270 Dr. J. E. Gray on Hyalonemata. 



the spicules of the top of the coil. Sponges permeate and 

 overrun everything in their neighbourhood. 



Prof. Max Schultze observes that no one who has opened 

 the sponge and examined the extremely fine ends of the long 

 siliceous threads in the axis of the sponge " can doubt that the 

 most intimate organic union exists between the porous sponge 

 and the ^ Glass Kope/ and that both, therefore, form an organic 

 whole." (Ann. & Mag. Nat. Hist. 1867, xix. p. 155.) If Prof. 

 Schultze means that some particles of the sponge extend 

 themselves up between the spicules of the coil, that is, no 

 doubt, true ; but as we all know that sponges will extend them- 

 selves up between all kinds of structure, I cannot regard that 

 as any proof of organic union. And I suspect that this is 

 what he does intend when he refers to the examination of im- 

 perfect specimens which had been removed from the sponges 

 (p. 155) ; and he seems not to have seen any specimen that 

 never had a sponge attached to it (though such are now known 

 to exist), and erroneously suspects that M. Bocage's specimen, 

 which is now in the British Museum, was imperfect. 



It is curious that neither Prof. Schultze, Dr. Bowerbank, nor 

 any of the advocates of the spicules being developed from the 

 sponge has ever attempted to show how the spicules are deve- 

 loped by the sponge, whence they originate, or to show any 

 connexion between the individual sponge-spicules and the spi- 

 cules of the coil, or that there is any connexion between the 

 pores and tubes of the sponge and the coil. As far as I have 

 seen, the coil under the bark is a solid body composed of many 

 closely packed spicules united together by fibrous corium like 

 the lower surface of the bark, and which surrounds each and 

 at the same time unites all the spicules into a mass destitute 

 of any pores or canals ; and the end of the coil in the sponge, 

 in the four or five specimens that were cut open for the pur- 

 pose of examination, has always been separated from the 

 cavernous part of the sponge by a thick, very hard, compact 

 coat formed of felted spicules. As this coat and the cavernous 

 structure of the sponge are not represented in Schultze's t. 2. 

 f. 1, I suspect it is rather a diagram than a representation of a 

 specimen. 



Prof. Max Schultze states, "As yet only lime salts are 

 known in the skeletons of polypes." (Ann. & Mag. Nat. Hist. 

 1867, xix. p. 154.) And Dr. Bowerbank observes, " I be- 

 lieve that the animal power of organizing siliceous matter to 

 form either an internal or an external skeleton will be found 

 to be strictly confined to the great sabkingdom of the Protozoa." 

 (Proc. Zool. Soc. 1867, p. 904.) 



These authors have overlooked the analysis of coral quoted 



