548 
MORPHOLOGY. 
BOOK VI. 
The reader who would occupy himself further with this 
curious subject, may consult Miquel's Commentatio de orga- 
norum in Vegetahilihus ortu et Metamorphosi, Lugd. Bat. 1833, 
and Roper's treatise de Organis Plantarum. 
Engelmann has, moreover, i^de Antholysi pvodvomus) at- 
tempted to classify the principal aberrations from normal 
structure. He has collected a very considerable number of 
cases under the following heads. 
1. Retrograde metamorphosis {Regressus), when organs 
assume the state of some of those on the outside of them, as 
when carpels change to stamens or petals, liypogynous scales 
to stamens, stamens to petals or sepals, sepals to ordinary 
leaves, irregular structure to regular, and the like. 2. Folia- 
ceous metamorphosis {Virescentia), when all the parts of a 
flower assume more or less completely the state of leaves. 
3. Disunion (Disjunctio), when the parts that usually cohere 
are separated, as the carpels of a syncarpous pistillum, the 
filaments of monadelphous stamens, the petals of a mono- 
petalous corolla, 8cc. 4. Dislocation (Ajwstasis) : in this case 
the whorls of the flower are broken up by the extension of 
the axis. 5. Viviparousness (Diaphgsis), wlien the axis is 
not only elongated, but continues to grow and form new parts, 
as in those instances where one flower grows from within 
another. And finally, 6. Proliferousness (Echlastesis) , when 
buds are developed in the axils of the floral organs, so as to 
convert a simple flower into a mass of inflorescence. A very 
considerable number of instances are adduced in illustration 
of these divisions, and the work will be found highly useful as 
a collection of curious or important facts. 
The doctrines of morphology, and the evidence in support 
of them, may now be considered so far settled, as to require 
but little further illustration for the present. This is, liow- 
ever, only true of flowering plants : in the whole division of 
flowerless plants tliere has been scarcely any attempt to dis- 
cover the analogy of organs, and to reduce their structure to 
a corresponding state of identification. I some time since 
endeavoured to excite attention to this subject, by hazard- 
ing some speculations which had at least the merit of novelty 
to recommend them ; but I cannot discover that any one has 
