of the larger bars; and the crystalline structure of the mass might be overlooked with the action of this acid alone. Nitric acid, however, brings out the Widmanstättian figures most beautifully. The etched surface is a perfect miniature copy of the Texan iron; the largest bars of the Putnam county iron corresponding with those of medium size in the Texas iron, and thence diminishing to bundles of striæ hardly visible to the naked eye. The triangles and parallelograms are proportionally small. Query: Are the crystalline figures of meteoric irous, in any degree, proportional to the meteoric masses? If so, may we not infer from the size of them, whether the iron be an entire mass, or a fragment of a large one?

Neutral sulphate of copper produces no precipitate of metal on the iron; the slightest addition of acid causes the deposit of copper. Moreover, I find, that if the film of copper be wiped off as soon as formed, the sulphuric acid has etched out the figures superficially but very imperfectly. Liquid sulphuric acid, when cold, has no effect upon the surface.

In addition to the above description, I subjoin an interesting note from Prof. Shepard, containing an analysis of the iron, which he has very kindly furnished at my request.

"Charleston, S. C., February 10, 1854.

My Dear Sir-In comparing the Putnam county meteoric iron with specimens from other localities, I notice a striking similarity in its structure to that of the Texan mass. Like it, your iron is compact, nearly free from pyrites and but slightly disposed to rust on exposure to the air. But the resemblance between the two is seen to the greatest advantage, when etched samples are compared with one another. The Putnam county iron exhibits figures of the same shape and size as the Texas, viz., triangles and oblique-angled parallelograms, bounded by slightly raised edges, which are often wavy, and sometimes not continuously of the same thickness, but, here and there, bulging out into beads or knobs. The pyrites in my specimens is scarcely to be recognized, except in one or two very limited patches, which are irregular and vein-like.

The iron appears to have suffered a very remarkable disintegration to the depth of half an inch or more below the thick, scaly crust with which the mass was coated; in consequence of which it cleaves very regularly, like the Cocke county, Tennessee iron, into tetrahedral and rhomboidal fragments.

The specific gravity of the fresh internal portions of the mass is 7.69. A single analysis gave me the following result:

Iron,

89.52

Nickel, with traces of cobalt,

8.82

Tin, phosphorus, sulphur, magnesium and calcium,

1.66

100-00

Very truly, yours,

CHARLES UPHAM Shepard."

ART. XXXV.-On Conistonite, a new Mineral Species; communicated by R. P. GREG, F.G.S., of Norcliffe Hall, near Manchester.

Mr. B. WRIGHT, a mineral dealer in Liverpool, forwarded me some months since, a specimen, found at the copper mine near Coniston in Cumberland, by Mr. Marrat, a teacher of Natural History in Liverpool. The specimen was of a purplish-red color, somewhat resembling earthy cobalt-bloom, and implanted on it were a few small crystals resembling calcite. Thinking however the form of these rather peculiar, on trial I found the usual cleavages of that mineral wanting; and its peculiar behavior before the blowpipe soon convinced me that it must be a new species. I give the following general description:

Largest crystals not more than one-eighth of an inch across, and in general form not unlike the double four-sided crystals of Edingtonite. Primitive form probably a right rhombic prism. No cleavage observable. Fracture small conchoidal, uneven. Lustre vitreous. Transparent to translucent; colorless. Slightly sectile. H. 2.2. Sp. gr. = 2·05.

M

e

=

The faces M brighter and more distinct than e.

Does not effervesce in acids. Before the blowpipe becomes white and opaque, expanding into seven or eight times its original bulk. After exposure to heat almost instantaneously dissipated in acids, with strong effervescence.

As yet only two specimens of this interesting mineral have been found. I have called it Conistonite from its having been first discovered at Coniston.

It is very probable that the matrix in which the crystals of Conistonite are imbedded, will itself prove to be a new mineral species. Mr. Heddle supposes it to be oxalate of cobalt.

I transmitted to my friend, Mr. M. Forster Heddle, of Edinburgh, a few crystals of the Conistonite for analysis, which he kindly undertook to make; and he has sent me the following particulars respecting it.

a. "Sp. gr., determined on 3.666 grs., found to be 2:052.

b. Powdered mineral absorbs 23 per cent. of moisture.

c. Soluble without effervescence in hydrochloric and nitric acids, and on addition of ammonia a precipitate is thrown down. d. When heated gives off water and carbonic oxyd, and is converted into carbonates; and then effervesces in acids.

SECOND SERIES, Vol. XVII, No. 51.- May, 1854.

43

e. Qualitative analysis made on a very minute quantity, gave indications of lime, magnesia, water and oxalic acid.

f. Quantitative analysis made on 3.83 grs.:

g. Uniting the soda and magnesia with the lime to calculate the formula, we get,

which gives the formula CaO, C2O3, 7HO; being an oxalate of lime with 7 atoms of water instead of one; or more probably oxalate of lime with 6 atoms of water of crystallization, thus Ca O, C2O3, HO+6HO; or Ca +.

h. The great interest of the mineral lies in the fact of the water of crystallization, rendering oxalate of lime dimorphous, the Whewellite of Brooke being oblique.

It is curious that the specific gravity of Conistonite should be greater than Whewellite; we should have expected that the additional HO would have lowered the gravity."

ART. XXXVI. - Introductory Essay, in Dr. Hooker's Flora of New Zealand.

(Concluded from p. 252.)

HYBRIDIZATION has been supposed by many to be an important element in confusing and masking species. Botanists of one class are apt to refer to its agency the unwelcome appearance of a specimen which combines two nominal species, founded on inconstant characters. Another class of naturalists appeal to the repeated occurrence of fertile hybrids, to negative the inference, otherwise unavoidable, that the production between two individuals of inherently fertile offspring, is a good reason for pronouncing them identical in species. Any continued effects froin hybridization in uncontrolled nature seem to be thoroughly guarded against in two ways; first by the constitutional debility, if not by the invariable sterility of the hybrid offspring, rendering it of transient duration; and secondly, by the fact that, when prolific at all, they usually become so through fertilization by one or the

other of the parents, when the offspring reverts to that specific type. Dr. Hooker justly remarks, that,

"As a general rule, the genera most easily hybridized in gardens are not those in which the species present the greatest difficulties. With regard to the facility with which hybrids are produced, the prev alent ideas on the subject are extremely erroneous. Gartner, the most recent and careful experimenter, who appears to have pursued his inquiries in a truly philosophical spirit, says that 10,000 experiments upon 700 species produced only 250 true hybrids. It would have been most interesting had he added how many of them produced seeds, and how many of the latter were fertile, and for how many generations they were propagated. The most satisfactory proof we can adduce, of hybridization being powerless as an agent in producing species (however much it may combine them), are the facts that no hybrid has ever afforded a character foreign to that of its parents, and that hybrids are generally constitutionally weak, and almost invariably barren. Unisexual trees must offer many facilities for the natural production of hybrids, which nevertheless have never been proved to occur; nor are such trees more variable than hermaphrodite ones."

May we not even say that they are less variable because unisexual, since their progeny is most likely to be originated from the conjunction of different trees, and individual peculiarities must needs be thereby blended and obliterated. When we consider how often it must happen that the ovules of one tree in an oak or pine forest are fertilized by the pollen of another; when we take into view the great number of unisexual plants, and consider also how many apparently hermaphrodite blossoms (far more than is generally supposed) are really submonacious or polygamous, we may find reason to suspect in this a more general provision of nature for limiting congenital or induced individual forms than would at first appear. That some such controlling or amalgamating agencies operate in nature may be inferred from a comparison of the general homogeneity of an indigenous species, over even a large area, with the ready development of marked varieties or races in the case of every cultivated plant which is multiplied from seed, and their perpetuation from generation to generation, which is almost always ensured merely by cultivating each stock by itself. For the general law of nature is, not merely that species are true to their characters, these characters being rightly apprehended, but that the individual progeny inherits and transmits the special peculiarities of the parent or parents. Hence, that an isolated race retains certain characteristics so long as kept separate is no proof that it constitutes a species. Many a variety of recent and known origin does this. But, on the other hand, whatever individuals, however distinguished by minor differences when separate, are found to blend into a fertile race when associated, must on sound principles be regarded as belonging to one species. Perhaps if zoologists would contemplate the wide varia

tions presented by many plants of indubitably one and the same species, and the still wider diversities of long cultivated races from an original stock, they would find more than one instructive parallel to the case of the longest-domesticated of all species, man.

Let it also be especially noted, that varieties are not always, not even generally, the result of external agencies, at least of such as we are able to detect. Certain varieties of plants are so originated: these are generally as transient as the cause that produces them, and under altered circumstances often disappear even during the life of the individual: the plant may outgrow them. But others arise, we know not how. It is past the wit of man to trace a connection between the diverse forms of the foliage, &c. of a polymorphous plant such as a Coprosma, Metrosideros or Alseuosmia in New Zealand, and any difference of circumstances attributable to station; still more so when these diversities occur side by side. Yet such are the varieties which ordinarily exhibit the greatest persistency, i. e. when kept from intermingling by mutual fecundation. What exterual circumstances can in the least account for the origin of the race of Dorking fowls, or Manx cats, or indeed of almost any of our domesticated races which were not produced by cross-breeding, that is by mingling the characters of two such races already in existence. Yet how certainly may we continue any of these races, under favorable circumstances, merely by maintaining the needful isolation; and how soon would they mingle and disappear if they were left to themselves. Is not this equally true of the human races ?

From such facts, from the study of species remarkable for their polymorphous vegetation, as well as from the wide differences between certain domesticated races and their original stock,— differences not to have been expected on any known principles, and often far greater than those which are reckoned satisfactorily to mark the limits between other species,-the systematic botanist, at least, learns the lesson, that the amount of variation of which any one specific type is susceptible is only to be ascertained from observation and experience.

Upon the third proposition, that "Species are more widely diffused than is usually supposed," our author's statements are brief, but very decided and remarkable. He has already declared in the previous section "that it is by far the smaller half of the vegetable kingdom that is confined to narrow geographical or climatic areas, and that very few plants indeed are absolutely local; whilst the operations of the gardener and agriculturist prove that a vast proportion of the plants of the two temperate zones are capable of growing in any moderate climate." "I do not think," he continues, "that those who argue for narrow limits to the distribution and variation of species, can have considered a garden in a philosophical spirit, or have weighed such facts as