GOETHE’S PROGRESSIVE METAMORPHOSIS 159 
Plants alone are considered, or if sporangia are not regarded too scrupulously 
from an evolutionary point of view, and if it be assumed that they may 
be and have been habitually generated at large in the course of descent 
upon pre-existent foliar organs. If these points be granted, then it might 
be possible to retain Goethe’s progressive Metamorphosis as the basis of 
an evolutionary story applicable to the Higher Plants. As a matter of 
fact, Botanists continued to analyse and describe the flowers of the Higher 
Plants in this way for a whole generation after the Origin of Species 
had been published. The flower was habitually regarded as the result 
of metamorphosis of a foliage shoot. Though the point was not always 
put into direct terms, the underlying assumption was that a conversion of 
vegetative parts into propagative parts takes place in the individual: that 
sporangia originated sporadically in descent, as they seem to do in certain 
cases now, and that such changes as are seen in the development of 
the individual had their place also in the history of its evolution. But 
increasing knowledge of the life-cycles of the lower forms, and of their 
comparison one with another, was meanwhile leading to sounder views of 
the origin of the higher Vascular Plants. Alternation of generations 
became gradually a more exact factor in the morphology of the last half- 
century. It seems no longer possible to look upon the Vascular Plant as 
a primary entity, as it was held to be in the time of Goethe. The 
sporophyte generally, and consequently the plant-body of all the Higher 
Plants which is a sporophyte, must necessarily be held to be secondary 
by all those who recognise antithetic alternation as a constant feature in 
descent of the Archegoniatae: for them the story of origin of the sporo- 
phyte must affect the interpretation of its parts. 
A fundamental question of method in morphology is involved in this 
discussion, viz. the question of the validity of conclusions based on 
observations of the ontogeny as against the well-founded conclusions of 
phylogeny. It will now be generally agreed that, provided the conclusions 
as to phylogeny be sound, they should have the precedence over those 
based on observation of the individual life. But in the practice of the 
middle part of last century it was customary to act in the opposite sense, 
and to take the successive events in the story of development of the 
individual as the basis of morphological history: such views on descent 
as are based on comparison were often left out of account or given only 
a second place. If this latter principle be adopted, then conclusions. 
harmonising with Goethe’s progressive metamorphosis will follow, and the 
sporophyll may be accepted as an altered foliage leaf; but if precedence 
be given to the results of a broad comparison, then a converse conclusion 
will necessarily appear the more probable. 
But there is also another question involved in Goethe’s view of “pro- 
gressive metamorphosis,” that of the origin of the sporangia which appear 
in the strobilus or flower. The assumption that sporangia can: be formed 
indiscriminately upon pre-existent vegetative parts was at the back of 
