264' Dr. Montague on the genus Xiphopliora. 



In one species of Marginaria, the M. Urvilliana, I have 

 found true spores, accompanied by paraphyses almost simple, 

 jointed, and not inflated at the extremity ; the other, M. Bonjana, 

 in more than twenty receptacles thoroughly examined, has only 

 presented microphytes, very much branched, jointed, and having 

 the terminal articulation of the branches dilated into a spore or 

 gemma, if we prefer this last name, which, becoming detached 

 from the filament, falls into the middle of the conceptacle enve- 

 loped by the membrane of the tube in the form of a perispore. 



In the Scytothalia Jacquinotii I have seen normal spores, ac- 

 companied by paraphyses almost simple, moniliform, and trans- 

 parent. 



It would appear from my researches, which unfortunately I 

 have not been able to follow out in a sufficient number of indi- 

 viduals, that in Himanthalia the two sorts of filaments, in place 

 of occurring on the same receptacle and in difi"erent conceptacles, 

 as in the genus Xiphophora, are met with on different individuals. 

 On four specimens analysed by me, two had the normal fructifi- 

 cation, which we call hasispermal ; the others only presented mi- 

 crophytes, to which we may also apply the name acrosperms, to 

 distinguish them from the first, although I freely confess that there 

 exist intermediate forms which \\\\\ render these denominations 

 somewhat vague. I state what I have seen in the examples of 

 Himanthalia in my possession, but I am far from affirming that 

 such is always the case. I would very much recommend the ve- 

 rification of this point to such botanists as may have opportunity 

 of doing so. 



The Fucus vesiculosus, of which I have only examined three 

 individuals, has invariably shown the basispermal fructification. 



In F. ceranoides these are absent, or at least I have only seen 

 one sort of filaments ; these are microphj^tes. 



LjT^igbye figures the two kinds of filaments and of fructifica- 

 tion in F. seiratiis ; now on more than ten individuals which I 

 have examined (it must be acknowledged in a dried state) I have 

 only met with the microphytes of the preceding species, differing 

 from them only a little in shape. 



As certain Floridece present the two modes of propagation 

 united on the same stem but not confounded together, we also 

 find in Fucus canalicidatus, inclosed in the same conceptacle, the 

 filaments of the two kinds, that is to say, the basi- and acrospermal 

 fructification. 



It is nearly the same with F. distichus ; in it we observe all the 

 transitions from true spores to what we may consider as gemmse 

 or propagines. 



Lastly, in a great number of examples of F. nodosus, L. {Hali- 

 dnjs nodosa, Lyngb.), I have only observed microphytes ; and what 



