Polymorphism in the Flower of Silene maritima. 9 
types were also met with on the famous Chesil Bank in Dorset, thus 
indicating a wide distribution. In some of the forms to he described 
the sexual organs are incomplete, but in the four cases, where both 
stamens and stigmas are present, there is marked protandry. The 
sequence of development is as follows:—there are ten stamens in 
two whorls of five members each and of these the outer series 
elongate first and shed their pollen ; at this stage the second series 
may be seen with their anthers about half-way up the corolla tube 
(Text-fig., e). When this inner series has developed and dehisced 
the anthers of the outer series have usually either shrivelled, or 
fallen off the filaments. By the time all the anthers have shed their 
pollen the styles will have elongated beyond the corolla tube and 
their stigmatic surfaces diverged and curved backwards. 
It may perhaps be well to mention that the unisexuality of some 
of the forms referred to above in which there are no functional 
stamens, have not been brought into this condition by the action of 
Ustilago antheraruin ; this fungus is of very rare occurrence at 
Blakeney, so far having only been observed in one instance. 
Description of Forms. 
The commonest of all the forms has flowers from 20 to 25 mm. in 
diameter, and each of the five petals is divided into two lobes which 
either touch or slightly overlap in the median line (Text-fig. a). 
The contiguous petals also overlap and thus the flower at a short 
distance has the appearance of possessing a sympetalous corolla. 
Where the main portion of the petal joins on to the claw there is 
an abrupt waist-like narrowing and at this point two scale-like 
structures (the coronal scales) may be present, but are usually 
either small or entirely absent. 
In Plate I, Fig. la, this form is shewn at the stage when the 
outer five stamens have dehisced and the inner series have appeared 
at the mouth of the corolla. Fig. lb shews the same in a later 
stage ; the filaments of the outer series can be seen, but the anthers 
have dropped, the inner series have dehisced, and the stigmas are 
spread out for the reception of pollen from a flower in a younger stage 
of development. The points of variation are : the extent to which 
the petals are cleft ; the development of the coronal scales ; and 
the number of stigmas, which may vary from three to five. 
Whilst fully recognising that the various types may themselves 
be aggregates of more closely allied forms it will be convenient both 
for description and reference, if we designate each by a name. The 
