80 



QUEKETT'S LECTURES ON HISTOLOGY. 



the same sponge were others of smaller size, and with fewer branches, as 

 represented by d, e, and/; to such spicula the term hranclied may be well 

 applied. Another sponge contains spicula of the form -I have termed 

 tuhercidated ; they are of large size, and covered with rows of flattened 

 tubercles, as shown at c, in fig. 14. The sponges to which they naturally 



a, bi-curvatc spiculum ; b, curved spiculum ; c, tuberculated spiculum ; d, e, f, g g, branched 

 spicula ; h, bi-curvate anchorate spicula ; i, stellate spicula ; k, I, m, multi-radiate spicula. 



belong I have never seen, but all mj^ specimens were obtained from the 

 root of an Alcyonium, Alcyonium favosum, from Sumatra, and were mixed 

 with grains of sand and spicula of various kinds, from other sponges. A 

 similar species, from a different part of the world, in the possession of a 

 friend, when boiled in nitric acid yielded spicula of precisely the same 

 kind ; so much so, that when a specimen was shown me, I pronounced 

 from whence it came. 



" The siliceous remains of a small sponge, attached to the root of a 

 Gorgonia, Isis ochracea, I found extremely rich in peculiar forms of 

 spicula. The most striking was of a reticular figure, covered with minute 

 spines, as shown at A, in fig. 15. It forcibly i-eminded me of the siliceous 

 skeleton of the Dictyochalix pumiceus, before alluded to, and probably 

 may be a portion of a siliceous sponge. Other spicula occur in the same 

 specimen, the most remarkable of these are in the form of scales, as shown 

 at B, c, E ; they may be known by their flattened figure, and by having 

 black dots in the centre. The edges of some of these spicula are smooth, 

 but in most cases they are serrated. Another very singular form of 

 spiculum is also found in the same sponge : it is of small size, and pin- 

 shaped at one extremity, and at the other is rounded, but in the centre of 

 the rotundity there is a short conical spine ; two of these spicula are 

 shown at d d. Spicula of the shape termed curved are occasionally met 

 with in certain small sponges ; one of these, of peculiar figure, is repre- 

 sented at h, in fig. 14. In another sponge from the South Seas, bi-curvate 

 spicula, of the shape shown at a, arc very common. Mr. Shadbolt, how- 

 ever, has detected some still more curious spicula than these last ; they 



