The passage discusses the debate surrounding the theory of coral reef formation and subsidence, particularly in the context of the Fiji Islands. Darwin and his contemporaries, such as Agassiz, LeConte, Hunt, Semper, and Rein, had differing views on the role of subsidence in the formation of atolls and barrier reefs. Darwin initially supported the theory of subsidence but faced significant challenges when he observed that all three types of coral reefs (fringing, barrier, and atoll) could coexist in the same area, including in the Pelew Islands, where both upraised and living reefs were present. This contradicted the idea that the character of a reef could be used to determine the existence of subsidence or uplift. Darwin later acknowledged the difficulty of this issue, suggesting that future observers would need to decide between his theory and others. The passage also highlights the recent discovery of upraised coral reefs in the Fiji Islands, which was not known to Darwin in his 1874 edition of "On the Origin of Species." These findings have led to a reevaluation of the theory of subsidence, as the presence of both upraised and living reefs in the same area suggests complex geological movements. The author, H.B. Guppy, points out that Darwin's 1889 edition of his work still did not address these new findings, indicating a lack of awareness or acceptance of the evidence. Additionally, the passage includes a brief note on the hibernation of martins in the Argentine Republic and an account of atmospheric electricity, describing the electrical phenomena experienced by surveying parties in the western United States, particularly the tingling sensations and hissing sounds associated with lightning.The passage discusses the debate surrounding the theory of coral reef formation and subsidence, particularly in the context of the Fiji Islands. Darwin and his contemporaries, such as Agassiz, LeConte, Hunt, Semper, and Rein, had differing views on the role of subsidence in the formation of atolls and barrier reefs. Darwin initially supported the theory of subsidence but faced significant challenges when he observed that all three types of coral reefs (fringing, barrier, and atoll) could coexist in the same area, including in the Pelew Islands, where both upraised and living reefs were present. This contradicted the idea that the character of a reef could be used to determine the existence of subsidence or uplift. Darwin later acknowledged the difficulty of this issue, suggesting that future observers would need to decide between his theory and others. The passage also highlights the recent discovery of upraised coral reefs in the Fiji Islands, which was not known to Darwin in his 1874 edition of "On the Origin of Species." These findings have led to a reevaluation of the theory of subsidence, as the presence of both upraised and living reefs in the same area suggests complex geological movements. The author, H.B. Guppy, points out that Darwin's 1889 edition of his work still did not address these new findings, indicating a lack of awareness or acceptance of the evidence. Additionally, the passage includes a brief note on the hibernation of martins in the Argentine Republic and an account of atmospheric electricity, describing the electrical phenomena experienced by surveying parties in the western United States, particularly the tingling sensations and hissing sounds associated with lightning.