us 



HARDWICKE'S SCIENCE-GOSSIP. 



the former, and the more friable, darker, thicker 

 layers of the latter. These conclusions seem evident 

 from the following :— First, the immense accumula- 

 tion and peculiar formation of the guano-beds con- 

 trasted with the thin white coating of birds' dung 

 seen not merely on the main islands, but also on the 

 detached rocks, many of which are too high out of 

 the water to allow for a moment the supposition 

 . that guano, if once formed on them, could have been 

 washed off. Next the evidence of a pressure^ 

 greater than that which any trampling of birds 

 could have caused, evidenced by the density of the 

 strata, being nearly as great at the surface as at the 

 base of the hills, showing that it could not have 

 arisen from mere pressure of the superincumbent 

 mass of guano, but which appearance might have 

 been produced by the weight of one of these sea- 

 lions, — much more by^a number of them. Next by 

 the appearance presented by the top of the south 

 island, the numerous dead sea-lions actually in the 

 process of becoming guano, as evidenced by an 

 examination of the more recent bodies, the unde- 

 cayed skins of which contain within them a substance, 

 in appearance at least, identical with the brown 

 guano found on the summit of tlie hills, and also 

 similar to that in the thicker strata. The absence 

 of the organic remains of birds in the interior of 

 the guano; for though, as already stated, bones 

 appear to decay rapidly, yet feathers resist the action 

 of the guano for a long time. The small quantity, 

 equivocal position (always near or on the surface), 

 and peculiar appearance 'of the remains of birds at 

 present met with ; dried up and turning into a sub- 

 stance as unlike the true guano, or the decomposing 

 seals, as the white deposits on the headlands, — in 

 fact, appearing to be purely of accidental occurrence, 

 and having almost as much to say to the formation 

 of the guano as the lizards and rats which are found 

 along with them. One bird there is a species of 

 spheniscau, that possibly might assist in forming 

 guano ; but though this bird is very numerous on 

 various rocky islets along the coast of Peru, yet on 

 none of them is guano found, though they are just 

 as favourably situated for its formation as the 

 Chinchas; and as birds are known to burrow in 

 the guano, the occurrence of birds' eggs in it is 

 easily accounted for. G. H. K. 



THE SEA-HORSE. 



(^Hippocampus brevirostris.) 



THE establishment of aquaria at the Crystal 

 Palace, Brighton, Manchester, and elsewhere, 

 is likely to develop a large amount of public 

 curiosity in the marvellous creatures which 

 inhabit the great deep, of whicli the world at large 

 has been iu utter ignorance, and of which our best 

 learned scientific men have known but little. 



The cuttle-fish with its long tentaculse and its 

 powerful suckers, its ink-bag, and its long but 

 doubtful history, will continue to have the attention 

 of the student, as well as of the mere lover of the 

 curious. Strange facts connected with the natural 

 history of various fishes are continually being 

 brought to light, and every day adds to the interest 

 of the large aquaria. Marine and fresh- water animals 

 can be studied in what may be called to a large 

 extent their natural conditions, where they may 

 exhibit their peculiar habits and instincts, and live 

 and breed from generation to generation. It will 

 probably be difficult to create these conditions in 

 all cases, but already they are perfect iu many. In 

 the latter cases referred to, the student of natural 

 history may sit beside the tanks and test all the 

 conditions of animal life. Such are the advantages 

 of the large aquaria. 



Fig. 150. Sea-horse {Hippocampus bretnrostris). 



One of the most interesting events connected with 

 public aquaria has recently been referred to by the 

 press, in connection with the birth of Sea-horses 

 {Hippocampus brevirostris) at the temporary tanks 

 of the Manchester Aquarium Co., Limited. It is 

 very doubtful whether such an event ever occurred 

 before in Great Britain, but it is quite certain that 

 it is the first time that the Hippocampus has been 

 bred in a public aquarium.* 



The Manchester Company, whose chief building 

 is now in the course of erection, have had for some 

 time a large number of these creatures in temporary 

 tanks in a building erected for the reception of 

 such marine and fresh-water animals as do not 

 require a large space, in order to acclimatize them, 

 and have them ready to remove in a healthy con- 

 dition to their permanent home in the large 

 building. 



On Monday, the 21st July, the curator noticed a 

 young Hippocampus rise upwards through the water 

 and swim about with great activity, — vertically, as 

 is the custom of the parent. It hovered about the 

 top of the water, occasionally descending an inch or 



* Since writing the above, I have a communication from 

 Mr. King, of Great Portland-street, informing me tliat he has 

 succeeded in breeding the Sippocampus, 



