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The two following classes are named by prefixing Greek numerals, to the word ADELPHIA, which signifies brotherhood.

15. MON-ADELPHIA,

16. Di-adelpHIA,

Connexion.

Stamens united by their filaments in one set or brotherhood. Two brotherhoods.

The next class is named by prefixing SYN, signifying together, to GENESIA, which signi

fies growing up.

17. SYN-GENESIA,

S Five united anthers, flowers compound.

Fig. 9.

16

17

15

The next class is named by an abbreviation of the word GYNIA, which signifies pistil, prefixed to ANDRIA, showing that the stamens and pistil are united.

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Position.

18. GYN-ANDRIA,

The two following prefixing numerals to house.

19. MON-CECIA,

S Stamens growing out
of the pistil.
classes are named by
CIA, which signifies a

Stamens and Pistils on separate corollas upon the same plant, or in one house.

What classes depend on the connexion of the stamens ?-Explain the signification of their names-What classes depend on the position of the stamens ?

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The name of the last class is a compound of two Greek words, CRYPTO and GAMIA, signifying a concealed union.

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The number of classes as arranged by Linnæus, was twentyfour. Two of them, Poly-delphia, (many brotherhoods,) which was the eighteenth class; and Poly-gamia, (many unions,) the twenty-third class, have, by late botanists, been rejected as unnecessary.

The eleventh class, Dodecandria, which included plants whose flowers contain from twelve to twenty stamens, has been more recently omitted. The plants which belong to these have been distributed among the other classes.

A few botanists retain the whole twenty-four; among American writers who adopt but twenty-one, are Eaton, Torrey, and Nuttall.

THE ORDERS OF LINNÆUS.

The orders of the first twelve classes are founded upon the number of PISTILS.

What does Gynandria signify ?-Monœcia ?-Diocia ?-Natural ClassClasses omitted-Orders of the first twelve classes, on what founded?

The orders are named by prefixing Greek numerals to the word GYNIA, signifying pistil.

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8. OCTO-GYNIA,

9. ENNEA-GYNIA, 10. DECA-GYNIA,

6. this order seldom found.

7. this still more unusual. 8. very rare.

9. very rare.

10.

13. POLY-GYNIA, over ten pistils.

The classes vary as to the number of orders which they contain.

The orders of the 13th class, Didynamia, are but two.

1. GYMNOSPERMIA.

seeds usually four

lying in the calyx.

2. ANGIOSPERMIA.

seeds numerous

in a capsule.

From GYMNO, signifying naked, and
SPERMIA, signifying seed, implying
that the seeds are not covered.
From ANGIO, signifying bag or sack,
added to SPERMIA, implying that the
seeds are covered.

The orders of the 14th class, Tetradynamia, are two, both distinguished by the form of the fruit.

1. SILICULOSA. Fruit, a silicula, or roundish pod.

2. SILIQUOSA. Fruit, a siliqua, or long pod.

The orders of the 15th class, Monadelphia, and of the 16th class, Diadelphia, are founded on the number of stamens, that is, on the characters of the first twelve classes, and they have the same names as Monandria, &c.

The 17th class, Syngenesia, has its five orders distinguished by different circumstances of the florets, as;

1. EQUALIS. Stamens and pistils equal, or in proportion; that is, each floret has a stamen, a pistil, and one seed. Such florets are called perfect.

2. SUPERFLUa. Florets of the disk perfect, of the ray containing only pistils, which without stamens are superfluous. 3. FRUSTRANEA. Florets of the disk perfect, of the ray neutral, or without the stamen or pistil; therefore frustrated,

or useless.

4. NECESSARIA. Florets of the disk staminate, of the ray pis

How are the orders named ?-Orders of the class Didynamia-Of Tetradynamia-Of the classes Monadelphia and Diadelphia-Of the class Syngenesia.

tillate; the latter being necessary to the perfection of the fruit.

5. SEGREGATA. Florets separated from each other by partial calyxes, or each floret having a perianth.

The orders of the 18th class, Gynandria, of the 19th class, Monœcia, and the 20th class, Diœcia, like those of the 15th and 16th classes, depend on the number of stamens.

The orders of the 21st class, Cryptogamia, constitute six natural families.

1. FILICES,-includes all Ferns, having the fruit on the leaves.

2. Musci, Mosses.

3. HEPATICAE,-Liverworts, or succulent mosses.

4. ALGAE,-Sea-weeds, and frog spittle.

5. LICHENES,-Lichens, found growing on the barks of old trees, old wood, &c.

6. FUNGI, Mushrooms, mould, blight, &c.

No confusion is produced in taking the character of some classes, for orders in other classes; for example: if you have a flower with ten stamens, united by their filaments into one set, you know by the definition of the classes that it belongs to the class Monadelphia, you can then, because it has ten stamens, place it in the order, Decandria.

Having explained the principles on which the artificial classes and orders are founded, we will now place them before you, in a synoptical or general view.

"SYNOPSIS OF THE CLASSES AND ORDERS OF LINNÆUS."

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Of the classes Gynandria, Monoecia, and Diœcia-Of the class Cryptogamia -Synopsis of artificial classes and orders.

Connexion of the Stamens by filaments or anthers.

Position of the Stamens relative to the Pistils.

Invisible or
Caducous.

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fila- Characters and names of preceding classes. As, 1. Monandria,

ments united in 1 set.

16. DIADELPHIA, filaments 2. Diandria, 3. Triandria, 4. Teunited in 2 sets-papili- (trandria, 5. Pentandria, 6. Hexandria.

onaceous.

17. SYNGENESIA, anthers
united--flowers com-
pound.

18. GYNANDRIA, stamens
on the pistil, distant
from corolla.
19. MONŒCIA, stamens in
flowers separate from
pistils, on the same
plant.

20. DIŒCIA, stamens in
flowers separate from
pistils on separate plants

21. CRYPTOGAMIA,stamens
invisible, wanting, or
very caducous.

Disk and ray florets compared. 1. Equalis, 2. Superflua, 3. Frustranea, 4. Necessaria, 5. Segregata.

Characters and names of preceding classes, (as under the classes 15 and 16,) 7. Heptandria, 8. Octandria, 9. Enneandria, 10. Decandria, 12. Polyandria, 16. Monadelphia.

Natural families. 1. Filices, 2. Musci, 3. Hepaticae, 4. Algæ, 5. Lichens, 6. Fungi.*

We have now exhibited the Linnæan system; a thorough knowledge of it can be gained only by a series of inductions made by the analysis of single plants. You cannot be too much impressed with the idea, that a knowledge of nature can be acquired but by the observation of material objects.

LECTURE V.

[The beginner in Botany may omit the whole of the fifth Lecture, except the "Directions for pronouncing the names of plants."]

Condensed view of the Natural orders of Linnæus and Jussieu.

After you have analyzed a number of plants, you will begin to observe a striking resemblance in many genera, and your own minds will suggest the propriety of arranging them into groups, without any reference to the artificial class or order where they may have been placed. We thus form natural families.

Among resemblances which give rise to natural families; are,

1st, resemblance in seeds,

2d, in pericarps, or the envelopes of seeds,

3d, in stamens and pistils,

4th, in corollas and calyxes,

5th, in the modes of inflorescence, or the manner in which the

flowers grow together upon the stalks,

6th, in leaves,

7th, in roots and stems.

In order to form a correct idea of the natural methods of classification, it is necessary to observe many plants, and the most constant characters of most of

* Eaton.

Synopsis of artificial classes and orders-What is necessary in order to gain a knowledge of nature ?-Arrangement of plants into natural families-Impor tant resemblances which give rise to natural families.

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