Diagrammatic sketch of a flatworm (Planaria)

Flatworm

Diagrammatic sketch of a flatworm (Planaria)

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This is a fresh water flatworm.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This is a marine flatworm.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This is a fresh water flatworm. This is an anatomy of freshwater flatworm (Planaria), showing the excretory system, with flame-cell. The alimentary canal is stippled.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This shows the nervous system of the flatworm.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. The free forms are usually small, barely reaching a length greater than five or seven cetimeters (2 to 3 inches). Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This is the flame-cell of the flatworm showing the flagellum (f), the nucleus (n), space among the organs of the body, (v) waste material.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds, or along the seacoast while a variety of other species are parasitic. Some of the parasitic species attain the great length of six to thirteen meters (20 to 40 feet). This parasitic flatworm diagram shows the (m) mouth, the (o) opening of the reproductive system, and (s) sucker and spines for attachment. The digestive system is stippled and the nervous system is black.

Flatworm

Flatworms are flattened, leaf-like forms living in damp places on land, in freshwater streams of ponds,…

Illustration showing different rhompalura gairdii flat worms. The left and the right worms are the female, and the middle is the full grown male.

Rhopalura Gairdii Flat Worm

Illustration showing different rhompalura gairdii flat worms. The left and the right worms are the female,…

"Diagrammatic sagittal section of Microstomum, showing a chain of four zooids produced by fission. b, brain of the original zooid (the exponents indicating corresponding structures of the more recently formed zooids); c, ciliated pit; d, dissepiments indicating different stages in the separation of the zooids; e, eye-spot; ent, entoderm; g, gut; gl., glandular cells about the mouth; m., mouth of the original worm." -Galloway, 1915

Microstomum

"Diagrammatic sagittal section of Microstomum, showing a chain of four zooids produced by fission. b,…

Nervous system of a flatworm. Labels: G, cerebral ganglia and eyes; St, the two lateral nerve trunks; D, intestine with mouth.

Nervous System of the Flatworm

Nervous system of a flatworm. Labels: G, cerebral ganglia and eyes; St, the two lateral nerve trunks;…

Structure of the protonephridium (excretory organ) of a flatworm. A, part of the excretory apparatus of a tapeworm; R, edge of body; c, collecting tubules. B, terminal cells with flame of cilia. C, diagram of terminal cell, excretory capillary, and canal.

Protonephridium

Structure of the protonephridium (excretory organ) of a flatworm. A, part of the excretory apparatus…

The cestodes or tapeworms (Toenia solium), are parasitic flatworms. The body is usually of great length up to 50 feet, and terminates in a head. From the head the body extends backwards in a ribbon-like body. Shown here is a tapeworm with the head showing in the upper lefthand corner.

Tapeworm

The cestodes or tapeworms (Toenia solium), are parasitic flatworms. The body is usually of great length…