610 DR. M. T. MASTERS ON THE PASSIFLORACEZÆ. 
bricate in æstivation, as has already been stated; hence, although the imbrication of the 
sepals may well be attributed to their successive formation one after the other, the oldest 
outermost, the most recent innermost, the others intermediate, yet the imbrication of the 
petals cannot be attributed to a like cause, but to a process of accommodation by which 
one part grows over the edge of its neighbour, and thus occupies less room. The five 
stamens are formed simultaneously opposite to the sepals (though, by oversight, they 
are represented as opposite to the petals in the left-hand diagram). The three carpels 
are, in my opinion, placed opposite to the three bracts, alternating, or nearly so, with 
sepals 1 and 4, 2 and 5, and 5 and 3 respectively. This, however, is not the position . 
assigned to them by Payer, according to whom the three carpels alternate with the three 
bracts, and are placed opposite to the sepals 1, 8, 2. If Payer's version be true, the 
sepals, stamens, and carpels would all be superposed, as may be thus represented :— 
3(5) Bracts. 
5 Sepals. 
5 Petals. 
5 Stamens. 
3(5) Carpels. 
and we should have an exception to the usual rule of alternation, only to be explained on 
an assumption not supported by any evidence, viz. that a second or inner row of stamens 
is entirely suppressed. If the explanation here given be correct, we have no violation 
of the law of alternation, thus: 
3(5) Bracts. 
5 Sepals. 
5 Petals. 
5 Stamens. 
3(5) Carpels. 
The only deviation from the ordinary symmetry of a pentamerous flower would here 
consist in the absence of two bracts and of two carpels. 
According to Payer's usual nomenclature the first-formed bract would be the * bractée 
mére;" the other two, lateral bracts. Wydler, also, in a passage pointed out to me by 
Prof. Hichler, of Gratz, adopts this view, but calls the first-developed bract the bractea 
generatrix, and says it belongs to the tendril. The lateral bracts are regarded by 
Wydler as prophylla. In the opinion, then, of these writers, the first bract belongs 
to an axis of a different and prior generation to that supporting the lateral ones. It 
appears to me, however, that there is no warranty for such an opinion. The course of 
development, as well as the position of the bracts in the adult flower, is sufficient to 
show that in Passiflora the three bracts are formed in succession from the same axis. 
In those species in which the bracts are more numerous than three and scattered, they 
are disposed in one continuous spiral series, and there seems no valid reason in this 
| instance for dissociating the anterior or inferior one from the others. | | 
Theoretically, then, we are justified in assuming that the flower of Passiflora is pen- 
