REMOVING floor-to-ceiling walls at the top of a stairway can turn an upstairs hallway or room into a light and airy landing and also bring increased light and openness to the stairwell. For safety, the floor surrounding the stairway must be partly enclosed. One solution is to install a railing around the opening.
A sponge is a member of the phylum Porifera. It is a simple animal with many cells, but no mouth, muscles, heart or brain. It is sessile: it cannot move from place to place the way most other animals can. A sponge is an animal that grows in one spot like most plants do.Nevertheless, sponges are quite successful. sponge is a member of the phylum Porifera. It is a simple animal with many cells, but no mouth, muscles, heart or brain. It is sessile: it cannot move from place to place the way most other animals can. A sponge is an animal that grows in one spot like most plants do. Nevertheless, sponges are quite successful.
This is the simplest type and is called the Ascon type of canal system. In this type of canal system, water enters from outside through Ostia into the Spongocoel, and then, leaves through the Osculum to the exterior. Sponges having Ascon type of canal system are known as Asconoid Sponges.his article reveals the Biology of Sponges (phylum Porifera) by studying the Morphology, Anatomy, Histology, and Physiology of Sponges. The author has also included the Reproduction and Development of Sponges. Porifera is a phylum comprising of the multi-cellular invertebrate animals called Sponges.