o*. TRANSACTIONS OF THE SECTIONS. 85 
On some Vegetable Monstrosities illustrating the Laws of Morphology. 
By E. Lanxester, MD., ERS. 
The author stated that the only way of arriving at a proper knowledge of the im- 
port and relation of the organs of plants, was to study the history of the development 
of each organ from its primitive cells; by this means those laws of morphology had 
been evolved which were so successfully applied to systematic botany at the present 
day. Although morphology must principally rest on observation, more especially 
with the aid of the microscope, as experiment could hardly be made in this depart- 
ment of inquiry, yet nature sometimes experimented as it were for us, and by 
arresting organs in their process of development, presented to us in a permanent 
form, the various transitionary stages of a normal development. Plants, or parts of 
plants presenting these forms, were called ‘‘ monstrous,” ‘‘ monsters,’’ or ‘‘ mon- 
strosities,” terms borrowed from the animal kingdom. These permanent forms of 
the lower stages of development were found in all parts of the plant, and were worthy 
of study as confirming or modifying the general laws of morphology. The follow- 
ing instances had revently occurred under the author’s observation, and he thought 
them worthy of record. 
In the earliest periods of the history of the development of the leaf its position was 
alternate, one leaf above the other, subsequently the leaves in many families became 
opposite or verticillate. An instance was given of the original alternate type remain- 
ing in the Hippuris vulgaris, in which the leaves, instead of. being in whorls, were 
_ - arranged alternately in a spiral upon the stem. : 
4 In the conversion of the leaf-bud into the flower-bud, bracts were the organs 
which indicated the earliest change in the leaf. Two instances were exhibited, one 
_ of Plantago major, found by the author, and the other Plantago media, presented 
_ tohim by Dr. Lindley, in whose garden it grew as a permanent variety, in which the 
bracts normally situated at the base of the flower, and smaller than that organ, 
retained the character of fully-formed leaves. 
The sepals, petals and stamens exhibited still further departures from the ordinary 
_ character of the leaf. These however often retained the appearance of the leaf after 
the tendency to form the flower had commenced. As an instance of this specimens 
were exhibited of the Brassica Napa, in which, in the place of the sepals, petals and 
stamens, there were developed three rows of succulent leaf-like organs. This had 
arisen from the attack of a fungus. Reference was also made to specimens of Tri- 
_ folium repens, which had been gathered by the author in company with Professor 
__E. Forbes, Mr. A. Henfrey and Robert Austen, Esq., at Chilworth Manor, in which 
the parts of the flower exhibited the characters of the leaves, and the short flower- 
_ stalks were elongated into the character of the stem. 
The highest tendency of the plant was the production of the flower, and where 
_ this tendency was greatest we must seek the typical form of the vegetable kingdom. 
_ This was found in the Composite. In this family the tendency to the production of 
_ flowers was so strong, that arrests of development were seldom recorded. A speci- 
men of Tragopogon pratensis was exhibited in which the pappus was converted into 
_ foliate appendages; the corolla was of a green colour, and the style had assumed 
_ also a foliaceous character. 
_ The most central organ of the flower, the pistil, was also in its external parts in 
| the earlier stages of its growth identical with the leaf. In the Trifolium repens and 
 Tragopogon pratensis just mentioned, it retained this form. The origin of the placenta 
and ovules, within the carpellary leaves, must still be regarded as an undecided point. 
| An instance of the capsule of the Papaver somniferum was exhibited, in which, in the 
interior of the capsule at its base, the growing point, there was present an abnormal 
_ growth, consisting of four leaf-like organs, opposite each other, separate above and 
united at the base, forming a kind of pedicel ; each of tne leaves was partly united by 
_ the margins, forming a kind of cavity which was covered by a curve of the leaf at its 
_ apex; one of the leaves was divided into two parts, each containing a cavity; on 
the edges of the leaves above was a changed condition of the tissue resembling the 
_ Stigma, thus confirming the theory which regarded the stigma of Papaveracee as 
_ the result of the union of the two edges of two carpellary leaves. The author re- 
garded this monstrosity as affording evidence against the theory of the development 
of the placenta and ovules independent of the carpellary leaf. 
