The medullated wool fiber
AuthorJ. F. Wilson
Author AffiliationsJ. F. Wilson was Assistant Professor of Animal Husbandry and Associate Animal Husbandman in the Experiment Station.
Hilgardia 4(5):135-152. DOI:10.3733/hilg.v04n05p135. June 1929.
Abstract does not appear. First page follows.
Classification of Hair Medullae
The classification of the various types of medullae found among all types of hairs has been described by Hausman.(1) Medulla types of infra-hominid hairs are shown as (a) absent; (b) discontinuous, in which the medullary substance is displayed at fairly regular intervals throughout the length of the shaft; (c) intermediate, in which the medullary cells are found so closely contiguous as to present a medulla unbroken but uneven in contour; (d) continuous, in which the cells of the central lumen are apparently completely anastomosed or so closely packed as to give a regular tubular appearance to the fiber; and (e) fragmental, in which the medulla is found only as an occasional fragment at irregular intervals. Medulla types of human head hairs are classified as (a) absent; (b) fractional, which is seemingly almost identical with the fragmental type among infra-hominid hairs; (c) broken, in which the medulla may be heavy but does not form a continuous canal; and (d) continuous. Hausman has shown that among the infra-hominid hairs the greatest hair-shaft diameters were found in those carrying the fragmental medullae, while in human head hair, the largest were associated with presence of the continuous medulla.
The writer’s examination of medullated wool fibers from several breeds of sheep, but largely from the Lincoln and Romney, indicates that the medulla types found in wool follow more closely Hausman’s classification for human head hair than that for infra-hominid hair, the coarsest fibers being associated with the continuous rather than with the fragmental medulla.
 Hausman Leon Augustus. The relationships of the microscopic structural characters of human head hair. Amer. Jour. Phys. Anthrop. 1925. 8:173-177. DOI: 10.1002/ajpa.1330080205 [CrossRef]
 Blyth Janet S.S. Studies on the fleece fibers of British breeds of sheep. Zeitschrift für Tierzuchtüng und Züchtungsbiologie. 1926. 7:383-417.
 Bliss H. J. W. Kemp (Part I). Jour. Text. Inst. 1926. 17:T264-T267. DOI: 10.1080/19447022608661384 [CrossRef]
 Matthews J. Merritt. The textile fibers. 1924. 4th ed. New York: John Wiley &; Sons., Inc. p. 1-1053.
 Woolman Mary Schenck, Beers McGowan Ellen. Textiles. 1921. New York: The Macmillan Company. p. 1-428. DOI: 10.1515/9783111631523.447 [CrossRef]
 Hawkesworth Alfred. Australasian sheep and wool. 1920. Sydney: Wm. Brooks and Co., Ltd. p. 1-594.
 Bowman F. H. Structure of the wool fiber. 1908. London: Macmillan &; Co., Ltd. p. 1-475.
 Lewis Frederick T., Stöhr Phillipp. A textbook of histology. 1913. 2d ed. Philadephia: P. Blackiston’s Sons &; Co. p. 1-539.
 Anonymous. Wool Record and Textile World. 1925. 31: 424p.
 King A. T. Some chemical aspects of wool research. Jour. Text. Inst. 1927. 18:T361-T368. DOI: 10.1080/19447022708661419 [CrossRef]
 Parr Sir James. New Zealand sheep and wool. Wool Rec. and Textile World. 1929. 35:157-160.
 Nathusius W. Das Wollhaar des Schafs in histologischer und technischer Beziehung mit vergleichender Berücksichtigung andererück Haare und der Haut. 1866. Berlin: Weigant und Hempel. xvi + 1-200p.
 Hausman Leon Augustus. The hair of mammals. Amer. Nat. 1920. 54:496-523. DOI: 10.1086/279782 [CrossRef]
 Barker S. G., King A. T. A comparison of measurements of diameters of wool fibers with the micro-balance and the projecting microscope, with applications to the determinations of density and medulla (kemp) composition. Jour. Text. Sci. 1926. 17:T68-T74.
 Duerden J. E. Kemp fibers in the Merino. Jour. Text. Inst. 1926. 17:T268-T273. DOI: 10.1080/19447022608661385 [CrossRef]
 Duerden J. E., Ross Spencer M. The coat of the Angora. S. Afr. Jour. Sci. 1927. 24:418-420.
 Wilson J. F. A macroscopical analysis of the fleeces of four Romney rams. Hilgardia. 1929. 3:583-594. DOI: 10.3733/hilg.v03n19p583 [CrossRef]
 Speakman John B. The gel structure of the wool fiber. Jour. Text. Inst. 1926. 17:T457-T471. DOI: 10.1080/19447027.1926.10599977 [CrossRef]
 Wilson J. F. Macroscopical detection of the medullated wool fiber. Science. 1928. 67:512-513. DOI: 10.1126/science.67.1742.512-b [CrossRef]
Also in this issue:Lamb consumption: Varies according to population group and to size of family annual income
Dairy industry, 1949: Progress report of research conducted by members of the staff of the Division of Dairy Industry at Davis
Fruit size and leaf composition: Concentration of potassium in orange leaves found to be associated with fruit sizes
New sugar beet pest: 100% control of sugar beet crown borer achieved in 1949 tests
Wax sprays for sweet cherries: Fail to increase size of fruit in experimental tests in Davis in 1946 and in San Joaquin County in 1949
Walnut aphid control: Aphicide in May codling moth spray effective in northern California
Alfalfa caterpillar control: Treatment of fields by airplane application of spray advances destruction of pest
Cantaloupe mosaic insect vectors of virus disease resist insecticides in field tests
Tomato spacing: Close spacing increased early yields in 1946–1949 experiments
Tomato insect studies: DDD and DDT in three-year tests with chlorinated hydrocarbons
Harvesting asparagus: Comparative effects on yield of cutting and of snapping studied
Housing lumber: Depends upon family income, cost of ownership, population growth