206 Proceedings of the Royal Irish Academy. 



vegetable kingdom, but possessing a " third or middle nature," serving to 

 connect the two. Or, as another authority writing in the year 1633 

 expressed it, they " are not wrought together of the froth of the sea as our 

 Author affirmes, but rather of a nobler nature than plants, for they are 

 said to have sence." They are therefore referred by the writer to the 

 " Plant-animalia," that is, " such as are neither absolute plants nor yet living 

 creatures, but participate of both." While yet another writer defines the 

 Zoophyta, among wliich he classes sponges, as " having stems vegetating and 

 changing into animals." Several authorities maintained that sponges were 

 merely sheltor.s built by worms or oilier animals for their own use, or were 

 nests built by certain aquatic insects for the reception of their eggs. 



During the eighteenth and early part of the nineteenth centuries 

 naturalists still diflered as to whether sponges should be regarded as plants 

 or animals, and it was not until the middle of the latter century that their 

 auimal nature was definitely established. 



The earliest references to the fresh-water sponges must be looked for in 

 works on botany. The first mention of them was apparently made by John 

 Ra}' in the first volume of his " Hisioria I'lanlarum," published in 168G. He 

 describes a sponge from the River Yare under the title " Spongia ramosa 

 fluviatilis Newtoni." From his description it is evidently a branching 

 specimen of S/xnu/Ula hriuiru. A few years later, in 1691, I^eonard 

 Plukenet in his " Phytographia," Part I, Plate 112, fig..*?, gives a clearly 

 recognizable figure of SjxmgUla Incustris from the River Isis, near Oxford 

 under tlie description " Spongia fluviatilis anfractuosa perfragilis ramosissima 

 nostras." The later references to the fresh- water sponges in Ray's books are 

 cliieUy quotations from the two preceding works. 



Linnaeus in his earlier writings classed the Spongillidae with the lower 

 fungi under the name Lilho(iliy ta. Later on he introduced the names Spongia 

 laetuUris and Sponrfia fliiriaiUii. Although it is impossible to determine with 

 accuracy what were the sjwnges referred to, these two specific names have 

 become established, and have long been applied to the two commonestEuropean 

 species, now named SpontfiUa laciistris and Ephijdatia fluviatilis. These two 

 species were apj>areutly the only ones known for a considerable number of 

 years, although they were descril»e<l from lime to time under dilFerent names. 



In 1848-9 Carter published papers on the fresh-water sponges of the 

 Island of Bombay, thus making known for the first time the occurrence of 

 fresh- water si>onges l>eyond the confines of Euroijc. In 1863 P.owerbank 

 published his " Monograph of the SiKuigilliilae "(11), adding to the previously 

 known forms several new species from North am! South America and one 

 from Australia. Carter's paper on the known sfiecies of Spongilla followed 



