Lumbriculus variegatus - The blackworm

Lumbriculus variegatus, more commonly known as a blackworm, is an oligochaete worm found in many freshwater habitats across Europe and North America. It is technically not microscopic, but very small and to see the details and internal anatomy, we have to use a microscope.

Blackworms are only about a millimeter in thickness, but they are able to reach a length of up to 10 centimeters. Blackworms eat things like microorganisms and decaying plant material. To digest its food, the worm has a dedicated digestive tract running down the center of the body. This is like a miniature version of the human digestive tract and works in basically the same way by squeezing ingested food through the tube with rhythmical massaging movements called peristalsis (see video further down).
Another clearly visible structure in the worm is its circulatory system. The animal lacks a true heart, but instead pumps blood through the blood vessels with several pairs of muscularized vessels able to contract and work as a heart.

Myriophyllum beautiful but a nuisance

Myriophyllum or Red stem is a water plant that prefers to take root on the transition from land to water. The stems can grow up to 2 meters long and protrude a few decimetres above the water. Red stem grows particularly well in shallow, warm and nutrient-rich waters. The plant usually roots in shallow riparian zones, but free-floating stems without roots can also survive in nutrient-rich deep water. Red stem is originally from South America.

Myriophyllum was imported for trade in pond and aquarium plants. The plants come into nature because people throw away excess plants in public waters, after which they can spread further.

A better image for your stereo microscope

In compound microscopes, an illumination parallel to the optical axis is the standard. A lot of hardware is implemented to ensure this axial illumination: Center-adjustable Field and Aperture diaphragm, centerable light rings for Phase contrast and Darkfield for transmitted light, center-adjustable objectives and/or centerable rotatable stages in Polarization microscopes. With all these microscopes we are working on 2-dimensional samples.

In stereo microscopy, a 3D image from a 3-dimensional sample is our ambition. Different viewing angles for both eyes create different images on the retina of the left and the right eye. Our brain is going to process both images. This concept is best comprehensible in the Greenough construction of a traditional stereo microscope: two complete separate beam paths from objective to the eyes, mounted in a relative angle of 11°-16°. But even in the modern, more flexible CMO (Central Main Objective) concept a different viewing angle is realized.

Greenough type                       CMO (Galilean) type 

Desmids - Beautiful single celled algae

There are many different types of algae, differing in both size, shape, color, habitat and more. Some types are multicellular and very large like seaweed, some are microscopic and colonial like Eudorina, while others consist of only a single cell. Some of these are called desmids (desmidiales).

Desmids are highly symmetrical unicellular green algae which can take on many different shapes depending on the specific species. The desmids also vary in size between species, the smallest being only a couple of microns and the largest reaching a size of several hundreds of microns and are visible with the naked eye. Desmids are most commonly found in freshwater where several thousand species can be found.

Protected against harsh conditions

As mentioned in a previous publication, helm grass is what we encounter in the dunes among others in the Netherlands. The Ammophillia arenaria can withstand the salty water and salty sea air. Ammophillia arenaria can be planted on all types of soil, only on clay soil it is best to make the soil poor with masonry sand. The soil must be calcareous.

Red blood cells - the cells that help you breath

Adult humans carry around 5 liters of blood in their circulatory system. Roughly half of that is cells, and the other half is a pale yellow liquid called plasma. The vast majority of these cells are erythrocytes, more commonly known as red blood cells (RBCs). Our red blood cells are the most abundant cell type in the human body accounting for approximately 70% of all your cells. They measure roughly 7 microns in diameter and around 1-2 microns in thickness.