Record. xxvii 



the rotating mirror. Whatever the result may be, it can hardly 

 fail to teach something of interest. 



Dr. Hermann von Schrenk presented a paper entitled, ''On 

 the Effects of Water on Wood Fiber.'' 



February 18, 1907. 



Vice-President Spiegelhalter in the chair; attendance, thirteen. 



Professor A. S. Langsdorf presented a paper on ''Hysteresis 

 of the Electric Current." 



Dr. J. Arthur Harris discussed the question of "Fertility in 

 Plants." 



March 4, 1907. 



Vice-President Thacher in the chair; attendance, twelve. 



Dr. N. M. Glatfelter discussed a number of geological speci- 

 mens, which he presented to the museum. 



Dr. E. P. Lyon presented a paper on "The Enzymes of Ferti- 

 lized and Unfertilized Eggs." 



Dr. Lyon stated that the results of prehminary experiments 

 with sea urchin eggs show that the amount of enzyme present 

 in the unfertilized egg is actually greater than in the fertiUzed 

 egg. It has been suggested by many that the essential process 

 of fertilization is the carrying into the egg of an enzyme by the 

 spermatozoon. 



In discussing Dr. Lyon's paper. Dr. Abbott described results 

 which he had obtained by subjecting chick embryos of different 

 stages of development to the yoke of eggs in other stages of de- 

 velopment. The yolk from one stage seemed in some cases to 

 have a toxic influence upon the embryo of another stage. 



March 18, 1907. 



Mr. J. H. Kinealy in the chair; attendance, twenty-four. 



The announcement of the death of Professor Henri Moissan, 

 an honorary member of the Academy, was referred to Dr. Launce- 

 lot W. Andrews, for the^ preparation of proper resolutions. 



Mr. C. H. Thompson presented a review of the Hterature re- 

 ferring to the thirteen- and seventeen-year cicada. 



Special Anniversary Lecture. 



March 26, 1907. 



At the suggestion of Mr. Frank Schwarz the Academy decided 

 that it would hold a public meeting with a popular lecture as 



