504 Mr. Correa de Serra on the 
pollen can exist in an active state under a mucous appearance ; 
and if the antheras of perfectly submersed flowers are nothing 
else than closed vessels filled with mucous pollen ; what doubt 
can we entertain, that the mucilaginous vesicles of the sub- 
mersed Algce (which contain also their seeds) are anthers, 
and very appropriate to the nature and situation of these 
plants ? 
An observation made by Gleichen shews more clearly the 
propriety of such a fructification. The pollen of any flower, 
when put into water, in a very short time begins to move, and 
its particles agitate themselves in every direction, perfectly re- 
sembling the most lively animalcula. Their activity in this 
state lasts some time ; but, if the least quantity of salt be put 
into the liquor, death quickly ensues, from which they never 
more recover * This inclosed mucilaginous fructification was 
therefore the only one which could ensure existence to ve- 
getables living chiefly in sea-water, with which their mucus is 
found to be immiscible.-f 
A still more urgent consideration will, I hope, determine 
those who may hesitate to consider the mucus of these plants 
as pollen, and the vesicles which contain it as antherae. The 
parts of fructification, in all plants, are temporary, and their 
existence is relative to their particular functions, and to each 
other. The moment the fecundation happens is a moment of 
crisis : henceforth the fecundated parts proceed to grow and 
perfect themselves, the fecundating ones change and decay. 
This is a general law of nature, to which we know no ex- 
ception, nor can any be easily conceived to exist. We must 
remark, that there is an epoch when the mucous substance in 
* Gleichen Observ. Microscop. pag. 32. f Gmelin Hist. Fucorum, pag. 27. 
