Dec. 14, 1871] 



NATURE 



I2g 



fortnight for England, and the same amount of time for 

 France. The Commission proceeded in October 1S68 

 to France to commence their fortnight's tour, and in June 

 1870 presented their report, which has now been laid be- 

 fore Parliament. The Report occupies about fifty pages ; 

 and 150 more are very usefully taken up with a series of 

 appendices. Ten plates are also included in the volume. 



The Report commences with a list of the places visited 

 by the Commission, from which we notice the omission 

 of Dul'in Bay, although Howth and Malahide had each 

 at one time a respectable name for oysters. It then pro- 

 ceeds to give the natural history of the oyster, which we 

 pass over without further comment than that it is a pity 

 the Commissioners did not consult some person tolerably 

 skilled in malacology ere they printed it — to criticise it 

 would be but to break a butterfly on a wheel. The 

 various branches of oyster fisheries are well described, 

 and an interesting epitome is given of Coste's labours. 

 It would appear that the great bulk of the oysters bred at 

 Arcachon are sent to Marennes and Tremblade, where 

 the green tint, so much esteemed in France, is imparted 

 to the beard of the oyster. Such a prejudice exists in 

 England against this green tint, that the Essex oysters are 

 largely exported to France. It should be recollected that 

 oysters impregnated with copper have always a greenish 

 tinge of body, while those with green beards do not owe 

 their colour to copper but to their peculiar feeding. The 

 reporters suggest that the Diatomacea; are probably the 

 cause, and give figures of some Diatoms, to which we 

 would call the attention of Dr. Donkin, who is writing a 

 monograph of this group ; to say the least, they are very 

 comical. 



The diminution in oyster production which has taken 

 place in England, though very considerable, is not so 

 great as in France. The Hayling Island enclosure is 

 described, and plans of the beds given. The various 

 methods of oyster culture are described, and appropriate 

 places for their cultivation are pointed out. In reference 

 to this portion of the subject, we may refer to the 

 elaborate report on the temperature of the surface of the 

 sea on the coasts of Great Britain, Ireland, and France, 

 by Prof. Hennessy, in which he deduces that : 



" I. The temperature of the sea on the coast of Ireland 

 varies within narrower limits than on the coast of Great 

 Britain, or, in other words, it is more equable throughout 

 the year and also during the summer season, when oyster 

 breeding takes place. 



" 2. The temperature of the sea at noon on the Irish 

 coast, especially on the south and west coasts during the 

 months of June and July, is, upon the whole, higher than 

 on the coast of Great Britian, and less than on the west 

 coast of France. 



" 3. This temperature seems to be sufficient for the re- 

 quirements of oyster breeding, and therefore, a fortiori, 

 the temperature about two in the afternoon under the con- 

 ditions above referred to. 



"4. The highest temperature of the seas surrounding 

 Ireland, and probably also of those suiTounding Great 

 Britain, is during the month of August, and the least 

 during the month of February. 



" 5. Any advantages as to temperature possessed by the 

 seas which wash the Irish coast are unquestionably due 

 to the thermal influence of currents connected with the 

 Gulf Stream." 



Prof. Sullivan also appends an important Report on the 

 Composition of the Soils of Oyster Grounds, and on the 

 qualities which exert most influence on oyster cultivation, 

 and comes to the conclusions : — 



" I. That the influence of the soil upon the breeding 

 and growth of oysters is complicated by : tem- 

 perature, especially during the spawning season ; 

 sudden alternations of heat and cold, due to cur- 

 rents ; alternation of depth of water, especially as 

 regards whether the maximum of sun-heat and 



light concords with low water during the spawning 

 season ; velocity of tide, angle of inclination of 

 shore, &c. 

 " 2. That the soil of oyster grounds may be made up of 

 materials of any of the great classes of rocks, 

 arenaceous, argillaceous, or calcareous, provided 

 they contain — 

 " 3. More or less of a fine flocculent highly hydrated 

 silt, rich in organic matter, which indicates that 

 Diatomaceffi, Rhizopoda, Infusoria, and other 

 miru'e creatvrps rhrurd. 

 "4. That the chaiactci and abundance of such small 

 organisms in a locality seems to be the true test of 

 a successful oyster ground. 

 '■ 5. And lastly, that although oysters do undoubtedly 

 assimilate copper from water where mine-water 

 containing traces of that metal flows into the sea in 

 the neighbourhood of the oyster beds, the copper 

 is chiefly, if not exclusively, confined to the body 

 of the oyster, and does not appear to reach the 

 mantle or beard. That the so-called green oysters 

 of Essex, Marennes, and other places, on the other 

 hand, are green-bearded and contain no copper, 

 nor can the most minute trace of copper be detected 

 in the soil of the oyster grounds where such green- 

 bearded oysters are produced.'' 

 The Report concludes with the following recommenda- 

 tions : — 



" I. That all regidations with regard to the close time 

 around the Irish coast should be strictly maintained. 



" 2. That the inspectors of Irish fisheries should have 

 power, whenever they determine to reserve a bank or any 

 portion thereof from public dredging for the purpose of 

 recover)', to make such arrangetnents as may seem desir- 

 able for keeping the restricted part free from weeds and 

 vermin. 



" 3, That there should be procurable at each coastguard 

 station, at a small cost, general information as to oyster 

 culture, and simple instructions as to the best modes of 

 proceeding. 



" 4. That the inspectors be empowered to adopt such 

 other means as they may deem necessary to afford infor- 

 mation and instruction to those requiring it with respect 

 to oyster culture. 



" 5. That having unsizable oysters in possession in places 

 where it is prohibited by any bye-law to take oysters from 

 any public beds under a certain size, shall be pnmd facie 

 evidence that such oysters were taken in places so pro- 

 hibited ; such regulations not to apply to private oystei 

 grounds. 



" 6. That facilities be afforded to the coast population 

 to acquire the use of small portions of foreshore, or 

 sea bottom, for oyster cultivation, and to obtain loans on 

 satisfactory security for the preparation of same, and for 

 the purchase of oysters, collectors, &c. 



" 7. That landed proprietors desirous of cultivating 

 oysters on the shores adjoining their lands, be empowered 

 to avail themselves of the provisions of the Irish Land 

 Improvement Acts, for the purpose of oyster cultivation." 

 We would commend the perusal of this Report to those 

 interested in this subject ; of its importance there can be 

 little doubt ; and while we agree with the commissioners 

 that no very extraordinary profits are to be made out of 

 oyster culture, and that hence it is not a subject for exten- 

 sive commercial speculation, yet we know of none more 

 deserving of the attention of those interested in the general 

 welfare of this country. E. P. W, 



ARTIFICIAL MILK 



AMONG the many sorrowful records of the Siege of 

 Paris, one of the most enduring, and not the least 

 touching in its melancholy eloquence, is afforded by the 



