Jan., i894. RESEARCHES ON SEAWEEDS. 51 



have ventured, in describing the anatomy of the genus Tuvbinavia, to 

 take a third view, viz., that both conceptacles and cryptostomata are 

 of equal antiquity, and that neither is an outcome of the other. 



For some reason that I hardly understand, all these views, and 

 apparently mine in particular, have supplied a source of innocent 

 merriment to Mr. George Murray, who, both in the Journal of Botany 

 and his Phycological Memoirs, has treated the " ancestors of the 

 Fucaceae " as if they came from Wardour Street. As will be seen 

 later on, fate has been so ironical that his researches have thrown 

 fresh light on the whole dark subject and possibly a way out. 



The matter was in this stage when, as Mr. Murray has since 

 shown, an important side-light was thrown on the subject by the 

 investigation of the development of the conceptacles of Splachnidium. 

 This strange-looking plant had been often mentioned and described, 

 but never properly investigated, till Mr. Murray, suspecting that it 

 might prove interesting in connection with the question of cryptosto- 

 mata, handed it over to Miss Mitchell and Miss Whitting for 

 examination. The result (4) exceeded his anticipations. The first 

 point of interest was the strange persistent apical cell which the 

 authors describe in the following way : — 



" The apical cell in Splachnidium rugosmn differs entirely in 

 appearance from the surrounding meristem ; it has a pear-shaped 

 body bounded by a thick transparent mucilaginous wall, and a 

 filiform basal process stretches towards the interior of the thallus. 

 This cell and the very active surrounding meristem are sunk in a 

 slight depression ; the two outer layers of the meristem by radial 

 division form the epidermal cells, which continue to divide radially 

 until the part of the thallus in which they lie has reached maturity." 



" The apical cell persists throughout the life of the plant, and not 

 only does it appear at the apex of the main branch, but cells of the 

 same kind are found at other points where growth is taking place, ^.g"., 

 in the young conceptacles and at the point of formation of lateral 

 branches. It seems as if its appearance were the herald of every 

 local development." 



Except for a slight difference in the casting of external layers of 

 the mucilaginous cell-wall, and in the junction of the process at its 

 base with the filaments of the thallus, the initial cell of the concep- 

 tacle was found to resemble in every particular the apical cell described 

 above. Former investigators had supposed these conceptacles to be 

 cryptostomata, like those of Fucaceae, to which this alga was 

 supposed to belong, and in their earlier stages they are exactly 

 similar, " the tufts of hairs extending," like those of Cystoseiva, " a long 

 distance beyond the ostioles." Mr. Murray (6), in comparing these 

 points in Splachnidium and Fucus, says : " In Fucus it will be remem- 

 bered that hairs are not produced until the formation of a young 

 conceptacle with an ostiole, while the initial cell has decayed. The 



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