Materials, products and services - the Green Guide Online provides details of the life cycle environmental impacts of construction materials and components, and the Green Book is a free online database of products and services.
Spermicides are used globally for birth control, with or without condoms. As the only means of birth control, spermicides are rarely effective. However, in conjunction with condoms, spermicides are somewhat effective in birth control.
The male gametangia are most commonly called antheridia. They produce sperm cells that they release for fertilization. Antheridia producing non-motile sperm (spermatia) are called spermatangia.