他引的 W. F. Willcox (年譜長編初稿 p.1593 姓氏拼錯) 是位名統計學家
參考後文 Wikipedia 關於 Walter Francis Willcox的介紹
我們可知道他在19世紀末1892 就在胡適以後就讀的康乃爾大學開統計課 (1890年 全美的大學 有16個統計課程)
所以會說"現在的文明的國家之中 沒有舉行 國勢普查的 恐怕只有我們這個古國了.........究竟那一個數字對呢? 誰也沒有真實可靠的統計來解答
人口如此 其他必須依據人口為基礎的死亡率 人口增加率 文盲百分比 等等 當然都沒有確實數字了ㄅ......"
Walter Francis Willcox, Ph.D., LL.D. (March 22, 1861 – October 12, 1964) was an American statistician. He was born in Reading, Massachusetts to William Henry Willcox and Anne Holmes Goodenow. He was graduated from Phillips Academy, Andover, in 1880; Amherst College in 1884 with an A.B. and in 1888 received and A.M. degree from Amherst College. He received an LL.B degree (1887) and a Ph.D. (1891) from Columbia. In 1906 he received an honorary LL.D. degree from Amherst College.
He was a Cornell University faculty member from 1891 to 1931 within the President White School of History and Political Science. He held the presidency of the American Statistical Association in 1911-12 and of the American Economic Association in 1915. As well as essays and magazine articles, he published The Divorce Problem, A Study in Statistics (1891; second edition, 1897), and Supplementary Analysis and Derivative Tables, twelfth census (1906).
Willcox initiated the first statistics course at Cornell in 1892, one of the earliest university courses in statistics in the United States, and one among 16 universities with such courses in the 1890s. His research interest was in vital statistics. Emil Julius Gumbel described his body of work, collected in Studies in American Demography, as "the type of old-fashioned writings which will continu e to be of value notwithstanding all progress achieved in mathematical statistics." 
- Studies in American Demography, Ithaca, New York: Cornell University Press (1940).
- International Migrations, Volume II: Interpretations (Editor), New York: National Bureau of Economic Research (1931).
- Walter Francis Willcox papers, #14-10-504. Division of Rare and Manuscript Collections, Cornell University Library.
- ^ Rice, Stuart A (1964). "Walter Francis Willcox March 28, 1861 - October 30, 1964". Revue de l'Institut International de Statistique / Review of the International Statistical Institute (International Statistical Institute (ISI)) 32 (3): 340–346. http://www.jstor.org/stable/1401885. Retrieved 2008-05-11.
- ^ Leonard, William R.; Leonard, William R (1961). "Walter Francis Willcox: Statist". The American Statistician (American Statistical Association) 15 (1): 16–19. doi:10.2307/2682503. http://www.jstor.org/stable/2682503. Retrieved 2010-05-31.
- ^ Leonard, W.R.. Op. Cit.: 16.
- ^ Gumbel, E.J. (1941). "Review of Studies in American Demography". The Annals of the American Academy of Political and Social Science (American Academy of Political and Social Science) 218 (1): 239. http://ann.sagepub.com/cgi/pdf_extract/218/1/239. Retrieved 2010-05-31.