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THE MAGAZINE

OF

NATURAL HISTORY.

MARCH, 1834.

ORIGINAL COMMUNICATIONS.

ARt. I. On designating Genera and Subgeneroond on the Principles of Classification which they involve. [VI. 385. 481. 485., VII. 62, to 66.] By the Rev. LeoNARD JENYNs, A.M. F.L.S.

MR. STRICKLAND seems (VII. 62.) to inser, from what I have written (VI. 385.) on the subject of classification, that my plan is “to distinguish subgenera by signs or letters.” I beg to state that he has misunderstood me entirely. So far from adopting this plan, I am of opinion that in all cases subgenera should be named. What I remarked (which, I presume, led Mr. Strickland to this inference) was, that many modern genera had been established on characters too trivial and unimportant to entitle them even to the rank of subgenera; and I intimated that, where such had been adopted principally with a view to convenience, and because of the large number of species contained in the old groups of which they formed portions, it would have been better to have substituted for them mere sectional divisions, indicated by signs.

With respect to the much agitated question as to whether we are to employ the name of the genus or subgenus in designating any species we may wish to speak of, it appears to me it must be left in a great measure open for each individual to decide as he pleases. It would be difficult to lay down any rule, on such a subject, which would be generally adopted. For my own part, I should say, that, on all ordinary occasions, it is quite sufficient to use the former only ; but where I was naming the species, with the particular view of pointing out its affinities and its exact situation in the system, I

should there employ both ; and I should write the name cf Vol. VII. – No. 38. h

the subgenus in a parenthesis. Thus, I should usually say (speaking of the Lapland bunting), Emberiza lappónica; but, in the particular instance just alluded to, Emberiza (Plectróphanes) lappónica.

I cannot forbear adding, on this occasion, that I fear I have been much misunderstood on the subject of the division of genera. The object of my former communication [VI. 385.] was not so much to find fault with the subdividing of old genera, where there may appear just ground for the subdivision, or the calling of the new groups by this title, if we object to the adoption of that of subgenera, as with the not appreciating the relation which these new groups bear to the old one, and to the other genera in the same family with which this old one was considered of equal value. Perhaps, however, my meaning will be rendered more intelligible than it was in that article, by the assistance of a diagram. Let us, then, suppose the family of Ardèidæ, for instance, and three of its included genera, to be represented in the following manner,

Ardèidæ

Ardea

Ciconia Platàlea; assuming that the above three groups, placed in the same line, are of equal value amongst themselves, but all subordinate to the one above, in which they are included, and which we here designate by the name of family. Suppose that, on farther investigation, we find that, in like manner as this family includes three genera t, so that one of these genera, say Ardea, includes also three subordinate groups. What do we do? We attach the same name, Ardea, though in a restricted sense, to that subordinate group which is more typical than the others; while to the remaining two we affix, perhaps, the new names of Botaúrus and Nyctícorax; and we carry on the diagram in this manner, —

Ardèidæ

[blocks in formation]

Ardea Botaurus Nycticorax; in which we still have the old group A'rdea held together by certain characters as before; only we distinguish in it three

* This is what Cuvier recommends, in his Histoire des Poissons, 4to edit. tom. ii. p. 41. note ). In a former work he advises that, on ordinary occasions, the nanie of the subgenus be suppressed. (Règ. An., tom. i. p. xvii.)

+ I am not really asserting that there are no other existing genera in this family, but merely selecting these three as sufficient for my argument.

if we

minor groups, each of which has some additional characters peculiar to itself, of less importance than those common lo all. Now, it is perfectly arbitrary in what point of view we choose to consider these three new groups; we may either affix names to them or not; we may call them genera, please, or subgenera, or mere sections of the old genus A'rdea: but what we must not do (and here, I would observe, is the principal ground of my complaint) is, having determined them to be genera, first to abolish the original group. A'rdea, and then to place them on the same footing with Ciconia and Platàlea *, in this manner,

Ardèidæ

Ardea

Botaúrus Nycticorax Ciconia Platàlea; or, raising Ardea to the rank of a family, and the group which we here call Ardèidæ to one of a still higher denomination, not to raise Cicònia and Platàlea also; for these three groups, A'rdea, Cicònia, and Platàlea, having been assumed to be of equal value, it is clear that, whatever rank we assign to one of them, we must assign the same to all.

I am unwilling to extend this communication, or I should make some comment on the objections which Mr. Newman has brought forward (VI. 485.) against the expressions which I adopted in my former article. (VI. 385.] I shall simply observe, that, when I talk of principles of classification, I do not mean principles of my own setting up, as that gentleman seems to think, but such as have been laid down by those who have studied most deeply the philosophy of the science, and such as are generally acknowledged by all professed naturalists. Of this nature is the only principle to which I had occasion to allude ; viz., that all groups bearing the same title should be groups of the same value.

I conceive that every systematist would assent to this principle, at the same time that no one would ever think of asserting that it was now, for the first time, brought forward and offered to his notice.

L. JENYNS. Swaffham Bulbeck, Cambridgeshire,

Jan. 14. 1834.

* The arrangement adopted, not merely in Mr. Stephens's continuation of Shaw's Zoology, to which reference was before given (VI. 388.), but in the latest ornithological work which has app red in this country. See Selby's Illust. of Brit. Orn., vol. ii. (Water Birds) p. 8. &c.

ART. II. Observations on the Habits of the Rook.
By CHARLEs WATERTON, Esq.

Last year I partly promised [V. 241.] that, on some dismal winter's evening, I would sit me down, and write the history of the rook. The period has now arrived. Nothing can be more gloomy and tempestuous than the present aspect of the heavens. The wind is roaring through the naked branches of the sycamores, the rain beats fiercely on the eastern windows, and the dashing of the waves against the walls of the island warns us that one of November's dark and stormy nights is close at hand; such a night, probably, as that in which Tam O’Shanter unfortunately peeped into Kirk Alloway. Foreigners tell us that on these nights Englishmen are prone to use the knife, or a piece of twisted hemp, to calm their agitated spirits. For my own part, I must say that I have an insuperable repugnance to such anodynes; and, were a host of blue devils, conjured up by November's fogs, just now to assail me, I would prefer combating the phantoms with the weapons of ornithology, rather than run any risk of disturbing the economy of my jugular vein, by a process productive of very unpleasant sensations, before it lulls one to rest. According to my promise, I will now pen down a few remarks on the habits of the rook, which bird, in good old sensible times, was styled frugilegus. It is now pronounced to be praedatorius. Who knows but that our great ones in ornithology may ultimately determine to call it up to the house of hawks 2 If this useful bird were not so closely allied to the carrion crow in colour and in shape, we should see it sent up to the tables of the rich, as often as we see the pigeon. But prejudice forbids the appearance of broiled rook in the lordly mansion. If we wish to partake of it, we must repair to the cottage of the lowly swain, or, here and there, to the hall of the homely country squire, whose kitchen has never been blessed by the presence of a first-rate cook, and whose yearnings for a good and wholesome dish are not stifled by the fear of what a too highly polished world will say. There is no wild bird in England so completely gregarious as the rook; or so regular in its daily movements. The ringdoves will assemble in countless multitudes, the finches will unite in vast assemblies, and waterfowl will flock in thousands to the protected lake, during the dreary months of winter: but, when the returning sun spreads joy and consolation over the face of nature, their congregated numbers are dissolved, and the individuals retire in pairs to propagate their respective species. The rook, however, remains in society the year throughout. In flocks it builds its nest, in flocks it seeks for food, and in flocks it retires to roost. About two miles to the eastward of this place are the woods of Nostell Priory, where, from time immemorial, the rooks have retired to pass the night. I suspect, by the observations which I have been able to make on the morning and evening transit of these birds, that there is not another roosting-place for, at least, thirty miles to the westward of Nostell Priory. Every morning, from within a few days of the autumnal to about a week before the vernal equinox, the rooks, in congregated thousands upon thousands, fly over this valley in a westerly direction, and return in undiminished numbers to the east an hour or so before the night sets in. In their morning passage, some stop here; others, in other favourite places farther and farther on ; now repairing to the trees for pastime, now resorting to the fields for food, till the declining sun warns those which have gone farthest to the westward that it is time they should return. They rise in a mass, receiving additions to their numbers from every intervening place, till they reach this neighbourhood in an amazing flock. Sometimes they pass on without stopping, and are joined by those which have spent the day here. At other times they make my park their place of rendezvous, and cover the ground in vast profusion, or perch upon the surrounding trees. After tarrying here for a certain time, every rook takes wing. They linger in the air for a while, in slow revolving circles, and then they all proceed to Nostell Priory, which is their last resting-place for the night. In their morning and evening passage, the loftiness or lowliness of their flight seems to be regulated by the state of the weather. When it blows a hard gale of wind, they descend the valley with astonishing rapidity, and just skim over the tops of the intervening hills, a few feet above the trees: but, when the sky is calm and clear, they pass through the heavens at a great height, in regular and easy flight. Sometimes these birds perform an evolution, which is, in this part of the country, usually called the shooting of the rooks. [V. 239.] Farmers tell you that this shooting portends a coming wind. . He who pays attention to the flight of birds has, no doubt, often observed this downward movement. When rooks have risen to an immense height in the air, so that, in appearance, they are scarcely larger than the lark, they suddenly descend to the ground, or to the tops of trees

exactly under them. To effect this, they come headlong

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