146 Kansas Academy of Science. 



BIOTROPISM. 



By Lyman C. Wooster, Ph. D. 



WHEN Lamarck declared, in 1801 and 1809, that the efifects of 

 use and disuse on cells and organs are inherited, he raised 

 Buch a storm of opposition that followers of Lamarck have been 

 few from that time to the present. Indeed, Lamarck's theory has 

 been killed many times, but always there have been a few faithful 

 disciples ready to assist in its resurrection. Paleontologists have 

 found Lamarck's theory so perfectly in accord with what they find 

 in the crust of the earth that they, as a class, have followed his 

 leadership in most things, styling themselves Neo-Lamarckians. 



An increasing number of biologists in this twentieth century fol- 

 low Lamarck in his contention respecting the inheritance of the ef- 

 fects of use and disuse of cells, organs and the individual ; and declare, 

 with him, that it is life (Aristotle's entelechy) that is the efficient 

 agent in the modification of species to meet a changing environ- 

 ment, and that life is the bearer of such modifications, making 

 possible their continued inheritance. 



But the larger number of biologists (it is strange that they class 

 themselves as biologists) maintain that the entelechies are the 

 products of the chemist's crucible, and that environment, including 

 the physical forces, is the chief agent in the development of the 

 life powers. College textbooks on plant and animal physiology are 

 loaded with discussions of geotropism, heliotropism, phototropism^ 

 thigmotropism, traumatropism, rheotropism, chemotropism, hydro- 

 tropism, aerotropism, thermotropism, and several other external 

 influences, while not in a single textbook, not even in the latest 

 dictionary, will be found biotropism, a perfectly legitimate word. 



When a root pushes through the soil toward the center of the 

 earth, this movement is said to be an example of geotropism, not 

 biotropism; when a house plant bends toward a sunny window^ 

 the textbook makers say that it does so because of phototropism, 

 and do not hint of biotropism, though the more careful ones admit 

 that there is an inexplicable element in the problem. 



This mechanistic tendency of so many human minds is probably 

 due to the great preponderance of culture subjects in school and 

 college curricula of the past several hundred years. The mathe- 

 matical formulae, especially, apply so readily in the explanation of 

 the action of the physical forces, and the atomic theory serves the 



