Popular Science Monthly/Volume 9/October 1876/Miscellany

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MISCELLANY.

A Preliminary Note on Menopoma Alleghaniense of Harlan.—At the Buffalo meeting of the American Association for the Advancement of Science, Prof. A. R. Grote read a paper with the above title on the Menopoma, an aquatic salamander, with soft, leathery, scaleless skin, inhabiting the tributaries of the Mississippi River. After the examination of a large number of specimens, the characters separating the species Menopoma Alleghaniense and fuscum, as recently accepted by Cope, were found inconstant, and Grote comes to the conclusion that "there is only one and not two species inhabiting the water-shed of the Mississippi." After watching the habits of the animals in the aquarium, Grote succeeded in ascertaining the fact that the outer layer of the skin is shed as in snakes and toads, and is, in some cases at least, swallowed by the animal, since it was in one instance taken out of the mouth of the specimen. Grote succeeded in obtaining eggs laid on August 30th, and draws attention to the fact that the Menopoma puts on a "marriage-dress" during this period of its life, the tail broadening, and a plaited extension of the skin appearing along the sides of the body. The habits of the Menopoma seem, to be nocturnal, and its eggs are laid along the muddy banks of the streams it frequents. The egg contains a yolk about the size of a pea floating in a glairy white fluid, surrounded by a membrane like that enveloping the albumen in a bird's-egg, and taking in a certain amount of water by endosmosis.

 

Insect Parasites in Muddy Trout-Ponds.—In the fall of 1873 the owner of a pond near Amsterdam, in this State, put into the pond some yearling trout. About the middle of last July a few dead fish were seen floating upon the water. On the tail of one of these dead fish was found "a very curious green bug, about the size of a pumpkin-seed; long legs, red eyes, and a long stinger." Hereupon the owner of the pond consulted Mr. Seth Green, and the latter expressed his belief that the insects were destroying the trout. "The cause is," he writes, "that you have no quick-running water, like a creek, with gravel bottom, running in your pond. By having such a place, when any insect is fastened on a trout, he will go to the quick-running water, and will soon rub it off. Putting trout in a pond with mud and weedy bottom that contains water-insects, and no stream flowing into it, is like tying a man's hands and placing him where there are plenty of mosquitoes, gnats, and black flies. The running water and gravelly bottom answer the same purpose in keeping the trout free from insects as our hands do in keeping the mosquitoes from us."

 

Management of the Bedding in Sleeping-Cars.—A writer in the Sanitary Journal, of Toronto, calls public attention to a source of danger existing in the sleeping-arrangements of certain railway-carriages. The beds in each section are opened out at night, after having been tightly closed for a period of twelve or fourteen hours. "Into these beds," says the author, "a stranger enters, probably partially recovered from some infectious disease, such as small-pox, scarlet fever, etc. He makes his exit, and at once these beds are closed and fastened down carefully again until the following night, when the same process of bed-making is observed, with a change of sheeting, as the case may be." The remedy suggested by the author does not appear to be sufficient: it consists simply of perforations in the bed-casings, with openings outward, so as not to communicate with the interior of the coach. But, if by this plan the germs of contagious disease are not destroyed, the bedding at least will be aired to some extent, and this will be no slight advantage.

 

A Neglected Naturalist.—Under the title of "A Neglected Naturalist," Mr. II. E. Copeland contributes to the American Naturalist a vindication of Constantine S. Rafinesque against the aspersions cast upon his scientific work by European and American critics. It is charged that the work done by Rafinesque only introduced confusion into botany and zoölogy by needlessly multiplying genera and species. But, according to the author, "thirteen genera, eight sub-genera, and sixteen species of the plants referred to in Gray's manual, are his. His writings on conchology have been considered worth editing by Binney and Tryon. Of our reptiles and batrachians four genera and six species bear his name. He described four genera and four species that are retained in the current literature treating of our mammals. The genus Helmitherus of birds was proposed by him." In 1820 Rafinesque published a "Natural History of the Fishes of the Ohio River." Mr. Copeland declares himself to be profoundly impressed by the accuracy of the work of Rafinesque as represented by this little volume. Of seventy-nine genera and one hundred and fifteen species of fishes known as inhabiting the Ohio and its tributaries twenty-nine genera and thirty-seven species were first described by this neglected naturalist, and the eliminating of seasonal and sexual forms from the rank of species, and the identifying of more of his genera on a better acquaintance with the fishes of the Ohio, will constantly make the ratio greater.

 

Marsh-Water as a Vehicle of Ague-Poison.—In his volume on "Practical Hygiene" the late Dr. Parkes adduces a number of facts to show that marsh-water is a vehicle of ague-poison. The more commonly-received opinion, however, is that the air of marshes is the sole cause of intermittent fevers. Certain observations made at Tilbury Fort, on the river Thames, appear to confirm Dr. Parkes's view. In the "Army Medical Blue-Book" it is stated that the troops at Tilbury Fort are supplied with water collected on the roofs of buildings, and stored in underground tanks at or below high-water mark. The officials at the neighboring railroad-station use spring-water pumped from a well. Now ague has, for a long time, been common among the troops at Tilbury Fort, and almost unknown at the railroad-station. During some cleansing and repairs to the tanks, spring-water was obtained from the latter source for several months together, during which time ague disappeared from among the soldiers at Tilbury, but on the tank-water being again brought into use, cases of ague again made their appearance, the disease ceasing on discontinuing that, source of supply. Samples of water from these different sources were submitted to chemical analysis, when it was found that the amount of organic matter in the tank water was greatly in excess of that in the spring (railway-station) water, while the presence of vegetable and fungoid matter made it evident that there had been soakage of water from the surrounding marsh into the tanks.

 

Dry Thunder-Storms.—A correspondent in Oregon, Missouri, communicates some observations on weather phenomena, especially upon the influence of forests on rainfall. "When the earth has become dry, parched, and very warm, on occasion of thunder-storms, I have often," he writes, "noticed for hours, while it was thundering overhead, the mist, falling from the storm clouds, to roll back, after nearly reaching the earth, in the form of lighter vapor. I think this rain, or mist, in falling, passed down to the stratum of very hot air on the earth's surface, and became a steam, large volumes of white vapor forming suddenly and rolling back and up. Now I am confident that, if the earth had been shaded by trees, this rain would have fallen on the ground.

"This phenomenon can be seen here every hot, dry season. It has, no doubt, escaped the attention of all but very close observers. Mine was called to it by a question asked while one of these dry thunderstorms was prevailing—a common thing—dry thunder-storms—thunder rattling overhead, but not a drop of rain falling. The white mist is not easily observed overhead, where all is light; but opposite to the sun, under the dark storm-cloud, it is very plain, and must attract attention."

 

Fertilization of Plants.—Mr. Thomas Meehan discovers in the "sleep" of plants an agent in their self-fertilization. The fertilization of the common Claytonia Virginica had been somewhat of a mystery to him, as, in view of the prevailing theory of cross-fertilization by insect agency, this plant ought not to be a self-fertilizer; but from repeated observation he was satisfied that no insects had visited plants that had yet seeded abundantly. Watching the process of fertilization, he found that the stamens on expanding fell back on the petals expanded during daylight. At night, when the flower closed, the petals drew the anthers up in close contact with the pistils. Cross-fertilization could be accomplished by insects if they visited the flower, but they did not, and actual fertilization only occurred in this way. In many cases, especially late in the season, the stamens recurve so much as to be in a measure doubled up by the nocturnal motion of the petals. The anthers were not drawn into contact with the stigmas in these cases, and, as a result, the flowers were barren.

In the Ranunculus bulbosus, our common buttercup, in the evening following the first day's expansion of the young flower, the immature anthers and the young stigmas would be found covered with pollen-grains. The inference would generally be, that this had been carried there by insects. But, as he had been especially on the lookout for insects as visitors to the buttercup, and feeling sure that none of any consequence had been to them, he examined these flowers carefully, and found that, on the first expansion of the flower, a single outer series of stamens burst their anther-cells simultaneously with the expansion of the flower, and, by contracting the cell-walls, ejected the pollen to the smooth petals, from which it easily fell to the immature anthers and stigmas, when the flower closed for the night.

Knowing that another species of buttercup, the Ranunculus abortivus, had fixed spreading petals which did not close at night, and which, though with comparatively large nectariferous glands full of a liquid secretion, was wholly neglected by insects, and yet had every flower seeding profusely, he was anxious to find, in view of his other discoveries, how these were fertilized. Visiting a wood after twilight, to ascertain if any nocturnal insects visited them, he found that, though the petals did not close at sundown, the slender pedicles drooped, inverting the flower, and in this way the pollen found its way from the petals to the stigmas without any difficulty whatever.

 

Functions of the Root-Hairs of Plants.—In an article published in the Gardener's Monthly, Prof. B. C. Halsted points out the functions of the "root-hairs" of plants. These so-called root-hairs are thread-like structures, consisting of elongated surface cells of the root. These hairs absorb water out of the soil either by capillary attraction, or by the process of diffusion, or by osmotic action. It is a well-known fact that porous bodies absorb liquids to a greater or less extent. A dry cloth hung so that one corner will dip into water soon becomes saturated. This is capillary attraction, and has a place in root-absorption. From an extended study of the properties of liquids, the law of diffusion has been established, viz., that when two or more miscible liquids of different densities are placed in contact, interchange will take place till the whole liquid is homogeneous. This property of liquids will account for the movement of the absorbed sap to any part of the same cell—from the tip of the hair to its base. But there is another kind of diffusion—osmose, or membrane diffusion. When liquids of different densities are separated by a thin membrane, diffusion takes place through this partition with a rapidity depending on the nature of the liquids and membrane, the greater flow being toward the denser fluid. The cell-wall of a root-hair is such a membrane, separating the denser liquid within the cell from the thinner one without; and, as this membrane is a living, growing one, it may be specially effective for osmotic action. From the function, position, and delicate structure of the root-hairs, at least one important practical conclusion can be drawn, viz., the importance of preserving them when a plant is to be potted or transplanted.

 

The Philosophy of Dreams.—Prof. Ferrier recently delivered, at the London Institution, a lecture on "Dreaming," explaining its phenomena by the results of his famous experiments on the localization of faculties in the brain. For each class of impressions there are, he said, special regions of consciousness in the brain. The impressions received are photographed on the brain, and are capable of being revived. But for this power of recalling them no knowledge would be possible. Memory, or the registration of sense-impressions, is the ultimate basis of all our mental furniture. Bach piece of that furniture has its function, like the litters in a compositor's case. We have a sight-memory, a hearing-memory, etc. When thinking, or engaged in ideation, we ire but recalling, as shown by Herbert Spencer and Bain, our original sensations ami acts of cognition. Commonly the reproduction is very faint, but in some instances it is nearly or quite as vivid as the original sensation. This is especially true of poets, painters, religious enthusiasts, and others. Those portions of the brain which are most continuously in action during waking-hours require the longest rest during the hours of sleep. Hence the centres of attention would sleep while the functions allied to reflex actions would more easily waken.

The brain in sleep Prof. Ferrier compared to a calm pool, in which a stone causes ripples, liable to interruption by other ripples similarly caused. So the ripples of ideation get confused. But, again, the circle on the pool may not be interrupted, and then the ideation will be regular. The current of ideation may be coherent or incoherent. The most vivid association, which is commonly the latest, dominates over the rest. Dr. Reid, the metaphysician, once dreamed of being scalped—there was a blister upon his head. Dr. Gregory, from having a bottle of hot water at his feet, dreamed of walking up the crater of Etna. Visceral conditions are the most frequent sources of dreams; the hungry dream of feasts, the thirsty of water, the dropsical of drowning. Dr. Ferrier happily compares incoherent dreaming to the changes in a kaleidoscope. There is nothing new in dreams; the blind do not dream that they see, nor the deaf of music. In such cases there is a letter missing from the font of type. Our fancy is awake during dreams, and the faculties which should check it are asleep. Hence it is that nothing surprises us in dreaming.

 

Locusts in Africa.—In his work, "The Victoria Falls of the Zambezi," Eduard Mohr gives an impressive description of a flight of locusts witnessed by him in the region of the Vaal River. "I noticed," he writes, "on the western horizon what I took to be columns of smoke, rising higher and higher until they reached the zenith. I thought the bush must have been set on fire, for the whole of the horizon from the northwest to the southeast was already apparently enveloped in clouds of smoke. This, however, was caused by no fire, but by locusts. Presently a few, then dozens, then hundreds, then thousands, of locusts fell upon us, coming down in such heavy showers that the air was darkened with them; and through the whizzing, whirling veil they flung about us we could look with the naked eye at the sun, which, although high in the heavens, had the blood-red, rayless appearance usually peculiar to the time of setting." He adds that the natives, with their horses and cattle, as well as elephants and other wild ruminants, feed on them greedily; the author found them perfectly tasteless.

 

Natural History in New Guinea.—The Italian naturalist, D'Albertis, continues his explorations and studies of natural history in the island of New Guinea. He recently made the ascent of a mountain 1,200 feet high, on Yule Island, obtaining a good view of the plains watered by the Amama River. This river D'Albertis has partly ascended on several occasions; he states that it traverses an extensive and fertile district well suited for grazing. The Nicura River, into which the Amama debouches, is bordered by mangroves, eucalyptus, grass-trees, etc. He remarks that the natives appear everywhere ignorant of the uses of metals; and he is of opinion that Wallace and others are right in recognizing the existence of two races in the island. The aborigines he considers are confined to the western and interior portions, while the inhabitants in the other parts represent a taller, lighter-colored, and more intelligent race, which displaced the older tenants.

 

Sulphide of Carbon as an Insecticide.—The use of carbon sulphide is recommended by J. B. Schnetzler, of the Lausanne Academy, as a means of destroying the insects which infest herbaria and entomological collections. The Academy collection of Swiss flowering-plants having been attacked by Anobium paniceum, M. Schnetzler had a wooden box made large enough to contain five fasciculi of the herbarium, each composed of about 200 plants. Four ounces of carbon sulphide were poured into the five fasciculi; the box was tightly closed, and the whole left for a month. All the insects were destroyed, and no injury was done to the specimens, or to the papers to which they were fastened. The expense of the operation is very small. M. Schnetzler recommends that the boxes should be placed under a shed, as in case of the escape of vapor there might be danger of explosion. The same process may be employed for collections of insects.