638 ZOOPHYTES. 



gemmation, buds forming at apex and lengthening rapidly as they 

 are produced. Foot-secretions go on simultaneously, giving strength 

 to the growing shrub ; and by this means ramose zoophytes result, 

 whose slender branches and branchlets contrast strongly with the 

 clumsy forms of the Alcyonia. 



The polyps may differ in their positions, and budding may be 

 either uninterrupted or periodical. In most species the animals of a 

 stem are situated obliquely, the polyp at its interior part diverging 

 but little from the axis, and gradually turning outward, and becoming 

 nearly at right angles with it at its outer extremity ; and the new 

 buds form successively above the preceding polyps, and nearly in the 

 same position. Budding going on continuously, the basal secretions 

 form a continuous axis to the stem, as in the Gorgonias and Coral- 

 lium, in which there is no evidence of periodicity in its increase, ex- 

 cepting the appearance of successive layers in the axis. 



In other cases there first forms a small group of polyps, in shape 

 and structure like the lobe of a Xenia, the bases of the several polyps 

 being in the same horizontal plane. The foot-secretions, in such a 

 case, form at the bottom of the group, and can only accumulate in 

 thickness; the tissues of the cluster by other secretions form a layer 

 of a different character upon that below, which is sometimes more or 

 less penetrated by the polyp-tubes. After a while, budding takes 

 place above, and there is another succession of foot-secretions and 

 tissue-secretions; and the process continued gives rise finally to a 

 jointed stem, as in the Melitasas. The joints are at first very small and 

 short, but the polyps constituting them continue to grow and bud for 

 a while, until they are much enlarged. The genus Isis affords other 

 examples of periodical budding, but with some peculiarity, as the 

 calcareous and alternating corneous joints are alike separable from a 

 polyp-crust, which covers the whole uninterruptedly. The crust in 

 the Melitseas covering the calcareous joints, appears to be only the 

 softer extremities of the united polyps, corresponding to the extremi- 

 ties of the tubes in the Tubiporse. In the Mopsese, the corneous joints 

 are situated at the axils of the branches, and their production is con- 

 nected with a periodical multiplication of buds, which produces the 

 furcate mode of branching. 



The hues of the Gorgonidse are various and gorgeous. The brightest 

 red, crimson, purple, orange, yellow, are common, besides white, 

 brown, and black ; and the polyps add other and more delicate tints, 

 where these star-like flowers are in full blossom. It is not unusual to 



