SCIENCE-GOSSIP. 



271 



the place for specimens, none were to be found. 

 No doubt the taller grass had killed the whole by 

 shutting out necessary light and air. 



Se.xual reproduction in Prasiola is quite unknown, 

 and doubtless does not exist. Non-sexual propa- 

 gation takes place by the protoplasm rounding 

 itself off and escaping from the cells by solution of 

 the walls, forming gonidia which have no power of 

 spontaneous movement, being destitute of cilia, 

 but are dispersed by water. Vegetative reproduc- 

 tion is very copious, as any portion separated from 

 a frond will continue to live and grow, while 

 the lobes and proliferations, which are produced 

 freely at its margins under favourable circum- 

 stances, are especially liable to become detached, 



and will originate a new plant. It has been 

 stated on good authority that Prasiola is but 

 the adult stage of what is usually considered 

 another plant ; or, indeed, it might be said, of what 

 is looked upon as a series of plants. The most 

 definite is generally known as Lyngbya ; but it 

 would occupy too much space to enter now on that 

 part of the subject. 



I shall be pleased to forward specimens of 

 Prasiola, and Lyngbya also, so far as available 

 material will allow, to anyone sending address 

 and stamp for postage. 



9, Agamemnon Road, Wc^t Ilampstcad, 



London, S. 11'. ; February, 1897. 



(To be continued.) 



THE EGGS OF THE PEARLY NAUTILUS. 



■pROFESSOR Ray Lankester has written an 

 interesting letter to the "Times," describing 

 the successful search, by Dr. Arthur Willey, a 

 friend and former pupil of his, for the eggs of the 

 pearly nautilus. " Two and a-half years ago 

 Dr. Willey " — says Professor Lankester — " left 

 England for the South Seas to conduct his search. 

 The pearly nautilus is the only living represen- 

 tative of the great group of extinct animals whose 

 shells are known as ammonites. So rare were 

 specimens of the animal itself that twenty years 

 ago I paid ;^i8 for two preserved in spirit. Yet 

 they are trapped in baskets like lobster-traps by 

 the natives of some of the Melanesian Islands and 

 used as food. The structure of the animal is 

 extremely curious, and an admirable account of it 

 formed the first and in many respects the ablest 

 scientific memoir produced by Sir Richard Owen. 

 The nautilus is allied to the cuttle fishes, but 

 differs from them in most interesting ways. To 

 fully understand its structure and the mode of 

 building up of its chambered shell it is necessary 

 to know its young stages whilst it is growing and 

 forming within the egg. To gain this knowledge 

 will be a great triumph ; it has been one of the few 

 important embryonic histories not yet ascertained 

 by the enterprise of latter-day naturalists. 



"Dr. Willey proceeded first to Ralum, in New 

 Britain, where he spent a year trapping the nautilus 

 in seventy fathoms of water and dredging in vain for 

 its eggs. He then tried a station on the coast of 

 New Guinea, where he was nearly drowned by the 

 capsize of his small craft. After passing through 

 New Caledonia, he arrived last summer in Lifu, 

 one of the Loyalty Islands, where nautili can be 

 captured in three fathoms depth only. Here he 

 constructed a large submarine cage in which he 

 kept specimens of the nautilus, feeding them daily. 



On December 5th last his patient endeavours were 

 rewarded. Some of the nautili had spawned in the 

 cage, and thenceforward he was able to obtain 

 abundant samples of the eggs. Each egg is as 

 large as a grape, and is deposited separately by the 

 mother nautilus. At present we have received but 

 few further details from Dr. Willey, but he has 

 doubtless by this time obtained the young in all 

 stages of growth, and will return to England with 

 the materials for a most important memoir. 



" Dr. Willey was enabled to undertake this quest 

 by his appointment to the Balfour studentship, 

 founded by general subscription in memory of 

 Frank Balfour, whose heart would have been 

 rejoiced by the work thus carried out in his name. 

 He was also assisted by the Government grant 

 fund of the Royal Society. It is a legitimate 

 source of gratification to British men of science 

 that a successful result has followed from the 

 application of these funds. By aid of the same funds 

 Mr. Caldwell, twelve years ago, discovered the 

 eggs of the Australian duck-mole and echidna and 

 the larval stages of the remarkable fish, ceratodus, 

 of Queensland — an animal which, like nautilus, is 

 a survival of most ancient extinct forms. Our 

 younger naturalist travellers have in this past year 

 elsewhere given proof of their energy and devotion 

 and done credit to the British name in the field of 

 science. Mr. Spencer Moore is on his way home 

 from Lake Tanganyika, where he has successfully 

 studied the freshwater jellyfish and other 

 important animals living in those waters ; whilst 

 Mr. Graham Kerr is returning from the Paraguay 

 River with an abundant supply of the embryos of 

 the South American lepidosiren, an exceptionally 

 interesting fish which, until four years ago, was 

 known by but six specimens in European 

 museums." 



