572 



NATURE 



[April 12, 1888 



A 



THE CULTIVATION OF OYSTERS. 



REPORT from the British Consul at Baltimore on the 

 oyster- fisheries of Maryland, which has just been laid before 

 Parliament, contains much interesting information respecting the 

 cultivation of oysters. The method of farming most successful 

 in America consists in depositing clean oyster-shells upon the 

 bottom, just before the spawning-season, to which the young 

 attach themselves, and then placing among the shells a few 

 mature oysters to furnish eggs and young. As soon as the 

 young oysters caught in this manner are large enough to handle, 

 they are distributed over the bottom. Another system is by 

 artificial propagation, properly so called — that is, by producing 

 the seed-oyster itself, or procuring it by methods less simple than 

 the shell-sowing process. This method is due to a discovery by Dr. 

 W. K. Brooks that the Ostrea virginiana, or American oyster, is 

 not, like the Ostrea edulis, or oyster of Northern Europe, herm- 

 aphrodite, but is exclusively male or exclusively female. The eggs 

 of the European oyster are fertilized within the valves of the 

 parent, while in the case of the American oyster, fertilization 

 takes place in the broad and open waters. By experiment Dr. 

 Brooks discovered how artificial fertilization could be procured, 

 and the next great step of finding a simple and practical method 

 of rearing the young oysters which have been hatched artificially 

 was the work of M. Bouchon Brandsle, the French naturalist, 

 who experimented with Portuguese oysters, which, like the 

 American variety, are of distinct sexes. He succeeded in rearing 

 many seed-oysters fit for planting. Another highly important 

 industry which is springing up in the United Spates, and which 

 also owes its existence to a careful study of the habits of the 

 bivalve, is that of "muzzling" oysters, by which they can be 

 sent long distances in their shells with perfect safety. Until 

 recently, the general practice was to pack the raw oysters in ice, 

 but a sudden rise of temperature is liable to render a whole 

 week's supply useless. Oysters feed twice a day ; and always at 

 the still moment preceding the turn of the tide, and at no other 

 time, except when feeding, do they open their shells. When 

 taken out of their natural element, they attempt to feed at 

 regular intervals, and so soon as the shells open, the liquor they 

 contain is all lost, the air takes its place, and the oyster is 

 covered with a thick coating of slime, which is the first stage of 

 decomposition. As long as the shells are closed, the oyster is 

 fit to eat ; it feeds on the liquor in the shell, and will thus keep 

 in good condition for a considerable time. To secure the keep- 

 ing of the shells closed, a method has been invented of tying 

 them with stout wire, which can be done with great rapidity, 

 and now arrangements are being made for despatching American 

 oysters in their natural condition all over the civilized world. 



SCIENTIFIC SERIALS. 



The Quarterly Journal of Microscopical Science, February, 

 1888, contains : — On the Photospheria oi Nyclifikanes norvegica, 

 G. O. Sars, by Rupert Vallentin and J. T. Cunningham 

 (Plate 23). The authors give an account of their examination 

 of the luminous organs of this little crustacean ; it is a distinctly 

 northern form, being absent from the Mediterranean and the 

 warmer parts of the Atlantic. It is abundant on the west coast 

 of Norway ; the adults seem to live on' the bottom and never 

 swim far from the ground, while the young, up to half or 

 three-quarters the size of the adult, occur abundantly at the very 

 surface, and at all intermediate depths. Mr. Murray found 

 swarms in the Faroe Channel, and it seems common in the 

 the Clyde sea-area ; the authors took it in abundance off 

 Brodick Bay. The histological details of the luminous organs 

 are given in detail, and agree for the most part with those of 

 G. C. Sars. — On the eai-ly stages of the development of a South 

 American species of Peripatus, by W. L. Sclater (Plate 24). 

 These details are worked out from a species found by Mr. 

 Sclater in Demerara, and called by him P. imthurni ; the early 

 stages present great differences when compared with those de- 

 scribed by M. Sedgwick in P. capensis. — On the anatomy of 

 Allurus telraedrus- (Eisen), by Frank E. Beddard (Plate 25). 

 The specimen described came from Teneriff'e ; there are several 

 structural differences between this genus and AUolobophora. — • 

 On the development of the Cape species of Peripatus ; Part iv, 

 the changes from the G stage to birth, by Adam Sedgwick, 

 F-R.S. (Plates 26-29). — On the occurrence of numerous Neph- 

 ridia in the same segment of certain earthworms, and on the 



relationship between the excretory system in the Annelida and in 

 the Platyhelminths, by Frank E. Beddard (Plates 30 and 31). — 

 On the anatomy of the Madreporia, iv., by Dr. G. Herbert 

 Fowler (Plates 32 and 33). The author gives the result of his in- 

 vestigations of the species of seven more genera of the Madre- 

 pores, which, among other important results, seem to establish a 

 relationship between the external body- wall and the corallum, 

 which depending on the presence or absence of coenenchyma 

 may yield a distinctive morphological character. In all those 

 genera in which a coenenchyma is found, whether they belong to 

 the Perforata or Imperforata, the body-wall rests on the little 

 spikes or echinulations which stud the surface of the corallum. 

 A new species of Seriatopora is described as S. tenuicornis ; it 

 was found by Dr. S. J. Hickson at the Celebes ; it comes near 

 S. caliendru?n. 



Transactions and Proceedings of the New Zealand Institute 

 for 1886, vol. xix. (Wellington, May 1887). — The principal 

 contents of this volume, edited as usual by Sir James Hector, 

 are as follow : — Zoology : E. Meyrick, monograph of New Zea- 

 land Noctuina, describes sixty-three species. — W. M. Maskell, 

 on the "honeydew" of Coccidse, and the Fungus accompanying 

 these insects ; Further notes on New Zealand Coccidre ; On 

 the freshwater Infusoria of the Wellington district. In the 

 second paper a new genus and two new species are described ; 

 in the last many new species are described, and several well- 

 known British forms are recorded ; all these papers are illus- 

 trated. — G. V. Hudson, on New Zealand glow-worms. — T. W. 

 Kirk, notes, double earth-worm ; New species of Ixodes ; Zootoca 

 vivipara, in New Zealand ; New species of Alpheus. — A. Purdie, 

 Pasiphila Uchenodes sp. nov,, and descriptions of larvae of three 

 species of the genus. — A. T. Urquhart, on new species of 

 Araneidea ; On the work of earth-worms. — W. W. Smith, notes 

 on New Zealand earth-worms, gives some very interesting de- 

 tails. — W. Colenso, deformed bill of a Huia ; New species of 

 Hemideina ; Gestation of a species of Naultinus. — T. Jeffery 

 Parker, on Palinurus lalandii and P. edwardsii, decides that 

 there are constant though slight differences between the two 

 species ; P. edivardsii, Hutton, being the New Zealand form, 

 the other being the Cape of Good Hope form. — C, W. Robson, 

 new giant cuttle-fish {Architeuthis kirkii). — J. A. Newell, 

 anatomy of Patinella radians. — T. F. Cheeseman, Mollusca of 

 the vicinity of Auckland. — J. Adams, land Mollusca of the 

 Thames gold-fields. — A. Reischek, Hauturu Island and its 

 birds ; Ornithological notes. — S. Weetman, Moa remains on the 

 Great Barrier Island. — R. Haeusler, Foraminifera from Hauraki 

 Gulf. — P. Goyen, descriptions of new spiders. — Botany : J. 

 Buchanan, new native plants ; Hemitelia sniithii, a branching 

 specimen. — T. F. Cheeseman, on the New Zealand species of 

 Coprosma. — W. Colenso, on tree ferns ; On some new Phseno- 

 gamic plants ; On some new Cryptogamic plants ; Fungi recently 

 discovered in New Zealand. — Catherine Alexander, on the glands 

 in the stem and leaf of Myoporum Icetum. — T. W. Rowe, on 

 the development of the flower of Coriaria ruscifolia. — J. Baber, 

 medicinal properties of some New Zealand plants. — D. Petrie, 

 descriptions of new native plants. — Geology : J. Park, ascent of 

 Ruapehu, the exact height was not apparently determined, 

 "about 9000 feet high." — There is a series of important papers 

 on the eruption of Tarawera Mountain and Rotomahana, by J. 

 A. Pond and S. Percy Smith, Major Mair, L. Cussen, Arch- 

 deacon Williams, E. P. Dumerque, and H. Hill.— Prof. F. W. 

 Hutton, on the geology of the Trelissick or Broken River Basin, 

 Selwyn County ; On the so-called gabbro of Dun Mountain ; 

 On the geology of the country between Oamaru and Moeraki ; 

 On the geology of the Valley of the Waihao in South Canter- 

 bury. — A. McKay, the Waihao greensands and their relation 

 to the Ototara limestone. — Sir J. von Haast, notes on the age 

 and subdivisions of the sedimentary rocks in the Canterbury 

 Mountains, based upon the palseontological researches of Baron 

 von Ettingshausen. — W. S. Hamilton, notes on the geology of 

 the Bluff" District. — ^J. Goodall, on the formation of Timaru 

 Downs. 



Reale Istituto Lomlmrdo, March 8. — This number is mainly 

 occupied with E. G. Celoria's determination of some new orbits 

 of the double stars 02 298 in the constellation of Bootes and )8 

 Delphini, The results of thirty-nine distinct observations are 

 tabulated, and compared with previous more or less approximate 

 determinations of these orbits by Burnham, Dawes, Dembowski, 

 Duner, Engelmann, Asaph Hall, Perrotin, Schiaparelli, 

 Seabroke, Struve, and Wilson. 



