March 17, 1905.] 



SCIENCE. 



427 



that all mutations pass through a mucronate 

 stage such as is characteristic of the adult 

 mutation after which the species is named. 

 (The term mutation is here used in the sense 

 in which it was originally proposed by 

 Waagen, and not in that in which it was sub- 

 sequently used by de Vries, /. e., for the re- 

 sult and not for the process.) A still earlier 

 stage in development (nepionic) shows the 

 non-mucronate features of the ancestral species 

 similar to 8. duodenarius of the Onondaga. 

 The mucronate feature is carried to excess in 

 a number of mutations of the Lower Hamilton 

 group. It is especially persistent in the Mich- 

 igan region. This type of outline is accom- 

 panied by a rib in the median sinus and a 

 depression in the fold. In Ontario the prim- 

 itive mucronate type gives rise upward to a 

 number of mutations which are especially 

 characterized by progressive increase in height 

 without corresponding lengthening of the 

 hinge. The median plication and depression 

 quickly disappear. 



Acceleration and retardation in development 

 are the chief principles which explain the de- 

 velopment of the great number of mutations. 

 For the principle of retardation the term 

 hradygenesis (from i^pacU'c, slow) was pro- 

 posed, corresponding to the term tachygenesis 

 proposed by Hyatt for acceleration. 



In the New York province the primitive 

 mucronate type gives rise to high and short- 

 hinged mutations, but these retain the median 

 rib and depression. In form these are tachy- 

 genetic; in respect to the surface features, 

 bradygenetic. In the arenaceous beds of the 

 later Hamilton in eastern New York, a muta- 

 tion with many ribs and moderate mucrona- 

 tions exists. This is in many respects a 

 bradygenetic type. Side by side with ex- 

 tremely accelerated or tachygenetic types in 

 all horizons (i. e., very short-hinged, non- 

 mucronate, high and thick mutations) occur 

 slightly retarded or bradygenetic types which 

 retain in the adult the mucronate character 

 which is typical of the young of all the muta- 

 tions. 



A. W. Grabau, 



Secretary. 



Columbia University. 



THE PIIILOSOPHICAL SOCIETY OF WASHINGTON. 



The 596th meeting was held February 4, 

 1905. 



Mr. J. F. Ilayford, chief of the Computing 

 Division of the Coast and Geodetic Survey, 

 reported briefly on the completion of the reduc- 

 tions of the leveling between Seattle and 

 several points on the Atlantic coast; the ap- 

 parent difference of level between the two 

 oceans is 187 mm., 0.6 foot. The levels run 

 at Nicaragua gave a difference of zero. 



Mr. Bernard R. Green then spoke on ' Public 

 Buildings in Washington,' presenting many 

 lantern views, and outlining the problems that 

 have been forced on his attention during the 

 many years he has been connected with the 

 erection of such buildings. Attention was called 

 to the peculiar far-sighted plan of the city, 

 with its two centers at the Capitol and White 

 House, marked by monumental buildings. The 

 majority of the government buildings, he held, 

 should be expressive of their use and so be 

 of the workshop or office type rather than 

 monumental, and should be well scattered. 

 The future buildings of the monumental class 

 will probably be of the modified classical type, 

 massive, of stone, and relatively low, e. g., 

 eighty feet. The cost of these is high ; the 

 State, War and Navy Building cost $1.06 per 

 cubic foot, the Library of Congress sixty-three 

 cents, including decorations. Buildings of the 

 other class may be of the columnar type, a 

 steel skeleton structure which carries the outer 

 walls, and costs twenty-five to thirty cents per 

 cubic foot. 



Mr. S. W. Stratton, director of the Bureau 

 of Standards, then spoke on ' The Archi- 

 tectural and Engineering Features of Scien- 

 tific Laboratories,' exhibiting many views of 

 such buildings and especially the new ones 

 of the Bureau of Standards. The most im- 

 portant conditions to be secured are freedom 

 from vibration and jars, and perfect control 

 of the ventilation and temperature of the 

 rooms. An excavated basement is a great source 

 of trouble; the heating and power-plants and 

 machinery should be in a separate building. 

 Substantial reinforced concrete floors render 

 piers unnecessary in the first story, while in the 

 second story wall-brackets are generally better 



