The Vegetable World: Being a History of Plants, with Their Botanical Descriptions and Peculiar Properties

Labiate, ha Composite, the Umbellifere, the Crucifere, and

“It is iticcine’ that the embryo is identical in all plants of calthese families; it is monocotyledonous in the Graminacez sMiacex, and dicotyledonous in the other five. The structure

Seed is also identical, the monocotyledonous embryo being | oe| axis of a fleshy albumen in the Liliacez, and upon a farinaceous perisperm in the Graminacee, while the 2 nous embryo isBasti at the summit of a hard vere bumen i

vary in general in their mode of insertion, being hypogynous in! the Graminaceew and Cruciferse, upon the corolla in the Labiata! and Compositz, and upon an epigynous disk in the Umbellifere. | He obtained thus the true value of certain characters which ought” neyer to yary in the same family; but along with these he found”

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Fig. 292,—Laurent de Jussieu. others more variable, which he sought to appreciate also, either si? , assist him in the study of other families analogous to them, or 1” ee) Bi explaining those which he had formed, by applying his first rules along with many others founded on observation. _ _cannot, however, follow him here into these details, which resul *

after immense labour, in the establishment of a hundred families, comprehending all the vegetables then known.

“We see in these remarks a principle employed which had altogether escaped the notice of Adanson—namely, that subordination of character which in the method of Jussieu is, to use his own expression, ‘weighed but not counted.’”

When the families were constituted, Laurent de Jussieu grouped them into fifteen classes, as in the following table:—

Such, then, was the arrangement into which Antoine-Laurent de Jussieu distributed the twenty thousand plants known to botanists in 1789. The hundred orders or families he further subdivided into 1,754 genera. That the French botanist had acquainted himself with the principles of Ray's classification is unquestionable; in fact, Jussieu possessed the happy art of adapting the labours of others to perfecting his own conceptions. He made use of the simple language and accurate descriptions of Linnæus, divested of his pedantry. Ray had demonstrated that rigorous definitions in natural history are impossible, and, accepting the decision, Jussieu does not attempt to found his family orders or genera on any single character belonging to objects so various in their habits and organisation as plants.

During the last forty or fifty years other botanists have attempted various systems of classification, but none so successfully as the late Dr. Lindley, whose works are distinguished beyond all

rs for careful research, directed by a vast and comprehensive sp of his subject. In the classifications of De Candolle, End- + Ticher, and of M. Brongniart, the distribution of plants into families is founded, like that of Ray and Jussieu, on the consider- : ation of the cotyledons; of the petalous, monopetalous, and apetalous corolla; finally, upon the mode of insertion of the stamens. Names have changed; things remain the same; and if in their details the ries of families present certain differences, it only arises from he fact that a linear series is incompatible with the natural stem, and that the connection of the intermediate groups may expressed in various ways without affecting the general princi-es of the system. “The formation of natural orders by De says Ad. Brongniart, “is even now a model which irects botanists in their studies to the affinity which connects the various forms of vegetation. Many of these orders have doubtless been subjected to important modifications, both as extendingand imiting them; the numbers have been more than doubled; but. the number of epohinn now known is increased more than sixfold. _ Since the publication of the ‘Genera Plantarum,’ many points in ihe organisation of plants which were either scarcely touched pan were altogether unsuspected, have now been considered,and is found that they do not destroy, but confirm and perfect uhe work of Jussieu. One is even astonished to find that the pumerous discoveries in the anatomy and organigraphy of plants sce the beginning of the century have not introduced greater modifications into the constitution of the natural groups admitted by the author of the ‘Genera Plantarum.’ It is here that we ecognise the sagacity of the savant who established them, and the soundness of the principle which guided him.”

The natural classification of plants, their distribution into families, well defined, and founded upon affinities, have been perfected and placed upon a basis more and more certain in our own 4ays. Botanists have set themselves the task of unravelling and ablishing the characters which dominate, and those which are subordinate, in each family; great numbers have spread them-ves over the globe, exploring the most distant regions, interro-ing the solitudes of forests and plains, which no.European had 0 visited, and aave studied in their native wilds many exotic

plants, comparing them with European species, thus giving us 4. means of pointing out more precisely the genera, tribes, and species} of each natural family. Monographs of a great number of such | families have thus been traced with profound patience. The study of the formation and evolution of organs; the discovery of the |

Fig. 203.—De Candolle. true mode of reproduction in eryptogams, still unknown in De Jussieu’s time; that of infloresceace, of the ovules, of the embryo* of the fruits, have furnished elements for perfecting the limits of families and advancing natural classification.’ Auguste Pyramus de Candolle is one of the botanists of th ‘

century who has most contributed to the general adoption of 4 natural families. His “Essai sur les Properties des Plantes” is _ celebrated for the knowledge which it displays of the comparative _ physiological and physical action of vegetables, and the physical ' organisation which naturally connects certain plants as a group. His “Prodromus Systamatis Naturalis regni Vegetabiles,” especially _ the latest edition by his pupils and his son, is also a wonderful _ work for the extent and precision of its details.

In our own country, from the days of Ray, we have always had zealous followers of the science of botany, more especially in the class which may be called field botanists. Withering, Sir Edward

Smith, and hundreds of followers more or less eminent, employed their leisure in the fascinating and healthy pursuit of species, and perhaps the most valuable contributions to science are the detailed descriptions of species, with their habits and habitats, which ___ have enriched our botanical literature. Nor was the study of the _ physiology of plants—a science which may be said to owe its _ existence to the researches of Grew and Malpeghi— neglected. = To the former belongs the merit of having pointed out the differ- _ ence between seeds with one and seeds with two cotyledons, on which Ray founded his system of classification.: co The German botanists have always been distinguished for their _ patient and laborious investigations, and it was reserved for the first of Germans, the poet Goethe, to effect the last great revolution that as the ideas of botanists have undergone. In 1790, shortly after the _ @ppearance of De Jussieu’s “Genera,” he published a pamphlet on the “ Metamorphosis of Plants.” At this time the functions of the

ans.CeeSeee+. aeOrgans of plants were supposed to be pretty well understood. : Goethe had probably in the courseof his reading stumbled upon _ the notion which has existed from the times of Theophrastus, that _ Certain forms of leaves were mere modifications of others whose _ 4ppearance was very different; a doctrine which Linnzeus seems to have entertained at one time, as he speaks in his “ Prolepsis ‘ ae _, antarum” of the parts of a flower being mere modifications of

5 leaves whose period of development was anticipated. Goethe a | ay -P this theory, and demonstrates that the organs to which e many different names are applied, namely, the bracts, calyx, rela, Stamens, and pistil, are all modifications of the leaf; the

bract being a contracted leaf, the calyx and corolla a combination of several, the stamens, contracted and coloured leaves in a state of disintegration, and the pistil, leaves rolled up according to certai laws. These views of the poet met at first with little attention from

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Fig. 294.—Robert Brown. he; botanists, and we are chiefly indebted to Robert Brown for ~ elucidation of Goethe’s theory. In his “ Prodromus of the ¥ ee of New Holland,” and in many papers in the Philosophical ‘‘ Linnean Transactions, he demonstrates its truth as well as *