OF THE SPONGIAD^E. 115 



taken a very limited view of matter possessing vitality, and 

 have grounded their hypothesis only upon supposed ana- 

 logy." He also observes, " The true character of Spongia 

 is that of a living, gelatinous flesh, supported by innume- 

 rable cartilaginous or corneous fibres or spicula, most com- 

 monly ramified or reticulated, and furnished more or less 

 with external pores or small mouths which absorb the water, 

 and which is conveyed by an infinity of minute channels or 

 capillary tubes through every part of the body, and is there 

 decomposed and the oxygen absorbed as its principal nou- 

 rishment, similar to the decomposition of air in the pul- 

 monary organs of what are called perfect animals." 

 ' Wernerian Memoirs,' vol. ii. pp. 74, 75. 



Lamouroux's conclusions regarding the nature of sponges 

 are so thoroughly vague and supposititious as scarcely to 

 require notice. 



Lamarck has placed the Spongiadae in a higher position 

 than any naturalist who had preceded him, giving them 

 precedence of the sertularian and celliferous corallines, and 

 even of the corallidse ; but I cannot concur with him to 

 the full extent of his conclusions, which, like those of most 

 previous writers, were derived to a much greater extent 

 from comparative reasoning than in actual observation of 

 the animals in a living and natural condition. 



Professor Schweigger's opinions are very much more 

 those of a practical naturalist, and it is evident that he had 

 closely observed them in a living condition ; but he too 

 shares the erroneous opinion of his predecessors, that the 

 oscula were the organs of imbibition, and that no water 

 entered through the dermal surface. Professor Bell, in the 

 'Zoological Journal' for June,' 18 24, states that he saw the 

 action of the streams from the oscula, but, like previous 

 writers, concluded that they were organs of imbibition as 

 well as excurrent organs. And it was not until the excel- 

 lent and accurate " Observations and Experiments on the 

 Structure and Functions of the Sponge ' : were published 

 in the ' Edinburgh Philosophical Journal,' vols. xiii and xiv, 

 by Professor Grant, that a correct notion was entertained 

 by naturalists of the inhalant and exhalant powers of those 



