Specimens can be roughly divided into: animal specimens, bird specimens, fish specimens, insect specimens, plant specimens, bone specimens, shrimp and crab specimens, fossil specimens and so on.
Plant specimens are classified according to the purpose of use.
Fish specimen
1. Full specimen: usually used to identify plants, scientific names and Chinese herbal medicines. This specimen is also used for vegetation investigation in a certain area. For example, investigate the plant resources of a school or a mountain. The vegetative organs such as roots, stems and leaves of higher plants are one of the basis for identifying plants, but they are often different due to different growth environments. Flowers and fruits have relatively stable heritability, which best reflects the inherent characteristics of plants and is an important basis for identifying and distinguishing plants. When collecting specimens, you must try to collect specimens with roots, stems, leaves, flowers and fruits. Herbs also have to dig underground. It can be seen from the root system whether it is annual or perennial. In addition to rhizome, the underground part often contains deformed roots and stems, such as water chestnut, lily, Jerusalem artichoke, cabbage, Polygonatum sibiricum, Fritillaria, seven leaves and one flower. Woody plants should collect representative branches, preferably with a small piece of bark. The shape and arrangement of sporangium, rhizome, scales and indumentum are important taxonomic characteristics of ferns, which should be paid attention to when collecting. The whole specimen is often made into wax leaf specimen and primary color impregnation specimen.
2. Anatomical specimen: The purpose of making is to observe and study the internal tissue structure of an organ of a plant. For example, dissect the bulb of onion and observe the structure of its basal plate, bud, bulb and fibrous root. Observe the lateral membrane placentation and seed placement position of melon in the cross section of cucumber; Cut the peach blossom vertically and observe the various parts and shapes of the flower. To collect such specimens, only one healthy and representative organ needs to be selected, and it is not necessary to collect the whole branch. Anatomical specimens are usually made into preservative impregnated specimens.
3. Phylogenetic specimens: The purpose of making is to observe and study the life history of plants, that is, the process from seed germination to growth, flowering and fruiting of a plant, which is often used in biology teaching, introduction, cultivation and scientific research. This kind of plant specimen must collect different growth and development stages of plants. For example, to sample the germination process of kidney beans and corn seeds, it is necessary to collect samples of their embryo germination, taproot and bud growth, true leaf growth and other stages. This specimen can be made into wax leaf specimen or impregnated specimen.
Dry specimen set
4. Comparative specimens: Comparative specimens mainly compare the similarities and differences of an organ of different plants. For example, to compare the seed morphology of dicotyledonous plants and monocotyledonous plants, it is necessary to collect mature fruits, such as rape, soybean, cucumber and tomato, remove the peel, dry the seeds, and collect the fruits of wheat, rice and corn for comparison. Compared with various forms of roots, we can collect cotton with straight roots, rice and wheat with fibrous roots, radishes with bulbous roots, carrots with conical roots, radishes with cylindrical roots, adventitious roots of tuber potatoes, corn and sugarcane, and parasitic roots of Cuscuta chinensis and Taxilli. Comparing the stems of various shapes, we can collect peaches and Ficus carica with erect stems, morning glory and honeysuckle wrapped around the stems, strawberries with stolons, grapes with climbing stems, gourds, Parthenocissus tricuspidata, prickly hawthorn, Gleditsia sinensis, cactus with fleshy stems, epiphyllum, water chestnuts with bulbs, Chinese cabbage with bulbs, onions and garlic. Compared with the types of corollas, we can collect peach blossoms with petals, rape and shepherd's purse with cross corollas, soybeans, rosewood and broad beans with butterfly corollas, safflower with tubular flowers, Jerusalem artichoke with tongue-shaped flowers and wheat flowers with single cotyledons. Comparing various inflorescences, we can collect Chinese cabbage in raceme, plantain in spike, sunflower in umbel and sunflower in head. Comparing fruits of various shapes, we can collect plums and apricots with drupes, persimmons and grapes with berries, apples and pears with pears, peas and Robinia pseudoacacia with pods, radishes with pods, Indigofera, sunflowers with achenes, rice and wheat with caryopsis, elms and Acer with samara. The contrast specimens can be made into wax leaves or air-dried specimens, and the effect of soaking fruits in primary colors is better.
Specimens are animals, plants, minerals and other objects. After various treatments, it can be preserved for a long time and kept as original as possible for exhibition, demonstration, education, appraisal and textual research.
Specimen processing methods can take whole individuals (even multiple individuals, such as bacteria, algae and other microorganisms, or fungi and other individuals are small and live in one place), or take some of them to make specimens, which can be made by physical air drying, vacuum, chemical antiseptic treatment and other methods.
There are two main methods to make specimens: needle insertion method and liquid immersion method.
For insects, acupuncture is generally used to make specimens.
needle punching
Making specimens by needle insertion requires the following eight steps:
1. Kill. Death In order to make specimens with complete shape, vivid color and shape, it is often necessary to use newly caught live insects to make them die quickly in a short time. Pesticides with high toxicity and strong knock-down ability, such as chloroform and carbon tetrachloride, can be used from manufacturing bottles or poison tubes.
Poison bottles and poison tubes can be made of wide-mouth glass bottles, and the size of the bottle mouth can be determined according to the size of the insect body. Cork stoppers should be made of cork, not rubber stoppers which are easy to corrode. First spread some sawdust on the bottom of the bottle, then pour the liquid medicine into the bottle until it is just saturated and the liquid medicine does not flow out, and then cover the medicine layer with thick paper or cork pieces. There should be several air holes in paper or sawdust so that toxic gases can escape.
2. Removing internal organs Before making specimens, the internal organs of insects must be taken out first, so that they can be dried quickly after the needle is inserted. But an extremely thin insect like damselflies in dragonflies doesn't have to gut.
When dissecting, tweezers can be directly inserted into the connective membrane of the neck, chest and back of the worm to take out various organs. Or cut an incision along the connecting membrane between the back plate and the web on the side of the abdomen, and then take out the organ with tweezers.
Then knead it into a long cotton plug with absorbent cotton, and slowly stuff it into the hollowed-out insect abdominal cavity with tweezers to keep the original size of the insect.
3. After the temporarily stored insects are killed by poisonous gas, they should be taken out of the poison bottle as soon as possible, and put into a cotton paper bag prepared in advance after viscera removal, so as to avoid the insects from being squeezed, deformed and damaged during carrying.
The paper wrapped in cotton paper should be chosen with good water absorption and cut into squares. The size depends on the size of the insect's body, so it can just wrap the insect's body. Absorbent cotton can take a small piece about 0.5 cm thick, slightly smaller than paper, and put it in the middle of the paper after flattening.
It is best to prepare a piece of Zhang Xiaobai paper and stick it on absorbent cotton as a temporary cotton swab to record the time and place of collection.
When you are ready, you can temporarily wrap the worm inside after taking out the internal organs to prevent it from being damaged and deformed.
The storage period should not be too long. Open the package in 1~2 days and ventilate and dry it to prevent deterioration.
4. The volute which is still soft, dry and hard is usually brittle. If you don't take measures to soften it, it is likely to break into small pieces when you touch it, so you must soften it before inserting the needle.
The softening method is: replace the glass with a soft pot or other utensils, add distilled water to the bottom, add a few drops of carbolic acid, put the worms on the shelf overhead, cover them and seal them for 2-3 days before softening.
If there is no equipment to change the soft tube, you can also directly soak the worm in warm water or soften it with hot air.
Dry specimen set
5. Insect needles for fixing insect specimens are made of stainless steel, from fine to thick, with seven grades: 00, 0, 1, 2, 3, 4 and 5.
From No.0 to No.5, all the needles in six grades have caps. Only No.00 has no needle cap, only half the length of other needles, as a double needle insertion specimen.
Insects that are not dry, hard or soft after death are fixed with the above needles. Which needle to use depends on the size of the bug.
At the beginning of needle insertion, the insect body to be made should be placed on the needle table or the seam of the table, and then the appropriate gauge needle should be selected according to the size of the insect. Insect needles should be inserted on the right side of the dorsal midline of the front wing base, Hemiptera insects should be inserted in the middle of the chest or the right side of the midline of the small shield, and other insects should be inserted in the middle of the chest.
6. After the whole posture is completed, the insect after needle insertion must make local adjustment according to the most correct posture of the insect, such as the position of the wing, the bending degree of the insect's foot, the elongation direction of the antenna, etc. Make it have the same posture as a live bug!
Some insect lovers like to fix insects according to their favorite posture, and can adjust the posture and position of insect body, wings, legs or tentacles according to their own requirements.
7. Drying After inserting the needle and adjusting the posture, you can put the insect in a safe and ventilated place and dry it for a period of time in the next step. This stage usually takes 1~2 weeks, which can be completely dried.
8. The last process of antiseptic preservation is to add a proper amount of moth-proof and mildew-proof chemicals to the prepared insect specimens, and then insert labels. If the number of specimens is large, it is necessary to classify the specimens into specimen boxes and place them in dry and dark places.
If it is necessary to make an insect ecological landscape box, insect specimens can also be placed in the same glass cover with dried plants and flowers, or in other art frames.