Apbil 16, 1915] 



SCIENCE 



567 



Nathaniel L. Britton: "The Forests of Porto 

 Eico. " (10 minutes.) 



J. Walter Fewkes: "Pictures on Prehistoric 

 Pottery from the Mimbres "Valley in New Mexico, 

 and their Relation to Those of Casas Grandes." 

 (20 minutes, illustrated.) 



Charles B. Davenport: "Inheritance of Tem- 

 perament." (15 minutes.) 



Charles B. Davenport: "Inheritance of Hunt- 

 ington's Chorea." (12 minutes.) 



8 P.M. — Annual dinner of the members of the 

 Academy and their guests and presentation of the 

 Draper medal, held in the Oak Room of the Hotel 

 Raleigh. 



WEDNESDAY, APRIL 21 



10 A.M. — Oak Room, Hotel Raleigh. 



Business meeting of the Academy for the elec- 

 tion of members and two members of the council. 



1.30 P.M. — Luncheon in the private dining-room 

 of the Hotel Raleigh. 



2.45 P.M. — Auditorium, National Museum. 



Public scientific session. George H. Parker, 

 official representative of the academy upon the 

 Special Commission appointed by the President of 

 the United States to study and report upon the 

 Alaskan fur seals during the summer of 1914. 

 Subject: "The Fur-Seal Herd of the Pribilof Is- 

 lands. ' ' (Hlustrated. ) 



4 P.M. — Auditorium, National Museum. 



Second William EUery Hale Lecture, by Thomas 

 Chrowder Chamberlin, of the University of Chi- 

 cago. (Open to the public.) Subject :" The Evo- 

 lution of the Earth." (Illustrated.) 



Jacques Loeb: Stimulation of Growth. 



The speaker intends to discuss the stimuli which 

 induce development and growtli in three cases. 



1. Artificial parthenogenesis, or the nature of 

 conditions which cause the egg to develop. It has 

 been shown that all substances which cause a cyto- 

 lysis of the surface layer of the egg start the de- 

 velopment; and that the spermatozoon must con- 

 tain a substance of that character; but that in 

 addition a second treatment is required to insure a 

 more normal development. The alteration of the 

 surface layer increases the rate of oxidations in 

 the egg by 400 to 600 per cent, and the same ef- 

 fect is produced by the entrance of the spermato- 

 zoon into the egg. 



It seems that under certain conditions this alter- 

 ation of the surface is reversible and it is inferred 

 but not yet proven that in this ease the accelera- 

 tion of the rate of oxidations is reversed. This 

 reversibility is a fundamental fact, since the altera- 



tion of conditions of active growth and rest are a 

 prerequisite for the continuity of life. 



2. Metamorphosis. Phenomena of growth occur 

 in the larval metamorphosis when certain organs 

 disappear and new ones begin to grow. A number 

 of facts have indicated that substances circulating 

 in the blood are responsible for these phenomena 

 of growth and this conclusion was put on a perma- 

 nent basis by the discovery of Gudematseh that it 

 is possible to induce in tadpoles at any time the 

 outgrowth of legs and complete metamorphosis by 

 feeding them with thyroid. 



3. Regeneration. By regeneration we mean the 

 phenomena of growth started by the removal of 

 some part. It can be shown that in these eases also 

 the growth is induced by the collection of (prob- 

 ably specific) substances at places where they could 

 not gather under normal conditions. 

 Lafayette B. Mendel: Specific Chemical Aspects 



of Growth. 



A review of the methods employed in the in- 

 vestigation of chemical problems of growth. 

 Analysis of the tissues of growing individuals has 

 failed to contribute much of specific importance, 

 owing to the tendency of the body to maintain a 

 fixity of composition under varying conditions of 

 diet. The study of nutrition in growth is more 

 profitable. This has involved a determination of 

 the constructive units essential for the building up 

 of an adult organism. Recent contributions re- 

 specting the r61e of the individual nutrients, and 

 particularly the proteins, are considered. The part 

 played by the amino acids derived from proteins 

 in digestion has been investigated. Some of these 

 can be synthesized in the organisms; others ap- 

 parently can not, and must be furnished in some 

 form in the dietary. The newer researches suggest 

 that in addition to the familiar foodstuifs certain 

 as yet undetermined food accessories (also called 

 "vitamines") are needed. The evidence for this 

 view and the facts regarding the existence of spe- 

 cial chemical determinants of growth are discussed. 

 Eugene P. Du Bois: The Basal Metabolism dur- 

 ing the Period of Growth. 

 In order to compare the basal metabolism of 

 children with that of adults it is best to use as a 

 basis the calories per square meter of body sur- 

 face per hour. The average figure for men is 34.7 

 calories with a plus or minus variation of 10 per 

 cent. For a short time after birth the average 

 for infants is 20 per cent, below this figure. The 

 metabolism then rises rapidly and reaches a point 

 50 per cent, above the adult level at the age of 2 

 years, remaining at this height until the age of 6 



