ORDER ACTINOIDEA. 39 



The developement of young from the ovules before their ejection, 

 has been for a long time asserted, and Dalyell and others have shown 

 that it is of common occurrence. The ovules being bathed by the 

 sea-water, which gains access to the visceral cavity, there is little 

 occasion for the doubt with which the statement has been by many 

 received. The ovules have a white milky appearance, and are of 

 various sizes in the same cluster. They have usually a globular 

 form, but are often a little oblong or of irregular shapes. Wagner 

 has shown that they have the characters of true eggs. On leaving 

 the parent, they are said to move about by means of the vibratile cilia 

 with which they are provided. After a short time the young Actinia 

 appears, and generally fixes itself shortly after to some object at hand. 

 When first produced, the tentacles are scarcely apparent; a single 

 series gradually developes, and afterwards they go on increasing as 

 the animal grows, and do not attain their full number until it is a 

 perfect adult. 



29. The Actiniae have the same power of reproduction from arti- 

 ficial sections as the Hydra. Portions cut or torn off are soon resup- 

 plied, and the parts separated develope what is needed to become 

 perfect animals. The process of budding has been observed only in 

 the coral-making species. 



The Zoanthidce. 



30. The dissections, by which this division of the Actinoidea is 

 here illustrated, were made on a living specimen of the Palythoa ceesia, 

 at the Feejee Islands, representations of which are given on plate 30. 

 This species grows in rounded attached masses, of the size of the fist, 

 which consist of a large number of united polyps. When unexpanded, 

 the mass has externally a grayish leathery appearance, with small 



nineteen days eight or nine could be enumerated in another, which now "affixed itself as 

 a young Actinia by the base." (Jameson's Journal, xxi., 1836, p. 89.) "Iu the course 

 of six years, a specimen preserved by the author produced above two hundred and seventy- 

 six young, some pale, like mere specks, with only eight tentacula, others florid, and with 

 twenty. They are frequently disgorged along with the half-digested food, thirty-eight 

 appearing thus at a single litter. An embryo extracted artificial ly from the amputated 

 tip of a tentaculum, began to breed in fourteen months, and survived nearly five years. 

 Monstrosities by excess are not uncommon among the young : one produced naturally 

 consisted of two perfect bodies and their parts, sustained by a single base, exhibited em- 

 bryos in the tentacula at ten months, bred in twelve, and lived above five years. While 

 one body was gorged with food, the other remained ravenous." (Dalyell, in 4th Rep. 

 Brit. Assoc, 1834, p. 599.) 



