SECT. III. GEMS. 411 



opinions Hedwig and others, that several tribes of 

 what are usually denominated cryptogamous plants 

 are propagated solely by gems. 



The Lichens, according to Gaertner, are of this 

 description ; that which is usually regarded as their 

 seed being merely a powdery propago bursting from 

 the surface of the plant, and vegetating without 

 changing its form. Hedwig, after Adanson, con- 

 tends indeed that the granules immersed in the 

 scut dice of the Lichens are true seeds. But it is to 

 be recollected that all Lichens are not furnished with 

 scutellce, nor all scutellce with granules ; and much 

 less, consequently, with a sexual apparatus. 



The Fungi also, according to Gaertner, are alt 

 gemmiferous, having no sexual organs, and no pollen 

 impregnating a germe. In the genus Ly coper don 

 the gelatinous substance that pervades the cellular 

 tissue is converted into a proliferous powder; in 

 Clavaria the fluid contained in the cavities of the 

 plant is converted into a proliferous powder also : 

 and in the Agarics, Hydnum, and Boletus, vesicles 

 containing soboliferous granules are found within 

 the lamina, pores, or tubes. Hedwig, on the con- 

 trary, ascribes to the Fungi a sexual apparatus, 

 and maintains that the pollen is lodged in the volva. 

 But here it is to be recollected as in the cases of the 

 scutellae of the Lichens, that all Fungi are not fur- 

 nished with a volva, and consequently not furnished 

 with pollen. 



The Conferva and Ulva, together with the ge- 



