404 EXPERIMENT STATION RECORD. [Vol.35 



of growth and of minor axes was recognized, and the results of 

 studies on planarian worms and on hybrids were held to demonstrate 

 the existence of metabolic gradients along these axes. The behavior 

 of an excised piece of the body of one of these animals was shown 

 to have a definite relation to the region of the body from which it 

 was taken, and the reconstitution of parts was shown to proceed at 

 a rate and in a way that were in definite relation to the metabolic 

 gradient involved. 



The dedifFerentiation of the cells of the bodies of these sample 

 animals was affirmed. The importance of dedifferentiation in pro- 

 ducing the embryonic condition in somatic cells was emphasized in 

 its relation to rejuvenescence and reproduction. The theory of a 

 germ i^lasm, universal in the Metazoa, contained in cells separate 

 from the soma was held to be compromised, if not invalidated, by 

 the fact that differentiated somatic cells in these simple organisms 

 can be brought into the embryonic condition and made to function 

 in the reconstitution of the organism. Reproduction becom-es a phase 

 of general growth djmamics and related to metabolic factors. 



Dr. V. E. Shelford, of the University of Illinois, as leader of the 

 seminars, supplemented Professor Child's discussion by accounts of 

 the studies by himself and others regarding the intimate influence of 

 environmental factors on metabolic processes, interpreting life 

 cycles, and even morphogenesis, in these terms. 



In the second week Dr. Benjamin Moore, formerly of the Uni- 

 versity of Liverpool and now connected with the London Hospital 

 Medical College, presented the elemental chemical synthesis of 

 growth. He discussed, among other things, the energy transforma- 

 tions in metastable inorganic colloidal systems and the morphologi- 

 cal changes accompanying them, and showed how certain products 

 of the inorganic systems closely simulate living structures. It thus 

 appears altogether probable that in the process of evolution inor- 

 ganic matter passes into organic through a synthesis involving an 

 uptake in energy and an increase in molecular complexity. The cell 

 as an energy transformer was considered, and the relation of the 

 action of light on formaldehyde in high concentrations and upon 

 organic products formed in life processes was demonstrated. Some 

 attention was also given to other photosynthetic actions and the 

 theories of photosynthesis, as well as to the relationships of a 

 physico-chemical basis for the origin of life to Pasteurism, evolution, 

 and heredity. 



Dr. E. V. McCollum, of the University of Wisconsin, as leader of 

 the seminars that week, discussed the fundamental food require- 

 ments of animals in the light of recent investigations on the kinds 

 and combinations of food nutrients and feeding stuffs necessary for 



