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5. P. sparganifolius Lsest. Widely differing from the Irish 

 plant from Maam (Galway); for the present it will perhaps be 

 advisable to follow Mr. Bennett in the Student's Flora (ed. 3, p. 535), 

 and adopt the name P. Kirkii Syme for our plant. 



6. P. fluitans Roth. Exactly the English form. 



9-11. P. f h),j nifn ins, d< ep to shallow water or land (?) forms. 



12-18. P. alpifius. Of these f. iontjifolia Tis. is a very remark- 

 able plant, with the opposite leaves subtending the peduncles, 10-1 1 

 in. long. No. 18, formerly distributed by Dr. Tiselius as var. 



■■■■■■■ - 



19. "P.duhiu, lit-., foimi mbridd /'. nanu,,.^ ■ l>. nutans.'" 

 (see note 19, p. 5; the first of the author's notes). Of these speci- 

 mens, b., submerged leaves, resembles a form of /'. jluitnns that 

 has occurred in Cambs. and Surrey; specimen a. is very like some 

 forms of P. crassifolms Fryer. Probably Dr. Tiselius is correct in 

 his estimate of the parentage of this hybrid form, which would be 

 more naturally placed next to P. fluitans. 



20-27. Beautiful forms of the P. heUmphyUux of English bota- 



28. "P. gmmineush. (3, , flwtuans Tis.f^a form which seems so 

 distinct as to deserve specific segregation. See "b., planta junior 

 fohosa," which approaches /'. falratus y. m «}«r Fryer, while "a., 

 planta fructificans," is not unlike a plant distributed by the Messrs. 

 Jjinton as " P. Lonchites," from the River Boyne, Ireland. 



30. " Potan>n,,rton arami,;,,* L., y. sr/.tnitromaiis Tis. (major)," 

 and 81, "y. xej.n-ntriontdis lis. i minor j," are very near, if not 

 identical with, the form figured in this Journal, tab. 317, as " P. 

 yramineus L. V. t/raminifulius Fries," from Huntingdonshire. 



34-50. "P. nitens Web.?" These seventeen sheets represent 

 the most important part of Dr. Tiselius' work, and certainly will be 

 the most interesting and useful to Lintish botanists, especially to 

 those who are able to collect in the Scotch rivers and lochs. Here, 

 for the first time, we are able to see the fruit of nitens, produced on 

 forms which are quite typical. Other fruiting forms are open to 

 some doubt, and many students will be inclined to place them 

 under ■•aiamtneux L." No one, however, has had such opportunities 

 of studying nitn <-iorms in tin living state as Dr. Tiselius, and his 

 opinions on the specific status of these forms, if they do not com- 

 mand our immediate assent, at least demand a suspense of judgment 

 until fuller investigation has proved them to be erroneous. With 

 little doubt the greater part of these ro'tena-forms are hybrids, pro- 

 bably all are so ; and they afford a valuable mass of evidence on the 

 questions of variation and the production of new specific forms by 

 natural hybridisation. 



38. " P. nitens Web. ?, forma jemtlandica Tis." A distinctly 

 nitens-hke form with a few fully developed drupelets. 



41. " P. nitens Web. ?, forma perfoldatifolia Tie."; formerly dis- 

 tributed by the author as "nitens f. latifoUa." If this plant, as the 

 author suggests (note 41), is nitens X perfoliate, care must be taken 

 not to confound certain British forms of typical nitens which have 



