ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1921.tb05541.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

SUMMARY1The “wild hop” (Humulus LupulusL.) is composed of a number of forms1which show distinctive physiological, or “constitutional,” characters, as measured by the grade of susceptibility to the attack of the mildewSphaerotheca Humuli.These characters vary from extreme susceptibility, shown both in the open and under greenhouse conditions, to a high degree of resistance in the open and complete immunity in the greenhouse. Of 291 ♀ seedlings, 165 seedlings, or 56.70 per cent., show extreme susceptibility, while 18 seedlings, or 6.19 per cent., are “commercially resistant” in the open. The remaining seedlings fall into groups representing intermediate grades of susceptibility.2Of 480 seedlings, ♂ and ♀, 27 seedlings, or 5.63 per cent., are completely immune—and 7 seedlings, or 1.46 per cent., semi‐immune—under greenhouse conditions.3The majority of the seedlings which show complete immunity under greenhouse conditions show a high degree of resistance in the open.4The distinctive degree of susceptibility possessed by a seedling, both as shown in the open and under greenhouse conditions, has shown no change after the plant has been cultivated for five years

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1921.tb05542.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

SUMMARY1The fleeces of certain wild and primitive species of sheep were examined.2That of Marco Polo's sheep was found to be the one most suitable for examination, since samples of both summer and winter coats were available. In the former coat there was hair only and still growing. In the latter coat it was mostly full‐grown and much less pigmented. The white appearance was due to the presence of a film of air between the pigment granules of the cortex and the eye of the observer.3Wool is present in the winter coat but absent from the summer one.4The microscopical structure of hair and of wool are briefly described and attention is called to the disposition of the wool in the fleece ofO. orientalis, since this most closely resembles that of the wool of the modern domesticated breed

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1921.tb05543.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

SUMMARY1Insects which are parasitic alike on grasses, cereals, and other crops will, when these latter are unavailable, take up their quarters in the grasses and plants growing in the situations herein mentioned and, when the crops are again available return to them and commit their ravages.2Observations were conducted over a period of nine months on certain insects which attacked both grasses and cultivated crops in a limited area in Shropshire, viz. the farm of the Harper Adams Agricultural College, near Newport, and the immediate neighbourhood.3The observations indicate a danger of harbouring pests among the vegetation on headlands, hedgerows and waste places; grasses in particular, being susceptible to their visitation, are decidedly important factors in tiding pests over from season to season and this in itself suggests the advisability of keeping hedgerows and headlands clean.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1921.tb05544.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

摘要:

SUMMARYThe infection of the apple stem by the canker fungus through the leaf scare is described.The fungus appears to enter through small cracks which appear in the leaf scar tissues, in the autumn immediately after defoliation and in the spring when the buds are swelling.The possibility of preventing this infection by disinfecting the leaf scare by fungicides is discussed and results of preliminary trials recorded.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1921.tb05545.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1921.tb05546.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1921.tb05547.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1921.tb05548.x

出版商:Blackwell Publishing Ltd    

年代:1921

数据来源: WILEY