28 3/r. Brown, on the Proteacea of Jussieu. 



velope, it will be still better to call it perianthium or perigoniumj 

 which latter term was proposed by Ehrhart, and is adopted by 

 Decandulle. 



A circumstance raeritinor the attention of the theoretical bota- 

 nist, respecting the calyx in this order, is its invariable division 

 into four leaves or segments ; for the single exception noted by 

 Linnaeus in his description of the male flowers of Brabejum, he 

 himself seems afterwards to have distrusted, from the manner in 

 which he has introduced it into the amended generic character 

 given in the Mantissa; and I may add, that in nearly 400 species 

 of the order, which I have examined, I have not met with a 

 single exception to this rule. 



With this uncommon constancy in point of number, it is re- 

 markable that there is, in the whole order, a strong tendency to 

 irregularity in form, the various kinds of which are of great im- 

 portance in characterizing genera. 



Before the expansion of the calyx the margins of its segments 

 are applied to each other; and from the unequal degrees of co- 

 hesion in many cases subsisting among them after expansion, se- 

 veral kinds of irregularity arise. I am not sure that any term 

 has been contrived for this manner of aestivation, except it be 

 the ttstivatio valvata of Linnaeus ; but as he has not defined it, and 

 as his commentator Reuss has given the very different aestivation 

 of grasses as an example, I have, in introducing this circumstance 

 into the general description of the order, specified it at length. 



From the colour of the calyx, many genera of Proteaceae are 

 indicated with tolerable certainty. Thus Synaphea is distinguished 

 from Conospermum by its yellow flowers ; and no instance of 

 yellow flowers has been met with in the numerous genera Serruria 

 and Spatalla, nor any of purple in Leucadendron. In some ge- 

 nera 



