24 ON THE PROTEACEiE OF JUSSIEU. 



all Proteaceae is a circumstance of the greatest importance 

 in distinguishing the order from the most nearly related 

 tribes ; and its constancy is more remarkable, as it is not 

 accompanied by the usual position or even uniformity in 

 the situation of the external umbilicus. 



37] If Gaertner had not described the plumula of Protea 

 argentea, I should not have hesitated to assert that it was 

 inconspicuous in the whole order. 



The number of cotyledons when more than two is a 

 circumstance of little importance. In Persoonia, the only 

 genus of the order in which a plurality of cotyledons has 

 been observed, I am not even certain that their number is 

 constant in those species in which this anomaly occurs. 



In the following part of this essay it may be observed, 

 that the genera into which I have subdivided the great 

 African family Protea, are in most cases similar to those 

 already proposed by Mr. Salisbury in the Paradisus Lon- 

 dinensis : from that essay however they are certainly not 

 derived, but before its publication were formed and sub- 

 mitted to the judgment of Mr. Dryander, at whose sugges- 

 tion they are now offered to the Society. That the results 

 of an examination conducted by two observers wholly inde- 

 pendent of each other, are so similar, will probably be con- 

 sidered as some proof of their correctness. 



As Mr. Salisbury's generic names have the unquestion- 

 able right of priority of publication, I have in most cases 

 adopted them, though I wish some of them had been 

 differently constructed. But as I cannot accede to his 

 application of the Linnean names Protea and Leucaden- 

 dron, I shall here, that I may not disturb the following 

 arrangement, assign my reasons for differing from him in 

 this respect ; and as in so doing I am obliged to trace the 

 progress of Linnaeus's knowledge of the family, I persuade 

 myself that this will in some degree compensate for the 

 otherwise unwarrantable length of the discussion. 



The name Protea, which originated with Linnaeus, first 

 occurs in the folio edition of his Systema Naturae pub- 

 38] lished in 1735 ; no generic characters are there given, 



