’s accounting sheets 22.1.

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