Memoranda on the Origin of the Botanical Alliances, 247 



very readily, an abbreviated expression for the series, in which 

 the solutions may be exhibited, but which would often be 

 hard to determine by indirect methods. 

 Trin. Coll., Camb., July 20, 1837. S. S. GREATHEED. 



XXVIII. Memoranda on the Origin of the Botanical Alliances. 

 By Sir Edw. Ff. Bromhead, Bart., MA., F.B.S. L. $ E* 



\ GARDH mentions Batsch as the first writer who at- 

 ■**■ tempted to form alliances on a sound principle, though 

 unsuccessfully; and Dr. Lindley justly notices " Agardhii 

 opera gestumatissima Bartlingiique, qui viam ad meliores res 

 aperuere." Agardh's work and a selection of others, which 

 I in vain endeavoured to procure from the Continent, Dr. 

 Lindley most kindly forwarded to me from his own library. 

 By this I have been enabled to institute a comparison with the 

 alliances proposed by botanists of every school, a test very 

 useful in confirming sound assemblages, ascertaining their 

 true limits, and developing the ground of their formation. 

 Such a reference is moreover a necessary act of justice to the 

 founders. 



Usneales. — These are the Bhizophyta or Sporidiacea? of 

 Rudolphi: "Sporangia spuria vel nulla, sporidia substantias vel 

 superficiei immersa, cotyledonidia nulla." Linnaeus doubted 

 whether the Fungi should form part of the series in an arrange- 

 ment of plants. They have been made sufficiently numerous 

 to form one or more distinct alliances ; some have represented 

 them as passing into Lichens, others as passing into Alga?. 



Usneos^e are nearly the Sporidiferce of Agardh, and the 

 Fungales of Dr. Lindley. 



Jungermanniales. — These are the Musci (hepatici and 

 frondosi) of Hedwig, who omits Riccia. They are the Foliacece 

 of De Candolle, the Musci of Bartling, and the Muscales of 

 Dr. Lindley. 



JuNGERMANNios#: are nearly Dr. Lindley's second section 

 of Acrogens. 



Lycopodiales. — The Tetradidymce of Wahlenbergh, found- 

 ed u quaternata dispositione sporarum," add to this alliance 

 Ophioglossaceae, and doubtfully Equisetaceae. Agardh ex- 

 cluded the latter; Dr. Lindley excluded also the former from 

 his Lycopodales. Lepidodendrum is now added : there can- 

 not be any reason why extinct genera should be overlooked in 

 botany more than in other branches of natural history. All 



* Communicated by the Author. 



