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Occurrence of Anacharis Alsinastrum (Udora canadensis) in the Trent, near Burton-on-Trent. By EDWIN BROWN, Esq.

I DISCOVERED a few days ago Anacharis Alsinastrum growing in profusion in the Trent, near this town; it also grows in the canal in this neighbourhood.

It now

Several years ago I paid considerable attention to the botany of this neighbourhood before entomology engrossed my leisure moments, and I feel convinced this plant did not then grow in our streams, otherwise it would have been discovered before. This fact, taken in connexion with the very recent discovery of the plant in Great Britain, leads one to the conclusion that it is not indigenous. forms very large submerged masses in the Trent, of a striking appearance. I have, however, found as yet but few flowers, and those are all the so-called female flowers. Contrary to the experience of Mr. Babington, as given in the Annals of Natural History,' every flower I have examined contained three stigmas and only two filaments.

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The rapid dispersion of this species throughout the country appears to have an analogous instance in the wonderfully speedy diffusion of the mollusk Dreissena polymorpha over the beds of all our rivers and canals.

Burton-on-Trent, August 20, 1849.

EDWIN BROWN.

Notice of 'The Rudiments of Botany; a familiar Introduction to the Study of Plants. By ARTHUR HENFREY, F.L.S., Lecturer on Botany at St. George's Hospital, author of 'Outlines of Structural and Physiological Botany.' With Illustrative Woodcuts.' London: Van Voorst, 1849.

If there were room for a rudimentary work on botany this unpretending little volume might edge its way into notice, for it is cleverly written, of enticing appearance, and very prettily illustrated. We heartily wish it success, but at the same time we must not abandon the critic's office of criticising where opportunity offers. Mr. Henfrey is evidently a very ardent book-botanist; he reads a great deal, reads very attentively, and understands and applies what he reads: this was very observable in his 'Outlines,' and in noticing that work we bore willing testimony to its excellence, especially in the points to

which we are now alluding. This quality, however, occasionally leads Mr. Henfrey into the solecism of making too much display of knowledge lately acquired: thus he reads, is struck with the beauty of a theory or hypothesis that comes suddenly under his notice: he devours and digests it, and then serves it up to every one who falls in his way. We recollect once telling a little boy the Guy Fawkes legend, greatly to his astonishment; and we heard him many, many times within the next day or two repeating the mystery to every one he talked to, children, servants, even graybeards who had seen fifty fifths of November, were informed "There was once a very wicked man," &c., &c. Mr. Henfrey is the exact counterpart of this child; he is delighted with every new acquisition of knowledge, and supposes it as new to others as to himself. After all, this weakness, if it be one, is a pleasing weakness, and but that hypotheses thus implicitly received, and thus constantly intermingled with fact, occasionally obscure what would otherwise be extremely clear and simple, we would not hold up so much as a little finger against it. Now certainly a proof of our allegation must be given; and although the truth of the allegation has forced itself on us all along, as we read from titlepage to colophon, or rather to lion, for the book ends with the effigy of a lion rampant, still there is no salient point to cite as an apt illustration. However, beginning the book again, the first description— that of the flower-offers a sufficient, though perhaps not forcible example of our meaning. It would appear our author has lately found, devoured and digested Dr. Lindley's striking remarks on Morphology: it will be seen how those remarks are served up for our benefit in the following few lines, which we extract consecutively :

"The flowers are composed of a number of different parts, and as these are considered to be in reality peculiar forms of leaves, like them they are, in the first instance, combined and folded up in buds. A flower-bud is to be compared with the leaf-bud, which afterwards unfolds into a stem bearing leaves. In the flower no internodes are formed between the leaves, and they thus remain grouped in circles or a close spiral. The flower of the Wall-flower presents us with four leaves in the outer circle, and these will be best examined on a bud, as they fall off soon after it opens. These are green, like the true leaves, but are smaller and much changed in their general appearance. They are called sepals, and collectively they form the calyx, or cup of the flower, which is always known from the other parts by being the outermost circle. To the calyx succeeds another circle of four bodies, which still retain in some degree the character of leaves,

although their brilliant colour here, as in most plants, affords a ready mode of distinction. These bodies are called petals, and the collective name of corolla is applied to them. All the coloured leafy bodies within the calyx of the flower are considered to belong to the corolla. The two circles just described are present in the greater number of flowers, but they are not actually necessary for the formation of fertile seeds. They enclose and protect, while young, those bodies especially devoted to the formation of the seed. They are therefore called enveloping organs. Within these enveloping organs, which we may now remove with a penknife, we find, in the first place, six bodies or organs, each of which consists of a little thread-like stalk, bearing at its end a yellow oval mass. These organs, which are still to be considered as peculiar forms of leaves, are called stamens; the thread-like stalk is the filament, the mass above, the anther, which, in advanced stages of the flower, will be found to have burst by two splits, displaying two cavities, which previously contained a fine dust, called the pollen, now scattered around. In the centre of the flower appears a green body, which is found to be constructed of two or four leaves, united at their edges so as to enclose a cavity within. This green body is called the pistil, when regarded as one piece; and the summit, which is somewhat swollen, is the stigma."-p. 9.

Now, if our readers will kindly take the trouble to read the entire extract, leaving out the italicised passages, which bear only on the ingenious hypothesis of Morphology, and not on the description of the floral envelopes, he will find it much clearer, more intelligible, and more instructive.

With regard to the hypothesis itself, it has some facts very much in its favor; and we have observed in several instances that, the sap being diverted from its course by Aphides, the pistil has assumed a leaf-like appearance; and such abnormal appearances as this have been urged in support of the hypothesis: but those acquainted with gardens, and hedges, and woods, and orchards, and who learn from such things as well as from books, must have observed other phenomena. For instance, a species of Aphis infests the roots of Pyrus japonica just at the surface of the soil, and the effect of its diverting the sap from its usual course is to cause the root to throw out flowerbuds, and brilliant scarlet flowers are frequently thus produced on the root the morphological hypothesis applied in this case must lead to the conclusion that the root was a flower, and merely assumed the functions of a root for especial purposes; and yet science denies VOL. III. 4 P

to the root the power of even bearing a bud. Again, another species of Aphis attacks what gardeners call the Midsummer shoots, and these shoots thus attacked, particularly in apple-trees, and very particularly in the Ribstone-pippin, produce flowers in place of leaves, and spread open rosy blooms to the hot suns of July and August: ergo, on morphological principles the leaves are normally blossoms, although usually assuming the form and functions of leaves. Now all this does not negative the assertion that the pistil is composed of four leaves, but we think it abundantly shows that such a conclusion is at present conjectural only, and does not take rank with the established facts which are generally supposed to be 'The Rudiments of Botany.'

Again, this really clever book occasionally, we may perhaps say frequently, wants that perspicuity which is so essential in an elementary work. The reader will perhaps observe this sufficiently in the paragraph already cited, but we will take the next, in order to avoid repetition.

"There are other perennial plants which have their stem under ground, and display above ground every summer a new stalk bearing flowers, which again dies down to the ground in autumn, as, for instance, the Asparagus or the Hop, or looses its flower-stalk every year, and produces a tuft of leaves, which live through the winter; as, for instance, the Daisy and the Flag."-p. 21.

In both extracts the italics are our own. Now we have to remark that the word again seems unmeaning, because the stalk in question has not died before. Indeed, the student will have great difficulty in deducing any meaning whatever from this obscure paragraph; but the botanist, after two or three perusals, and recurring to his knowledge of the plants mentioned, will perceive the terms loosing and dying are not intended to be contrasted, but are used to express the same meaning he will also perceive that Mr. Henfrey, in addition to the provincial, and we think inelegant, word loosing, has given a new and incorrect name to the stem of the Asparagus and Hop: he calls it a stalk bearing flowers, and then contrasts it with the true flower-stalk of the Daisy and Flag. Again, the leaves of the Daisy and Flag should be distinguished from the others as persistent. Mr. Henfrey knows all this he is a good structural botanist, and his writings abundantly testify his knowledge; the confusion does not exist in his mind, but in his mode of expression. "Botany, like every science and art, requires that particular names should be applied, in an

exclusive sense, to particular things."*

Had he attended to this rule instead of merely reciting it, he would not have introduced a new and inelegant word for dying, or a new and inappropriate term for stem.

There is one other subject on which we must say a few words in the way of disapprobation : we allude to the explanation of system being confined exclusively to the Linnean. Without entering into the merits of the two systems, surely the general use of the Jussieuian, demands that in any rudimentary work it should be carefully explained. We grant that Mr. Henfrey has a perfect right to prefer or recommend either system, but he should fully instruct beginners in that which is now universally employed.

K.

On the Experiments of raising Primulæ, &c., from Seed.

By the Rev. J. S. HENSLOW, M.A., F.L.S., &c.

6

IN running my eye over the Phytologist' I see the record of sundry experiments with Primula and Anagalles, recalling two old experiments of my own, in which I considered I had obtained Primula vulgaris from Primula veris, and Anagallis arvensis from Anagallis cærulea. I have not lost sight of this inquiry since, and may some day have an opportunity of reverting to it. Unless a thought is recorded at the moment it is often not recorded at all, and I wish to say that although negative testimony is never entirely worthless, and often very valuable, it cannot be of much weight in comparison with a little positive testimony in deciding the question at issue. Thousands and millions of seedlings may and will come true, to use a common gardening expression, in most cases where a strong impress of a particular character has been mysteriously imparted to some variety; and yet a fortunate opportunity may at length arise for establishing the possible, or at least for pointing out the probable, specific identity of plants whose forms are extremely dissimilar. We all know the beautiful blue of the common borage (Borago officinalis). It must be five or six years since I observed a white variety in a single plant in a hedge between this village and Ipswich. I brought home a few seeds, and the plants that sprung up have been allowed to seed freely among some currant-bushes in my kitchen-garden, and numerous specimens have since appeared. Every one of them has

*This axiom was first contended for by Mr. Newman (Ent. Mag. i. 395, et seq.)

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