Frederick Leroy Sargent

“ They feed on the water plants, and seem to have a special liking for the long-branched antennæ which grow at the mouth of the bladders, and, all unconscious of the trap, on, on they go, their sickle-shaped jaws cutting the antennæ which they eat as they advance, until their heads reach the mouth of the bladder, when they heedlessly touch the valve and the trap is sprung and they are drawn within, never more to escape, but to be slowly devoured. ”

“ The play of the muscles and internal organs are plainly visible, and you can always tell what he has chosen for dinner. Diatoms and desmids form a portion of his diet. His mouth is below the wheel. When he is hungry he anchors himself by his forked tail and sets his wheel in rapid motion, which makes a powerful current sufficient to bring quite large objects to his head, frequently too large to admit into the mouth. He will often repeatedly try to take a desmid entirely too large for his mouth, and his manœuvres are quite comical as he whirls it round and round, nipping it on all sides. ”

“ Very pretty flowers are found among the grasses, sedges and common weeds. The different trees as they bloom in spring—the maples, elms, willows, poplars, sassafras and hosts of others—all have flowers that are perfectly lovely. Most of these flowers need to be picked to pieces under the magnifier to show up their full beauty. The parts of flowers, both small and large ones, deserve attention. Frequently one meets with remarkable forms. ”

“ The Sabella which inhabits the tube, is of itself a most attractive object. Most elegant fringed filaments proceed from the head, and wave back and forth like a fan, and near the ends of these delicate slender filaments are little black balls, supposed to be eyes. If they are eyes, the Sabella has no lack of vision, and this may account for his seeming watchfulness. He is always on the alert and drops down into his house at any approach. ”

“ XIII.—HOW TO SEE A DANDELION.
A simple microscope, some mounted needles, a sharp knife and a pair of small forceps, are the only things needed to begin with.
There are many kinds of simple microscopes sold, some of which are of moderate price and answer every purpose; but if one has a little mechanical skill the cheapest way is to buy a magnifier and make the rest of the microscope one's self. What is known as the "bellows pattern," with three lenses, is one of the best of the cheaper forms of magnifiers, and is an admirable little instrument. ”

“ You have now found out how to get your eye close to an object and see something that is very small; this is usually called magnifying it, because it seems to make it look large. Suppose you have a lens that will let you see a flea through it held just one inch from it, this lens is now an addition to your eye, as [13] we measure from the lens. If you had another flea held ten inches off, so big that it would just be hidden by the little flea, the one farthest off would be ten times as large as the near one. ”

“ After a little practise you will be able to separate the different parts of insects and look at them with higher powers. The moth fly will soon be on the wing, and your aunt will not call you cruel if you kill and cut up large numbers of them. Put a little of the dust that comes off from the wing of a moth on a glass slide, look at it with a high power, and you will find that each particle [25] of dust is a pretty leaf-like scale. You have seen in summer the dust on the wings of butterflies; remember this, and look at this butterfly dust with your microscope. ”

“ Another tree-like group is that of the Vorticella, of which you will sometimes find in the Cochituate, the species Vorticella nebulifera. Each animal is at the top of a stem, and this stem has the peculiar property of being able to coil up and draw its head down close to the bottom. This appears to be a defensive movement, for whenever a big ugly creature comes by, down go the whole family so quickly [38] that your eye cannot follow the movement. Sometimes they will all bob down when you tap the stage of the microscope so as to jar them. ”

“ Sometimes he is gloomy and draws himself in so that he looks like a ball; then he will stretch out full length, and opening his wheel, shoot through the water with great speed. Again he will attach his tail to some fixed object, and by the aid of his wheel draw a rapid current of water through his mouth; it is thus that you can best observe him, and by and by you will discover that the apparent wheel is only a result of the rapid sweeping movement of the long hairs or cilia which fringe the opening in the top of the head. ”

“ If we look at the seaweeds which grow on the rocks we may see many white specks adhering to every part of the plants. With a lens we find the minute specks are spiral shells of many species belonging to the class Foraminifera, and very closely allied to the amœba. The shells are of most elegant form and pattern. The large sea-shells which we so much admire are not half so lovely in form or color as these seen through a microscope. Some of the living animals and the castles in which they dwell are crimson in color, others a delicate pink. ”

“ The lens in the eye can change its shape a little, so that it will focus objects a mile off, or ten inches off, but it cannot be pushed in and out like the tube in your camera. You can do this, however, if you take another lens and hold it outside your eye and let the light go through that first before it comes to the lens in your eye, and in this way you can get a focus in your retina, and the outside lens thus forms a part of that optical instrument called your eye. ”

“ With a large hand-lens, you can see a whole fly at once and magnify it two or three times; but when you put it on the stage of your compound microscope and try to magnify it still more, you will find that you can only see a part of it at a time, and the higher the power you use, the less can you see; in [24] other words, the more you magnify an object, the smaller is the field of view.
HEAD OF MOSQUITO. MAGNIFIED 15 DIAMETERS.
An inch-objective will show the head of an housefly, which in a bright light is a very beautiful object. ”

“ When you go to collect them take a small wide-mouth bottle and, having found a place where there is what you want, lower your bottle, mouth down, in the midst of them and when it is well under water turn the mouth upwards. A good many of the animals will run in with the water. If the first time you do not get what you want, the second time you may. When you want to examine them at home you can fish them out with a glass tube and put them in a watch crystal or on the glass stage of the microscope. ”

“ Many of our young people spend the month of August at the seaside, and if those who wish to learn something of the curious microscopic animals will stroll along the beach when the tide has receded, until they come to rocky places and little pools filled with salt water and various marine plants, they will find a form of animal life quite different from that in fresh water ponds. These little pools along the rocky coast are the homes of countless numbers of zoophytes—animals which have a stronger resemblance to plants and flowers than any we have found in fresh water. ”

“ Objects through which you can see light are called "transparent," and are the easiest to look at with the microscope, because you can lay them on a glass slide and throw light up through them with your mirror. Thick objects through which light cannot pass are called "opaque," and are more difficult to examine, and can only be seen with low powers and a bright light. ”

“ It is much better to use a good simple microscope than a poor and cheap compound one; be sure and remember this and not be enticed to buy such an one by any representations as to its great magnifying power. ”

“ It seems strange that innocent-looking plants should capture and kill animals; but this is really what the Bladderworts (Utricularia) are all the time doing. They grow in ponds and swamps, some species in deep, still water, others in shallow ponds.
Fig. 1 shows a portion of the stem of Utricularia clandestina, natural size. The little bladders are so nearly transparent, that on bringing them under the microscope, or even under a good lens, you can see the numerous creatures that they have captured, some partly consumed, others still alive. ”

“ Insects may be kept well in alcohol until winter, and then careful studies may be made of them.
When using the magnifier in the field, hold it in such a way that the smallest lens will be nearest the object when the lenses are combined and be careful not to shade the object with the hand or the hat brim. Just enough light should fall on the object to make its examination comfortable for the eyes. If you rest the hand holding the magnifier on the hand that holds the object, both lens and object can be held much steadier. ”

“ The study of the different parts of insects is one of the most fascinating of the many uses of the Simple microscope. Although all insects are made up on the same general plan and corresponding organs occur in most of them, there is an endless variety in the forms under which we see the different organs and the uses to which they are put. ”

“ The desmids are wonderfully beautiful plants; the markings and colors are exquisite. A number of species are found in the sediment of every swamp and pond.
The diatoms often grow in long ribbon-like masses (fig. 3) , and then partially separate, remaining joined together at the angles so as to form a zigzag chain as seen at figure 4. They have the power of moving through the water, changing their places like animals.
A great variety of forms are found, both diatoms and desmids, many still undescribed, inviting the young microscopist to study and name them. ”

“ Their entrance is easy enough; there is a sensitive valve at the mouth of the bladder, which, if they touch it, flies open and [63] draws them in as quick as a flash. These downward-opening bladders not only entrap animalculæ, but, more wonderful still, the strong larvæ of insects. The larvæ most frequently caught are those of the mosquito and chironomus. Often the mosquito is caught tail first—the entire body inclosed and the head left sticking out. It always looks as if the victim might walk or wriggle out, but it never does ”

“ The stems of the tree are jointed, and the little creatures can sway the branches about and even throw them into a spiral coil so as to bring themselves near the main stem. This gives them the appearance of being very polite toward each other; they bow and courtesy as if preparing for a grand quadrille, and they are decked out in gay colors, red, green, and yellow. The margins of the little cups are fringed with hairs, or cilia, which they can put in such rapid motion that it makes a current in the water and brings little particles to their mouths which they consume as food. ”

“ Commencing in the centre we find in both a pistil, consisting of an ovary at the base and a stigma at the top and a style between. In the Dandelion the stigma is split in halves, while in the morning-glory it is not split but has three little knobs. Around the pistil come the stamens in each case. Each stamen is composed of two parts: a slender stem (the filament) and a little sac at the end (the anther) which is filled with pollen dust. In both cases the filaments grow out of the sides of the corolla. ”

“ An object one hundredth of an inch in diameter, or of which it would take one hundred placed side by side to make an inch, is about the smallest thing that can be easily seen by the unassisted eye. Take a piece of card and punch a little hole through it with the point of a small needle, hold it towards a lamp or a window, and you will see the light through it. ”

“ Each one has its own organs of existence, although attached to its brothers by its stem. Each has a bright red eye, and a long slender whip, called a flagellum, with which it lashes the water, and when all the flagellæ are in motion, the whole tree swims about. The individuals are very small indeed, and it will take your best objective to show the flagellum. ”

“ The best thing for the rod is a piece of brass wire one quarter of an inch thick; a lead pencil however is a good substitute. Before bending the end of the brass wire arm it is well to heat it red-hot at the point of bending, to take out the temper: as otherwise it may break. The holes in the handle of the magnifier should be drilled as near the front as possible and so arranged that when the magnifier is in position the smallest lens will be near the object. ”

“ During the cold weather it is not pleasant to make excursions into the country and search for objects for the microscope; so you will look about and see what you can find at home; and if you live in Boston, Cochituate water will invite your inspection. ”