26 



NATURE 



[March 3, 192 1 



are well defined, and both these features indicate that 

 there has been movement along the contact, so that 

 it may be classed as a fissure lode on an igneous con- 

 tact. It is certainly too regular in strike to consider 

 it a replacement along what superficially appears to 

 be rather regular igneous contact. Where the gangue 

 is extremely hard indurated schist this is much jointed 

 or broken, further pointing to a settling movement 

 along the contact planes. The lode underlies 75°-8o° 

 easterly, which is the dip of the schists on the 

 hanging walls. The gangue in the lode consists 

 of diorite in various stages of alteration, soft 

 weathered schist, and hard indurated schist. Where 

 the last-named occurs replacement appears to be con- 

 fined to the fracture-faces, which are coated with 

 cobaltite in process of oxidation to erythrite. 



A few chains north of No. 4 shaft there are some 

 old abandoned workings on the contact. These were 

 worked for copper, and there is a good deal of copper 

 carbonate associated with the mullock. With the 

 copper occurs a vein of scheelite 2-4 in. wide, from 

 which well-developed crystals of that mineral have 



been obtained. Although so closely contiguous, there 

 is no appearance of cobalt stains. 



In the diorite dyke in juxtaposition to the cobalt 

 lode there is a quartz outcrop running at right angles 

 to it which contains cobaltiferous wad as well as 

 jasper-brown iron ore. Although it does not meet 

 the cobalt lode at the surface, it has possibly a 

 genetic relationship to the cobalt lode, and it is sug- 

 gested that it may have been a channel of supply, 

 thus accounting for what, at the present time only, 

 appears a definite localisation of the cobalt in the 

 contact lode. A sample of the wad from this outcrop 

 contained : 



Metallic cobalt 

 Metallic nickel 

 Arsenic 



52 per cent. 



nil 



09 per cent. 



It is very desirable, however, that the whole of the 

 diorite contact should be prospected, particularly the 

 eastern contact, on account of copper carbonates, 

 scheelite, and cobalt ores having been already found 

 along it. 



The Study of British Roses. 



THE study of our British roses has been rendered 

 increasingly difficult by successive attempts to 

 classify the numerous forms — species or varieties — 

 in a satisfactory system. The late Mr. J. G. Baker 

 in his "Monograph of British Roses" in 1869 recog- 

 nised thirteen species and a moderate number of 

 varieties. In the " London Catalogue of British 

 Plants" (1908) some of Baker's varieties are raised 

 to specific rank, and twenty-five species and a large 

 number of additional varieties are recognised. 

 WoUey-Dod's "List of British Roses" (1911) included 

 about 170 names, but in his " Revised Arrangement " 

 recently published in the Journal of Botany the 

 number of names having full specific rank is reduced 

 to eighteen, the author remarking that most of the 

 very detailed descriptions of D6s6glise and other 

 specialists can scarcely be other than those of an 

 individual bush or specimen which cannot be com- 

 pletely matched by any other. 



The present position is discussed in the New Phyto- 

 logist (vol. xix., Nos. 7 and 8) by Mr. J. R. Matthews, 

 who considers that only by culture, combined 

 with cytological study, will it become possible to 

 determine finally the genetic relationships of the 

 numerous micro-species into which old, well-known 

 species like Rosa canina, Linn., have been split. The 

 study of external form has so far failed to give a 

 satisfactory solution of the . problem, and the ana- 

 tomical method followed by Parmentier has not proved 

 more successful. Several hybrids — that is, crosses — 

 between distinct species have been recognised among 

 British roses, and it is not improbable that the diffi- 

 culty in classifying the genus may be largely due to 



hybridisation and segregation, complicated, it may 

 be, by rehybridisation. Hybrids between closely 

 similar parents would be difficult to diagnose, and 

 in actual practice would, as a rule, be considered dis- 

 tinct species or varieties ; and it is suggested that a 

 large portion of the total number of named variefies 

 of roses has arisen in this way. 



The work of Jeffrey on hybridism in the Rosaceae 

 indicates that certain recognised species are, from 

 the study of their pollen, in reality concealed hybrids 

 (crypthybrids), and Miss Cole more recently from 

 the study of the pollen in numerous roses concludes 

 that the great majority of so-called species are reallv 

 of hybrid origin. There is no experimental evidence 

 to show whether these species-hybrids segregate or 

 remain stable ; but presuming segregation to occur 

 in the genus Rosa, we might expect to find a large 

 number o.f visually distinct forms showing various 

 combinations of Mendelian unit-characters, such as 

 hairiness, leaf serration, glandularity, glaucousness, 

 etc. 



Mr. Matthews attempts a theoretical analysis of 

 some of the British species of roses on the basis" of a 

 few separate characters such as these. The species 

 selected are the aggregate species generally recognised 

 by systematists, and the author suggests that the 

 numerous sub-species and varieties of these aggregates 

 which have been described represent some of the 

 various combinations of unit-characters which might 

 be expected to result from the process of segregation. 

 The argument is confessedlv entirely hypothetical, and 

 the author emphasises the importance of experimental 

 work to establish the hypothesis. 



Commerce and Customs of Papua. ^ 



T N his Report on the Territorv of Papua for the 

 -*• year ending June, 1919, the Lieutenant-Governor, 

 the Hon. J. H. P. Murray, shows that, as in so many 

 other parts of the world, the scarcity and irregularity 

 of shipping facilities are acting prejudicially to the 

 progress and development of the Territory. This is 

 especially indicated by the decrease of exports upon 



1 "Commonwealth of Australia. Papua. Annual Report for the Year 

 1918-19." Pp. 117-I-2 pis. (Printed and Published for the Government of 

 the Commonwealth of Australia by Albert J. MuUett, Government Printer for 

 the State of Victoria.) 



which the prosperity of the country mainly depends. 

 Rubber alone showed an increase, but the quantity 

 is as yet small (207 tons as compared with 144 tons 

 in 1918). Another important vegetable export, copra, 

 has decreased (2598 tons as compared with 3189 tons 

 in 1918). Native-made copra forms a large propor- 

 tion of the output, and, owing to variation in the 

 production, this does not increase steadily like .the 

 plantation product. The production of sisal hemp 

 has also decreased, whilst the value of all the crops 

 has been much reduced by a fall in prices. The 



NO. 2679, VOL. 107] 



