FORE-WORD. 



Whilst pursuing my studies on the Desmidiea? in 1882 — 3 I received each year 

 from Mr. J. Suthehland, then travelling in India, two small bottles containing Alga?, 

 eollected in Central and Northern India — the exact localities not being clearly stated. 

 Among the Alga? were many Desmidiea?, some being apparently new. 



In determining these in 1883 — 4 I had recourse to the only memoir upon the Indian 

 Desmidies, that of Dr. G. C. Wallich, F. L. S. ('Descriptions of Desmidiaceae from Lower 

 Bengal', in the Annals and Mag. Nat. Hist. vol. V, ser. 3, pp. 184, 273, 1860), but that 

 failed to assist me very much, as the memoir itself had been only partially proceeded with. 



However, in 1884 I communicated with Dr. Wallich, from whoin I received a most 

 courteous reply, containing a very kind offer to place the residue of his 1855 gatherings 

 at my disposal; whieh offer was most gladly aceepted by me. Learning, in the meanwhile, 

 that Dr. W. had presented slides of Desmids, and also his original Mscr. and sketches, to 

 the Royal Microscopical Society of London, I asked permission to examine them; and the 

 Couneil of the Society (with Dr. Wallichs assent) generously allowed me to have the 

 Mscr. volume and slides for a considerable period, during which I took ample notes. When 

 in 1884 — 5 I made my examination of the rernnant of Dr. Wallich's gathering (preserved 

 in dilute spirit for 30 years!) I discovered that many forms existed therein not described 

 in the Mscr., and I also found that Dr. W. had seen and noted, when in India, many 

 plants unseen by me; hence this little memoir has attained larger proportions than I or 

 Dr. Wallich expected. In my own examination I made över 1,100 sketches before I at- 

 teinpted any analysis or description of the forms. The greater part of my own Mscr. was 

 compiled, but not written in extenso, in 1885 — 6. 



In 1889 a valued correspondent, Dr. G. von Lagerheim (then at Freiburg in Breis- 

 gau, and now of the University of Quito, Ecuador), kindly sent me some specimens of 

 Indian Utriculariae — from the Riks-Museum, Stockholm. These yielded many interesting 

 and novel plants, which form welcome additions to the list, and for which I beg to 

 sincerely thank him. 



