Hair in its relation to questions of homology and phylogeny

Danforth, C. H.

doi:10.1002/aja.1000360103

Cited by 41 publications

(20 citation statements)

References 8 publications

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“…Vibrissae are of taxonomic importance in some mammalian species (Danforth 1925). Although they are relatively well developed in pinnipeds, they have not been used in any systematic study for lack of quantitative data (Ling 1966).…”

Section: Discussionsupporting

confidence: 44%

Morphological and histological features of the integument of the New Zealand sea lionPhocarctos hookeri

Orr

Kirk

Cawthorn

1983

New Zealand Journal of Zoology

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Section: Discussionsupporting

confidence: 44%

Morphological and histological features of the integument of the New Zealand sea lionPhocarctos hookeri

Orr

Kirk

Cawthorn

1983

New Zealand Journal of Zoology

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“…Our findings lend support to the concept of Danforth (1925) who studied Mus musculus that the disposition of vibrissae developed in the course of evolution is invariable. According to our evidence, the majority of deviations appear to be concerned with a reduction in the vibrissal number in a group due to species specialization (Lyne 1959).…”

Section: Resultsmentioning

confidence: 49%

“…Different classifications have been developed to identify vibrissae (Maurer 1895 ;Danforth 1925 ;Lyne 1959 ;Kratochvil 1968). None of these patterns providing a detailed description of rodent vibrissal apparatus, we are proposing a classification of our own, retaining the names of the respective tufts as used by the above authors (Fig.…”

Section: Morphology Of Vibrissal Apparatusmentioning

confidence: 43%

The structure and function of the vibrissal apparatus in some rodents

Sokolov¹,

Kulikov²

1987

Mammalia

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The vibrissal apparatus has been described for various ecological groups. A classification of vibrissae has been developed and distribution patterns have been described. Experimentally, 4 functional vibrissal classes have been revealed : (1) vibrissae performing the function of orientation proper ; (2) the ones in control of the position of the food which the animal is taking into its mouth ; (3) guard vibrissae and (4) vibrissae controlling the position of the body in relation to the substrate.In 9 species under study, the « vibrissal field » is reconstructed and its relationship with species ecology revealed. When effective use of vision is hampered by habitat conditions, lack of vision is compensated for by high development of the vibrissal field.Presumably, the « vibrissal field » spans the dead zone of the distant senses, permitting of more rapid and more efficient orientation in medium.Resume. -La disposition des vibrisses des rongeurs est decrite en fonction des divers groupes ecologiques auxquels ils appartiennent. Un classement des vibrisses est propose ; leur repartition sur le corps est decrite.On reconnait quatre groupes de vibrisses selon leurs functions : 1°) vibrisses servant seulement ä 1'orientation ; 2°) vibrisses contrölant la position de la nourriture lors de sa prise dans la bouche ; 3°) vibrisses de guet ; 4°) vibrisses contrölant la position du corps par rapport au substratum.Pour les 9 especes etudiees, un « champ vibrissal » est mis en evidence ; son etendue relative est comparee, en fonction de l'ecologie de 1'espece.On suppose que le champ vibrissal interesse une zone depourvue des moyens d'apprecier la distance, ce qui permet a animal de s'orienter plus sürement et plus rapidement.The adaptation of an animal to the habitat associated with search of food or a mate, particularly that involving the sense organs, is a most interesting problem and a challenge to a zoologist.Of great significance in this respect is the role of vibrissal apparatus, a specialized tactile organ, regarded, not infrequently, as a systematic character (Pocock

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“…Vellus is persistent over many parts of the body throughout life, and, on the head, all three types, vellus, intermediate, and terminal hairs, are found. For the head, Danforth (1925) has estimated that, in the adult, six to 25 per cent of the total number is of the vellus type. Whereas there is some evidence that the hairs produced by a given follicle may show continuous, though slight, change throughout life, it is true that the greatest change, at least for the head hair, is effected soon after birth.…”

Section: Resulls and Discussionmentioning

confidence: 45%

Changes in Morphology of Hair During Childhood

Duggins

Trotter

1951

Annals of the New York Academy of Sciences

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The general appearance of hair, as seen by the naked eye, is sufficiently variable to warrant including the type of hair as one of the chief differentiating characteristics of race. Microscopic study of individual characters contributing to the differences in appearance of head hair of a Negro, a Mongol, and a White has shown definite variations in index, size, pigmentation, medullation, and other morphological features. Nevertheless, the range of variation of a given character within a race is not only very wide, but it also overlaps the range of the same character of the other races.The appearance, or general effect, of heads of hair within a homogeneous group may often be very different, and it is believed that this effect is different for the same head at d8erent ages. Structural characters of human head hair from many different individuals of various ages have been studied. Wynkoop (1929), in studying head hair of a series of 82 individuals (presumably White), found little, if any, correlation between the age of the individual and the diameter of the shaft. She also reported that the type of medulla bears no relation to age of the individual but that there is a correlation between the type of medulla and the size of the hair. The larger hairs are more likely to have continuous medullas, while the smaller hairs have either very scanty or no medullas. In a series of 340 American Whites (Trotter, 1930), there was no significant variation in index between different age periods, but the size of the shaft was found to be significantly less in groups under the age of 10-15 years than in older groups. Gamble and Kirk (1941) examined hair from 37 White persons of varying ages for scale count and found both the means and ranges of the scale counts to be approximately constant for the same individual but variable between individuals. In addition, a single hair was determined to be characteristic of all hairs counted for the individual with respect to mean and nearly always with respect to range of scale counts.A study of hair from the same individual over a period of years is expected to present evidence from which the magnitude and significance of individual variations, in relation to both physiological and chronological age, may be determined. This is a report of findings in a study of four characters, i.e., index, size of shaft cross section, incidence of medullation, and the scale count, on hair from the same individuals, beginning at birth and extending to 14 years of age. I t is expected that the study will be conducted through 25 years of age and that other characters will be investigated as well.Material and Method A collection of monthly hair samples starting at birth was begun in 1930. Sixteen American White children are contributors, the last one having been 'This investigation was sup orted (in art) by a research grant from the Viking Fund, Inc. and (in part) 2 a research grant from the kivision oPResearch Grants and Fellowships of the National Institutes of t In partial fulfillment of the requirements for ...

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Hair in its relation to questions of homology and phylogeny

Cited by 41 publications

References 8 publications

Morphological and histological features of the integument of the New Zealand sea lionPhocarctos hookeri

Morphological and histological features of the integument of the New Zealand sea lionPhocarctos hookeri

The structure and function of the vibrissal apparatus in some rodents

Changes in Morphology of Hair During Childhood

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