XOVEMBKR 27, 1903.] 



SCIENCE. 



689 



Professor Kciser read a paper on a method 

 of determining the amount of free lime in 

 cements. He finds that this can be done by 

 determining the amount of water absorbed. 

 Uy measuring this absorption in samples con- 

 taining known amounts, the precautions to be 

 taken in manipulation have been found. The 

 determination only requires about twenty 

 minutes. 



Professor Nipher presented a diagram on 

 which was drawn the curve of speed of the 

 trotting horse. This curve represents the 

 equation published by him twenty years ago. 

 On the same diagram was shown a belt of 

 observed values representing the performance 

 of every horse who has broken the speed rec- 

 ord since 1845. In some cases a single horse 

 has broken the record several times in the 

 same year. All such observations were in- 

 cluded. The points representing these ob- 

 servations formed a belt within which was the 

 curve of predicted speed. The agreement 

 was considered very satisfactory. 



At the meeting of November 2, 1903, Dr. 

 J. A. Harris presented for publication a paper 

 on ' Polygamy in Solanum ' and a paper on 

 'The Germination oi-Pachira' and Mr. B. F. 

 Bush presented a paper entitled ' A New 

 Genus of Grasses.' 



The secretary addressed the academy on its 

 past history and prospects, in connection with 

 the occupancy of its new home. 



William Trele.\se, 

 Recording Secretary. 



THE BIOLOGICAL SOCIETY OF WASIIINOTON. 



TllE 374th meeting, the first of the fall, 

 was held Saturday, October 17. 



Under the head of ' Notes ' L. O. Howard 

 stated that attention having been drawn to 

 the great variance in the statements regarding 

 the length of the thread of a silk worm's 

 cocoon, he had had the threads of four speci- 

 mens measured. The.v were found to be from 

 880 to 1,102 yards in length, the published 

 figures referred to varying from 1,100 yards 

 to 11 miles. 



T. S. Palmer spoke on ' Indexing Scientific 

 Names, with special reference to the Genera 



of Mammals.' After mentioning tlie recent 

 appearance of Sherborne's ' Index Animaliuin,' 

 and the volume of Waterhouse supplementing 

 the ' Nomenclator Zoologicus ' of Scudder, he 

 said that for nearly fourteen years past he had 

 been engaged in the preparation of a list of 

 the genera of mammals, living and extinct. 

 This work was to give the date and place of 

 publication, the character and location of the 

 specimen, etymology, and indicate whether or 

 not it was preoccupied. The list, which con- 

 tained about 5,000 names, was to be arranged 

 both alphabetically and zoologically, so that 

 it would be possible not merely to ascertain 

 whether or not a given name had been used, 

 but to see readily what genera were com- 

 prised in any given group. Mr. Palmer then 

 spoke of some of the difficulties that had been 

 encountered in tracing some of the names and 

 their derivation, and said that it was hoped 

 that the list would be issued in December. 



O. F. Cook presented a paper on ' Central 

 American Mutations of Coffee,' saying that 

 some of the varieties of coffee were well 

 marked and known by special names. He 

 said that a study of these variations had led 

 to conclusions directly opposed to those of 

 de Yries drawn from observations on prim- 

 roses; that instead of these variations being 

 natural steps in the evolution of species, they 

 were the result of close inbreeding and indi- 

 cations of degeneration. 



W. P. Hay described ' Terrapin Culture in 

 the United States,' giving the results of his 

 observations on the diamond back terrapins 

 in the region of Chesapeake Bay. He gave 

 a resume of the laws relating to terrapins, 

 intimating that they were the most stringent 

 where least needed and practically not enforced 

 anywhere. The turtles were impounded in 

 large numbers and the eggs were deposited 

 freely and many hatched, but owing to the 

 prevailing conditions and lack of care the 

 larger proportion of young were destroyed. 

 The young grew about an inch during the first 

 year, but attained maturity slowly, probably 

 agreeing in this respect with Chrj/semys picta. 

 Like this species, four distinct sizes of eggs 

 could be distinguished in the diamond back 

 terrapin aside from the general mass of small. 



