1895. ] NEW YORK ACADEMY OF SCIENCES. 185 
In conclusion, I will add that this investigation was sug- 
gested to me by Professor rood, and I wish here to express my 
great indebtedness to him and to Professor Hallock, and also to 
Professor A. A. Michelson, of Chicago University, for aid fur- 
nished during its progress. I am also under obligations to 
Herbert G. Torrey, Esq., Assayer of the U.S. Assay Office, who 
most kindly placed at my disposal large masses of molten gold 
and silver. 
R. A. MILLIKAN. 
STATED MEETING. 
April 8th. 
After a brief notice by Pres. Rees regarding the lecture to be 
held in connection with the American Museum of Natural His- 
tory by Mr. Ives, on “ Color Photography,” the Biological Sec- 
tion organized, with Dr. Britton in the chair and an attendance 
_ of about one hundred. 
Prof. E. B. Wilson delivered the lecture of the evening, “ The 
Fertilization and Early Development of the Ovum.” A brief 
historical review of the subject was given, followed by a discus- 
sion of the results of his own researches on Toxopneustes. <A 
series of lantern slides, fifty in number, from photo-micrographs 
taken by Dr. Edward Leaming, was finally used to illustrate the 
fertilization phenomena. The following stages were prominently 
shown: The entrance of the sperm cell, its rotation, the origin 
of the archoplasm from the ‘“ middle piece,” the nearing of the 
pronuclei, the maturation of the eggs, the spindle for the exten- 
sion of the first polar body, karyokinesis. y 
Before adjournment Prof. Kemp read by title two papers : 
G. F. Marruew, “ New form of Graptolites from the Cambrian ;” 
H. P. Cusutne, “ Petrographical Notes on Rocks from Alaska.” 
H. P. Cushing, Petrographical Notes on some Alaska Rocks. 
J. F. Kemp, 
Rec. Sec. Biol. Sect. 
