INTRODUCTION. 



Sponges have been known to science for a long time, i'roin the nuuierous 

 references to them in Homer, it may be inferred that the bathing-sponge 

 was in use amongst the ancient Greeks. Aristotle distinguished, in his Uepl 

 ^wiijv laropias, three species of Sponges ; his opinion was that Sponges were 

 animals. 



Other Authors of the Classical and the Middle Ages did not add any observa- 

 tions to those made by the great Alexander's great tutor. 



Although some of the papers of these aiithors were perhaps not absolutely 

 and entirely fanciful, yet we may say that the true nature of Sponges was 

 discovered by Grant in 1825. 



The manner in which the older celebrated authors — Linne, Cuvier, Lamarck, 

 and Lamouroux — treated the Sponges was by no means satisfactory ; and also 

 the works of Pallas and Esper (certainly the best of their time) are not so 

 good as they might have been. 



Very little was done to establish the knowledge of species until Bowerbank 

 and O. Schmidt studied the British and Adriatic Sponges respectively. 

 Through their labours the standard of spongiological works was raised 

 very considerably. 



F. E. Schulze subjected a number of Adriatic Sponges to a very careful 

 anatomical and histological examination, and published the results of his 

 labours in the form of a series of monographic essays, which are the most 

 important contributions to our knowledge of Sponges. It may be said that 

 F. E. Schulze has established a " new school " of Spongiology, represented by 

 Vosmaer, Polejaeff, and myself. 



But, in spite of Schulze's labours, and those of Carter, Sollas, myself, and 

 others, our knowledge of Sponges was not on a satisfactory footing until 

 now. 



Through the extensive collections made by the ' Alert' and ' Challenger' in 

 all parts of the \a orld, and through my own labours in the Australian seas, we 

 have been placed in the possession of sufficient material to attain a much 

 clearer insight into the nature, affinities, and distribution of Sponges. 



The results of these labours are laid down in four large monographs, two of 

 ■which have lately appeared and two are in the press. 



Three of these monographs (by F. E. Schulze on the Hexactinellida, by 

 Eidley and Dendy on the IMouaxonida, and by Sollas on the Tetraxouida) appear 

 in the ' Challenger ' Reports. The fourth, written by myself, deals with the 

 Horny Sponges, and is being published by the Koyal Society. 



