Gymnastic therapeutics formed the subject of a course of lectures given at the Thousand Islands Conference in 1900, and a series of articles published in Volumes I and II of _Physical Training_ (November, 1901, to April, 1903); and material prepared originally for classes at the Training School and for the Athletic League Letter appeared later under the title “Physical Education by Muscular Exercise” as Part II of the seventh volume (“Mechanotherapy”) in _A System of Physiologic Therapeutics_, edited by Dr. S. S. Cohen (Philadelphia, 1904). The duty and opportunity of the Association in its relation to boys was emphasized at the Mobile, Alabama, Convention in 1897, in Volumes VII and VIII of the _Association Outlook_ (1897-1899), and before the Physical Directors’ Conference at Dayton, Ohio, in June of 1899. Other studies led to papers on “Some Psychical Aspects of Muscular Exercise” (Appleton’s _Popular Science Monthly_, October, 1898) and “Psychological, Pedagogical, and Religious Aspects of Group Games” (_Pedagogical Seminary_, March, 1899). How indefatigable was Dr. Gulick’s pen may be gathered from the bare enumeration of the periodicals which he employed successively as a regular means of expression: The Physical Department of the _Young Men’s Era_ (1890, to September 1), the _Triangle_ (February, 1891, to January 15, 1892), _Physical Education_ (March, 1892, to July, 1896), _International Training School Notes and Association Outlook_ (January to July, 1897), the _Association Outlook and Training School Notes_ (October, 1898, to July, 1900, two volumes), and _Physical Training_ (November, 1901, to June, 1903, two volumes). He was also editor of the _American Physical Education Review_ from June of 1901 through 1903.[280]