608 DR. M. T. MASTERS ON THE PASSIFLORACEE. 
MORPHOLOGY OF PASSIFLORA. 
Having briefly adverted to the conformation of the flower in the several genera of the 
order and traced its mode of evolution in Passiflora, 1 am now in a position to offer some 
remarks on the morphology of Passiflora itself, taking that genus as the most complex 
one of the order. In a flower of the section Granadilla, where the bracts are well deve- 
loped and approximate to the flower, there are three bracts formed successively, five sepals 
also formed successively, five petals formed simultaneously, alternating with the sepals 
and with them raised upwards on the edge of a tube, which is not developed until the 
other parts of the flower are well developed, and which is therefore to be considered a 
tubular prolongation of the thalamus or receptacle. Alternating with the petals are five 
stamens, formed simultaneously and strictly hypogynous. "Three carpels constitute the 
- pistil, which is at first sessile, but which afterwards becomes raised by the elongation of 
the central portion of the receptacle; the latter in its upward course bears not only the 
pistil but the stamens also. The various rings of the corona are not developed till after 
the formation of the other parts of the flower; and the date of their evolution corresponds 
with that of the receptacular tube, thus preceding that of the gynophore. 
The three bracts in the unopened flower-bud are imbricated, one bract overlapping the 
other two. The sepals and petals are quincuncially imbricate, the stamens valvate and 
appressed against the pistil The three carpels are also valvate, so that they form a 
one-celled pistil with three parietal placentas. 
The position of the parts of the flower, in relation to the axis and to the floral leaf, 
in the axil of which the flower originates, remains to be considered ; and as I have been 
led from my observations to form slightly different conclusions on this matter from those 
of Payer and others, it becomes necessary to explain in what way my interpretation 
differs from that of other botanists, and to suggest the probable cause of the slight di- 
vergence of opinion. The flower-stalk of a Passion-flower is formed in the axil of a leaf; 
and it has already been seen that the tendril is merely a flowerless branch originating 
from the same growing point as the peduncle. Between the leaf, then, anteriorly and the 
main axis posteriorly is the flower-bud, enveloped in its three bracts; and by the side of 
the bud is the tendril. In the early stages of the flower-bud the two stipules belonging 
to the leaf are relatively very large. In point of time of development they are far in 
advance of the leaf; and they are placed, not anteriorly like the leaf or leaf-stalk of which 
they are integral portions, but laterally ; they are thus placed with their edges fore and 
aft, as regards the axis, and shut in the flower-bud and the tendril on the sides. In this 
early stage, then, the flower-bud and tendril are completely enclosed in a kind of case 
formed anteriorly by the leaf, laterally by the stipules, and posteriorly by the axis. Bearing 
in mind this arrangement of the parts in the axil of the leaf, the position of the bracts, 
sepals, Sic. with regard to the anterior or posterior part of the flower may be readily 
Payer and most authors state that the odd bract is anterior, the two others lateral, as 
regards the main axis. I believe this to bean error, and consider the bracts to be placed — 
laterally, as regards the axis—two on the side adjacent to the tendril (which fits into the — : 
