

POLYMORPHISME DES ALGUES 1 27 



ties from many parts of the World, and can truly say that 

 Prof. G. v. Lagerheim did not give to much prominence 

 to simple différenciations. Many of thèse différencia- 

 tions are combinations of characters wich are repeated 

 in hundreds and I may say in thousands of individuals and 

 can therefore be rightly considered as constituting dis- 

 tinct varieties. Moreover how is it that identical species 

 of thèse minute forms of plant life, wich Wolle would 

 hâve us believe so easily give rise to différenciations and 

 vagaries, are found in such widely separated places as 

 Madagascar and the United States, wich precisely the 

 same characters the same marking, granule for granule! 

 Such is the case with Enastrum trigibberum ». 



Certaines espèces comme Micrasterias foliacea qui se 

 retrouvent dans des pays éloignés et qui sont cependant 

 rares: «America, India, Burmah, Queensland. Triplo- 

 ceras gracile : N. et S. America, Europa, India, China, 



Australia, New-Zealand » « Docidium baculum with 



Worldwide distribution, and yet a Malagassy spécimen of 

 the type could not be distinguished from an English spé- 

 cimen, » et p. 404 « Klebs was certainly in error in grou- 

 ping together many of the forms that he lias figured in 

 his Desmidiaceae Ostpreussens and concerning such treat- 

 ment of thèse plants. I will again quote a few remarks 

 made by Archer. « The inexperienced lumping together 

 of species is as much to be deprecate as their over multi- 

 plication. I should draw attention to a circumstance I am 

 disposed to look upon as an almost an umpeacheable 

 argument as to their actual spécifie distinetness. I allude 

 to the fact, that, no matter how numerous or how few 

 the fronds, the conjugating spécimens always conju- 

 gate, like form or species, with like form or species the 



