210 THE ANDUCECIIJM OF MEKTZELIA. 
+ 
CajopJiora and its allies, where the stamens appear ceutrifugally on 
cushions or bosses ; stating his conviction that " these two series of 
genera ought to constitute, if not two distinct Orders, at kiist two Yei7 
distinct tribes of the same Order."* In his ' Legons snr les Pain. Nat. 
des Plantes/ he has adopted the first of these two alternatives, and 
• ' _ 3 J 
broken up the old Order Loamceee into two Orders, the '' Mentzeliees 
and the '' Loasees'' Summing up the essential characters of the Me?it- 
zeJiees, he expresses himself in the following terms : — " By their inferior, 
unilocular ovary, with three parietal placentae ; by their capsular fruit 
and albnminons seeds; and by their regular quinary flower, the Meut- 
zeliees approach the loasees : but are widely separated from them by 
then- stamens, which are disposed in sevei^al whorls, and not in a single 
one [of five compound stamens], and the development of which recalls 
that of the EosacefBj"-\ 
Having been much interested by Payer's description of the deve- 
lopment in Mentzelia and Bartonia, and by the analogy he has pointed 
out between their androeclum and that of the Rosacece, I was induced 
to examine the development of the flower in MeJitzelia anrea with con- 
siderable attention. I have been able to verify, in every essential, 
almost all the details given by Payer. My researches, however, al- 
thoufrh confirmatorv of the accuracy of Payer's facts, "have led me to 
adopt a ver,^ different interpretation of the morphological constitution 
of the androecium, — my opinion being based, to a great extent, upon 
observation as to the period at which the carpels appear, a point to 
which Payer has not adverted. 
In the young flower of Mentzelia aiirea, from about the period when 
the petals make their appearance, the receptacle becomes concave or 
cup-shaped ; and on the inner surface of this receptacular cup the sta- 
mens are developed in the following manner: — ^In the first place, there 
appear/r6 stamens, alternate with the petals, and near the upper edge 
of the cup ; then, a little lower down, a range of feti stamens, so dis- 
posed that each of the five primary is accompanied by two secondary 
stamens, one on either side ; later, and stiU lower down, a third range, 
consisting of ttcenty stamens arranged so that each of the ten stamens 
of the second degree is accompanied by two of the third, one on either 
side; then a fourth i*ange, also of twenty stamens, alternating with 
* Payer, ' Orgauogenie/ p. 390. 
t Payer, 'Lctjoiis sur les Fam. Nat. do3 Plantes,' p. 114. 
