METRIDIUM. 11 



tacles, at first only few in number, are in fact so many extensions 

 of the inner chambers, gradually narrowing upward till they 

 form these delicate hollow feelers which make a soft downy fringe 

 all around the mouth. (Fig. 7.) They do not start abruptly from 

 the summit, but the upper margin Fig . 7 . 



of the body itself thins out to a 



form more or less extensive lobes, ' 

 through which the partitions and ; f^; 



chambers continue their course, ^^y\ "'- ^^jiM 



and along the edge of which the '> h 



'-;- :- , - . ""v'U'.iy /TKET,-^". ^~-^ 



The eggs are not always laid in ^ \ ^ 



the condition of the simple planula t ^^iK^'"' ' 



described above. They may, on the "' 

 contrary, be dropped from the par- 

 ent in different stages of develop- 

 ment, sometimes even after the tentacles have begun to form, as 

 in Figs. 8, 9. Neither is it by means of eggs alone that these 



Fi;:. 8. Fig. 9. 



animals reproduce themselves ; they may also multiply by a pro- 

 cess of self-division. The disk of an Actinia may contract along 

 its centre till the circular outline is changed to that of a figure 8, 

 this constriction deepening gradually till the two halves of the 8 

 separate, and we have an Actinia with two mouths, each sur- 

 rounded by an independent set of tentacles. Presently this sepa- 

 ration descends vertically till the body is finally divided from 



Fig. 7. View from above of an Actinia with all its tentacles expanded ; o mouth, b crescent-shaped 

 folds at extremity of mouth, a a folds round mouth, 1 1 1 tentacles. 

 Figs. 8, 9. Young Actiniae in different stages of growth. 



O Q/3 

 A "5 '' 



