— 35 — 



mycology. Several of his minor projects, revealed in our correspondence, may 

 be passed over; but matters of larger import must be noted. In 1916, after 

 the matter had been very strongly urged. Doctor Riddle promised to furnish 

 the manuscript for the Arthoniaceae in the North American Flora. I had been 

 working for several years on the Graphidaceae, and was greatly pleased that 

 he was to work on the most closely related family. In one of his latest letters 

 he wrote of being at work on the Arthoniae. He was also much interested in 

 tropical lichens in general, and American botany has lost much along this line 

 through his early death. Another major project mentioned in one of his letters 

 after returning to Harvard was a manual of the lichens of eastern North America. 

 His position where he had access to the Tuckerman Herbarium made this plan 

 seem especially feasible, and American mycology has lost heavily through his 

 not being able to carry this ambition to completion. Cut down in the prime of 

 life, he still left, in the papers cited below, probably 50 new species and much in 

 the way of critical notes and additions to distribution. Perhaps I should have 

 added to the citations below some notes on contents, but those especially in- 

 terested may find these in the bibliography of North American botany in the 

 Bulletin of the Torrcy Botanical Club. 



Inclination would lead me to a more detailed account, but I must close 

 with the question as to what man or what men will take the place of our departed 

 friend and worker. We need both amateurs and men trained as was Doctor 

 Riddle. Let us hope that systematic botany may soon regain some of its tem- 

 porarily lost prestige and that in this happy time there may come a number of 

 workers able and willing to carry forward the task begun by our departed lichen- 

 ist. 



In closing, I wish to express to Mrs. Riddle and to Mr. Edward B. Chamber- 

 lain my thanks for data which have aided in the preparation of this paper. 



Doctor Riddle's Botanical Publications 



Contributions to the cytology of the Entomophthoraceae: preliminary dis- 

 cussion. Rhodora 8: 67, 68. 1906. 



On the cytology of the Entomophthoraceae. Proc. Am. Acad. Arts. Sci. 

 42: 177-195- Pl- 1-3. 1906. 



Notothylas orbicularis in Massachusetts. Rhodora 9: 219, 220. 1907. 



Notes on some lichens from the Gaspe Peninsula. Rhodora 11: 100-103. 

 1909. 



A key to the species and principal varieties of Cladonia occurring in New 

 England. Rhodora 11 : 212-214. 1909. 



Preliminary lists of New England plants, — XXI II. Cladoniaceae. Rho- 

 dora 11: 215-219. 1909. 



The North American species of Stereocaulon. Bot. Gaz. 50: 285-304. f. 

 1-9. 1910. 



"The Lichens of Minnesota," a review. Bryologist 13: 97-100. 1910. 



