abundance of vitellin granules, very small, transparent, varying in form, more commonly rounded, insoluble in water and soluble in acetic acid. We repeated this experiment several times before being certain of its character. The eggs of the Tritons show a like composition. The exterior white is like that of the Frog's egg. The citron or green vitellus, according to the species, contains fat and a considerable number of vitellin granules quite rounded, which we have studied in the egg taken in the oviduct near being hatched, and in the ovula still enclosed in the ovary. The examination of these last has shown us this remarkable fact, that the vitellin granules increase with the age of their formation. They are very much smaller in the ovula than in the vitellus of the egg. These granules are also insoluble in water and soluble in acetic acid. The egg becomes hard when cooked in boiling water; it then contains albumen too, as well as that of the frog. We have already mentioned that MM. Martin-Saint-Ange and Baudrimont saw the granules of the Frog; they have even given their figure. M. Rud. Virchow has also given some accurate observations on the granules of Frog's eggs, Toads and Tritons. (Zeitschrift für Wissenschaftliche Zoologie, par MM. Siebold and Kölliker, vol. iv, part 2, p. 236; 1852.)

The characteristics which we describe, lead us to the conclusion, that the granules contained in these eggs are of the nature of ichthin, that is, that they are of a like nature with those of the Ray's and the Shark's eggs. The simple view of the grains under the lens of a microscope suggested this idea; their characteristics confirm the identity, which has brought us to the establishment of this curious and important physiological fact, that the Batrachians besides undergoing, in consequence of their metamorphosis, a primary condition of existence like that of fish, lay eggs whose composition has the greatest affinity to those of fish.

This similarity holds even in the ovules, for we have already remarked that the granules of the ichthin from a Ray are smaller in the ovules than in the yolk of the egg of these fish. We there show, in fact, a like composition for the white surrounding the vitellus, and the presence of ichthin, that immediate new principle abundant in the egg of cartilaginous fishes.

M. Virchow whom we quote, has likewise observed the granules (Dotterplättchen) of the eggs of Ray and of fish (loc. cit.). We should mention too, that J. Müller has seen and drawn the granules of the smooth Ray and of the smooth Hound-fish (Galeus lævis) (Dotterkörner), Mem. Acad. de Berlin, tome xxvii, page 221, pl. 5, 1842.)

We shall give, in the complete work which will be published with plates in the Archives du Museum d'Histoire Naturelle, a detailed account of the researches of our predecessors.

Of the eggs of Crustacea.-Coloring matter of the Crustacea. The Crabs of our soft waters and Lobsters have supplied the eggs necessary for our researches. Lobsters, carrying from fifteen to twenty thousand eggs under their abdominal appendages, are the most convenient for the kind of researches which we have undertaken.

Their eggs do not contain ichthulin; no sort of granules are found in them. They are essentially formed of an albuminous and saline liquor, holding some fatty bodies suspended in it. The albumen of the eggs of Crustacea seems to us different, in some respects, from the albumen of other eggs. Its coagulation begins about 74° C.; the study of this substance will necessarily find place in the work which we are now preparing on albuminous substances.

This

We have also studied the Sea Lobster (Palinurus). Crustacea, as plentiful as the ordinary Lobster (Homardus) on granite shores, and not touching the chalky cliffs, is very uncommon in the North. The Sea Lobster does not seem to pass. the Islands of Ushant, and is not found in the British Channel. Further, it is very common on the rocks of Bretagne. It lives at a much greater depth than the common Lobster, for it is necessary, in order to take them, to let down the baited hooks to a depth of seventy fathoms. The eggs of these Crustacea are very small, hardly as large as a seed of the poppy. We have counted about 130,000 of them under their abdominal appendages. We had, in the early part of March, a living Sea Lobster, whose eggs were so developed that the two black eyes of the little fœtus were distinguishable through the shell. We have to regret that we could not save it alive, so as to see the young hatch, to follow the phases of their metamorphosis. Science already possesses some observations made on the embryo of the Lobster, but it has none as yet registered on the development of the eggs of the Sea Lobster, and many other Crustacea.

The study of the eggs of Lobsters enabled us to obtain in a state of purity, that curious matter which takes a red color when the shell of Crustacea is submitted to the action of heat. Till now it has not been conveniently studied, because the solvents always presented it in a state mixed with fatty bodies, and besides, the solvents such as ether or alcohol, give it in the reddish condition, that is already modified; it exists dissolved in the albumen of the eggs of Crustacea; by heating the liquid, the albuminous matter coagulates, carrying with it, in the shape of a lake, the coloring matter, which is then of a very beautiful red. The precipitate is retaken by the alcohol, which dissolves the coloring substance, and leaves the albumen in an insoluble state. The detection of this coloring matter, in the egg of the Crustacea, is undoubtedly an interesting fact, if it be remembered that

art has already taken advantage of this substance. The following method enabled us to obtain the coloring matter as it exists in Crustacea, still presenting its green color.

The green coloring matter of Crustacea is soluble in albumen; besides, when Lobster's eggs are crushed, the albuminous liquid which passes by filtering, is strongly colored green, and holds in solution the coloring matter. The ordinary methods, such as the action of heat, that of neutral solvents, desiccation, &c., which are applied to extract this singular substance, present it already modified. In fact, when alcohol or any other agent is used, the substance which till then, was green, instantly turns red; but by an unexpected and for our work, very fortunate circumstance, the only liquid which does not alter this coloring matter, that is water, enabled us to obtain it in a pure state; in fact, when the green albuminous liquor mentioned above, was weakened with a large quantity of water, the coloring matter is precipitated, and can easily be gathered on a filter. We have thus been enabled to establish the following properties, which we think, are of a nature to interest men of science. This substance is green, resinous and uncrystallizable; it changes and becomes red under very curious circumstances. To effect this transformation, it suffices to submit it to desiccation, even at the ordinary temperature. The salts which have affinity for water can transform the green coloring matter of Crustacea into a red substance: the salts, on the other hand, which do not combine with water, exercise no action on this singular coloring matter. The action of a vacuum rapidly produces the red color. Simple rubbing immediately reddens the green substance. Alcohol, ether, the acids, effect the same change. There are not, to all appearances, in the vegetable or animal organization, coloring substances comparable with this of the Crustacea; modifying with such facility under the action of the simplest agents. We tried to determine whether this substance presented the same characteristics when still fixed in the shell of Crustacea; the result of our experience is, that in this case, the green substance bears itself just as it does when isolated. Thus a Crab's shell, which shows the green discoloration, becomes red the moment it is rubbed with a hard body. It is not the heat developed by the rubbing which effects this singular modification, for it has been effected while the shell was very damp, and be sides, it is manifested rapidly on a Crab's shell placed under the receiver of an air-pump and submitted to the action of the vacunm. The change of color by rubbing explains how anatomists who have sought for the cause of the discoloration of Crabs when boiled, have always seen the red matter under the coat, as thin as the epidermis which they removed to observe the shell under the microscope. The simple rubbing of the utricles, touched by the scalpel, sufficed to make the green color red. We are fortunate

thus to have been able to complete the history of one of the most curious coloring matters produced by animal organization.

Of the eggs of Arachnids and Insects. We submitted to analysis eggs of different species of spiders: they contain albumen, fatty bodies and a large amount of a substance precipitated by water. Ant's eggs gave us the same results. These researches are to be continued in the course of the coming season. Of the eggs of Mollusks.—The analysis of Snails' eggs, which we shall complete next season, seems to show us that the eggs of Mollusks differ entirely in their composition, from those of other animals. Those which we procured, presented no trace of fat; they were made up exclusively of hyaloid membranes containing a viscous colorless liquid. This liquid contains in solution au organic azotized substance, not albumen, for it did not coagulate with heat. It is precipitated by acetic acid and dissolves in hydrochloric acid without any violet color.

Conclusions. We have shown, in three successive communications composing our memoir, the facts established by our researches on the eggs of different animals, belonging to all the great classes of Ovipara. Let us by way of recapitulation, endeavor to state in some general propositions, the most important consequences which seem to be the results of this first work. We have shown:

1st. That there exist fundamental differences between the composition of the eggs of animals, and that under this collective name of egg, desiguating the product of the ovarian apparatus intended to contribute to the perpetuity of the species, very diverse bodies are comprised different as possible from one another.

2nd. That among the vertebrated animals, the eggs of birds, of reptiles, and of fish, present in their composition, differences which the simplest analysis cannot mistake, and besides that the eggs of Sauria and Ophidia bear great analogy to those of birds, while the eggs of Batrachia resemble those of the cartilaginous fishes.

3d. That the eggs of Arachnidæ and insects differ altogether, as to their composition, from the eggs of other animals.

4th. That those of Crustacea, organized for living in water, do not at all resemble those of fish or of other amphibious vertebrata.

5th. That this extends to the eggs of Mollusks.

6th. That these differences correspond not only to classes or orders; that they extend to natural families even, without stopping there, since we have proved that an egg of a cartilaginous fish has not the same composition with that of an osseous fish; but further, that a Carp's egg is very different from a Salmon's egg; that the egg of an Ophidian such as an adder's, does not contain the same principles as those of the Chelonia.

7th. That if the composition of different proximate principles is the same in very nearly allied species, the form and the size of vitellin granules vary in a manner sufficiently appreciable to be able to be recognised and assigned to each species.

8th. That the albuminous substances furnished by eggs of birds, reptiles, fish, crustaceans, present in their chemical properties and in their point of coagulation, differences which permit us to suppose that these bodies are made up of different proximate principles.

9th. That an egg changes its nature,-that its liquids alter considerably at different epochs of its formation, when detaching themselves from the ovary, and resting in the oviduct before being hatched.

10th. After having established in the eggs of different animals, the presence of several new proximate principles, icthin, ichthulin, icthidin, emydin, and comparing these results with those which MM. Dumas and Cahours obtained in the analysis of hens' eggs, we do not hesitate to propose to science to admit the existence in eggs of a new class of organic bodies, comprising some proximate principles which we will hereafter designate under the name of Vitelline substances or Vitelline bodies.

ART. VIII. Observations on the Extent of the Gold Region of California and Oregon, with notices of Mineral localities in California, and of some remarkable specimens of Crystalline Gold; by WM. P. BLAKE, Geologist of the U. S. Pacific R. R. Survey in California.

THE information contained in the following brief notes was partly obtained in connection with the government exploration in California for a practicable route for a railroad to the Pacific, and partly during a visit to the mining region and a residence of several months in San Francisco. The localities and minerals found in the course of the explorations for the government will receive a more extended notice in the report now in preparation.

GOLD. It is not yet possible to state the boundaries of the great gold-field of California. It has been gradually expanding on the north, west and east with the progress of exploration, until placers have been worked under the snows of the high ridges of the Sierra, and it appears probable that the crest of that great mountain chain is overlaid by the precious dust. On the north and west, new placers of unequalled richness are constantly discovered, and gold is brought from nearly all of the numerous ranges and ridges that trend off from the upper or northern portion of the Sierra Nevada, and traverse nearly the whole breadth