Arcella vulgaris has caught Synura

This testate amoeba lives in the mud and vegetation in standing water and also in the bottom, between algae and other plants. Arcella Vulgaris is a testate Amoeba with loose pseudopodia protruding from the pseudochitine shell. Testate amoebae are amoebae with an umbrella-shaped hard cover. The cover is for protection and is excreted by the animal itself. They nourish on diatoms, unicellular algae, animal protozoa such as flagellates and ciliates.

Nettles - The healthy stingers

The plant urtica dioica, more commonly known as the stinging nettle, is a plant many of us are unpleasantly familiar with. The quite fitting name ‘nettle’ comes from the anglo-saxon word ‘noedl’ which means ‘needle’ and the latin ‘urtica’ means ‘to burn’. The plant is found worldwide but was originally native to Europe. At its tallest, the nettle grows to around two meters and are equipped with medium sized leaves. Despite many myths both the stem and the leaves are able to sting you as both are covered in the tiny needle-like structures called trichomes or spicules responsible for the burning sensation you get after contact with the plant.

Viburnum's annoying ‘hair’

The Viburnum rhytidophyllum or Leatherleaf plant is native to central China and is especially decorative along the roads, even in the shade. The plant is a shrub 3 to 4 m high. The leaves are lance-shaped, 15-20 cm, pendulous, leathery with relief, dark green on top, light green and hairy. ‘Hairy’; that is, occupied with stellate (star-shaped) nonglandular trichomes. Trichomes can have many functions like defence against harmful insects, humidity regulation and even a sensory function. 

Lengenbach, rare minerals in Switzerland

In the Swiss region of Valais (Wallis) a mine known as Lengenbach is “exploited”. From this small quarry, with a few more than 10 meters of mine face, minerals are not extracted for industry, but for research.

The exploitation works, which began in the s. XIX, are carried out in Triassic dolomites, rich in sulfosalts of Pb, Tl, Ag, and Cu, very rare worldwide, along with numerous other interesting and aesthetic mineral species. Of some of these sulfosalts a single specimen is known. It is the type locality (TL) of 46 different mineral species, making it the fifth most prolific locality in the world (TL: indicates that a mine is the first place in the world where a certain mineral species has been described).

Cutaneous Histiocytoma dog

Histiocytoma

A cutaneous histiocytoma is a benign skin tumor. It consists of an accumulation of a large amount of histiocytes in the skin. Histiocytes are cells that are involved in the immune system. We usually see histiocytomas in young dogs up to the age of 3 years.

In a short time there is a skin tumor ranging from a few millimeters to a few centimeters. Usually they are at the head, lips, ears, neck, legs and chest. They are not painful and do not cause itching, unless there is an inflammation. If they start to itch because of the inflammation, it means that the body is cleaning them up. Regularly this swelling looks fiery and choppy.

Some of the smallest crustaceans in the world

Crustaceans are a huge group of animals living all over the world. There are more than 67.000 known species which dramatically vary in size from around 0.1 mm to almost 4 m. Most are aquatic animals, like crabs and shrimp but some are terrestrial like the woodlouse. All crustaceans have a tough exterior called an exoskeleton used to support and protect their body. This armor is mainly made up of long polymers called chitin combined with calcium carbonate to make it hard. Here we will look at a few of the smallest crustaceans you might encounter in a water sample. The first one we take a closer look at is a copepod.

It is covered in symbiotic algae. The copepod is surrounded by 

younger individuals at different stages of development.

Flatworm digestive tract

The digestive tract of the flatworm, as shown here of a representative of the Dugesia genus, is not very complicated. 

This type of flatworm lives in fresh water. Flatworms absorb their food by mouth in the middle part of their lower body. A small tube shoots from the center of their body at the food and sucks it into the Pharynx. The fresh food is sent to and through the 'intestine', also known as the gastrovascular cavity. There the food is digested. It is spread on all parts of the worm, where the nutrients are needed for growth.

Mastocytoma dog

A mast cell tumor* (mastocytoma) is a potentially very malignant tumor of mast cells in the skin. This tumor is the most common skin tumor in dogs. It mainly occurs in the skin but not only there. A mast cell tumor can look very different. The tumor can be in the skin or under the skin. The presentation is usually like a solitary solid (sometimes soft) bump with a diameter of a few mm to as much as 10 cm. The overlaying skin is often alopecia (bald spot), erythematous (abnormal red), sometimes eroded or ulcerated (open wound). One should not squeeze the tumor; histamine granules* can be released (degranulate) This can cause an anaphylactic reaction, which means that the animal can get into shock. As mentioned, the tumor can be red in color, contain extra pigment or have the normal color of the skin.

As with all bumps on the skin, it is never possible to determine on the outside whether there is a tumor and what kind of tumor it is. Therefore, further investigation must also be carried out in the event of a suspicion of a mast cell tumor. This can be done by means of a FNAB (Fine Needle Aspiration Biopsy) or by means of a tissue biopsy. Cells are taken from the bump and these cells are assessed under the microscope (by a cytologist) as in this case. A FNAB gives a correct diagnosis in a large number of cases, but in all cases a tissue biopsy gives a correct and sometimes more extensive diagnosis.