In a considerable number of Sea-anemones, such as _Actinoloba marginata_ and _A. dianthus_, some species of _Sagartia_, _Actinia cari_, _Anemonia sulcata_, and _Calliactis parasitica_, the fertilisation of the eggs and their subsequent development take place in the sea water.[402] In a great many others, such as _Bunodes_ (several species), _Cereactis aurantiaca_, _Sagartia troglodytes_, _Bunodactis {379}gemmacea_, etc., the embryos are discharged into the water from the body-cavity of the parent, at a stage with six or twelve tentacles. In the Arctic species of the genera _Urticina_ and _Actinostola_, however, the embryos are retained within the body of the parent until several cycles of tentacles are developed, and in _Urticina crassicornis_ the young have been found with the full number of tentacles already formed. In _Epiactis prolifera_ from Puget Sound, the young Anemones attach themselves to the body-wall of the parent after their discharge, and in _Epiactis marsupialis_, _Pseudophellia arctica_, _Epigonactis fecunda_, and other species from cold waters, the young are found in numerous brood sacs opening in rows on the body-wall. It is not known for certain how these embryos enter the brood sacs, but it is possible that each sac is formed independently for a young embryo that has settled down from the outside upon the body-wall of the parent. The most specialised example of this kind of parental care in the Sea-anemones is seen in _Marsupifer valdiviae_ from Kerguelen, in which there are only six brood sacs, but each one contains a great many (50-100) embryos. The wonderful colours of our British Sea-anemones are familiar to most persons who have visited the sea-side. The common _Actinia mesembryanthemum_ of rock pools, for example, is of a purple red colour. The base is usually green with an azure line. Around the margin of the disc there are some twenty-five turquoise blue tubercles. On each side of the mouth there is a small purple spot, and the numerous tentacles forming a circlet round the mouth are of a pale roseate colour. Nothing could be more beautiful than the snowy-white _Actinoloba dianthus_ or the variegated _Urticina crassicornis_. Similar wonderful variety and beauty of colour are seen in the Sea-anemones of other parts of the world. Thus Saville Kent[403] in describing a species of the gigantic _Stoichactis_ of the Australian Barrier Reef says, "the spheroidal bead-like tentacles occur in irregularly mixed patches of grey, white, lilac, and emerald green, the disc being shaded with tints of grey, while the oral orifice is bordered with bright yellow."