190 ANTIIOZOA IIELIAXTIIOIDA. 



of most of the leaflets. Each ovary is composed of several 

 horizontal folds or plaits, which, when unfolded, show this 

 structure to be about three times the length it assumes when 

 attached to the leaflet. By carefully spreading out these 

 folds, the ovary, with the assistance of a lens, is seen to con- 

 sist of two very delicate layers of membrane, enveloping a 

 closely compacted layer of ova. After enveloping the ova, 

 the membranous layers are placed in apposition, and form a 

 kind of mesentery, by which the ovary is attached to the in- 

 ternal border of the leaflet. The two layers afterwards sepa- 

 rate to pass one on each side of the leaflet, thereby lining the 

 interseptal spaces from which this membranous investment is 

 prolonged into the tentacula, as well as into the cavities within 

 the structure of the li]) and mouth. At the summits of the 

 tentacula, and of the tubular eminences of the lip, the mem- 

 brane becomes continuous with the common integument, 

 whilst at the inferior part of the interseptal spaces it is con- 

 tinuous with the digestive sac. The breadth of the ovaries is 

 nearly uniform from the top to the bottom. Some irregulari- 

 ties are occasionally observed in their attachment to the leaf- 

 lets. Sometimes one leaflet supports two ovaries, and not un- 

 frequently two neighbouring ovaries are continuous with each 

 other at their inferior extremities."* 



The period of propagation is probably, in most Heliantho'ida, 

 not limited to any particular season. According to the obser- 

 vations of Cavolini, the Cai-yophyllia matures its ova in spring ; 

 and it is only at this season that I have found the Lucernariee 

 on our northern shores, when they are big with numerous eggs. 

 But in the Actiniae, ova in every state of developement may 

 be seen in the same individual throughout the year ; perhaps, 

 however, they are most abundantly laid in autumn. They 

 are usually of a roundish figure, and, like the gemmules of 

 polypes in general, contractile and motive, being carried about 

 from the action of the cilia that clothe the surface. " Under 

 the microscope they prove of diversified form, many resembl- 

 ing flattened pease, some elongated or exhibiting irregular pro- 

 minences, some almost spherical, others as if composed of two 

 or even of three unequal spheres, and some which cannot be 



* Lib. STipra cit. p. 104. 



