THE AUSTRALIAN GREAT BARRIER REEF. 131 



to that now living; and nothing but the general upheaval of the area on which it throve can 

 logically explain the fact of its decadence. The fringing reef off Magnetic Island, near Townsville, 

 presents closely analogous phenomena. Dead bivalve shells of large size, such as Tridacnas and 

 Pinnas, also occupy their original positions here, in close contiguity to the dead corals. Further 

 substantial evidence of slight upheaval in this district was afforded by a station-holder on 

 Magnetic Island, and by whom I was informed that, within the time he had been located there, 

 a very perceptible change had taken place in the small bay facing his property. In former 

 years boats could approach the landing place at all tides, excepting very low springs, whereas 

 now it was not possible to bring a boat in, at even ordinary low tide. The shallowing of the 

 water could not be accounted for by the silting-up of the baj-, there being no fresh water 

 flow into it, while the rocky bed of the bay itself had apparently been raised to a higher level." 



It is difficult to associate the phenomena described in the foregoing record with any other than 

 a movement of upheaval ; but, accepting this as proven, and premising for the nonce that the whole 

 length and breadth of the Barrier region exhibited a similar testimony of emergence, the amount 

 raised, a foot or two only, would be as nothing compared with the latitude of movement in one 

 direction or the other that is required to account for the construction of the Barrier's mass. Had 

 the Great Barrier been fashioned during a prolonged epoch of upheaval, substantial evidence of 

 such movement would be yielded by the strata of the seaboard which it skirts ; but of this there is 

 virtually none. The hypothesis that originated with Mr. Darwin, and received endorsement at 

 the hands of Mr. Jukes, that this famous reef, in company with others of its kind, must have been 

 built up during a prolonged period of subsidence, has up to a very recent date been accepted 

 without demur, and so far as it applies to the great Barrier individually, is propounded, as an 

 elementary axiom, in the leading Australian handbooks. 



In the face, however, of Dr. Murray's indictment of the subsidence theory, fully reported in 

 the preceding chapter (see pp. 83, ct seq.), and having regard more particularly to his uncom- 

 promising dictum (London Institution Lecture, Nature, Feb. 28, 1889) — "it seems impos- 

 sible, with our present knowledge, to admit that atolls or barrier reefs have ever been 

 developed after the manner indicated by Mr. Darwin," — the compilers, doubtless, have already 

 made provision for substituting the Murrayan interpretation in forthcoming editions. In this 

 they will be well advised to " bide a wee." The Darwinian subsidence theory is by no 

 means utterly defunct, and, from within the borders of the Great Barrier Reef and its environ- 

 ments, may yet receive the increment of direct evidence that is needed to rehabilitate it on a 

 more substantial basis than that upon which it was originally founded. Mr. Darwin himself, 

 in his famous work, "Coral Reefs," ed. iii., p. 128, frankly admits that "direct proofs of a 

 subsiding movement are hardly to be expected, and must ever be most difficult to obtain." 

 Mr. Guppy, whose views and evidence in favour of the anti-subsidence theory have been quoted, 



makes use of an expression, in the substance of a controversial letter to Nature, Vol. XL., 



s 2 



