530 mereill: the generic name nauclea of linnaeus 



of value is a point open to question since the transmission of the 

 glass can not be measured extremely accurately and visibility 

 curves appear very different for different observers. But in 

 the case of the transmission, absolute values are not required, 

 merely the form of the curve needs to be known. And in the 

 case of the visibility, only a short range of the curve is important, 

 and over this range the slope of the visibility curves of various 

 observers is in good agreement. 



In a more complete paper which w^ill be published at an early 

 date several specific pyrometer glasses are considered. One 

 of these glasses is a black absorption glass used with optical 

 pyrometers for extrapolating the temperature scale to say 

 2500°C. The calibration of such a glass by the usual method 

 necessarily tacitly involves the visibility or scope of the visibility 

 curve over a small range of color. Different observers obtain 

 practically the same calibration of the glass which would indi- 

 cate that the eifective wave length of the system could be de- 

 termined with greater accuracy than one would ordinarily 

 expect. Also the values of the effective wave length of a red glass 

 obtained by Hyde, Cady, and Forsythe by different methods 

 show such excellent agreement that a more accurate method of 

 computing the data is warranted. 



In conclusion, the writer desires to thank Dr. Waidner. Dr. 

 Kanolt, and Mr. Crittenden for suggestions given him in this 

 work. 



BOTANY. — On the applicatio7i of the generic name Nauclea of 

 Linnaeus. E. D. Merrill, Bureau of Science, Manila, P. 

 I. (Communicated by William R. Maxon). 



It sometimes happens that the current and universally ac- 

 cepted concept of a genus is quite different from that of the 

 genus as originally described. This is due to misconception or 

 to misinterpretation of the group on the part of later authors; 

 sometimes because the original genus is subdivided, the various 

 species being referred to other genera until all or most of them 

 are dissociated from the original generic name; and sometimes 

 because certain species have been added after the original de- 



