and Propagation of marine Plants. x 47 



ting two different males, on the fame plant, operating in a manner 

 not only diftincl from, but diredly oppofite to, each other : for one 

 of them (as we have juft fecn) is defcribed as internally fituated and 

 concealed in the air-bladders, while the other is external and ex- 

 pofed to view in thofe fmall open veffels upon the furface of the 

 plant*. But fuch an ceconomy does not appear to have proof or 



analogy 



* My friend Mr. Stackhoufe had adopted the fame opinion in his very ingenious invef- 

 tigation of thefe plants, and mentioned " the monoecious chara£ter as clearly difcerniWe 

 in fome" of the Fuci; as alfo the twofold ftate of the male flowers, one of which is reprc- 

 fented as externally fituated, and expofed to view in the urceolate veflels ; the other, con- 

 cealed in the air-bladders — " in intsriore vcjiailarum grandiorum." In a fubfequent fafci<' 

 cuius he informs us, with that true fplrit of candour which diredls his refcarches and en- 

 titles them to the mod refpeflful attention, that the doftrine of a monoecious chara£ler 

 mull be totally abandoned, fince upon a more critical and attentive examination he finds 

 " the previous fruClification is efFe£led internally." This laft point being admitted, there 

 hardly remains a fhadow of difference between our refpedive opinions, as far as relates to 

 the propagation of this curious tribe of plants. I muft obferve, however, that as I could 

 not in the firft inftance attribute to thofe capillary veflels the important funcSlion which 

 belongs to a ftate of florefcence, fo neither can I reconcile myftlf to a contrary extreme, 

 " that thofe filaments might be nothing more than an exuding mucus" — admitted in the 

 fecond fafciculus of Ner. Brit. p. 13. This opinion is taken up principally upon the dif- 

 appearance of thofe fine hairs when immerfed in water ; as if they at once became re« 

 folved into a mucous fluid. But the fad is, they ftiU remain in the fame unaltered ftate, 

 and may be difcovcred in the aquatic mlcrofcope in a ftrong light during their inimerfion. 

 Their extreme tenuity and minutenefs may caufe them to collapfe, and adhere to the fur- 

 face of the plant ; and their tone of colour, which may aftimilate itfelf to that of water, 

 will no doubt render them difficult to be feen. Thcf« pencilled clufters are reprefented in 

 the firft plate and fafciculus of the Ner. Brit, in their urceolate veflels. If they were 

 deftined to carry off the mucus, they would not be excluded from the internal mafs by 

 thofe callous veflels in which they are confined. If they were part of the fluid, they 

 would be of very difl^erent lengths. Befidcs, thefe filaments exift when the plants are in 

 their firft and moft tender ftate (as I have obferved upon a former occafion), and before 

 they produce the leaft appearance of mucus. This fluid is not conftaiitly produced, and 

 principally abounds in a ftate of maturity. In fummer time it may fomctimes be feen 



U 2 before 



