cured. This heat in the dark is especially favorable to an active respiration, as we find that the quantity of carbonic acid increases in proportion to the increase of temperature in the leaf, so that there seems to be a relation between the rapidity of growth and the energy of respiration.

This can easily be appreciated when we assume that a certain portion of the heat must enter into action in order to the formation of the immediate principles. The internal combustion, which is indicated by the absorption of oxygen and the throwing off of carbonic acid, is probably the source of the heat necessary for the formation of the new immediate constituents.-19 C, June 20, 1874, 235.

IODINE AND BROMINE IN FRESH-WATER PLANTS.

Zenger states that Petter detected iodine in the ash of the Cladophora glomerata in 1862, and that Jessler subsequently determined the amount to be 0.2343 grains in 9960 grains of the dried algæ. According to his own analyses, the ash of the plant amounts to 52.85 per cent., and 56,000 grains of ash contain 21.5 grains of iodine and 8.5 grains of bromine. The large amount of ash consists mainly of lime. He concludes from his own experience that iodine and bromine are present in much larger quantity than is suspected in fresh-water plants, and that they are also present in land plants, and suggests that fresh-water plants, by reason of their wide distribution, may become an important source of these elements. His most recent investigations of the aquatic plant Lemna minor show the presence of a large amount of iodine, and also of bromine.-18 C, April 14, 1875,

229.

ORGANIC SUBSTANCE IN THE PLANT.

A résumé of the past progress and present condition of our knowledge of the production of organic substance in the plant is given, in the Prussian Landwirthschaftliche Jahrbücher, by Professor Pfeffer, of the University at Bonn. Professor Pfeffer concludes that the production of organic substance from inorganic materials is dependent upon the action of chlorophyl, and requires in connection with the coloring matter of the latter nitrogenous protoplasm. The first product is generally starch, occasionally sugar, still less

frequently fatty oil. The agency of light is requisite, the yellow rays being chiefly efficient. Many plants require but little light or but little warmth for assimilation. An increase of temperature above blood-heat is injurious or fatal, while an increase of light is only beneficial. The chief absorption of carbonic acid for assimilation is effected by the leaves, which give off oxygen in return. Another and more constant vital activity of the plant is slow combustion, with the giving off of carbonic acid; and this is noticeable. only when the mass of assimilated carbonic acid sinks under that which is given off, as happens at night.

RESIN IN THE AGARIC.

It appears that the fungus known as the White Agaric (Polyporus officinalis) contains nearly sixty per cent. of resin, and it is suggested that this mushroom may advantageously be cultivated in large quantity on account of this ingredient.-18 A, April 23, 150.

OSTRUTHIN, A NEW VEGETABLE PRINCIPLE.

A new crystalline vegetable principle has been detected in the root of master-wort by Gorup-Besanez, to which he has given the name Ostruthin. It crystallizes in white needles or prisms, and contains no nitrogen.-21 A, Sept., 1874, 907.

REVISION OF THE SUB-ORDER TULIPEÆ.

A revision of the sub-order Tulipec, by J. G. Baker, has recently appeared in the journal of the Linnæan Society of interest to American botanists. This group of six genera and one hundred and seventy-nine species is confined to the north temperate zone, having its largest development in Eastern Asia, but ranging largely on the one side to Europe and on the other to California and the Rocky Mountains. The tulip is the only genus not represented in America, the lily extending across the continent, and the fritillary stopping short at the Rocky Mountains. On the other hand, the calochortus, numbering twenty species or more, is limited to our more western territories. Of the half-dozen erythroniums, one is restricted to the Old World, the rest to the New. It is singular that a species in the smallest genus (Lloydia serotina) should be the one most widely distrib

uted of all the lily tribe, and the only one that is really arctic or alpine. Jour. Linnean Soc., XIV.

COPTINE.

A peculiar principle called coptine has been found by Gross in the Coptis trifolia, or golden-thread, of Europe and America. This is associated in the plant with berberine, but is distinguished by being colorless, and by yielding a crystalline precipitate with potassia-mercuric iodide.-21 A, Sept., 1874, 912.

CHEMICAL COMPOSITION OF PLANTS.

Our knowledge of the chemical composition of plants used for food has been obtained for the most part from European analyses, which have, indeed, during the past two decades grown to be very numerous and complete. The most valuable tables of the composition of plants in use with us are of German origin. That these, in some cases at least, are not fully correct for American products is shown by some analyses lately made by Professor Storer. Samples of bog and meadow hay and other plants were found to contain only from 8 to 10 per cent. of moisture, and a sample of timothy hay yielded only 7.8 per cent. In the European analyses of different kinds of hay, 14 or 15 per cent. is generally given. Why hay in New England should contain only little over half as much water as in Europe is a matter worthy of investigation.

A BURIED FOREST IN ORWELL, ENGLAND.

Mr. J. E. Taylor, according to Nature, has discovered a bur ied forest in Orwell, England, represented by a layer of peat containing trunks, leaves, and fruit of the oak, elm, hazel, and fir, associated with the remains of mammoths. Mr. Taylor considers this forest to be contemporaneous with others along the coast which existed previous to the depression separating England from the Continent.-12 A, Oct. 29, 1874, 529.

DISTRIBUTION OF THE FERNS OF NORTH AMERICA.

Mr. John H. Redfield publishes in the Bulletin of the Torrey Botanical Club a paper upon the distribution of the ferns of North America, and arranges the species in six geographical

divisions. The first of these he calls the Cosmopolitan, which embraces two species (Pteris aquilina and Asplenium trichomanes), distributed over the globe in both temperate and tropical regions. Pteris aquilina lives in sandy barrens, and is found every where from Lapland in the North to New Zealand and Tasmania in the South, in America reaching from Labrador to Alaska and the Isthmus of Panama.

Species of the second, or Boreal division, occupy the northern part of the United States, extending through Canada and British America, some of them to Labrador, Greenland, and Alaska, and represented also in the northern sections of the Old World. Of these there are twenty-seven species.

In this group we find an illustration of what has been noted by Professor Gray in regard to flowering plants, namely, a much closer relation between the species of Western America and Eastern Asia than between those of Eastern America and Western Europe. Thus the Asplenium septentrionale is widely distributed in the mountains and colder portions of Europe and Asia, but is only known in this country in the Rocky Mountains as far south as latitude 32°.

Pellea gracilis, an American form, occurs in the Old World only in the Himalaya Mountains.

Third, the Appalachian division. The species occupy the mountainous and hilly regions east of the Mississippi, often to the coast, and northward to Canada, in some few instances occurring also in the Old World. The number under this head amounts to about thirty-eight.

Fourth, the Pacific division, which contains species extending to the western borders of the continent, from Alaska to California, in a few cases appearing also in the Rocky Mountain region. Here we have seventeen species.

Fifth, the New Mexican division. Of this some of the species occur in Mexico, and even in South America; a few also in California. There are twenty-seven species enumerated under this head.

The sixth, or the Tropical division, includes twenty-two species inhabiting the borders of the Gulf of Mexico, most of them extending to the West Indies and tropical America. Of these, one, Trichomanes petersii, is quite local, having been found only in Alabama and Florida.

Of 125 species enumerated, sixty-nine, or about fifty-five

per cent., are found in the New World only, and of these sixty-nine about fifty-three, or over forty-two per cent. of the whole, are restricted to the limits above assigned. There remain seventy-two species which we share with other portions of the world. Of these forty are found in common with Europe, four of them not occurring elsewhere.

We have thirty species in common with the Himalayas of Northern India, of which two are not found elsewhere. With Northern or Eastern Asia we have thirty species in common, and, taking the whole extent of Northern and Eastern Asia, we have forty-six species in common out of the seventy-two, showing a very decided preponderance in Asiatic forms, as already referred to.-Bull. Torrey Bot. Club, Jan. 1, 1875.

THE BLADDERWORT A CARNIVOROUS PLANT.

Mrs. Mary Treat communicates to the New York Tribune of February 1 some original observations upon the bladderwort (Utricularia), and its functions as a carnivorous species, as in the case of Sarracenia, Drosera, etc. Bladderwort grows abundantly in shallow ponds and swamps throughout the Northern United States, and is characterized by the possession of numerous little bladders scattered among the leaves, which were supposed to be used in some way for floating the plant, especially during the flowering season.

Mrs. Treat, however, had her attention called in the first place to the fact that the bladder-bearing stems really sank lowest into the water, and the subsequent detection of minute microscopical animals in the interior induced her to examine the subject in reference to a possible animal diet. She has finally satisfied herself that the true function of these bladders is to entrap the various forms of animals, some of them larvæ, probably of dipterous insects and others, entomostraca, such as Daphnia, Cyclops, and Cypris; and that, once inside of the bladders, the latter constitute so many little stomachs for their convenient digestion.-N. Y. Tribune, Feb. 1, 1875.

NEW SPECIES OF GLAUCIUM.

In working over the refuse of the ancient silver-mines of Laurium, in Greece, for the purpose of extracting the remaining percentage of metal, a considerable amount of soil has