18 Rhodora [JANUARY 
that evolution which is regarded as having eventuated in the most 
complex floral structures of our times.” From such studies of 
abnormality as De Candolle has made the fullest significance of 
teratological formations is to be gathered. 
SO-CALLED REVERSIONS AMONG MONSTROSITIES.— Such malformed 
carpels as those of Mr. Fernald’s Drosera are not infrequently 
spoken of as reversions. But the term reversion itself is to be 
understood in at least two senses. As Gray’s Structural Botany has 
been the schoolmaster to bring most of us to the study of morphology, 
and as the treatment of floral malformations in that work has proba- 
bly been misunderstood, Dr. Gray’s attitude had best be defined. 
Dn. Gray’s Views or REVERSIONARY MONSTROSITY.— In the Struc- 
tural Botany Dr. Gray says that in the vegetable kingdom monstrous 
forms often elucidate the nature of organs. ‘Three pages are there- 
fore given to the subject.* Abnormal forms are introduced as one 
of the two chief kinds of evidence upon which we may rest the doc- 
trine of the unity of type existing among all kinds of foliar append- 
ages of the stem. The readiness with which essential organs are 
transformed to petals and even to vegetative leaves appears to Dr. 
Gray to show that stamens, carpels, and foliage leaves are homolo- 
gous. “The commonest of these changes [abnormalities] belong to 
what was termed by Goethe retrograde metamorphosis ; that is, to 
reversion from a higher to a lower form, as of an organ proper to the 
summit or center of the floral axis into one which belongs lower 
down.” 
The use of the word “reverson” and the statement that essential 
organs of the flower and foliage leaves are homologous, appear at 
first sight to represent the abnormalities in question as reversions in 
the phylogenetic sense. To take the words in this sense would, 
however, be to attribute to Dr. Gray a view which he has not main- 
tained in the Structural Botany. When we seek for definitions of 
homologous, we find a studious avoidance of any suggestion of his- 
toric community of origin for homologous structures. Homologous 
is defined as being “of one name or type,” i. e. “ideal plan or pat- 
tern.” Organs are homologous with leaves which “accord with 
leaves in mode of origin, position and arrangement on the axis or 
stem.” When, therefore, abnormal flowers show that pistils and sta- 
mens are the homologues of leaves they merely demonstrate that 
1 Structural Botany, pp. 171-173- 
