of Bennettites gibsonianus , Carr. 451 
of course be less satisfactory, the smaller the riumber of the 
derived forms from which we can abstract its characters. 
Saporta 1 unites Bennettites with Williams onia y but I cannot 
enquire at present whether or not there are any grounds for 
this proceeding ; he also places both genera in his ‘ stade 
proangiospermique.’ I have already endeavoured to show that 
there are in fact certain points of resemblance between the 
structure of the flowers in Bennettites and the formation of the 
ovary in Angiosperms, but that we know too little of the other 
characters to carry the comparison further. Though there is 
something very attractive in the idea of the ‘ stade proangio- 
spermique,’ yet we naturally hesitate when we find Saporta 2 
conceiving of Progymnosperms and Proangiosperms simply as 
ancestral groups of our modern classes and saying : * In every 
way we see clearly that Gymnosperms and Angiosperms form 
two branches which have proceeded from one common stock 
of heterosporous Cryptogams, but have taken different direc- 
tions from the beginning.’ I cannot say that such filiation is 
impossible, but its probability seems to me to be diminished 
by the fact that I meet everywhere with accumulating evidence 
that descent works in more complex ways than by the 
method of simple alternatives. I suggested in a former paper 3 
that the formation of the superior and inferior ovary, of 
monosepalous calyces, of monopetalous corollas, of the in- 
florescences in the depressed urn-like receptacles of Ficus y 
of the ceramidia of Polysiphonia y of the conceptacles of 
Fticus , of the perithecia, pycnidia, and spermogonia of 
so many Fungi, is based on one and the same prin- 
ciple, which I have endeavoured to express by the term 
cuptdar formation . I look upon this as one of the means 
placed within reach of the plant in the course of its develop- 
ment for producing constantly increasing complexity of its 
organisation, while the repeated application, so to speak, of 
this means in a great variety of derived forms at very various 
1 Saporta, G. de, ‘ Paleontologie Fran^aise, terrain jura ssique/ vol. iv. 
2 Saporta, ‘devolution du regne vegetal/ vol. i (1885), p. 201. 
3 Solms-Laubach, Bot. Ztg., 1889, p. 741. 
