534 Prof. T. R. Jones — Destruction of Marine Animals. 



tlie Dorsetshire coast that immense numbers of the ' Poulpe ' 

 {Octopus vulgaris) have been killed and washed ashore at Charmouth. 

 Is it not probalDle that these sudden influxes of fresh water — • 

 especially when at a much lower temperature, and charged with 

 sediment — may have produced similar results in past times, as now, 

 and may to a great extent explain the occurrence of marine organisms 

 in a very abundant and unusually perfect state? — H. W. 



" Note. — Sir W. Denison has remarked (Geol. Soc. Journ. vol. xviii. 

 p. 458) that the great rains of the S.W. Monsoon periodically destroy 

 millions of fish and other marine creatures off the coast of India. 

 Severe frosts during low tides are highly destructive to the Littoral 

 zone of sea-life, as noticed by Hugh Miller and others ; and volcanic 

 emanations also destroy animals and plants far and wide in both 

 deep and shallow seas. — Edit. Geol, Mag." 



Under the same heading I have from time to time collected several 

 memoranda relating more particularly to Fishes, and herewith offer 

 them to present notice, not that they form a complete series of such 

 observations, but only as being suggestive, and perhaps useful to 

 some one desirous of fully carrying out the subject. 



I. Fish are killed in very large quantities by either unusual or 

 periodical influx of fresh water from the land. 



1. On the Death of Fishes during the Monsoon off the Coast of 

 India. By Sir William Denison, Governor of Madras. Quart. Journ. 

 Geol. Soc. vol. xviii. p. 453 ; 1862. 



'•■ On steaming between Mangalore and Cananore, on the west 

 coast of the Peninsula, I was sensible of a very offensive smell, 

 which at last I found to proceed from the sea itself. When I landed 

 at Cananore. I found that the sea-breeze brought in a similar smell — 

 a little modified in intensity of course ; and, on inquiry, I found that 

 for some time after the S.W. Monsoon the sea was always very 

 offensive, — that thousands of Fish were thrown up on the shore dead. 

 The cause of this was attributed to the mass of fresh water poured 

 "into the sea during the Monsoon, In three months, 120 inches of 

 rain, on an average, fall upon an area of, say, 60 miles in width, for 

 the whole length of the coast-line, from each running mile of this 

 coast ; therefore there will be about 800,000,000 of gallons poured 

 into the sea daily; but, as most of this will come out of the rivers, 

 of course at certain points the quantity will be multiplied twofold. 

 The natural consequence will be the destruction of all animal and 

 vegetable life, which, being adapted for salt water, must die after a 

 time in fresh water. There will therefore be layers of Shells 

 covered by strata of sand and mud. Seaweeds in various stages of 

 decomposition, and Fish, small and great, deposited at the bottom of 

 these seas. I saw thousands of dead fish floating ; and there were, 

 no doubt, thousands lying dead at the bottom." 



2. In August, ] 872, an influx of fresh water into the sea all along 

 the southern shore of Tobago, coming from the great South-American 

 rivers (150 miles from the mouth of the Orinoco and 900 from that of 

 the Amazon), killed the Starfishes and other marine animals [Nature, 

 December 19th, 1872, p. 124). 



