Distribution of the Laminariaceoe. 335 



A great impulse was given toward a closer examination and a 

 more correct determination of specific differences by Le Jolis's pub- 

 lication in 1855-56 on the confusion existing in regard to the two 

 European species of digitate Laminarioe.^ In J. G. Agardh's " De 

 Laminarieis,'" there is a most able discussion of a number of points 

 of resemblance existing between the genera of the group in connec- 

 tion with the description of new points in the morphology of the 

 species. Most important too, are the descriptions and remarks to 

 be found in the fourth and fifth portions of the " Observationes 

 Phycologicae " of J. E. Areschoug,^ where a number of rare forms 

 receive full treatment. 



Since then a considerable number of forms have been described 

 by Kjellman, Foslie, Bornet, and others, and there has been a very 

 active study of the different forms and varieties of the different 

 species, particularly among the Scandinavian algologists. But, as 

 yet, there exists no classification of the group as a whole, that is 

 natural or complete. Consequently this subject together with some 

 of the main features of distribution have been taken up by the writer 

 in the present article. 



The order of the Laminariacese or kelps is one of the most dis- 

 tinct and well-defined among the Ph^eosporese, or, even among Algae 

 in general. The members of the order are all of comparatively 

 large size, while the species of Macrocystis reach a length even sur- 

 passing that of tropical " climbers " and those of Lessonia possess 

 stipes which in size and grosser structure strongly resemble the 

 trunks of the ordinary dicotyledonous trees of temperate climates. 



They all with the exception of Chorda, possess a distinct stem 

 or stipe and an expanded leaf or blade. The principal meristematic 

 region in all is intercalary,* being situated in all except the genus 

 mentioned, at the place where the stipe passes over into the blade 

 viz: at the transition-place (Uebergangstelle). 



The organs of fructification are essentially the same in all the 

 species and are crowded together into broad patches or " sori." In 

 Chorda the sori completely cover the whole surface of the frond, 

 but in all the other genera they are of much more limited extent, 

 although of irregular and variable outline. The sori are made up 



' Compt. Rend., t. 40, p. 473, 1855, Mem. Imp. Acad. Cherbourg, t. 3, 1855, Nova 

 Acta, Bd..25, II, 1856. 2 Hmd's Univ. Arsskrift, t. 4, 1867. 



'^ Nova Acta Reg. Soc. Sci. Upsal., ser. 3, Bd. 12, I and II, 1884-5. 

 * Cf. Janczewski, Mem. Soc. Nation. Sci. Nat. de Cherbourg, t. 19, pp. 109-113, 1875. 



