436 



SCIENCE 



[N. S. Vol. XLV. No. 1166 



The Intensities of X-Bays of the L Series: 

 David L. "Webster and Harry Clark, Jeifer- 

 son Physical Laboratory, Harvard University. 

 A discussion of the intensities in the case of 

 platinum as functions of the potentials pro- 

 ducing them. 



The Use of Vaseciomized Male Mice as 

 Indicators: C. C. Little, Harvard Medical 

 School. 



Photographic Magnitudes of Stars in the 

 Selected Areas of Kapteyn: Frederick H. 

 Seares, Mount Wilson Solar Observatory, 

 Carnegie Institution of Washington. 



Archaeology of Mammoth Oave and Vicin- 

 ity: A Preliminary Report: IST. C. ^Nelson, 

 American Museum of ISTatural History, ISTew 

 York. Two isolated horizons of culture have 

 been found ; one indicating an agricultural peo- 

 ple, the other a hunting people. 



The Production in Dogs of a Pathological 

 Condition which closely Besemhles Human 

 Pellagra: Eussell H. Chittenden and Frank 

 P. Underbill, Sheffield Laboratory of Physio- 

 logical Chemistry, Tale University. The ab- 

 normal state is due to a deficiency in' some 

 essential dietary constituent or constituents 

 presumably belonging to hitherto unrecognized 

 but essential components of an adequate diet. 



The Complete Enumeration of Triad Sys- 

 tems in 15 Elements: F. N". Cole, Louise D. 

 Cummings and H. S. White. There are 

 eighty types. 



New Data on the Phosphorescence of Cer- 

 tain Sulphides: Edward L. ISTichols, depart- 

 ment of physics, Cornell University. 



The Reactions of the Melanophores of the 

 Horned Toad: Alfred C. Redfield, zoological 

 laboratory of the Museum of Comparative 

 Zoology, Harvard College. 



The Coordination of the Melanophore Re- 

 actions of the Homed Toad: Alfred C. Eed- 

 field, zoological laboratory of the Museum of 

 Comparative Zoology, Harvard College. 



Petrified Coals and Their Bearing on the 

 Problem of the Origin of Coals: Edward C. 

 Jeffrey, botanical laboratory. Harvard Uni- 

 versity. Coals containing " coal balls " are 

 abnormal, but there is no good evidence that 



" coal balls " are organized from material 

 accumulated in situ. 



The Effect of Degree of Injury, Level of Cut 

 and Time within the Regenerative Cycle upon 

 the Rate of Begeneration: Charles Zeleny, 

 department of zoology, University of Illinois. 



Preliminary Note on the Distribution of 

 Stars with Bespect to the Galactic Plane: 

 Frederick H. Seares, Mount Wilson Solar Ob- 

 servatory, Carnegie Institution of Washing- 

 ton. A comparison of Mount Wilson counts 

 with Kapteyn's, in which good agreement is 

 foimd, as compared with both the results of 

 Chapman and Melotte are not homogeneous. 



Ifational Research Council; Research Com- 

 mittees in Educational Institutions; Central 

 Committees on Research; Reports of Meet- 

 ings of the Executive Committee. 



Edwin BrowELL Wilson 



Massachusetts Institute of Technology, 

 Cambridge, Mass. 



SPECIAL ARTICLES 



A QUANTITATIVE METHOD OF ASCERTAINING 



THE MECHANISM OF GROWTH AND OF 



INHIBITION OF GROWTH OF 



DORMANT BUDSi 



1. Each plant possesses a number of dor- 

 mant buds, which may grow out when they 

 are isolated but which remain dormant under 

 normal conditions. The problem to be solved 

 is the mechanism of inhibition in the latter 

 and of growth in the former case. Former re- 

 sults published by the writer on Bryophyllum 

 calycinum- indicated that both phenomena 

 are reciprocal, inasmuch as the growth of a bud 

 depends upon the availability of certain mate- 

 rial, while the inhibition is due in general to 

 the non-availability of such material, and this 

 non-availability is frequently brought about 

 by the absorption or withdrawal of the mate- 

 rial by another growing organ. Thus each 

 node of Bryophyllum calycinum has two 

 leaves and in the axil of each leaf is foim.d 



1 From the Laboratories of Tlie Eockef eller In- 

 stitute for Medical Research, New York. 



2Loeb, J., Bot. Gaz., 1915, LX., 249; 1916, 

 LXII., 293; 1917, LXIII., 25. "The Organism as 

 a Whole," New York, 1916, p. 153. 



