287 



resemble concej)lacles in form ond oiigin>. This statcment stånds 

 for Hoi:, for Ihe nulliors slie Iias (juolcd (Smiih and Wiiittino in 

 IMiycol. MiMuoirs I) only say llial »a seclion across Iho leaf forciblv 

 lec-alls Ihe concoplacles of Splachiiidiiiin and olher l)io\vn algae». Il 

 ncod liardly be said Ibal Hoi;'s slalemcnl is (|uite withoul fonnda- 

 tion, as I bo sori of Macrocijslis or Poslelsia have nolhing in coni- 

 Mion, neilbcr in slruclure nor in origin, wilh Ibo conceplacle of 

 Fuciis. Hul Uoi-: concbides Ibal in Ibis fealiire as well as in Ibe 

 conlcnls of Ibe reproduclive sacs, Sj)l<uhni(linm is inlerniediale 

 belween Ibe Iwo orders nienlioned; we do nol know indeed, ulial 

 Ibese sacs conlain — mosl Hkely zoospores, boniologons i)olb wilb 

 Ibe spores of Lamiiuirid and wilb Ibe sexual bodies of Fucns: if 

 tbey are gameles, as in Ibe Phaeosporeae, Ibey are not bomologous 

 wilb eilber. »b^urlber invesligation will doublless sbow a mucb 

 more inlimale conneclion l)elween Ibe Laminariaceae and Ibe Fuca- 

 ceae Iban is al present recognized», Hok continues, l)ul I very 

 nuicb douhl Ibat tbis propbecj' will ever be fulfilled. It may be 

 placed wilb eilber groiip, only, the presence of conceplacles »makes 

 il wise to regard Spldchiiidium as a primitive member of Ibe Fuca- 

 ceae». In my opinion it is exlremely different from bolb. I bave 

 looked for natural alTinilies among tbe Chordariaceae; Ihe slruclure 

 is nol essenlially dislinct from Chordaria, Lealhesia elc; the mulli- 

 cellular assimilalors are represented by tbe bairs of the growlb 

 zone, hut Ibey are a juvenile fealure in Splachuidiiun. Tbe spor- 

 angia bave Ibe same origin and Ibe same appearance in bolb cases, 

 Ibey are localed in a sorl of conceplacles, as tbe sexual organs in 

 Fucus, hut Ibe developmenl of tbe conceplacle is not idenlical in 

 Ibe two cases. 



Splachnidium is quile a uni(|uc lype; still I believe tbere are 

 reasons to regard it as represenling a branch of tbe Chordariacedc, 

 perbaps a »bigber slage». I do nol lind suITicient grounds for 

 suppressing tbe order Sphtchnidiaceae, wbich, from a taxonomic 

 poinl of view, is well circumscribed. Tbere is no evidence Ibal 

 Spl(ichi)idiiim is inlerniediale belween Ibe Chorddiiaccae and any 

 olber order. 



Julv, 1920. 



