Dense irregular connective tissue. Dense irregular connective tissue has fibers that are not arranged in parallel bundles as in dense regular connective tissue. Substances formed[edit] This tissue comprises a large portion of the dermis. This type of tissue is also in the protective white layer of the eyeball and in the deeper skin layers.
Definition of VERMICULITE. : any of various micaceous minerals that are hydrous silicates resulting usually from expansion of the granules of mica at high temperatures to give a lightweight highly water-absorbent material. See vermiculite defined for kids. ADVERTISEMENT.
Perlite, like vermiculite, is also a silicate material, but mined from volcanoes. Perlite is light and of a uniform size and consistency, making it ideal for aeration and drainage. Perlite and vermiculite can be used in soilless growing, such as what you would find in hydroponics.