Wednesday, 17 July 2019

Don't fall into a pitcher plant

A pitcher plant (Nepenthes) is a soloist. The cups of this whimsical eye-catcher vary in length from a few centimeters to more than 30 cm. They are actually transformed leaves that develop when the plant receives sufficient light. Insects find nectar on the lid above the cup and crawl around the cup, looking for more. Just below the cup rim they find new nectar, but immediately below is a slide of wax. They slip into it and fall into the cup.

The scrambling of the creatures activates the glands in the cup which thereby release a strong acid. This acid digests the insects in two days. Only the shell of the animal remains. The plant grows as an epiphyte in trees.

Prepared slide by Lieder

Wednesday, 3 July 2019

Breathing under water


Gills are the respiratory organs of many aquatic animals. With fish, the gills are in a space behind the head. Fishes exchange gasses with water through the gills.

Gas exchange

The water comes in through the mouth of the fish, then flows along the gills, and is released through an opening behind the gills. The gills are made up of a gill arch with rakers - which prevent plugging of the organ by particles - and filaments on which lamellas are located. As the water flows along the lamellas, oxygen penetrates into the fish's blood. For optimal absorption of oxygen, the water flows in an opposite direction to the blood.

Carbon dioxide and other waste from the blood is transferred into the water via the gill lamellas. In this way the fish gets oxygen to keep breathing and leaves waste!

Tuesday, 18 June 2019


In the photos of the botanical prepared slide shown here, we see a part of the cross-section of a twig of Genista spec. The slide was made in 1964 and is in very good condition still. The coloring was done with the dyes acridine red, chrysoidine, and astra blue. The mounting medium is Caedax. Caedax is a synthetic substitute for Canada Balsam in microscopic techniques.

Genista or broom is a genus of shrubby plants known for their yellow flowers. Genista is originally from Southern Europe, Southwest Asia and North Africa and is well adapted to a Mediterranean climate with its hot dry summers, lean rocky ground and cool, wet winters.

With thanks to the Royal Antwerp Society For Micrography.

Wednesday, 5 June 2019

Large cattail

Typha latifolia, called ‘large cattail’ in English, is a water plant that is mainly found in eutrophic and acid water, along the shores of ponds, ditches and in swamps. This perennial has an upward and wide-spread growth habit. It is easy proliferating through rhizomes. If planted in a garden pond, locking it in a good pond basket is the message. The leaves are broad, linear and blue-green colored. Large cattail blooms from June to September with double cigar-shaped ears. The male ears are at the top, the female right below. After wind fertilization, the characteristic brown colored ‘cigars' form the female flowers. The seeds of cattail develop from the flowers on the cigars. The seed fluff is normally transported by the wind. The plant is hardy, endures sea breeze, air pollution and has a beautiful winter silhouette.

The fluorescence photograph taken from a longitudinal section of the leaf, highlight certain parts of the leaf, such as the reinforcement spirals of the transport vessels, the cell walls and nutrients stored in the cells.

With thanks to KAGM for the prepared slide, colored with astra blue and acridine red dye.

Wednesday, 22 May 2019

Pollen bring light into the darkness

A way of classifying pollen species is by monitoring auto fluorescence images of pollen grains. Several components of the exine (i.e. the outer layer of the pollen wall) show conspicuous auto fluorescence in the pollen grain.

The technique allows further morphological characterization of pollen (e.g. determination of pollen size and shape, and the number and type of apertures, the pattern of the exine, etc.), evaluation of pollen integrity, detection of additional components (e.g. the pollen coat) over the surface of the pollen wall, etc. The methods used can be considered non-disruptive and lack of sample preparation. Monitoring pollen auto fluorescence can be useful in disciplines like aerobiology, palynology e.g. in deposits of various type and age in order to determine age (for which conventional pollen analysis fails) and plant taxonomy.

As it is well known, pollen is a seasonal problem for millions of people around the world who suffer from allergenic reactions to the antigens embedded on the outer casing of these microscopic grains. The images presented reveal green auto fluorescence of Cucurbita and Lily pollen grains visualized utilizing blue light excitation fluorescence microscopy.

Wednesday, 8 May 2019

What is scabies?

Scabies is an infection of the skin caused by a scabies mite. The Latin name for this is 'Sarcoptes scabiei'.

The females of the scabies mite dig small passageways in the top layer of the skin and lay their eggs in it. These eggs come out after three to four days. The animals are grown-up within 18 days. The faeces, the secretions, the eggs and certain other substances cause an allergic reaction to human skin. This reaction causes itching, blisters, bumps, redness and scaling. With a first infection, it takes two to six weeks until these reactions are visible/palpable.

For a contamination there must have been a skin contact that lasts longer than 15 minutes. That is why most infections occur through sexual contact. There is no risk of being infected when shaking hands or touching them briefly. When you sleep in the bed, or wear clothes from someone who has scabies, the scabies mite can be transferred. The condition is contagious. Often, scabies occurs in bed- or housemates, which must then also be treated.

The symptoms of scabies are often so recognizable that the (skin) doctor can make the diagnosis on the eye. To confirm the diagnosis, the doctor uses a small knife to remove a skin scraping from a bump or a passageway. This scraping is placed under the microscope. The scabies mite can be clearly seen then.

Scabies can be treated by smearing the whole body with a special cream. Furthermore, clothing and bedding must be washed at 60 degrees.

Prepared slide by Lieder

Wednesday, 24 April 2019

The Dujardin coloring technique

The images shown are taken from a beautifully colored prepared slide from the archives of the Royal Antwerp Society for Micrography. The slide is already several decades old. It shows a cross-section of a twig of the plane tree. In spite of the age of the slide, the colors are still clear and fresh thanks to the use of the simple simultaneous Dujardin coloring method. During the coloring the colors were brought into balance with great skill, showing the various plant tissues. On the fluorescence image the plant various tissues are shown in a different manner.

Wednesday, 10 April 2019

Green curls

Cord moss or Funaria hygrometrica is one of the most common mosses in The Netherlands, especially in severely disturbed and nutrient-rich places such as vacant lots, semi-paved roads etc. A favorite habitat is burning places. A short time after the occurrence of a burn spot, Funaria hygrometrica is almost always present. The spread with spores via the air is extremely effective! In The Netherlands there are few large areas where there is so little disruption that there is no suitable place for Funaria hygrometrica, even if only temporarily.

Wednesday, 27 March 2019

This is not possible with our epidermis

The scales of a fish are slanted in the skin of the fish and consist of collagen, calcium phosphate and calcium carbonate. They overlap and form a firm layer that protects the fish against injuries, parasites and enemies. In many cases they also serve as reflectors or give colors.

Wednesday, 13 March 2019

What’s in a buttercup bud?

The images shown are taken from a beautifully colored prepared slide from the archives of the Royal Antwerp Society for Micrography. The slide is already quite old, from 1988. It shows a cross-section of a bud of the buttercup (Ranunculus) In spite of the age of the slide, the colors are still clear and fresh. Coloring has been carried out with the dyes sun-yellow, crocein scarlet and astra blue. The very thin coupe has been embedded in the resin Euperal. The use of yellow and blue colored dyes, resulted in green colored plant tissues, which is quite special.