f 
| 
tations for the fulfilment of particular purposes, it seems to me a matter of very little 
consequence to determine in these transitional stages precisely where the line should be 
drawn between leaf-organ and axial organ. 
Summary.—Recapitulating the main facts which the study of development brings to 
light, and noting the inferences that may be drawn from these facts, I may state briefly 
that the development of the leaves in Passiflora is basipetal, while that of the sepals, 
petals, and stamens is basifugal. The carpels, on the other hand, are basipetal in their 
mode of development. 
In the mature flower the sepals and petals are imbricate in æstivation, although in the 
first instance both are valvate. It might be surmised that the imbrication of the sepals 
would result from the successive development of those organs; but the petals, which are 
equally imbricate in the bud, are developed simultaneously. The imbrication, then, of 
these organs is a secondary operation in point of time, and, however important as a means 
of discrimination for classificatory purposes, does not seem to have any special morpho- 
logical significance beyond ensuring economy of space. 
It has already been shown that the so-called * conduplicate ’ arrangement of the leaf is 
due to increased development at the margins as contrasted with the central portions of 
the leaf, 
The tube of the flower is an expansion of the receptacle formed after the foundations 
of the flower are laid. The corona also is a late formation, its constituent filaments or 
membranes emerging from the inner side of the flower-tube at a late period of the forma- 
tion of the flower, and being referable neither to the petals nor to the stamens. The 
corona, then, is an organ sui generis, developed, as it would seem, for the fulfilment of a 
special purpose, as will be hereafter shown. As to the nature of the corona, it is im- 
portant to quote here Griffith’s significant words*. Alluding to the conflicting opinions 
as to the morphological nature of this series of organs, and to the notions held by Lindley t, 
who considered the coronal filaments to be rather of petaloid than of staminal nature, 
because the normal metamorphosis of the flower is centripetal, Griffith remarks, **Ob- 
servation, which does not rely on making lucky conjectures, and which argues from things 
seen by the eye, not from things imagined (seen by the mind), proves that they are 
neither the one nor the other." 
The gynophore, as before stated, is a secondary production, formed by the elongation of 
the thalamus subsequent to the formation of the other portions of the flower. | 
The only other point in the development that it seems worth while again to allude to 
is the dichotomy of that axillary tubercle which ultimately forms on the one side a ten- 
dril, on the other a peduncle. The branching here, as might have been anticipated, is not 
due to the formation of a new growing point or bud, but to a dichotomy or subdivision 
of the primary tubercle. 
606 DR. M. T. MASTERS ON THE PASSIFLORACER. 
TERATOLOGY. 
Several cases of deviation from the ordinary structure have come under my observation 
in certain species of Zacsonia and Passiflora. To some of these it may be interesting to 
refer. Ina flower of the garden hybrid x P. Belottii there were six sepals, six petals, six 
S eee E en T Veg. Kingdom, p. 333. | 
