PRtlCtmCATION OF TKE CRYPTOGAM!.*:. 



Fructification 

 af the fuci. 



Jucus serratus 

 described. 



General ana- 

 logy between 

 the marine 

 and other 

 plants. 



Vesicles the 

 male of the 

 fuci. 



will quickly ascertain, whether it is the original or a para- 

 site plant : if no wood vessel leads to it, it should be con- 

 demned at once. 



I shall now turn to the fructification of the cryptogamiae ; 

 beginning with the se,a weeds, but leaving out the conferva ; 

 which of itself would nearly occupy a letter. The fructifi- 

 cation of the fuci in general is exemplified in a specimen of 

 the fucus serratus; which 1 shall just describe. A jellylike 

 ma6s, with seeds bearing granules, and external papillae. 

 Though the apparent anomaly, that prevails in the fructifi- 

 cation of the fucus genus, is acknowledged by all, yet this 

 variety is more in appearance, than in reality, as I shall 

 prove in a future letter. Whatever may be the difference in 

 the formation of the marine plants, and in their means of 

 receiving nourishment ; in all the general lines of their fruc- 

 tification they differ not from all other plants. The line of 

 life composes the female plant invariably, and is always to 

 be known by its direction ; and the seeds are tied by the 

 same line. Hence it is easy to discover it ; since, wherever 

 a branch is going to shoot (in the thick fuci especially) if 

 we seek the line from which the bud proceeds, it will directly 

 point out the line of life, or vital mark. The wood .vessels 

 are always to be traced to the male plant, whether carrying 

 sap or no sap : for these are those peculiar juices already 

 mentioned, of a more oily nature and wholly destined to the 

 formatiori of the pollen. Fig. 3 is the tubercle of the fucus 

 serratus; CC is the line of life leading to it: fig. 4 is a 

 circle under the tjubercle, which has rays proceeding from 

 it, to which the seeds are always attached, and to which, 

 let them appear ever, so much scattered, they are invariably 

 fixed. As to the male plant, it is certainly the pencilled 

 vesicles on the frond as it is also in the vesiculosus and 

 many others. When much magnified, they are very cu- 

 rious ; in the first it is pitcher shaped, from out of which 

 tubercle the powder proceeds. In the vesiculosus it is a 

 aort of ring, in which the powder is formed, and worked into 

 the hairs. In both the wood vessels meander from male 

 tip male, and the hairs (if prevented sticking on the frond) 

 move much when breathed on, and when shaking out the 

 govvder, frpqa its filaments. See fig. 5, ee male, F the 



wood 



