974 PROF. W. N. PAKKEK OX 



to refer in debail to the history and literature of the subject. 

 Dr. Harmer's account of the difficulties which have recently 

 occurred in various English Waterworks owing to the presence 

 of Polyzoa, shows the importance of biological investigation in 

 dealing with such cases, as was pointed out in this country by 

 Professor Hickson in his presidential address to Section D of the 

 British Association at Southport in 1903. 



The Cardiff district is supplied with excellent soft water from 

 the TafF Fawr i-eservoirs in Brecknockshire, midway between 

 Merthyr and Brecon. From these higher reservoirs the water 

 is conducted by conduits into vaiious other storage-reservoirs 

 at a lower level, in the near neighbourhood of Cardiff, and 

 from those into filter-beds : the latter, of course, prevent the 

 access of organic particles and spicules into the service-pipes 

 supplied from them. The sponge had hitherto only been found in 

 the pipes leading to certain of the filters on the northern border 

 of Cardiff known as the " Heath " filters, from which the greater 

 part of the city is supplied. The water to these filters comes 

 from two storage-reservoirs, at Llanishen and Lisvane, situated 

 about a mile farther north. Careful examination has so far not 

 revealed any trace of the sponge in other parts of the system, 

 which therefore I need not describe further here*. 



The water from Llanishen reservoir passes through metal 

 screens with fine meshes, so as to strain off all but minute solid 

 particles, into a valve-shaft from which it is conducted by vmder- 

 ground pipes to a valve-chamber at the " Heath." It is then 

 again screened before flowing into a 3-ft. pipe, with which lateral 

 pipes are connected ending in bell-mouths, one to each of the six 

 filter-beds. 



The chief trouble occurred in this pipe, which was thickly lined 

 with a luxurious growth of the sponge, consisting of dense 

 incrustations giving off" numerous finger-like processes Avhich 

 branched and branched again, and some of which reached a 

 length of 8 inches or more, frequently showing concrescence f. 

 Other growths were found in the valve-chamber and screen- 

 chamber, in the corners and crevices of which it was not easy to 

 get access to them. 



On visiting the " Heath" on December 12th, 1911, the sponge, 

 packed with gemmides, showed no signs of djdng down for the 

 Avinter, and it appeared to me that had it been desired to culti- 

 vate the organism, probably no better pla,n could have been 

 devised than that furnished by the water-chambers and pipes 



* For further details with regard to the Cardiff Waterworks, see a paper by 

 C. H. Priestley, M.Iust.C.E., on the " Development of the Cardiff Water Supply," 

 read at the Sessional meeting of the lloyal Sanitary Institute at Cardiff on April 

 12th, 1912 ; also a description of the Waterworks by the same author issued from the 

 Cardiff Waterworks Engineer's Office, 19U8. 



t Cf. figures by Bovverbank, " A Monograph of the British Spongiada?," Ray 

 Society, 1864-1882"; and .Johnston, "A History of British Sponges and Lithophytes 

 (Corallines)," London, Edinburgh, and Dublin, 1882. 



