ePub 版

You will perceive, on examining the formation of the Rose, that its numerous stamens are attached to the calyx. A more perfect idea of their situation may be obtained, by removing the petals and cutting the calyx longitudinally. There. fore, because it has more than ten stamens growing upon the calyx, it belongs to the 11th class, Icosandria. The pistils being more than ten, it is of the 13th order, Polygynia. It belongs to the genus Rosa.

The shape of the calyx is urnform ;" the calyx is inferi. or,or below the germ; it is “five cleft,or has five divisions around the border;it is fleshy,or thick and pulpy,“ contracted towards the top;" “ petals 5,” (this is always the case with a rose in its natural state, unassisted by cultivation;)“ seeds numerous, bristly, fixed to the sides of the calyx within."

There is no seed vessel, or proper pericarp to the rose; but the calyx swells and becomes a dry, red berry, containing

many seeds.

The genus Rosa contains many species, distinguished, one from another, by the different shape of the germ, the smoothness or roughness of the stems, the presence or absence of thorns, the shape of the leaves, and the manner in which the flowers grow upon the stalks, whether solitary or crowded to. gether in pairs or scattered, and whether erect or drooping.

The Moss rose, (Rosa muscosa,) is distinctly marked by the hairs, resembling moss, which cover the stems of the calyx; these hairs are a collection of glands containing a resinous and fragrant fluid.

The apple blossom appears like a little rose; its calyx be. comes thick and pulpy, and at length constitutes that part which we usually call the fruit, though strictly speaking, the seed only, is the fruit. On examining an apple, you may notice, at the end opposite the stem, the five divisions of the calyx.

Analysis of the Poppy. The Peppy affords a good illustration of the 12th class, Po. lyandria ; 'here are numerous stamens, always more than ten, sometimes more than a hundred, growing upon the receptacle; the Poppy has but one pistil, and therefore belongs to the first order, Monogynia; the genus is PAPAVER. The Poppy has a “ca. lyx of two leaves,” but these fall off as soon as the blossom expands, and are therefore called “ caducous ;" the corolla (except when double) “is four petaled;" it has no style, but the stigma is set upon the germ,

and is therefore said to be sessile. --why is t in the 11th class ?-why the 13th order ?-Generic characters of the rose-Circumstances which distinguish the different species of the genus Rona- Apple blossom and fruit-Analysis of the Poppy.

The germ is large and somewhat oblong, the stigma is flat and radiated. The pericarp is one-celled or without divisions, it opens at the top, by pores, when the seeds are ripe. The spe. cies of Papaver which is cultivated in gardens, is the somnifer. um, which name signifies to produce sleep. It is often called Opium Poppy.

By observing the figures which stand at the right hand of PAPAVER in the description of genera, and also of species, you will find to what natural order the plant belongs. The number 27 refers to the natural orders of Linnæus; on looking for these

you will find against this number Rhæadæa, which includes plants with capsules and caducous calyxes. Such plants, as to medicinal properties are anodyne (causing sleep), and antiscor. butic (curing eruptions).

The number 62 points to the natural orders of Jussieu ;* on referring to these, you will find this number to stand against Papaveracea, which is a word in the plural number, signifying poppy-like plants. You cannot at present understand what is meant by natural orders or natural families, but when you have become familiar with the analysis, and different parts of plants, we will give an explanation of these orders, and of the principles by which they are arranged.

In the commencement of a new science, it is not to be ex. pected that every idea, or principle of arrangement will seem perfectly clear, as such may often relate to other

principles not yet explained. In architecture, we know it would be impossible to form a clear idea of the use or beauty of a particular part of an edifice, until it was considered in its relation to the whole. The beginner in any branch of scientific knowledge, is not like one travelling a straight road, where every step is so much ground actually gained; but the views which he takes are like the faint sketches of a painter, which gradually brighten and grow more definite as he advances.

The idea which was formerly entertained, that students must learn perfectly, everything as they proceed, appears to be founded upon a wrong view both of the nature of the mind, and of the sciences. The memory may be so disciplined as to retain a great many words, but words are only valuable as instru. ments of conveying knowledge to the mind; and if, after a careful attention to a subject, something in your lessons may appear obscure, you must not be discouraged by attributing the difficulty to the dulness of your own faculties; it may arise from want of clearness in an author's style, or the subject may be connected with something which is to follow; therefore, you should patiently proceed, with the hope and expectation that difficulties will gradually disappear.

* The table of contents will shew where the natural orders are to be found.

Natural order, how pointed out-Remarks respecting the commencement of a new science-Words of use only as instruments.

We shall not at present give any more examples of analyzing plants. With even the little practice you have now had, you can analyze flowers of any of the first thirteen classes ; but it is necessary


you to know before proceeding farther, that the two circumstances of the number and insertion of the stamens, are not all that you are to take into consideration, in the arrangement of the classes; this was not sooner observed, that your minds at first might not be confused with too many new ideas.

You are now prepared to comprehend the general features of the Linnæan system, and to study the whole of the classes and orders in a connected view. Before proceeding to this, it seems necessary

that you should have some knowledge of Greek and Latin numerals. In our next lecture we shall commence, by this necessary preparation, and shall then explain the characters of the classes and orders, and illustrate the same by draw. ings. Sensible objects are of great assistance to the mind, by enabling it to form definite ideas of the meaning of words. In abstract studies we cannot have such aid; and in order to comprehend instructions given upon them, it is necessary that the definitions of words should be well understood. Many persons are satisfied with a general notion of the meaning of abstract terms; thus, they speak of “a sensation of pity,” when they mean an emotion. A more critical knowledge of the meaning of words, would enable them to perceive, that sensation is a term appropriated to that state of the mind which immediately follows the presence of an external object: it depends on the connexion between the body and the mind,

The mind, separated from all the organs of sense, could have no sensations ; but it could have emotions, for they are feelings which the mind has, independently of the senses.

The great advantage of pursuing studies which relate to material objects, is, as we have before remarked, in being able to illustrate principles, and define terms by a reference to those objects themselves, or to delineations of them,

Assistance which the mind derives from sensible objects-Example of using terms indefinitely

Latin and Greek numerals.- Artificial classes and orders.

We shall now present you with a list of Latin and Greek numerals; these it is necessary to commit to memory, in order that you may understand the names given to the classes and or. ders. It is not in Botany alone, that a knowledge of these nu. merals will be useful to you; many words in our common language are compounded with them; for example-uniform, from unus, one, and forma, form; octagon, from octo, eight, and gonia an angle, hexagon, pentagon, &c.; decimal, from decem, ten. These few examples may show you the importance of knowing these numerals, which will serve as a key to the meaning of many words in common use.




Monos, single. Bis,


Dis, twice.






















Quatuordecem, 14.

Quindecem, 15.



Septendecem, 17.



Novemdecem, 19.



Multus, Many.

These are founded upon distinctions observed in the STAMENS.
According to this system, all known plants are divided into
twenty-one classes.

Importance of understanding Latin and Greek numerals-Latin numeralsGreek numerals-Classes of Linnæus, on what founded ?-How many ?

The first twelve classes are named by prefixing Greek numerals to ANDRIA, which signifies stamen.



One Stamen. 2. DI-ANDRIA,

Two Stamens. 3. TRI-ANDRIA,

Three Stamens. 4. TETR-ANDRIA,

Four Stamens. Number of 5. PENT-ANDRIA,

Five Stamens. Stamens. 6. HEX-ANDRIA,

Six Stamens. 7. HEPT-ANDRIA,

Seven Stamens. 8. OCT-ANDRIA,

Eight Stamens. 9. ENNE-ANDRIA,

Nine Stamens. i 10. DEC-ANDRIA,

Ten Stamens.

Fig. 6.

[ocr errors]
[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors]


The two following classes are named by prefixing Greek numerals to DYNAMIA, which signifies power or


Two Stamens longer Number and relative length. 13. DI-DYNAMIA,

more powerful

than the other two. * The name of this class does not now designate its character, since the number of stamens is often more or less than twenty.

First twelve, how named ?- Those which depend on the number of stamensthose which depend on number and position Number and relative length-Explain the signification of the names of the classes now described.

« 上一頁繼續 »