BOSTON PUBLIC LIBRARY
3 9999 06317 638
NORTHERN FUR SEAL
DEPARTMENT OF THE INTERIOR
FISH AND WILDLIFE SERVICE
NORTHERN FUR SEAL
Victor B. Scheffer
Biologist, Branch of Marine Mammals
BUREAU OF COMMERCIAL FISHERIES
[_MAR 3 1 200 q
DEPARTMENT OF THE INTERIOR
Stewart L. Udall, Secretary
FISH AND WILDLIFE SERVICE
Clarence F. Pautzke, Commissioner
BUREAU OF COMMERCIAL FISHERIES
Donald L. McKernan, Director
North American Fauna, Number 64
Published by U.S. Fish and Wildlife Service
United States Government Printing Office • Washington • 1961
For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington 2 5, D.C. - Price $1
Previous research 1
General structure of the body covering 5
Arrangement of the body layers 5
The skin: epidermis, dermis, and sweat glands 5
The pilosebaceous unit: follicle, root and shaft of the hair,
and sebaceous glands 7
The pelage 9
Fetal stages (sexes lumped) 10
Black pup, newborn (sexes lumped) 14
Synopsis of color pattern 14
Synopsis of pelage fibers 14
Guard hairs: larger examples 16
Guard hairs: smaller examples 17
Black pup, molting (sexes lumped) 18
Silver pup (sexes lumped) 19
Synopsis of color pattern 19
Synopsis of pelage fibers 19
Guard hairs: larger examples 20
Guard hairs: smaller examples 21
Underfur fibers 22
Yearling, pelagic (sexes lumped) 22
Yearling, autumn (sexes lumped) 23
Three-year-old, adolescent male (bachelor) 23
Three-year-old, adolescent female (young cow) 23
Adult male (bull) 24
Adult female (old cow) 24
Variation in length of pelage fibers with age and sex 26
Variation with season: the annual molt 26
First molt 26
Second molt 27
Third molt 28
Fourth molt 29
Molt in adults 30
Comparison with molt in other f urbearers 31
The sensory vibrissae 32
Prenatal development of the vibrissae 33
Postnatal development of the vibrissae 34
Pelage anomalies 35
Color anomalies 35
Effect of diseases, parasites, and physiological disorders
on pelage 36
Effect of sex abnormalities on pelage 39
Foreign growths 39
The Pribilof sealskin industry 40
1 1 istory of the industry 40
Killing, skinning, blubbering, and curing 41
Processing and marketing 42
The pelage — Continued
The Pribilof sealskin industry — Continued Page
Dimensions and weights of sealskins 45
Strength and durability of sealskins 50
Other features of the surface topography 51
Features of the head 51
Nostrils, mouth, and lips 51
Eyelids, eye glands, and iris 51
Features of the belly 53
Mammary gland complex 53
Penial opening and scrotum 56
Female external genitalia 56
Navel and tail 56
Features of the limbs 57
Flippers and claws 57
The blubber layer 59
Literature cited 65
Table 1. Length and weight of male fetal seals 71
2. Length and weight of female fetal seals 71
3. Mean lengths of underfur and guard-hair fibers 72
4. Length of longest vibrissa, by age and sex 72
5. Change in color of mystacial vibrissae, with age 73
6. Sizes of grading boards for raw, salted skins 73
7. Sizes of male sealskins taken in early season 73
8. Sizes of male sealskins taken in late season 74
9. Weights of female seals, early and late summer 74
10. Weight of fresh, male sealskin with relation to field
length of seal 74
11. Trade classification of raw, salted, male sealskin with
relation to field length of seal 75
12. Trade classification of finished, dyed, male sealskin with
relation to field length of seal 76
13. Trade classification of raw, salted, male sealskin with
relation to over-all dimensions 78
14. Trade classification of finished, male sealskin with rela-
tion to over-all dimensions 78
15. Length of ear from notch, by age and sex 78
16. Yield of oil from fur seals 79
Appendix A — Color notes 81
Silver pup, male 82
Silver pup, female 83
Yearling, autumn, male 84
Yearling, autumn, female 84
Three-year-old, adolescent male (bachelor) 85
Three-year-old, adolescent female (young cow) 86
Adult male (bull) 86
Adult female (old cow) 87
Appendix B — Glossary 89
Plates 1-112 95-206
The midsummer population of northern fur seals, Callorhinus ursinus,
is estimated at 1,978,000. Of this number, 1,800,000 or 91 percent, origi-
nate on the Pribilof Islands. The Pribilof herd is capable of yielding
80,000 to 100,000 sealskins a year.
The pelage of the adult seal is composed of clearly defined bundles,
each with a coarse guard hair and 35 to 40 fine underfur hairs ; there
are more than 300,000 fibers to the square inch. Each guard hair is
accompanied by a sweat gland and two large sebaceous glands. Area
of the haired surface of the body of the adult male is about 2.5 times
that of the female.
The pelage of the pup resembles that of certain land carnivores in
having small, scattered bundles, each containing 1 to 3 fibers, some of
the fibers being underhairs and some overhairs (guard hairs). The
first molt, from black birthcoat to silvery, adult-type molt, occurs about
mid-September, the second in August of the following year (on the
yearling), the third in September of the following year (on the 2-year-
old), the fourth and subsequent molts in late September or October.
The molt in the adult takes 4 or 5 months. Molting has little effect on
the commercial value of a sealskin, provided the skin has been taken
Dominant color of the adult pelage is light brownish gray ; most seals
are darker on back and chest, lighter on belly, throat, and sides. Color
patterns of the sexes are indistinguishable up to age 2 or 3 years ; color
patterns of seals from American and Asian waters are indistinguishable.
Colors are brighter (less brownish) in winter when the seal is at sea
and has completed its autumnal molt.
In addition to mutant color phases such as albino, piebald, and choc-
olate, one may see atrichia, pediculosis, pachyderma, and other skin
disorders ; and foreign growths, including marine algae and barnacles,
on the guard hair.
The flippers are naked. The only functional claws — used exclusively
for grooming the pelage — are on the middle three digits of each hind
flipper. The blubber on the fur seal is thinner than on phocids or hair
seals. From a fur seal weighing 66 pounds about 0.6 gallons of blubber
oil can be rendered.
Frontispiece. — Fur seals on breeding grounds, 5 July, shortly before height of
pupping season. Harem bull in background ; cows and newborn pups in fore-
ground. Adults are in old pelage, about ready to molt. (2824)
The northern fur seal, Callorhinus ursinus (L.), breeds on islands
of the North Pacific Ocean and adjacent seas. The midsummer, or
maximum seasonal, population is estimated at 1,978,000 animals; of
this number, about 1,800,000, or 91 percent, originate on the Pribilof
Islands of Alaska. Since 1867 the United States Government has
acted as custodian of the Pribilof herd and has regulated the taking
of sealskins for market. In 1958 the Pribilof herd produced 78,919
skins. It is quite certainly capable of producing 80,000 to 100,000
skins a year, the quantity depending partly on man's selection (by age
and sex) of the animals to be cropped and partly on natural fluctuation
in birth rate and mortality of seals.
During its 90-year regime, the Government has sought increasingly
to understand the zoology of the fur seal, the better to manage the
seal population as a national and international resource. However,
with regard to the fur-seal pelage — the basis of production — no sus-
tained effort to obtain zoological information was made until recent
years. In 1940, Government biologists concerned with management
research on the seal herd began to collect specimens and field notes,
looking toward a report on the growth and replacement of pelage
fibers. The present paper describes certain gross and microscopic
aspects of the pelage in relation to sex, age, and season of year. It
also describes, in a cursory way, other features of the surface topog-
raphy such as flippers, ears, tail, blubber, and mammary glands.
These features of pinniped anatomy are seldom preserved for study,
and when they are preserved they tend to lose their original shape
and color. It has seemed desirable, therefore, to describe and illustrate
certain appendages, soft parts, and subdermal layers of the body
covering in their natural condition. The scope of the present work is
indicated by the table of contents.
For advice in my research, I am grateful to many persons; I would
mention especially Ford Wilke, Chief, Marine Mammal Research,
Bureau of Commercial Fisheries, and Dr. George F. Odland, Clinical
Instructor, University of Washington Department of Anatomy.
World literature on the subject of mammalian hair, especially the
hair of man, domestic animals, and wild furbearers, is voluminous.
On the structure, growth, and replacement of fur-seal pelage fibers,
however, no scientific literature exists, partly because fur seals do not
inhabit North Atlantic waters and have not been available to European
zoologists for study. There are, to be sure, a number of fleeting
references to fur-seal pelage and many popular and scientific accounts
of the general biology of the seal. It may be helpful at this point
to list the more important papers that have contributed a background
to our understanding of fur-seal pelage. These papers will be
referred to later and individually, and will be described more fully
under Literature Cited :
Abegglen and others (1956-58), progress reports of investigations on the
Pribilof Islands; Baker (1957), general account of Pribilof industry; Barthol-
omew (1951), observations of living seals; Bartholomew and Hoel (1953),
breeding habits; Bowker (1931), leather; Clegg (1951), blubber; Fortune
(1930), sealskins; Fouke (1949), sealskins; Fouke Fur Company (1958), popular
account of sealskin industry; Fur Trade Review (1916), sealskins; Jordan and
others (1898), comprehensive account; Mathur (1927), leather; Minato (1949),
blubber; Miyauchi and Sanford (1947), blubber; Partridge (1938), leather;
Pearson and Enders (1951), reproduction; Rand (1956), general biology of the
South African fur seal Arctocephalus pusillus; Scheffer (1949 and later),
various reports touching on pelage and blubber; Scheffer and Kenyon (1952),
general account; Scheffer and Wilke (1953), growth data; Stevenson (1904),
sealskins; Stoves (1958), northern and southern fur seals Callorhinus and
Arctocephalus; Taylor and others (1955), comparisons of Asian and American
fur seals; Terao (1940), leather; Thompson (1950), general account of
Pribilof industry; U.S. Bureau of Fisheries (1916, 1917, 1922, 1938), sealskins
and blubber; U.S. Fish and Wildlife Service (1952-57), sealskins and blubber;
Wilber (1952), freak blubber.
Specimens were collected on the Pribilof Islands, at sea off the
American coast between California and Alaska, and at sea off Japan.
Land specimens were taken in summer and fall, pelagic specimens in
spring and summer, all between 1940 and 1959. Up to about 1949, the
age of an individual seal was estimated from body size ; thereafter from
tooth-ridge counts (Scheffer, 1950 a). It was determined directly
when the seal happened to be wearing a metal tag (Scheffer, 1950 b).
Government biologists have tested various methods of marking indi-
vidual seals for study purposes. The accepted method, now being
applied to 50,000 seals a year, is to fasten a corrosion-proof, individ-
ually numbered metal tag to one of the flippers of the pup. In the
past, as many as 10,000 seals a year were marked by a hot-iron brand
which left a rectangular patch of the skin permanently denuded.
Quick-drying, synthetic-base "traffic" type paint in yellow, blue, or
white, applied with a swab, has been used to mark individuals tem-
porarily in summer. Chemical depilatories have proved to be of no
practical value, since they penetrate with great difficulty the dense,
2-layered pelt of the seal.
Forty fetuses were examined, of which 25 were selected as showing
critical features of growth. About 200 pelts, mostly of known-age
seals, were preserved by tanning and were later studied in the National
Museum collection. Photographs (mostly at scale y 16 ) were taken of
149 of these pelts, and hair measurments were made of 114. In Sep-
tember 1958, on St. Paul Island, I made a special collection of bits of
skin, in formalin, from neck, back, and belly of 76 seals of assorted
age and sex.
More than a million seals have been killed commercially on the
Pribilof Islands since 1940, and their pelts have provided clues not
only to the procession of molt in autumn but also to the incidence of
freaks and diseased individuals in the population as a whole.
On several occasions, starting in 1952, fur seals were brought from
St. Paul Island to the Seattle Zoo. Here they were held in a large,
outdoor, fresh-water pool and were subjected to shearing experiments.
Observations were subsequently made of the rate of regrowth of under-
fur and guard hair. (For one reason or another, the schedule of
observations was often interrupted.) The total number of seals
marked by shearing was eight.
With the exception of color notes recorded in the field, studies of
pelage were carried out in the Seattle office of Marine Mammal Re-
search. As will be explained, the Munsell system of color notation was
used. Under the direction of Dr. George F. Odland, median sections
of skin, stained witli haemotoxylin and eosin, were prepared by Mr.
James Rankin. Slides of horizontal sections were prepared by tech-
nicians of the General Biological Supply House. At one time or an-
other, certain devices and techniques described by the following hair
specialists were used for the present study :
Carter (1039), horizontal sections and follicle populations ; .1. 1. Hardy (1935),
cross sections of hairs by special tool; Hardy and Plitt (1940), casts of
cuticular scales in plastic media; Mathiak (1938), cross sections of hairs by
razor blade; Stoves (1958), many aspects of fiber microscopy; Wildman (1954),
many aspects of fiber microscopy.
GENERAL STRUCTURE OF
THE BODY COVERING
Arrangement of the Body Layers
The layers of the body covering of the fur seal, from the outside in,
are (1) the hairy coat or pelage, (2) the skin proper (the leather of
the tanned pelt), (3) the panniculus adiposus or blubber, (4) the
panniculus carnosus or discontinuous, fleshy sheet of muscle beneath
the blubber, and (5) the tela subcutanea or loose, thin, whitish, con-
nective tissue which binds the skin to the muscles and bones of the
body. The layers are shown in plates 2-8. 1 (Leather technologists
commonly use the term "epidermal area" in a collective sense for all
the strata down to and including the sweat glands, and the term
"corium" for the deeper, fibrous strata. Roddy (1956), for example,
has observed that in most commercial fur skins there is no marked
distinction between "epidermal area" and "corium.")
The area of the haired surface of the body (that is, the surface ex-
clusive of flippers) has been measured on two tanned pelts, as follows :
Adult male, length of pelt 199 cm., area 1.57 sq. m. Adult female,
length of pelt 119 cm., area 0.62 sq. m. In this sample, the male pelt
has an area 2.5 times that of the female. Scheffer and Wilke (1953,
p. 145) had previously concluded that the adult male outweighs the
female about 4.5 times.
To the student of pelage, the two most interesting parts of the body
covering are the skin proper (epidermis, dermis, and sweat glands)
and the pilosebaceous unit (follicle, root and shaft of the hair, and
sebaceous glands). I shall discuss first the skin and second its out-
growth — the hair. (For definitions of technical terms, the reader is
referred to the glossary in appendix B, or to medical dictionaries.)
The Skin: Epidermis, Dermis, and Sweat Glands
Sections of skin from the back region of two 7-year-olds have been
studied in detail (plates 9 and 10). The epidermis is not over 60
microns thick, much thinner than the epidermis of the harbor seal,
reported by Montagna and Harrison (1957, p. 83) as 0.5 to 1 milli-
meter thick over the entire body. In the fur-seal epidermis, the
1 Plates follow page 93.
6 GENERAL STRUCTURE OF THE BODY COVERING
stratum corneum is about 15 microns thick, appearing in 4 to 8 layers,
more or less shattered, on prepared slides. It is sharply distinct from
the underlying stratum malpighii which is 18 to 35 microns thick.
The stratum malpighii consists of a superficial layer 1 to 3 cells deep
in which a stratum granulosum and a stratum spinosum cannot be
distinguished, and a stratum germinativum 1 cell thick. The cells of
the stratum germinativum are more or less columnar, deeply staining;
those of the superficial layer are cuboidal or flattened, faintly staining.
In life, the dermis is 3 to 4 mm. thick. While the dermis, in
general, is thicker in adult animals than in young, and in males than
in females, its follicular (hair root) portion does not vary appreci-
ably in thickness. On 12 slides selected as showing true median
sections with minimum distortion, there is surprisingly little dif-
ference in depth from surface of skin to base of deepest hair follicle,
measured at right angle to surface of skin. In a group of 2-year
males, 2-year females, over-10-year females, and one old bull, the
range in thickness (depth) was 2.0 to 2.8 mm., with an average be-
tween 2.3 and 2.4 Tanned and buffed as "Alaska sealskin," the leather
of a subadult male is less than 1 mm. thick ; tanned as saddle leather,
the skin of a bull seal is about 4 mm. thick.
An apocrine sweat gland is associated with each guard-hair follicle
(plate 11). The gland is sinuous and unbranched. A true median
section may expose 50 of its loops. The secretory portion of the gland
originates deep in the dermis, beneath, and to the rear of, the guard-
hair root. It may start at the 3-ram. level (depth), though more
often above 2.2 mm. The secretory portion is 1 cell thick. The gland
is largest at about the 1.4-mm. level, where a cross section may meas-
ure 80 by 120 microns; it begins to disappear at levels between 1.0
and 0.8 mm. Here it is replaced by the more superficial massed bulbs
of the underfur follicles. The duct of the sweat gland is several
cells in thickness and represents about one-quarter of the vertical
depth of the gland, though, much less than one-quarter of the entire
sinuous length of the gland. The duct rises through the common
follicular bundle at the right or left side, more or less between the
guard hair and the underfur fibers. It. empties into the pilosebaceous
funnel at the surface of the skin, above the twin exits of the sebaceous
glands. Near the surface, the sweat-gland duct has a lumen 10 to
15 microns wide. Here the duct is invested in a heavy epidermal
Early sweat glands, nebulous and more deeply staining than ma-
ture ones — certainly not functional — can be seen at levels between
1.2 mm. and 1.6 mm. below the surface of the skin of the back of
the neck of a full-term fetus. The sweat glands of a molting black
pup, on 1 September, are adult in character.
the skin: epidermis, dermis, and sweat glands 7
When a heat lamp is focused on the naked flipper of a freshly
killed seal, the black epidermis soon begins to blister. Before it does
so, droplets appear on the surface of the skin in a fairly regular
pattern (plate 12). These are assumed to be secretions of the sweat
The survival value of sweat glands beneath the dense pelage of
the fur seal is not clear. Aoki and Wada (1951, p. 123) confirmed
that sweat glands are present in the dog, not only in the foot pads
but also over the body surface covered by hair. Those authors in-
duced sweating both by drugs and by radiant heat. They con-
cluded "that the sweat glands in the hairy skin of the dog do not
participate actively in the central thermoregulatory mechanism, but
. . . subserve chiefly the protection of the skin from an excessive
rise of temperature."
The Pilosebaceous Unit: Follicle, Root and Shaft of the
Hair, and Sebaceous Glands
Details of the main body pelage and vibrissae will be given in the
next chapter. The present account is intended to provide background
information (plates 13-31). The pelage of the fur seal is made up
of bundles or tufts of hairs emerging from the surface of the skin
through a common pilosebaceous funnel and orifice. The hairs are
flattened and are generally directed hindward and downward, thus
contributing to the sleek, streamlined profile of the body. Each hair,
of course, originates in its own follicle. The anteriormost (upper-
most) hair in each follicular bundle is a coarse guard hair, deeply
rooted. Next in rank are 35 to 40 fur fibers arranged in stairstep
fashion, the root of the fiber at the rear of the bundle being nearest
the surface of the skin. The fur hairs originate separately, converge
tightly at the level of the upper dermis, and diverge outside the
body. They rise from the skin at a slope of 10° to 50° from horizon-
tal. The number of follicular bundles per sq. mm. on skin from the
back of adults has been estimated at 11 (on suede leather, plate (>)<
at 17 (on another sample of suede leather), and at 15 (on a horizontal-
section slide, plate 13). Selecting 15 as a reasonable average and
using 38 Abel's per bundle as a factor, it is calculated that there are
about 570 fibers per sq. mm., or 370,000 fibers per sq. in.
The hair follicle is considered by most anatomists to be an invagina-
tion of the epidermis. One can trace the stratum corneum and stra-
tum malpighii deep into the follicle, almost to its base. At the follicu-
lar level, the epidermis becomes the outer root sheath. An inner root
sheath clings for a short distance up the hair root. A connective tissue
8 GENERAL STRUCTURE OF THE BODY COVERING
papilla enters the bulb of the root, while surrounding the papilla are
the matrix cells or germinative cells of the hair.
The hair consists of a swollen basal bulb and a shaft. The bulb and
other buried regions of the hair are termed, collectively, the root. The
shaft is free and is largely outside the body. Listed in order from the
central axis outward, the shaft consists of a vacuolated medulla (ab-
sent in fine hairs) , cortex (usually pigmented) , and cuticle (made up of
overlapping scales). I have been unable to demonstrate arrectores
pilorum, or hair-erecting muscles, in the skin of the seal. Bergersen
(1931, p. 170) could find none in the skin of the harp seal Pagophilu*.
The paired sebaceous glands lie along the sides of, and within, the
common follicular bundle. They attend the guard hair, not the fur
hairs, although their secretion is shared by all members of the bundle.
Each gland originates at about the level of the underfur bulbs, or 1.0
to 0.8 mm. below the surface. The deeper portion of the gland is sub-
divided into 2 or 3 shallow, roundish, irregular lobes. The upper por-
tion is a rather smooth dome. At the level of greatest size, 0.6 to 0.4
mm. deep, the gland may measure 90 by 150 microns. Each gland
pours its secretion from the top directly against the right or left
posterior side of the guard hair, at about the 0.2-mm. level. The
lumen of the duct is 15 to 25 microns wide.
In a full-term fetus, the sebaceous glands are well developed, up to
40 by 70 microns in horizontal section, and apparently are functional.
Most of them are above the 0.5-mm. level.
The principal aims of this chapter are to describe the gross, as well
as the microscopic, aspects of the pelage on representative specimens
ranging in age from fetal to old adult. Since the fur seal exhibits
only two distinct kinds of pelage — the black birthcoat and the silver
adult-type coat — emphasis is placed on descriptions of the black pup
and the silver pup. Color pattern is discussed synoptically ; addi-
tional notes are given in appendix A. Because they represent special-
ized, nonmolting hairs, the sensory vibrissae are discussed last. The
naked, or nearly naked, parts of the body surface are discussed in the
To illustrate changes in the pelage during prenatal life, descriptions
of the hair primordia and hair fibers on 25 selected fetuses are given.
To illustrate changes in the pelage during postnatal life, descriptions
of typical individuals in each of the following classes are given ( where
no sex distinctions can be seen, male and female are treated as one) :
Pelage class of this pelage
black pup, newborn (sexes lumped) 2 weeks (e.g., 15-31 July).
black pup, molting (sexes lumped) 2 months (e.g., 1 August-30 Sep-
silver pup, persisting as yearling, pelagic 11 months (e.g., 1 October-31 Au-
( sexes lumped). gust).
yearling, autumn (sexes lumped) 13 months (e.g., 1 September-30
3-year-old, adolescent male (bachelor) 1 year (e.g., 1 October-30 Septem-
3-year-old, adolescent female (young cow) __ 1 year.
adult male (bull) 1 year.
adult female (old cow) 1 year.
In tracing the development of the pelage, I have usually omitted
reference to body size since growth tables have already been published
by Scheffer and Wilke (1953) and Scheffer (1955). An exception is
made in the case of fetal specimens. It has seemed useful to give
the weight of each fetus, since clearly the prenatal age of the speci-
men from implantation cannot be known. The mean date of im-
plantation is quite certainly in early November, a date that I have
chosen from study of the figures in tables 1 and 2. These tables show
length and weight of 366 fetal seals collected at sea between mid-
10 THE PELAGE
January and the end of June. Dr. D. G. Chapman (personal cor-
respondence) has estimated that, as of 21 November of the preceding
year, the average fetus would have measured : male, 5.4 cm. and 10 g. ;
female, 5.1 cm. and 10 g.
It has seemed useful to give also the relative weight of the fetus,
or its weight in relation to normal size at birth. Scheffer and Wilke
(1953, p. 133, 135) measured 39 newborn seals and reported certain
values. (See bottom row in tables 1 and 2 2 of the present report.)
These values for mean newborn weight are used as reference points in
describing the stage of development of the fetus. For example, a
male fetus of 2.7 kg. is described as "0.50 MNW", or one-half mean
Fetal Stages (Sexes Lumped)
Early stages, between the autumn blastocyst (a pearly sphere barely
visible to the naked eye) and the midwinter fetus (the size of a man's
thumb) are unknown. The height of the mating season is in July.
Three to four months later, the fertilized egg has become the blastula,
at which time it implants in the uterine mucosa (Pearson and Enders,
1951). As just stated, the estimated date of implantation is early
Fetus of 23.7 g. (0.0049 MNW), female, 14 February
This is the smallest fetus available for study (plate 32-A). Most
of the body is smooth. On forehead and crown there is faint but
distinct and regular pimpling. Each pimple marks the site of a hair
primordium beneath the skin surface. With a 5 X hand lens one can
see, through the translucent epidermis, a dark dot in each pimple.
This dot represents a concentration of melanocytes. A regular pat-
tern of dark dots extends along the back, though pimpling of the
surface has not begun here. Elsewhere than on head and back, faint
white dots, visible through the epidermis, mark the sites of primordia
in which the elaboration of pigment has not begun. Collectively, the
dots on the head impart a gray cast ; the rest of the body is whitish.
The primordia resemble those in the skin of a 5-month-old human
embryo (compare Montagna, 1956, p. 180, fig. 5).
Fetus of 103 g. (0.021 MNW), female, 20 January
The skin over the entire body, except flippers and other parts
destined to remain naked, is pimpled. No body hairs have erupted.
Pigmentation is beginning to show on the flippers in the form of
extremely fine, scattered, dark specks. It is heaviest at the base of
each fore and hind claw. It is barely visible on the nostrils.
2 Tables will be found at pages 71-79.
FETAL STAGES (SEXES LUMPED) 11
Fetus of 131 g. (0.024 MNW), male, 25 January
The forehead, crown, and eyelids are distinctly washed with gray.
The nostrils are conspicuously gray. No hairs have erupted.
Fetus of 260 g. (0.054 MNW), female, 19 January
Extremely fine black hairs have appeared on the face, top of snout,
around the eyes, and under the chin (plates 34 and 35). This first
pelage could easily be overlooked if one were not looking for it. The
hairs on the cheek posterior to the mystacial vibrissae are the longest;
those under the chin, the smallest. No external hairs can be seen on
back, tail, or other parts of the body.
The largest hairs are flattened, 1.5 mm. in length, about 12 microns
wide along most of the shaft, up to 50 microns in diameter at the flared
base, heavily pigmented. These are the young, distal portions of
black-pup guard hairs.
Fetus of 312 g. (0.058 MNW), male, 6 February
A few tiny hairs have erupted on the cheeks and above the eyes; the
rest of the body is naked.
Fetus of 372 g. (0.077 MNW), female, 16 February
This fetus was removed from an adult taken at sea and subse-
quently held in cold storage for 8 days (plate 36). On a photograph
of the fetus in storage, the head and flippers appear darker than the
rest of the body. This seems to represent the beginning of conspicu-
ous pigmentation, although it may be, instead, dark blood beneath the
thinner-skinned parts of the body.
Fetus of 454 g. (0.084 MNW), male, 15 February
A few hairs on the cheeks only.
Fetus of 575 g. (0.11 MNW), male, 13 February
At first glance, a naked fetus, though close inspection reveals fine
hairs over most of head and throat. The head and flippers are defi-
nitely darker than the rest of the body.
A horizontal section from the back of the neck of this fetus is shown
in plate 37. It exhibits a regular pattern of hair follicles, about 10
per sq. mm., each with a faintly pigmented hair. Some follicles reach
a depth of 0.5 mm. Scattered among them, and outnumbering them
10 to '20 times (depending upon how the count is made), are small,
dark primordia without hairs.
The hairs in their present stage of development cannot be identified
as the tips either of guard hairs or underhairs. Some may, in fact,
be lanugo hairs destined to be shed before the birthcoat is complete,
4 to 5 months hence. Quite certainly each marks the site of a perma-
553006 0—62 2
12 THE PELAGE
nent follicular bundle. And certainly additional bundles will appear,
since the bundles of the birthcoat are four times more abundant than
are the hair follicles of the present fetus. (Compare plates 37 and
The small, dark primordia shown in the fetus of plate 37 are dis-
tributed singly or in clusters of 1 to 4. When in clusters, they are
aligned with the long axis of the body, the anterior primordium being
the largest. I do not know what these primordia represent. They
are most likely very early stages of the birthcoat underhairs, or se-
baceous glands (which will appear in the birthcoat), or a combination
of the two.
Fetus of 580 g. (0.11 MNW), male, 31 May
This individual may have implanted very late in spring for, though
taken in late May, it resembles a February fetus. Vellus over entire
body, except palmar and plantar surfaces of flippers; well developed
only on head. The heaviest pelage is on each cheek posterior to the
mystacial vibrissae. Here the effect is of a smoky gray wash on the
side of the face. The blacker, heavier hairs are young guard hairs
up to 40 microns wide at the base, distinctly medullated. The vellus
fibers are young underhairs.
Fetus of 595 g. (0.12 MNW), female, 6 February
Hairs barely visible over body ; head well haired.
Fetus of 660 g. (0.14 MNW), female, 15 February
Hairs over entire body (plate 38-A) .
Fetus of 1.09 kg. (0.20 MNW), male, 25 March
Vellus has appeared on ear tips, giving a grayish cast.
Fetus of 1.19 kg. (0.22 MNW), male, 30 March
The pelage of the head has extended to the extreme tip of the
snout. On the upper surface of the fore flipper, one can clearly dis-
tinguish the haired (proximal) and nearly naked (distal) surfaces.
A 5X lens, however, reveals fine vestigial hairing over the distal por-
tion, destined in the adult animal to become naked. The bases of
the mystacial vibrissae are hidden in the dense pelage of the face.
Fetus of 1.11 kg. (0.23 MNW), female, 23 March
The ears are well haired and gray along their full length. The
blades of the guard hairs, which contribute virtually all of the black-
ness of the birthcoat, are now emerging from a background of young,
whitish underhairs. On the palmar and plantar surfaces of the flip-
pers, especially near their edges, one can discern a few fine hairs,
destined to disappear at birth.
FETAL STAGES. (SEXES LUMPED) 13
Fetus of 1.23 kg. (0.23 MNW), male, 27 March
The ears are thinly haired, whereas on a smaller specimen the ears
are thickly haired.
Fetus of 1.42 kg. (0.26 MNW), male, 22 March
The only conspicuous pelage is that of the crown and face.
Fetus of 1.45 kg. (0.27 MNW), male, 11 August
Prematurely born, found dead on St. Paul Island. The face, crown,
and ears are very dark gray. The upper surface of the fore flipper is
covered with distinct vellus, most of which will be retained up to the
normal time of birth.
Fetus of 1.45 kg. (0.27 MNW), male, 25 March
Although of same weight as the preceding one, this fetus is 39 cm.
in length as against 37 cm. (plate 39). A faint gray streak has ap-
peared along the back and around the base of the tail, marking the first
appearance of regularly spaced, coarse, dark guard hairs.
Fetus of 1.70 kg. (0.35 MNW), female, 12 April
The dark streak has spread along the back and rump. Growth has
been backward from the head and forward from the tail, leaving
an area on the back where the streak is less prominent. The face is
now handsomely marked with dark and light zones (plate 41-A).
Fetus of 1.93 kg. (0.36 MNW), male, 2 April
Generally speaking, the fetus is gray (plate 38-B). The head and
base of tail are dark gray. The pattern of dark guard hairs against
lighter underhairs, giving the effect of a dark wash, has spread down-
ward from the back to the flanks.
Fetus of 2.21 kg. (0.41 MNW), male, 2 May
The dark effect caused by coarse guard hairs has spread to the under
part of the body only at chin and throat (plate 40). The pelage has
been slowest to develop on the posterior region of the chest, between
the fore flippers. A few white-tipped guard hairs show on the
cheeks and sides of the head, behind the ears. Whereas many mam-
mals are marked with a dark streak along the back, the fur seal
exhibits a dark streak for a short time only, while the fetal guard
hairs are erupting.
Fetus of 2.27 kg. (0.47 MNW), female, 21 April
The dark guard hairs are approaching the chest.
Fetus of 2.72 kg. (0.50 MNW), male, 21 April
A fur seal delivered on the the breeding ground at this stage would
probably survive. (An aborted fetus of 1.59 kg, was seen alive on !*'>
14 THE PELAGE
July and was picked up dead on the following day.) At first glance,
the fetus would be called black. The black guard hairs are now
distributed over the entire body, though thinly on the chest, which
remains light colored. White hairs surrounded the penial opening,
especially its posterior margin.
Fetus of 2.44 kg. (0.51 MNW), female, 21 April
A transverse zone of gray persists on the posterior part of the chest,
between the flippers (plate 42). Coarse, black guard hairs are show-
ing for the first time here, starting along the midventral line.
Fetus of 3.43 kg. (0.71 MNW), female, one of twins, 9 May
All black, well haired, with a sprinkling of white hairs on sides of
neck and throat, on posterior part of belly, and in armpits (plate 43).
Vellus persists on the dorsal surface of the fore flipper.
Black Pup, Newborn (Sexes Lumped)
SYNOPSIS OF COLOR PATTERN
At first glance, the pup appears to be all black (plate 44). Above,
the coat is glossy black with a few scattered white hairs on forehead
and on neck behind ears. Corners of mouth may be stained brown-
ish by bile. Below, black, though stained brownish soon after birth ;
slightly paler (very dark gray) on posterior region of belly. Scat-
tered white hairs on throat and along lower lip, white crescentic spot
at each armpit ; white spots about 1 cm. in diameter at sites of 4 mam-
mary teats in both sexes, at penial opening, and at ventral margin of
The hair slope or "set" of the hair is hindward and downward from
the snout at all stages of development of the fur seal. In related
species, however, the birthcoat may have an attractive moire pattern.
I have examined tanned pelts of the newborn Steller sea lion Evmeto-
pias jubata exhibiting a hair pattern somewhat like that of lamb, kid,
or pony. Photographic reproductions by Samet (1950, p. 356) show
that the pelt of the newborn South American sea lion Otaria byronia,
the "tropical seal" of the fur trade, also has a rippled pattern.
SYNOPSIS OF PELAGE FIBERS
In order to make a distinction, I use "underhair" for the fine-fibered
layer of the juvenile coat and "underfur" for the homologous layer
of the adolescent and adult coats.
The black coat is the first pelage. It is mature (prime) at birth
and can be plucked rather easily with one's fingers. Traces of it per-
BLACK PUP, NEWBORN (SEXES LUMPED) 15
sist for 2 or 3 months after birth, that is, from mid-July to end of
September, by which time it has been replaced by the pelage of the
silver pup, autumn.
The black coat is a temporary body covering;, quantitatively as well
as qualitatively different from the adult coat. While both juvenile
and adult pelages include an overlayer of guard fibers and an under-
layer of fine fibers, the sizes and proportions of the fibers in the coats
of pup and adult are materially different. For example, the under-
hairs of the black coat are so thinly distributed that the newborn
pup may become soaked to the skin in driving rain, while the underfur
of the adult coat is dense and water-repellent.
The black pelage has a light brownish gray basal zone merging
gradually with a deep brownish black terminal zone. The two zones
are about equal in width (depth). The lighter effect is contributed
by the almost colorless underhairs, plus the pale shafts of the guard
hairs. The darker effect is contributed by the heavily pigmented
blades of the guard hairs. White-tipped guard hairs are rare. A
sample area the size of a man's hand, for example, may contain none
The pelage contains 75 to 80 percent underhairs (shorter, finer,
and more wavy) and 20 to 25 percent guard hairs (longer, coarser,
and stiffer). Measured as they lie in the pelage, the mean lengths
of the fibers are shown in table 8. The underhairs are a mixed lot
(plate 45). Their tips line up in a ragged rank difficult to measure.
In length, they range from 6 to 15 mm. The finest and most abundant
ones are fur-like, slender, wavy, without blade, and almost without
medulla. The largest ones are miniature guard hairs. The under-
hairs intergrade completely with the smallest guard hairs. Between
the largest underhairs and the smallest guard hairs, however, there
is a fairly distinct break in size, though not in shape and structure.
All of the hairs are attenuated at the root, showing that they have
ceased to grow. The root tends to be roundish in cross section, while
the older portions of the shaft are distinctly flattened. All of the
fibers taper to sharp points some to less than 1 micron, near the
limit of resolution. All of the fibers contain brown pigment in vary-
A horizontal section from the back of the neck of a full-term fetus
is shown in plates 46 and 47 (A and B). The follicular bundles are
arranged in a honeycomb pattern, about 40 to 45 per sq. mm. Each
bundle is embedded in a complex web of connective tissue. Each
bundle is seen as a circle of epidermal tissue (with deeply staining
nuclei) surrounding 1, 2, or ') hairs. One's are least common; two's
are most common. The hair nearest the anterior edge of the bundle
16 THE PELAGE
is always the largest and is a guard hair. The hairs nearest the pos-
terior edge of the bundle may be either underhairs or small guard
hairs. At superficial levels, to a depth of less than 0.1 mm., the hairs
are separated from each other within the bundle by a thin, translucent
corneal layer. Immediately below, the nucleated root-sheaths begin
to appear. Each hair root, with its sheath, is independent until it
leaches the common pilosebaceous opening; near the surface of the
skin. The hair roots sink to a depth of about 1 mm. At the posterior
side of the follicular bundle, a group of deeply staining cells may be
seen (plate 47-A). Each is the upper part of the structure which
will, in late summer, become the adult-type underfur bundle of the
silver pup. At depths of 0.6 to 0.8 mm., the primordia of underfur
follicles are active (plate 47-B). The follicles are taking; shape be-
tween, and posterior to, the mature underhairs or small guard hairs
of the black-pup pelage. Among the ordinary pup hairs, one can
occasionally see a giant guard hair with root sheath up to 250 microns
in diameter. Such a hair is a "premature'' adult-type guard hair.
In many stages of the fetus, one is able to see an occasional hair of
GUARD HAIRS: LARGER EXAMPLES
Slight differences between these and the guard hairs of the adult
seal will be pointed out on page 20. A sample fiber, length 17.5 mm.,
bends backward at a point about 8 mm. from the tip. The basal half
is nearly straight and is light gray : the terminal half or blade is nearly
straight and is deep brownish black. The fiber is strongly flattened
except at its root, which is attenuated and roundish in cross section.
The tip is about 0.8 mm. in length, very sharp. The blade is about
8 mm. in length and 18 by 157 microns in cross section. The cross-
section shape is crescentic, with the concave side facing posteriorly.
The shaft is flattened-elliptical in cross section, 25 by 82 microns. The
basal region of the shaft is slightly wider, 80 microns. The root is
25 by 42 microns and tapers toward the base.
The pigment is brown, distributed in fine, barely visible granules
in the cortex along most of the shaft, becoming much heavier in the
blade. Here it is intense brownish black, evenly distributed through
the cortex, both in grains and in little packets of grains aligned with
the long axis of the fiber. The tip of the fiber is distinctly pigmented ;
the root is clear. (The next crop of fibers, the replacement crop, will
consist of adult-type guard hairs, most of them white-tipped.)
A medulla is absent from the tip. About 0.8 mm. from the tip, a
blade with a conspicuous, unbroken (medium wide) lattice type of
medulla begins to appear. The medulla continues to the basal end of
the blade, where it becomes broken for a distance of 1.5 mm., then
BLACK PUP, NEWBORN (SEXES LUMPED) 17
again unbroken. Where the main part of the shaft is 82 microns
wide, the medulla is 53 microns wide. The root is without medulla.
The cuticular-scale pattern at the tip is coronal, irregular, margins
smooth. It resembles the pattern of the underhair tip. The pattern
of the blade is waved, irregular, margins smooth to rippled, near. The
main part of the shaft is diamond petal, margins smooth.
GUARD HAIRS: SMALLER EXAMPLES
These are small shield fibers varying in length from 10 to 15 mm.
As compared with the larger guard hairs, they are more flexible, wavy,
and slender. They have a shorter, less conspicuous, and narrower
blade, They usually have a swollen base which the large guard hair
does not possess, and the medulla tends to be broken rather than un-
broken. The color of the blade is brown, elsewhere the hairs are pale
gray. The tip is finer, more attenuated, than on the larger guard
On a typical small guard hair 13 mm. long, the blade is 4 or 5 mm.
long, with a cross section 16 by 71 microns. The cross section is more
elliptical, less crescentic, than in larger guard hairs. Cross sections
of the shaft (main part), shaft (basal region), and root are, respec-
tively : 16 by 46, 28 by 68, and 18 by 24 microns. Thus, the basal
region is nearly as wide as the blade.
Pigment is distributed as in the larger guard hairs, though more
sparsely. It starts in the tip, is heaviest in the blade, is lightest in
the shaft, and is absent from the root.
A medulla is absent from the tip and terminal part of the blade;
broken (interrupted) narrow in the widest part of the blade; broken
(fragmental) in the basal part of the blade; gradually increasing
toward the root until it becomes unbroken (medium wide) lattice, as
in the shaft of the large guard hair. A medulla is lacking in the root.
The scale pattern is diamond petal, margins smooth, along most
of the shaft, as it is on the larger guard-hair shaft. On the blade,
it is more nearly wide, irregular petal. Little distinction can be
made between the patterns of a small and a large guard hair.
The following description applies to the abundant fine hairs and
not to the less abundant coarser hairs which resemble guard hairs.
The underhairs are strap-shaped, clearly spiral, making 2 or 3 com-
plete waves (as viewed in one plane), slender, and without blade.
They range in length from 6 to 10 mm. The terminal one-third of
the underhair fiber, corresponding to the blade of the guard hair,
is pale golden brown; the basal two-third nearly colorless.
18 THE PELAGE
The tip is long and slender; blade absent; shaft cross section 12
to 14 by 20 to 22 microns, changing but little in size along its length.
The basal region, however, is distinctly swollen, to 24 by 40 microns.
The root is extremely slender, 8 by 10 microns.
Pigment, in the form of golden-brown grannies, flecks, and streaks,
is plainly visible in the tip in the terminal one-third of the fiber.
It gradually becomes paler and more diffuse toward the base. A few
granules can be seen even in the root.
A medulla is present only in the swollen basal portion of the shaft.
Here, where the shaft is 36 microns -wide, the medulla is 20 microns
wide, unbroken (medium wide) lattice. This section of medulla is
joined on both ends by a short section of broken medulla.
The cuticular-scale pattern is coarse pectinate near the tip, diamond
petal, irregular, along most of the shaft; diamond petal, regular, on
the basal swollen part. The scale margins are smooth.
Black Pup, Molting (Sexes Lumped)
The coat is brownish black, beginning to pale on face, flanks, and
belly; coarser and duller than on the newborn (plates 48 and 49).
Dorsal aspect: generally dark grayish brown (Munsell 5 YR 2/1) ;
paler on top of snout, upper lip, and flanks. Many hairs on crown
and back of neck are white or white-tipped. Bases of flippers are
assuming the deep-brown color of the adult. Ventral aspect : gen-
erally dark grayish brown (5 YR 2/1) ; paler on lower lip, chest (but
not throat), and belly. Armpits, around mouth, and around penial
opening stained dark orange yellow (7.5 YR 6/6) ; posterior region
of belly stained brown; whitish spots at the mammary teats still
risible in some specimens.
A brief description only will be given of the fibers of the transition
stages between black pup (newborn) and silver pup (plate 50). On
the back pelage of a female taken on 11 August, weight 9.3 kg. (20i£
lb.) adult- type underfur fibers and guard hairs are beginning to
appear among the pup hairs. A fur buyer would say that the new
pelage is starting to "peep," or that the pelt is in the "peepy" stage.
Many underfur fibers — fine, nonmedullated, and in bundles — have
moved up to the level of the pup underhair tips. Slightly below
them, adult guard hairs have moved out in even rank, their pigmented
blades collectively giving the effect of a distinct dark-gray band at
the base of the pelage. This band is 4 mm. wide. Where the bases
of the pigmented blades are still buried in the skin or leather, they
show as black vertical streaks.
On the crown of a female killed 22 September, weight 12.2 kg.
(27 lb.), the shedding black pup hairs contrast sharply with the new
crop of white-tipped guard hairs.
SILVER PUP (SEXES LUMPED) 19
On the back pelage of a male taken on 29 September, weight 14.7
kg. (32% lb.), the fall molt is nearly complete. In thickness and
resiliency, as judged by one's fingers, it ranks between the pelage
of the black pup and the silver pup. Underfur is thin. Adult-type
guard hairs have almost completely replaced pup overhairs. A few
unshed pup hairs show like black tree trunks in a forest of light
underfur. The surface of the pelage now has a pepper-and-salt effect
imparted by the white tips of the guard hairs. The dark band seen
in the 11 August specimen has moved out beyond the underfur. The
leather is paler, now that the guard-hair blades have passed through
it. While at the surface of the skin no fiber of any kind contains
pigment, intensely black pigment groups can be seen at the papillary
level of certain fiber roots, showing through the translucent leather.
These groups probably represent melanocytes of the forthcoming
crop of fibers.
Silver Pup (Sexes Lumped)
SYNOPSIS OF COLOR PATTERN
Dorsal parts rather uniform dark gray; face with conspicuous
"mask"; armpits and rump patches pale (plates 51 and 52, A and B).
First appearance of rump patches; light-colored streaks, each about
3 by 8 cm., extending forward from the level of the knee. On ventral
side, pale belly and anterior region of chest contrast with dark throat
and posterior region of chest. Underfur silvery gray. Sexes indis-
tinguishable on basis of color pattern. (Further details are given
in appendix A.)
SYNOPSIS OF PELAGE FIBERS
From the black coat — its predecessor — the silver coat differs mainly
in having underhairs, now called underfur fibers, which are longer.
curlier, paler, and in definite bundles: guard hairs somewhat shorter
and mostly white-tipped. From the autumn yearling coat — its suc-
cessor — the silver coat differs mainly in having underfur fibers which
are whitish rather than cinnamon-colored, and are straighter, less
A strip cut from the back of the silver pup shows a whitish layer
of underfur 11 mm. wide, topped by a black band 5 mm. wide (rep-
resenting the guard-hair blades) and a white band 1 mm. wide (rep-
resenting the guard-hair tips). The underfur fibers are twisted in
5 to 7 gentle waves. The pelt has a pepper-and-salt appearance.
On the living animal, the guard hair does not readily part itself
to show the underfur. On the black pup, by contrast, a driving
rain may part the thin black overcoat, revealing the light underhair
20 THE PELAGE
as a streak from forehead to rump. Measured as they lie in the
pelage, the mean lengths of the fibers are shown in table 3.
The fiber population consists of underfur fibers about 97.5 percent,
small guard hairs 2.25 percent, and large guard hairs 0.25 percent.
The underfur fibers are very distinct from the large guard hairs.
The small guard hairs resemble the underfur fibers in size, the large
guard hairs in structure. Since the small guard hairs stand alone
rather than in bundles, are medullated, and have a blade, they are
clearly to be regarded as guard hairs rather than underfur fibers.
In a mid-October specimen, all fibers have attenuated roots, though
they are still growing.
GUARD HAIRS: LARGER EXAMPLES
These important hairs are responsible for the over-all effect of
color, texture, and pattern of the seal's coat. Judging from photo-
graphic illustrations by Wildman (1954), fur-seal hairs resemble most
closely those of the American mink (Mustela vison) and ths Asiatic
mink or kolinsky (M. sibirica), somewhat less closely those of the ot-
ters (Lutra sp.). The large guard hairs of the silver pup and adult
fur seal closely resemble, in size and structure, the large overhairs of
the black pup. Differences are minor. For example, the pup over-
hair tapers more suddenly to a point and is pigmented to the tip ; the
adult guard hair tapers more gradually and usually has a colorless tip.
A large specimen is 22 mm. long, flattened, nearly straight in dorsal
or ventral view, bent backward near the middle in side view. The
bend is at a point one-third to one-half the distance along the shaft
from the tip. The terminal one-third of the shaft is widened into a
blade. The basal half is colorless, the terminal half (except for tip)
is brownish black.
The tip is 1.5 mm. in length and very sharp. The blade is 8 to 10
mm. in length, and has a flattened elliptical (boat-shaped) cross sec-
tion whose diameters are 35 by 158 microns. The main shaft cross
section is 32 by 118 microns. The shaft is nearly uniform in width,
or slightly smaller toward the base. The root is 0.8 to 1.0 mm. long
and 32 by 55 microns in diameter.
Pigment is in granules and longitudinal streaks, evenly distributed
throughout the medulla. It is absent in the terminal 1.5 mm. Toward
the middle of the blade, it becomes intense brownish black, obscuring
most other structures. It is absent from the basal half of the hair.
The tip is nonmedullated. In the blade, the medulla is conspicuous,
unbroken (medium wide) lattice; 65 microns wide where the blade is
118 microns. It becomes broken (interrupted) near the middle of the
shaft, below the blade; then gradually increases in importance toward
the base. At the base, it is unbroken (wide) lattice, 85 microns wide
where the shaft is 114 microns. The root is nonmedullated.
SILVER PUP (SEXES LUMPED) 21
The cuticular-scale pattern is similar to that of the small guard hair
just described. Where the scale margins are slightly crenate to
smooth on the smaller hair, along tip and blade, they are crenate on
the larger hair. The transition region at the base, between petal and
mosaic, is 0.4 to 0.5 mm. in length.
GUARD HAIRS: SMALLER EXAMPLES
Small guard hairs are clearly distinguished — for example, by pres-
ence of medulla and by solitary position — from underfur fibers. (In
the black-pup coat, it will be recalled, small guard hairs intergrade
with underhairs.) Small guard hairs outnumber the large ones by
about 10 to 1, but are less conspicuous because of their inferior posi-
tion, narrower width, and paler color. A typical small guard hair
is 14 mm. long, strap-shaped, with 4 or 5 gentle waves, a distinct
but narrow blade along the terminal one-third of the shaft, and a
slightly swollen base. It is mainly colorless, with brown pigment
beginning about 11 mm. from base, becoming deep brownish black
in blade, paling toward tip, giving the effect of a colorless tip about
The tip of the hair is very sharp. It increases in size for a distance
of 0.2 to 0.3 mm. toward the blade. The blade is about 3 mm. long,
with cross-section diameters 14 by 90 microns; cross-section shape an
ellipse flattened on the posterior side. The main part of the shaft
has cross-section diameters 14 to 18 by 30 to 35 microns. The basal
one-third of the shaft is thicker than, and nearly as wide as, the
blade, or 25 by 70 microns. The root is 1.0 to 1.2 mm. long, with
cross-section diameters 15 by 20 microns.
Pigment granules and streaks, evenly distributed in the cortex,
begin about 0.2 mm. from the colorless tip. Pigmentation becomes
intense, though never as intense as in large guard hairs, in the middle
of the blade, about 1 mm. down from the tip. Pigment granules
gradually disappear below the middle of the shaft. The basal half of
the shaft is colorless.
The medullary pattern varies with the size of guard hair. In a
14-mm. hair, the medulla is lacking in the tip. It is broken in the
blade, disappears in the middle third of the shaft, and becomes con-
spicuous, unbroken (wide) lattice toward the base. At a place where
the shaft is 53 microns wide, the medulla is 40 microns.
The cuticular-scale pattern at the tip is coronal to irregularly waved
mosaic, margins smooth (compare Wildman, 1954, fig. 102d, mink).
On the blade, it is irregularly waved mosaic, margins slightly crenate
to smooth (compare Wildman, 1954, fig. 94b, kolinsky). Along the
shaft, it is diamond petal, margins smooth (compare Wildman, 1954,
fig. 99a, otter). It changes rather abruptly along the basal 0.3 to
22 THE PELAGE
0.4 mm. of the shaft to irregularly waved mosaic, margins smooth,
on the root (compare Wildman, 1954, fig. 94b, kolinsky).
These are strap-shaped, twisting in many planes, slightly wider
and thicker in terminal third than in basal third, nearly colorless
along basal two-thirds and pale brown along terminal one-third ; cross
section more roundish near base, more elliptical in terminal one-third.
They are in bundles of 35 to 40. They stand slightly posterior to the
The tip is less than 1 micron wide and about 1 mm. long, with a
gradual taper. The terminal one-third of the fiber has cross-section
diameters 6 to 7 by 12 to 15 microns; the basal one-third, 3 to 4 by
6 to 7 microns. In between, the shaft diameters are transitional in
size. The attenuated portion of the root lies entirely within the skin.
It is virtually without structure; clear, smooth, and 5 microns in
Pigment is distributed thinly and evenly in the terminal one-third
of the fiber in dark-brown granules and longitudinal streaks. Pig-
ment is absent from the basal one-half to two-thirds of the shaft.
When mounted in o-dichlorobenzene, the basal region becomes almost
invisible. (This mountant has a refractive index of 1.552, as com-
pared with 1.548 for keratin.) A medulla is lacking.
The cuticular-scale pattern, starting from the tip, is coronal to
waived mosaic, margins smooth. Along the shaft it is pectinate,
margins smooth. It is similar to that on the underfur fibers of mink
(compare Wildman, 1954, figs. 94c and 102c and d). The tooth of
each scale curls slightly outward, giving the fiber a rather rough
The remarkable ability of the underfur to trap air bubbles and
repel water has long been known. Conrad Limbaugh, a professional
diver, has written (personal correspondence, 1957) of an undersea
observation of a Philippi fur seal off Isla de Guadalupe, Mexico, in
late November :
During our stay, the fur seal became more and more aggressive, occasionally
rushing us with a characteristic spin, emitting strings of bubbles from various
points on its pelt, especially from behind the ears . . . During all activities bub-
bles streamed from various points of the pelt so that the seal left a trail of
Yearling, Pelagic (Sexes Lumped)
The yearling, pelagic, continues to wear the coat of the silver pup,
though with individual fibers now grown to full length (plate 53).
It may be seen in table 3 that, between mean dates of 25 October and
YEARLING, AUTUMN (SEXES LUMPED) 23
22 April, while the silver pup is changing to yearling, the underfur
and guard-hair fibers increase in length 5 or 6 percent.
The first crop of underfur, appearing on the silver pup, is whiter
than all subsequent crops. It may take on a slight brownish stain
in winter, spring, and early summer. The second crop (yearling,
autumn) is definitely more pigmented, more pinkish brown, than the
first. And when the third crop erupts (2-year-old, autumn), it is
cinnamon-colored like that of the adult.
On an emaciated female yearling, weight 5.0 kg. (11 lb.) , taken alive
on the Washington coast about 15 January, the underfur of the back
was pinkish white (Munsell 7.5 YR 8/2), the pelage prime. On an-
other female yearling, weight 9.5 kg. (21 lb.) , taken at sea on 29 April,
the underfur fibers of neck and back were also 7.5 YR 8/2, those of
the belly pinkish gray (7.5 YR 6/2) .
Yearling, Autumn (Sexes Lumped)
Dorsal parts medium gray ; cheeks pale ; mask conspicuous, though
not as distinct as on the silver pup ; anterior region of chest and flanks
pale; chest between flippers distinctly brownish (a variable charac-
ter) ; bases of flippers and adjacent regions of body much browner
than on the silver pup ; belly often distinctly pinkish ; color patterns
of male and female indistinguishable (plates 54 and 55).
As compared with the skin of older animals, the yearling skin seems
more elastic and more lively ; it curls more readily when cut from the
body, and it floats higher on water. The color of the underfur is not
yet as dark as that of the adult. On a male taken 26 September, the
fur is light grayish brown to brownish pink (7.5 YR 6/2 to 7/2), ex-
cept near the bases of the flippers, where it is darker. On a female
taken 3 October, the fur is brownish pink (7.5 YR 7/2).
Three-year-old, Adolescent Male (Bachelor)
Dorsal parts rather uniform brownish gray, relieved by tan cheek
and top of snout ; ventral parts alternate dark on throat and posterior
region of chest, pale on anterior region of chest and belly. The
juvenile mask has almost disappeared; rump patches are beginning
to disappear; crown or "wig" hairs are beginning to lengthen and
stand erect. (See similar pelage in plates 56, 57, and 92.)
Three-year-old Adolescent Female (Young Cow)
Dorsal parts rather uniform brownish gray ; ventral parts relieved
by band of light yellowish brown across chest, along upper lip and
cheek, and on top of snout ; belly grayish brown. Color pattern usu-
24 THE PELAGE
ally indistinguishable from that of the male, though the female tends
to have paler upper lip (mustache line) and throat and never has a
coarse wig. Rump patches are usually present on both male and fe-
male 3-year-olds; are never seen on males older than 4 years; are
occasionally seen on the oldest females.
Adult Male (Bull)
Bulls with clean pelage, resting on clean sand in late summer, give
the impression of gray or dark gray animals. A few individuals are
pale warm gray or brownish ; a few are almost black. As compared
with the female, the adult male has retained only a moderately pale
face, and has attained a light gray mane and wig. Rump patches
have disappeared entirely (plates 58 and 59) .
The specimen described in appendix A was rather monotonous dark
grayish brown ; ventral parts somewhat lighter and browner than
dorsal : face not conspicuously marked ; hairs varicolored over most
of body, giving at close range a pepper-and-salt effect.
The guard hairs of the mane of the adult male are the largest of
any fur-seal hairs except the vibrissae. A specimen hair is 70 mm.
in length with a blade 89 by 240 microns in cross section ; about four
times as long and twice as wide and thick as a large guard hair from
an adult female. While the mane hair is an awn type, the blade does
not flare out as abruptly as on the ordinary guard hair, but is wide
for one-half to two-thirds the length of the shaft. The cross section
of the shaft is, near the tip, ovoid with a concave posterior side; in
the blade, more flattened, though still with a faint concavity; near the
base, cigar-shaped without concavity.
The longest mane hairs are white, without pigment. Medulla is
absent from the base; broken (fragmental to interrupted) along most
of the shaft, becoming unbroken (medium wide) lattice in the terminal
10 mm. When sunlight strikes a white mane hair, it is reflected from
the colorless cortex and the gas-filled cells of the terminal medulla,
giving a halo effect ( plate 59 ) .
Adult Female (Old Cow)
Most adult females are light-colored across face, chest, and belly.
Virtually all have a pale band along the upper lip, from one corner of
the mouth to the other, extending at times to the bridge of the nose,
backward to the cheeks, and above and behind the eyes. A pale streak
along the lower lip is not as bright as that on the upper. Seen from
the front, the face is often mask-like, with black, naked nose in center
and shiny black eye on each side. While some females are monotonous
dark brownish gray, all have a paler face, chest, and belly. Rump
patches are rarely visible. ( Plates 60-62. )
Figure 1.— Sketches representing (left to right) : 2 large guard hairs id front and
side view ; 2 small guard hairs in front and side view, and 3 underhairs or fur
hairs; about X 3. (Above) Birthcoat. (Below) First adult-type pelage, on
the silver pup of autumn. (4186 and 4187)
26 THE PELAGE
Variation in Length of Pelage Fibers With Age and Sex
The data in table 3 suggest that the prime imderfur fibers of the
first crop, on the yearling, pelagic, are about as long as those of sub-
sequent crops. The following changes in mean length throughout
life are noted (7-year-and-older males and 7-year-and-older females,
compared with yearlings, pelagic, sexes lumped) : Male — neck, in-
crease 14 percent in length ; back, increase 10 percent ; belly, decrease 9
percent. Female — neck, decrease 5 percent ; back, decrease 4 percent ;
belly, decrease 9 percent.
With respect to the guard hairs also, one may conclude that the
only real changes with advancing age are those in length of the mane
hairs and back hairs of the male. From yearling, pelagic, to adult the
following changes in mean length are noted : Male — neck, increase 156
percent in length ; back, increase 30 percent ; belly, increase 7 percent.
Female — neck, increase 1 percent; back, decrease 4 percent; belly
decrease 11 percent.
Sex discrepancy in length of pelage fibers first appears during ado-
lescence, in the 3- and 4-year-olds. In 7-year-old and older animals,
the male fibers are seen to be longer than the corresponding female
fibers by the following percentages : Neck — underfur 23 percent, guard
hair 153 percent. Back — underfur 15 percent, guard hair 35 percent.
Belly — underfur percent, guard hair 20 percent, The real relation,
of course, is perhaps between length of pelage and body size, since
the adult male is about 4.5 times as heavy as the female of the same
age (Scheffer and Wilke, 1953, p. 145) .
It has been mentioned that, regardless of age after 2 years and re-
gardless of sex, the follicular or hair-root portion of the skin does not
vary appreciably in thickness from 2.3 to 2.4 mm.
Variation With Season: The Annual Molt
Certain aspects of growth and replacement of hair have been de-
scribed. It will now be helpful to discuss the whole phenomenon
of molt, the autumnal turnover in which the pelage passes by degrees
through "staginess" into "primeness."
In the first molt, the coat of the black pup, newborn, is replaced
by the adult-type coat of the silver pup, autumn. The molt starts
at birth (mid-July), though it does not show on the surface for about
2 weeks. By mid-September about half of the pups, and by mid-
October all of the pups, have acquired a silvery gray pelage which
is nearly adult in character. It is a warm coat that will protect the
VARIATION WITH SEASON: THE ANNUAL MOLT 27
pup during its first migration through the icy waters of Bering Sea
in October and November. An individual termed a "silver pup"
will be designated arbitrarily on the first of January as a "yearling,
pelagic" though it undergoes no change in pelage at this time.
In the second molt, the coat of the yearling, pelagic, is replaced by
that of the yearling, autumn. The two coats are similar. It is believed
that less than half of the members of the yearling age-class reconvene
on the breeding grounds in their second autumn of life. Those that
do, return late in autumn, mostly after the first of October. Members
of all other age-classes return in nearly full numerical strength and
much earlier in the season, from May to August, depending on their
age. Most of the yearlings seen on land in autumn have already
molted into their second adult-type pelage, though growth of the
fibers has not quite ceased.
Shearing experiments carried out on a male and female silver pup
in Seattle Zoo throw light on the second molt. Patches were shorn
by electric barber-clippers on 24 November 1952, when the pelage
was judged to be prime. Length of underfur was 12 to 13 mm. ; of
guard hair 21 to 22 mm. One month later the patches had changed
from whitish to pale reddish brown, and had assumed a faintly
"stubbly" texture. Both changes were probably the result of exposure
rather than of fiber growth. Two months later, on 30 January 1953,
the patches were seen to be unchanged. On 5 July 1953, slight re-
growth of underfur — but not of guard hair — could be seen from a
distance of 6 feet. By 31 July the shorn patches were covered with
brown underfur to a depth of 3 to 5 mm. No guard hair could be seen
or felt. On 4 September, the fur was growing rapidly; depth now
12 to 13 mm., brownish. Sparse new guard hair was starting to
appear. Growth of guard hair was further advanced (20 mm.) on
the male rump patch than on the female shoulder patch (16 mm.).
On 17 September 1953, the male weighed 20.2 kg. and the female
15.4 kg. ; both in good health. "Apparently the underfur is fully —
or almost fully — developed. The guard hair is about half as dense
on the shaved spots as on the surrounding areas" ( K. W. Kenyon.
personal correspondence.). On 26 October 1953, the female died.
The underfur of her shoulder patch was slightly browner than adja-
cent normal underfur and had perhaps not attained its full growth.
On 16 April 1954 (as a 2-year-old, spring), the surviving male was
beginning to lose weight; rump pelage normal; underfur color light
reddish brown (Munsell 5 YR 6/3). On 14 May 1954, he died.
553006 O — 62 3
28 THE PELAGE
In summary, the new underfur started to grow in early July and
was nearly full grown by mid- August. The new guard hair started to
grow about mid-August and was full grown by the end of September.
On the tanned pelts of 17 yearlings killed 7 October to 7 November
1941, there are no black dots, signs of unprimeness, on the leather
side. On the earliest specimen that I saw, taken 26 September, the
pelage appears to be prime, though horizontal-section slides show
clearly that a few new guard hairs and a few fur fibers are still grow-
ing — that is, in certain follicular bundles, both the cylindrical root
of the old guard hair and the elliptical blade of the new guard hair
may be seen (plates 63 to 64), and behind the cylindrical roots of
certain old fur fibers, the elliptical shafts, faintly pigmented, of new
fibers may be seen. On a yearling taken 3 October, the molt is obvi-
ously not complete. About 5 cm. anterior to base of tail a sharp
molt line encircles the body (plate 65). Anterior to this line the
pelage is denser and more silvery ; posterior to the line, thinner, duller,
and browner. Fur hairs are 11 mm. in length and brownish pink on
the anterior region; 5 mm. in length and distinctly brown on the
posterior region. One rarely sees such a molt line on a fur seal.
The lengths of underfur and guard-hair fibers on 20 yearlings,
autumn, are shown in table 3. The fibers on neck and back have in-
creased slightly in length over those of the pelagic coat; the fibers on
belly have increased materially. The belly fibers are, in fact, as long
as they are ever to be on animals of older ages. The belly coat of the
fur seal, including both underfur and guard-hair layers, is relatively
thin over a wide area. ( Why ? )
The third molt is experienced by seals entering their third year of
life, that is, by "two-year-olds" (plates 66 and 67). Two-year-old
males and females, though preadolescent, have now been caught up
in the annual rhythm of return to the breeding grounds in summer.
Whereas the second molt was centered in August, the third is centered
in September. Eight specimen skins taken 20 August to 24 September
are stagy, with short guard hairs and with dark areas on the leather
side of the pelt. As indicated in table 3, the fibers are shorter than on
samples of yearlings and 3-year-olds. One may deduce that most of
the old fur and guard-hair fibers have dropped out of the 2-year pelt by
the end of August.
On St. Paul Island, from 7 to 23 September 1956, a sample of 122
skins from females of all ages was graded for staginess by an em-
VARIATION WITH SEASON: THE ANNUAL MOLT 29
ployee of the Fouke Fur Company. The following numbers of skins
were rejected as being commercially unusable :
Number Number Percent
killed rejected rejected
2-year-olds 8 6 75
3-year-olds 14 7 50
4-year-olds 21 2 9
5-year-olds 9 3 33
6-year-olds 12 3 25
7-year-olds 12 1 8
9-year-olds 3 2 67
10-year-olds 3 3 100
Over 10 years old 8 3 37
All ages 92 30 33
The sample is too small to be very useful. It does suggest that
September molt is more pronounced in the 2-year-olds than in older
It has already been noted that the true cinnamon color of the adult
underfur is first attained at the conclusion of the third molt.
The fourth molt is experienced by the 3-year-olds and is centered
around the end of September. The 3-year-old males contribute more
importantly than any other age-class to the annual yield of sealskins.
Molt during the regular killing season — up to mid-August — has never
posed a technological problem to the fur processors.
On a horizontal section from the back of a 3-year-old male, killed
27 September, about 1 follicular bundle in 10 contains the wide blade
of a newly erupting guard hair. A 3-year-old female shorn in cap-
tivity in early September 1957 had not quite recovered by 7 February
1958. That is, the new growth of autumn 1957 had evidently started
in late August. On the tanned skin of a bachelor killed on 23 Septem-
ber, there are distinct dark, unprime areas. On a 3-year-old male
killed on 27 September 1958, shed underfur was clinging abundantly to
the hind claws.
Records from the period 1874—77, when Pribilof natives were per-
mitted to make autumn "food killings", are of interest here (Jordan
and others, 1898, p. 262, 266, 267, 269) :
Number killed Number found stagy
17 August 134 5
23 August 207 7
7 October 133 All
19 October 176 57
24 October 104 All
31 October 163 All
13 December 825 A few
30 THE PELAGE
The food killings were made largely from the bachelor class. These
records show that molt was conspicuous in the month of October.
There is evidence that growth of the new underfur may begin as
early as July. Annually in summer, from 1904 to 1932, Government
agents on the Priblofs used to mark a few thousand bachelor seals by
shearing the top of the head. Whenever a shorn animal appeared
later in the summer on the killing field it was spared as a "breeding
reserve" (Scheffer, 1950 b, p. 7-8). One year later, however, the
guard hairs had recovered, and at this time the killing crew in-
advertently knocked down a few large bachelors that had been shorn
the previous summer. A veteran Fouke Fur Company employee has
written (personal correspondence) that "after the [marked] skins
had gone through processing and the guard hair had been removed,
it was discovered that the underfur had not grown out to any degree."
On the basis of modern information, this phenomenon can be ex-
plained. For example, young underfur fibers of an individual were
shorn in August 1930. In July 1931 the seal was killed, wearing a
short underfur coat of two components : the stumps of the 1930 season
and the new, short growth of 1931.
The fibers of the 3-year-old (except, perhaps, those of the neck)
are no longer than those of the silver pup and yearling (table 3).
Within, the 3 -year class, the fibers of the female are beginning to lag
behind those of the male.
MOLT IN ADULTS
There is little evidence on molt in adults with relation to calendar
date. Quite certainly, however, it is centered in October, somewhat
later than molt in the 3-year-old. Employees of the Fouke Fur
Company have long recognized that stagy skins are seen more often
in younger males (3- and 4-year-olds) than in older ones (5- and
6-year-olds) at any given time in late summer.
On a 5-year-old female in Seattle Zoo, shorn in early September
1957, the pelage had recovered by 7 February of the following year.
In other words, all of the new fibers erupted after early September.
(The reader will recall that on a 3-year-old companion, shorn and
killed on the foregoing schedule, the pelage had not quite recovered by
7 February because the younger animal had started to grow a new
crop of fibers in August. )
I have examined median sections of skin from adult seals, age 7 years
or older, taken in September 1958, including 2 males and 26 females.
On all of the sections, melanocytes in the guard-hair follicles are still
active. No club hairs can be seen.
In all six hind claws of an old female lying on the beach on St.
Paul Island, 25 September 1958, there were tufts or balls of underfur,
2 to 5 mm. in diameter, scratched from the pelt.
VARIATION WITH SEASON! THE ANNUAL MOLT 31
COMPARISON WITH MOLT IN OTHER FURBEARERS
The phenomenon of molt in furbearing animals has been studied
by Gimn (1932) in muskrat, by Bissonnette (1935, 1942) in ferret and
weasel, by Bissonnette and Bailey (1944) in weasel, by Bassett, Pear-
son, and Wilke (1944) in fox, by Bassett and Llewellyn (1948,1949) in
fox and mink, by Hall (1951) in weasel, by Rothschild and Lane
(1957) in ermine, and by Shanks (1948) in muskrat. Molt begins in
one or several places on the body and proceeds outward in waves.
Most of the fibers along the front of a wave are in the same stage of
molt. (In man, however, molting is mosaic, with new hairs popping
up here and there to replace old ones.) New hair or fur growth is
signaled by a massing of pigment in the follicles. This massing gives
a dark bluish cast to the body side of the pelt. The new hairs erupt
as the old hairs are being shed, although the momentum of new growth
usually carries on for a while after shedding is complete. The stimulus
or triggering mechanism in molt is change in length of daylight,
which stimulates in turn the optic nerve, the anterior hypophysis
(pituitary), and the hair-growth cycle. Melanocytes have already
ceased to function while the hair shaft is still completing its growth
in length. Thus, in a prime pelt, pigment is absent both from the
dermis and from the attenuated base of the shaft. In some species,
molt may be a rather long process ; in the silver fox it begins in early
May, when simultaneously the old hairs start to drop out and the new
ones to appear. (Growth and maturation of the guard hair precede
that of the underfur.) About 4% months later, by mid-September,
the old hair is shed. The new hairs continue to grow, and pigment
continues to leave the skin, until about the first of December, or date
of primeness. In general, the direction of the molt is: legs, rump
and tail, abdomen and sides, back, mane and crown.
Molt in the fur seal is an annual event, as in the silver fox but not
in the mink, where it is semiannual. Molt in the fur seal is rather
slow, requiring 4 to 5 months' time. It is gradual and unobtrusive.
Old fibers are shed singly as the new ones erupt. Thus the seal at all
times has a warm, water-repellent coat. As previously mentioned, a
distinct molt line is not often seen. The molt is not accompanied by
profound changes in the epidermis. In certain phocids (elephant
seal, Weddell seal, and monk seal), great tatters of epidermis peel
from the body along with the newly shed hairs. No pinniped has
more than two fundamentally distinct pelages: juvenile and adult.
The juvenile coat may be shed, for example, in the harbor seal, shortly
before birth. While in some species, the harp seal, for example, the
pelage may molt several times before it assumes its mature pattern,
its only real break in character is with the juvenile coat.
32 THE PELAGE
Rand (1956) has given a good description of molt in the South
African fur seal Arctocephalus pusillus. Molt here seems to differ
from that in the northern fur seal only in the longer time required
for the black birthcoat to disappear. In the pup coat of Arctoce-
phalus, change is not visible until the animal is 2 months old or older,
and the coat persists nearly 4 months. The corresponding periods
for Callorhinus are 6 weeks and 2^2 months. The second molt in
Arctocephalus, between December and February, corresponds to that
of Callorhinus, between June and August. (Incidentally, commer-
cial sealing in South Africa is largely directed against the yearling
animal, 8 to 10 months old ; while in Alaska it is directed against the
3- and 4-year males. )
The Sensory Vibrissae
All mammals, with the exception of man, are reported to have, at
some time in life, special sensory bristles on or near the face. Even
whales may have as many as 80 such bristles, their function sup-
posedly to detect water currents and macroplankton food (Nakai and
Shida, 1948). According to Pocock (1914), the sensory vibrissae
may be classified according to location as mystacial, superciliary,
genal, submental, and interramal. The presence of all five on one
kind of mammal is thought to be primitive. According to Noback
(1951, p. 481), the vibrissae may also be classified as active tactile
hairs, under voluntary control; as passive tactile hairs, not under
voluntary control ; as follicles with a circular sinus ; as follicles with-
out a circular sinus.
In pinnipeds, only the mystacials and superciliaries are retained
(plate 34). In all otariid seals, the superciliaries are unimportant;
in phocid seals, well developed.
I have made only a cursory examination of the vibrissal roots and
surrounding tissues in the fur seal (plates 68, A and B, and 69).
Br0ndsted (1931) gave 7 diagrams of the snout musculature and
innervation of the California sea lion Zalophus, a close relative of
the fur seal. He described the nasal muscle as being "colossal" in
pinnipeds. According to Miller (1952 and in personal correspond-
ence) certain features of anatomy of the dog may (?) resemble
those of the fur seal. In the dog, the vibrissae are moved by two
sets of muscles: levator nasolabialis and, beneath it, maxillonaso-
labialis. The vibrissae are supplied from at least one cranial nerve:
the trigeminal (5th cranial), mixed motor and sensory, leading to
its maxillary division and thence through the infraorbital foramen
to the infraorbital nerve. Whether the facial (7th cranial) nerve,
THE SENSORY VIBRISSAE 33
motor only, leading to the dorsal buccal nerve, plays a part also
PRENATAL DEVELOPMENT OF THE VIBRISSAE
On the evidence of 14 male male fetuses and 10 female fetuses,
the formula for mystacial vibrissae in the fur seal does not vary with
sex or age. On each side of the snout there are 5 or 6 rows contain-
ing (from top to bottom row) the following number of vibrissae:
or 1 ; 3, 4, or 5 ; 5 or ft; 5 or 6 ; 3=20 to 23 (plate 70-A) . The observed
mean total in males is 21.4 and in females 21.1. On all of the fetuses
there are two superciliaries on each side of the head ; the upper one
distinctly longer than the lower.
On the South African fur seal, Rand (1956, p. 10), has found
up to 33 mystacial and 2 superciliary vibrissae on each side of the
head. A common formula for mystacials is: 3-5-6-6-6-4=30. Like
those of Callorhiniis, the vibrissae of the southern seal are black at
birth, later turning white.
Fetus of 23.7 g. (0.0049 MNW), female, 14 February
On this smallest fetus in the collection, the complete vibrissal
pattern is set, though several of the individual bristles have not yet
erupted. There are no visible signs of additional, rudimentary (ves-
tigial) bristles. Vibrissa formula : 1-3-5-5-6-3 = 23. The outermost
(posterolateral) vibrissa in the row-of-six is the longest, 0.8 mm.
The inner (anteromedian) bristles are still beneath the epidermis,
though ready to erupt. Each erupted bristle is sheathed nearly to
its tip in a thick, translucent, tubelike extension of the skin. Black
pigment can be seen in the larger vibrissae. It is likely present
also in the smaller ones though obscured by epidermis. Two super-
ciliaries can plainly be seen as white parallel lines beneath the skin,
each 0.8 mm. in length, about ready to erupt.
In view of the fact that the vibrissae are already well established
on this fetus, far in advance of the guard hairs and underhairs, and
on a body which has attained less than 1/200 of its newborn weight,
one may deduce that the sensory bristles are very important to the
welfare of the seal. Danforth (1925, p. 67) has noted the remark-
able constancy of vibrissae as compared with other body hairs of
mammals, this "being due to their early appearance and the circum-
stances of their embryonic origin."
Fetus of 103 g. (0.021 MNW), female, 20 January
Mystacial vibrissa formula: 0-3^-5-5-3 = 20 (plate 70-A). The
outer (posterolateral) vibrissae in the row-of-four and in t he row-of-
five are the longest, all about 4.6 mm. All of the mystacial vibrissae are
dark brown, almost black. * All but the smallest have whitish tips,
34 THE PELAGE
suggesting that in the early stages of development the fiber starts
to grow in advance of the melanoblasts. The superciliaries have now
erupted and are distinctly unequal, the upper one of the pair meadur-
ing 2.3 mm. and the lower one 1.4 mm. in length. They also are
whitish at the tip.
Fetus of 6.80 kg. (1.3 MNW), male, 20 June
This is a full-term fetus taken at sea on 20 June, actually larger
than many newborn pups. The vibrissae are glistening black, with
the barest suggestion of pale tips on several. The largest vibrissa
is 64 mm. in length, flattened, tapered, and slightly curved. (Vibris-
sae are the only fur-seal hairs that taper all the way from base to
tip.) At the base, the cross section is elliptical and measures 0.39
by 0.55 mm. Halfway along its length, at a point where the vi-
brissa will first fit into the slot of a Hardy sectioning device, the cross
section is 0.28 by 0.33 mm. (plate 69). The pigment is dark brown,
cortical, and granular; mainly in clumps which increase in size and
darkness toward the central axis of the fiber. Toward the periphery,
pigmentation ceases rather abruptly, leaving a clear cortical zone
about 5 microns wide, inside the cuticle. The surface of the vibrissa
is smooth and without scale pattern. In cross section, the cuticle is
seen as a hyaline layer less than 1 micron thick.
POSTNATAL DEVELOPMENT OF THE VIBRISSAE
Measurements of the longest vibrissa on each of 31 newborn seals
are summarized as follows (table 4) : 17 males, mean 62.6 mm.
(51 to 75) ; 14 females, mean 57.4 mm. (52 to 63).
In both sexes, the vibrissae grow most rapidly in the juvenile and
adolescent years, before the end of the third year. On a yearling
male observed in Seattle Zoo during a 6-month period, February
to July, the longest vibrissa increased by 36.5 mm., or at a rate of
0.20 mm. a day. Here is evidence that growth of the vibrissa is not
confined to autumn, as is growth of the pelage proper. On the same
individual in its second year of life, between August and mid- April,
the longest vibrissa increased by 32 mm., or at a rate of 0.12 mm.
a day. The vibrissae are still growing at age 8 and, so far as the
data permit one to estimate, will continue to grow throughout life
( plate 70-B ) . The longest recorded vibrissa on a male is 334 mm. ( 13.1
in.) and on a female 220 mm. (8.66 in.). The record specimens were
old animals of unknown age. The female was extremely large —
weight 60.3 kg. or 134 lb. Comparing the mean values for newborn
pups with selected maximum values for adults, on the assumption
that maximum values represent unbroken and relatively unworn
bristles, one may estimate that the male vibrissa increases to about
5.3 times its newborn length ; that of the female, 3.9 times.
PELAGE ANOMALIES 35
Changes in color of the vibrissae with advancing age have been
studied with the objective of finding a useful age index. On St.
Paul Island in September, I examined vibrissae of 20 freshly killed
males, ranging in age from 4 to 6 weeks (estimated) to very old.
On the black pup and the silver pup, all vibrissae are black (Munsell
7.5 YR 2/0). On the yearling and 2-year-old, many vibrissae are
faded, grayish brown at the tip. On the 3- and 4-year-olds, the
over-all color effect is blackish, though many vibrissae are mottled,
most have faded tips, and a few of the small ones are all white.
Through ages 5, 6, and 7, the color is increasingly whitish, though
a few small, all-black vibrissae may be seen. (The superciliary
vibrissae gradually become worn down to, or broken off to, the level
of the guard hairs, and one can seldom find them on a seal older
than 6 years.) The single, very old bull examined had all-white
mystacial vibrissae — actually pale yellow (2.5 Y 8/4). Paling of
the base of the vibrissa begins when the pigment cells of the follicle
cease to function. Paling of the tip is a result of fading (bleaching) .
In this connection it is interesting to note a statement with regard
to human hair which, like the vibrissa of the seal, is a nonmolting
fiber: "The fact that in rare instances hair can quickly become gray
must be acknowledged . . . The old idea that hair is practically a
dead tissue, cut off from the metabolic influences in the body, must
be forsaken" (American Medical Association Journal, 1943, p. 162).
Graying in man may result either from loss of pigment or from
masking of pigment by gas bubbles in the cortex. Melanin can be
bleached in vitro in the laboratory by ultraviolet radiation. Quite
surely it can be bleached, though more slowly, by sunshine.
The color trend with age in the female vibrissae parallels that in
the male (table 5). The 5-year-old (entering 6th year) exhibits the
greatest variability in color. The vibrissae in about 67 percent of
the 5-year female class can be called "black and white."
In July 1947, I saw mystacial vibrissae being plucked by native
children from 3- and 4-year male seals on the killing fields of St. Paul
Island (plate 71). One lad reported that he gathered about 500 a
day and sold them for a cent apiece. The vibrissae were eventually
delivered to an Oriental broker in San Francisco to be used (it is
said) for cleaning the stems of pipes.
Three mutant color patterns have been observed in the fur seal :
albino, piebald, and chocolate.
36 THE PELAGE
The albino pup has white underhair, guard hair, and vibrissae
(plates 72, 73-A, 73-B, 74). The parts that are black and naked on
the normal pup (flippers, nose, and eyelids) are pinkish gray on the
albino. The pelage becomes stained soon after birth. On a cap-
tive which had completed its first molt into adult-type pelage in the
Seattle Zoo, the pelage on 2 December was reddish brown, or where
brightest it was yellowish red (Munsell 5 YR 5/6) (plate 73-B).
One rarely sees an albino older than a pup. Once or twice each
summer a light-brown bachelor with pink eyes and flippers may appear
in commercial sealing drives. A female albino lived to age 4 years
in San Diego Zoo, while a fully adult female was shot in the wild in
August (plate 74). With regard to incidence of albinism, Edward
C. Johnston (in U.S. Bureau of Fisheries, 1923, p. 112) reported 6
white individuals in approximately 177,000 pups counted. Biologists
on the Pribilofs now see perhaps 5 to 10 albinos each summer out of
500,000 to 600,000 pups born. Observed incidence of albinism is thus
between 1 in 30,000 and 1 in 100,000. According to Green (1947) 6
albinos were reported in 1,672,604 coyotes Canis latrans taken over
a 30-year period. This corresponds to 1 in 278,767.
Piebald (white splotched) seals are seen more often than complete
albinos (plate 75-A). One iris, neither, or both may be pinkish.
White areas may appear on naked parts as well as on haired. A
nearly full-term fetus had an unusual whitish belly, though the white
was not sharply set off as it is on a true piebald. On one peculiar
pup about 1 month old, the eyes and flippers were pink, the underhair
white, but the guard hair grayish brown ( plate 75-B ) . The character
for pigment in guard hair is perhaps distinct from that for underhair ;
further study is needed.
The "chocolate" mutant is named from the appearance of the new-
born pup. I cannot, certainly identify in later life a seal that was
chocolate at birth. Many variations of light brown, silver, and creamy
pelage, combined with normal dark flippers and eyes, are seen on the
breeding grounds (plate 76, A and B) .
EFFECT OF DISEASES, PARASITES, AND PHYSIOLOGICAL
DISORDERS ON PELAGE
The terms "rubbed" and "mangy" are used loosely on the Pribilofs
to describe pelage conditions where the hair fibers are sparse or patchy.
Rubbed areas are seen on seals of all ages and both sexes. Wherever
the guard hair is absent, the underfur becomes soiled and matted.
Occasionally the underfur is also absent and the naked skin is ex-
posed. Little study has been made of such pelage anomalies. Var-
ious degrees of "rub" or loss of guard hair are illustrated in plates
PELAGE ANOMALIES 37
77 (A and B) to 81. From the 6-year-old female illustrated in plate
77-B, samples of abnormal pelage were sent, in formalin and in dried
state, to Dr. Robert W. Menges (U.S. Public Health Service) ; similar
specimens were also sent from another 6-year-old female. Dr.
Menges has kindly advised that no evidence of ringworm or mites can
be found. The diagnosis in one case is "acquired canities" and in the
other "atrophy of skin and alopecia" (personal correspondence,
1959). (See also Menges and Georg, 1957.)
On a male black pup perhaps 2 or 3 weeks old, patches on the
back of the body and neck were hairless, wrinkled, pinkish gray,
with marginal fragments of brown, scabby, loose epidermis (plate 82,
A and B) . Seventeen lice were picked from ears, base of tail, eyelid,
head, and denuded patches. It is presumed that the lice were
scavengers on the denuded areas rather than causative agents in
loss of the hair. While the lice in this case were not identified, two
species have been collected frequently from fur seal pups: Antarc-
tophthirus caUorhini (Osborn) 1899, and ProeoMnophthirus fluctus
(Ferris) 1916. Further study of the environmental preferences of
the two species is proposed.
Murray (1958, pp. 404-405) kept lice from antarctic elephant seals
Miroimga leonina under sea water for more than 2 weeks.
It would appear that oxygen is obtained from sea water by diffusion through
the cuticle . . . Unlike other species of lice, Lepidophthirus macrorhini forces
its way into the skin and creates a burrow under the stratum corneum of
the epidermis . . . When the elephant seal moults the stratum corneum ... is
shed intact with hairs attached. Although some lice are lost at this time
many remain, since only the roof of the burrow which they inhabit is
Pachyderma, or thick skin, was observed on a bachelor killed 3
July (plate 83). Tough, whitish connective tissue had replaced
about nine-tenths of the blubber layer. The workman who tried to
remove the blubber in routine fashion was obliged to reject the skin.
The pelage was normal, the skin about five times thicker than nor-
mal. I am reminded of an ailment of cattle in which the hair is
lost and the skin becomes thick, dry, leathery, and deeply creased
(U.S. Department of Agriculture, 1954). This ailment, often fatal,
is the result of contact with highly chlorinated napthalene in cer-
tain petroleum lubricants. Do seals suffer damage from prolonged
contact with floating oil wastes on coastal waters I
Up to 1956, the skins of old female seals had not been taken
deliberately on the Pribilof Islands. In 1956, substantial numbers
were taken on an experimental basis. It was soon discovered that
skins of old females tend to be of poor fur quality. Both underfur
and guard-hair fibers may l>e uneven in length and insecurely rooted.
38 THE PELAGE
As a result, the pelt after unhairing may present a ragged, splotchy
appearance (plate 84). The causes — presumably physiological — of
poor fur quality in older animals are unknown.
The damaging effect of high temperature on fur seais is well known
to those who work in the sealskin industry. A seal driven too quickly
from beach to killing field, especially on a dry, warm day (60° F.),
may die of heat prostration. Its pelt is subsequently called a "road-
skin." "Temperatures of roadskin seals were between 42.3° and
43.9° C. . . . Seals with temperatures above 42° C. (107.6° F.) are
invariably prostrated or dead" (Ford Wilke and Karl W. Kenyon,
in personal correspondence, 1951 ) . Roadskin seals are flayed as soon as
possible, because about an hour after death the fur fibers loosen in
their follicles and can be plucked with one's fingers; the pelt is then
worthless. Initial processing is accelerated in order to get roadskins
into brine as quickly as possible in order to prevent loss of fur and hair.
Partridge (1938) studied horizontal layers sliced from fresh, shorn
Alaska sealskins. He found that seals driven a long distance from
the beach to the killing field tend to lose lipids from the "epidermal
layer" — actually the epidermis and upper dermis — containing the
sebaceous glands. He recorded percent lipids (of dry weight), as
Seal No. 1 Seal No. 2 Seal No. 4 Seal No. S Seal No. 5 Seal No. 6
Length of drive_ short short short long long (seal died)
Percent lipids.. 16.7 14.2 14.0 13.1 10.8 5.1
A fairly common, perhaps harmless, condition in which the blubber
is reddish orange rather than white will be mentioned on page 60.
From my diary in 1940 is taken a note on disease of the naked
During branding operations in September, we noted that several hundred
pups had warty areas % to y 2 inch in diameter on their flippers. These were
of the same texture as the surrounding skin and were up to % inch thick.
Occasionally a flipper with a small, round, raw sore (originating in such a
wart?) was seen.
Warts or blisters are commonly seen on older animals (plate 85).
Dr. W. J. Hadlow has written (personal correspondence, 1958),
as follows :
On the basis of my limited examination of several cutaneous nodules ... I
conclude that the lesion was formed from elements of the epidermal adnexa,
probably from modified sebaceous glandular elements. The lesion somewhat
resembled the general histologic pattern of the circumanal gland adenoma
of the dog. A striking feature of the seal lesion was the presence of numerous
large, acidophilic inclusions which occupied much of the cytoplasm of some
cells. The nodules developed in the dermis and did not appear to involve
directly the overlying epidermis, which usually was not appreciably altered.
In this respect the lesions are not warts in the true sense of that term.
PELAGE ANOMALIES 39
Abegglen and others (1956, p. 14, 20) found strange circular marks
on the fore flippers of approximately 50 bachelor seals in the
summer of 1956. No satisfactory theory about the origin of the
marks has been offered, although it is generally believed that they
are natural rather than artificial. Raw, circular areas are occasionally
seen on the fore flippers of seals taken at sea. These resemble lam-
prey scai*s, though lampreys would not be likely to attack seals.
An abnormal bachelor was killed on St. George Island in 1949.
The left flipper had apparently been bitten off in infancy, and the
fur had grown over the stump so tightly that when the skin was
blubbered no armhole was apparent on the left side. Biologists in
1947 tagged a pup with only one fore flipper. At the site of the
missing flipper the pelage was intact and continuous. The pup moved
successfully on land by "rock and roll."
Seals, particularly emaciated pups, are prone to suffer an eye in-
fection which reveals itself as a purulent whitish or yellowish dis-
charge. The disease has not been studied.
EFFECT OF SEX ABNORMALITIES ON PELAGE
Upon examination of five cryptorchids (adult males with infantile
testes), it was concluded (Scheffer, 1951) that the pelage tends to
be smooth in texture and uniform in color along the back, as on the
adult female (plate 86). Mane and wig are conspicuously absent,
as is the musky male odor of the body. One cryptorchid was dis-
covered in a harem during breeding season. Its "unmaleness" led
it to be treated as a female by the dominant, male of the harem
(plate 87-A). Its pelt is illustrated in plate 87-B. On another
cryptorchid, estimated age 15 years, a normal brown layer of guard
hair was present at the base of the flippers while underfur here was
entirely lacking. The depth of guard hair on neck, back, and belly
is less than the depth of corresponding guard hair on the normal adult
male (table 3) ; the depth of underfur about the same. The length
of mystacial vibrissae and length of ear are normal. On five cryptor-
chids, the maximum length of vibrissa was 286 mm. (compare table
4). The maximum length of ear w^as 58 mm. (compare maximum 57
mm. recorded for a normal male).
The finding (Scheffer, 1949) of a 4-year-old female with a promi-
nent clitoris and small ovaries has been reported. The tanned pelt of
this individual has no unusual features.
Supernumerary teats will be mentioned on page 53.
Brown algae, red algae, and gooseneck barnacles are occasionally
seen on the guard hair of living fur seals. Epiphytic green algae
40 THE PELAGE
have been reported from phocid seals, though not yet from fur seals.
Foreign growths are more common on seals at sea than on land.
Why do organisms attach to certain individuals but not to others?
Brown algae, Phaeophyceae, Ectocarpus sp. (identified by Dr. G.
F. Papenfuss) : On a female, 2 to 4 years old, nonpregnant, shot near
Farallon Islands, California, 12 December 1948, the pelage appeared
curly and brownish from an extensive growth of Ectocarpus (plate
88). The growth covered most of the body except nose, flippers, and
belly; the parts that are commonly rubbed during grooming activi-
ties at sea. Fragments of the dried plant, light brown in color,
remained on the pelt throughout the tanning process.
Red algae, Rhodophyceae, Erythrocladia sp. ("if not identical with
the species, is closely related to E. polystromatica Dangeard" Papen-
fuss, personal correspondence, 1945) : This plant is of fairly common
occurrence on seals. It gives a rusty, reddish brown tint to the guard
hair. Under a microscope, it has an attractive purplish color and
is seen to be made up of dense clusters or disks closely appressed
to the hairs. The first specimen from a fur seal was collected on a
bachelor seal on St. Paul Island on 2 August 1945. Three similar
collections made 22 June-3 August 1946 were identified by Papen-
fuss as Erythrocladia (polystromatica^.) .
Barnacles, Cirripedia, Lepas sp. (identified by Dr. Dora P. Henry) :
Gooseneck barnacles are seen on perhaps one fur seal in a hundred
taken at sea ; rarely on land. A bachelor killed on St. Paul Island,
18 July 1945, had several hundred barnacles L. hillil Leach attached
to the rump (plate 89) .
An emaciated yearling female, weighing only 6.4 kg. (14 lb.) was
found dead, in fresh condition, near Grayland, Wash., on 11 April
1948. Several hundred barnacles were attached in clusters to the
armpits, hind flippers, fore flippers (base only), and belly. An adult
female, weight 26 kg. (58 lb.) was found dead in the surf near Cape
Shoalwater, Wash., on 27 April 1948. Tufts of barnacles were at-
tached to the armpits. Dr. Henry wrote (personal correspondence)
'"The yearling female has young Lepas and larvae; the adult has
larvae only." The female mentioned previously as having Ectocarpus
growth had also gooseneck barnacles scattered over the body.
The Pribilof Sealskin Industry
HISTORY OF THE INDUSTRY
The Pribilof seal herd has been cropped annually, so far as anyone
knows, since the discovery of the breeding grounds in 1786-87.
Modern, sustained-yield management began with the Treaty of 1911,
THE PRIBILOF SEALSKIN INDUSTRY 41
at which time all northern fur seals were brought under international
protection and the killing of Pribilof seals was undertaken directly
by employees of the United States Government. The Government
now has an interest in all stages of the industry, namely, management
of the stock, cropping, processing, and marketing. The stages after
killing are handled primarily by a private contractor under Govern-
ment supervision (Baker, 1957; Fouke Fur Company, 1958; Scheffer
and Kenyon, 1952 ; Thompson, 1950) .
Previous to 1855 fur-seal skins were in little demand in Europe or America.
The fur was not fashionable . . . About 1825 the unhairing and dyeing of fur-
seal was introduced [by Denison Williams, a capmaker of Albany, N.Y.], and
although the article was very poor compared with the choice product of the
present time, it was a decided advantage over the former methods of dressing.
Between 1855 and 1870, through experiments on the part of Messrs. Oppenheim
& Co., and of Messrs. Martin & Teichman, in London, and of Mr. George C.
Treadwell, in Albany, the methods of dressing and dyeing fur-seal were greatly
improved, resulting in an exquisitely soft and downy texture and rich dark-
brown color, which was quickly adopted by the fashionable world for cloaks,
jackets, muffs, trimmings, etc. So popular did the fur become that the demand
quickly ran up ... to 200,000 during the eighties at greatly increased prices
. . . Since 1870 practically the entire world's product of fur-seal skins has been
sold in London. [Stevenson, 1904, p. 300-301]
No Pribilof sealskins owned by the United States Government were
shipped to London for processing or sale after 1912. On 16 December
1913, the Government began selling sealskins at public auction in St.
Louis, Mo. During World War I, with encouragement from the
Secretary of Commerce, the Gibbins and Lohn Fur Skin Dressing
and Dyeing Company developed a factory in St. Louis for processing
sealskins. The early success of the company was partly the result of
skills brought directly from London by Messrs. Gibbins and Lohn.
The first lot, including 1,900 dyed pelts, was sold on 20 September
1916 in St. Louis by Funsten Brothers and Company. Early in the
year 1921, the Government contract with Funsten was canceled and
a new one entered into with the Fouke Fur Company. Down to the
present time, this firm has been the sole contractor for handling the
United States' share of pelts from the Pribilof Islands (Fortune, 1930 ;
Fouke, 1949; Fur Trade Review, 1916; U.S. Bureau of Fisheries,
KILLING, SKINNING, BLUBBERING, AND CURING
The "island operations" have been described by many authors (see
above). Since about 1940 the annual harvest lias consisted almost
entirely of bachelor seals: 60,000 to 70,000 subadult males near the
end of their third or fourth year of life. Since 1956 the harvest has
also included a substantial number of females, from subadult to old-
42 THE PELAGE
adult. Future plans call for a sustained annual harvest of both males
On the killing field, the seal is clubbed on the head and the pelt is
stripped from the body, along with adhering masses of blubber and
other subcutaneous tissues. The raw pelt is washed overnight in
running sea water. On the following day, the blubber is removed
forcibly with a dull blubbering knife, and the tail, ears, and loose
tatters of skin are trimmed off (plates 90-92). The pelt is then
washed for 12 hours or more in circulating saturated brine, wrung,
dusted with boric acid and salt, barreled, and shipped to St. Louis.
A kind of spoilage, known as "pink," on the leather side of cured
sealskins was seen from time to time in the early years of the industry.
It was produced by halophilic bacteria, certain ones of which are able
to live in saturated brine. Spoilage is now controlled by dusting each
skin with boric acid before it is shipped. ZoBell (1946, p. 196-197)
has given a good review of spoilage in sealskins and other marine
PROCESSING AND MARKETING
A sealskin shipped from the Pribilofs may not reach the auction
block as a finished pelt for a year or two. The raw, salted skin is
held in cold storage in the original barrel until the factory is ready
to work it. There are more than 125 different operations in the
Fouke process, and it takes more than 3 months for the completion
of the dressing and dyeing of each skin, which is in work contin-
uously (Fouke Fur Company, 1958, p. 45-46). Processing includes
four main steps: unhairing, leathering, dyeing, and finishing.
The raw, salted skin is first graded for size (essentially length
and width) on a set of five graduated wooden boards, the proto-
types of which came from London before 1916 (fig. 2 and table 6).
As a result, each skin can then be processed with others of its size,
all of them receiving, for example, the same measured amount of
detergent. The five size-grades are small medium, medium, large,
extra large, and extra extra large. In actual practice, the raw pelt
is first graded as small, medium, or large. The "large" lot is again
graded into large, extra large, and extra extra large as a matter of
record and for possible research use. The three divisions of "large"
are then regrouped for processing.
Also at this time a particular blemish or undesirable feature may
be noted in the record, for example, bite, bruise, scar, or flay. The
location of the blemish may be charted on a special card (fig. 3).
The next important step is unhairing. The skin is quickly and
carefully preheated in a "cockle." It is then placed over a beam,
dusted with chalk, and the guard hairs are scraped off with a tool
THE PRIBILOF SEALSKIN INDUSTRY
Figure 2. — Outlines of the five boards used for size-grading raw, salted sealskins
X y 8 (see table 6).
Figure 3. — A sealskin "map" used for reference purposes in technological re-
search. On a finished, dyed, and trimmed sealskin, the small circles represent
ear holes ; the large ovals, fore flipper boles.
THE PRIBILOF SEALSKIN INDUSTRY 45
similar to a blubbering knife. At a much later stage in processing,
the skin is passed through a "dehairing" machine which clips off the
shorter, residual guard hairs. Poland (1892, p. 191-192) referred
to these as "water-hairs" and described a machine for clipping them ;
basically the same machine is in use today.
Leathering of the sealskin is essentially an oil, or chamois, dressing.
A chemical pretanning is not applied. The oil is derived from seal
blubber which has cured for months in salt. Mathur (1927) found
that this oil contains up to 7 percent free fatty acids. He concluded
that oil tannage is essentially a process in which, through the action
of free fatty acids (particularly oleic series), water is removed from
the skin but connective tissue fibers are left intact. Oil tannage
seems to be irreversible, in distinction to tannage by chrome, vege-
table, or alum.
The dyeing process is, to a certain extent, a trade secret. Various
inorganic and organic reagents, as well as complex vegetable and
animal pigments, are used to produce black, brown, and gray tones
in the underfur. The natural curl of the fur is removed, though a
bend or kink remains near the base of each fiber.
The finished pelt is graded for length on boards which are ruled
in one dimension only. However, the grading is not altogether ob-
jective, and a very narrow skin (for example) would be graded
slightly shorter than its actual length. The same terms — small
medium to extra extra large — as were applied to raw, salted skins are
applied to the finished pelt. The finished pelt is also graded for
quality, under a system long established, as follows :
Regular: fine, one (I), and two (II)
Scarred : A (same as fine and one, but scarred), and
B (same as two, but scarred) .
Three : (damaged, off-size, or very poor quality fur, virtually unsalable) .
The pelts are sold at twice-ye;irly auctions in St. Louis for the
account of the Government.
DIMENSIONS AND WEIGHTS OF SEALSKINS
For their practical value, certain data have been assembled on the
sizes of sealskins at various stages in the routine flow from killing
field to auction block. These are presented below
The question had been raised "For seals of any specified length.
do those individuals with greater girth tend to arrive earlier on the
breeding ground?'' Data provided by the Fouke Fur Company for
the period 1938-41 are given in tables 7 and 8 and ure compared
graphically in figure 4. These data show that the proportion of
larger skins taken before mid-July is approximately the same as the
proportion taken after. (In accepting this interpretation, one must
Figure 4. — Comparison of sizes of male sealskins taken in early season and late
season. Shaded column = early season ; unshaded = late. Data from bottom
row in tables 7 and 8 ; based on 105,249 skins taken in early season and 84,277
taken in late season.
assume that seals of comparable length are killed each year. This
is a reasonable assumption, in view of the fact that only seals measur-
ing between certain established length-limits are taken by the killing
crew.) In 1949, an answer to the same question was sought by other
means. During a 41-day period, 17 June-27 July, 558 bachelor skins
were segregated according to field length of seal. The range in
length was 38 to 51 inches. Each skin was weighed in freshly
blubbered and wrung condition, without mask and flippers. The
observed weights did not change appreciably, within a length class,
from early to late season. The mean weights for the 558 skins are
(pounds) : first quarter, 5.4; second quarter, 5.3; third quarter, 5.5;
fourth quarter, 5.1; mean for season, 5.3.
In the foregoing paragraph I have shown that, for bachelors
at least, the skin areas and skin weights of early-season individ-
uals are no greater than those of late-season individuals. Now
attention is called to table 9, in which the whole body weights of
THE PRIBILOF SEALSKIN INDUSTRY
early and late arriving females of known age are given. Here the
conclusion is inescapable that the earlier individuals, within an age
class, are heavier. The conclusions drawn in the two paragraphs are,
of course, not incompatible.
Relation between field length of the bachelor seal and weight of
the fresh pelt is shown in table 10 and figure 5. The greatest vari-
ation in skin weight is exhibited in the 44-inch animal. Seals with
a field length of 44 inches represent 3- and 4-year-olds in almost
equal numbers. Greatest variation in body size is commonly exhibited
during the years of adolescence in fur seals as well as other mammals.
Scheffer (1950 d, p. 388) found the highest coefficient of variation in
weight of fur seal testes in ages 3 and 4.
Relations between field length of bachelor seal and size classification
of skin in raw-salted and in finished condition are shown in tables
11 and 12 and in figures 6 and 7.
An attempt to translate a given trade classification, such as "small
medium," into dimensions of skin by inches has been made in tables
13 and 14. (The shape and size of the grading board has previously
38 40 42 44 46 48 50
Figure 5. — Weight of fresh male sealskin with relation to field length of seal.
(Data from table 10; vertical lines = range, circle = mean.)
48 49 50 51
Figure 6. — Trade classification of raw, salted male sealskin with relation to field
length of seal. (The "field length" in inches, snout to tip of tail on unskinned
animal, was obtained from 523 subadult male seals, mostly ages 3 and 4 years,
sampled at random between 18 June and 20 July 1946, on St. Paul Island. The
fate of the pelt from each seal was followed through processing by the Fouke
Fur Company. About one year after the kill, each pelt was classified in raw,
salted condition according to trade size, that is : small medium, medium, large,
extra large, or extra extra large. In the present figure, the left-hand column
(for example) shows that, of all 41-inch seals sampled, 57% produced a small
medium pelt, 36% medium, 5% large, and 2% extra large. )
been mentioned.) The length limits given in table 14 do not entirely
agree with those given by Bachrach (1946, p. 520). His limits are:
small medium, below 38*4 inches; medium, 38^ to 421^; large, 42^2
to 45!/2 ; extra large, 45*4 to 48i£ ; extra extra large, 48^ to 55 ; and
wigs, over 55.
In 1956 the Government began for the first time to take female
seals in substantial numbers as part of a long-term plan. In that
year, there were taken 22,680 females by 15 August and 26,884
THE PRIBILOF SEALSKIN INDUSTRY
N'. 41 42 43 44 45 46 47 48 49 50 51
Figure 7. — Trade classification of finished, dyed male sealskin with relation to
field length of seal. ( For explanation see fig. 6. )
females by 8 September. Quantitative data on female skins (size,
weight, relation to field length and trade classification) will not be
available for several years. Skins taken from old females in the
1956 and 1957 seasons were generally of poor quality, with fur sparse
and uneven in length on back of neck and belly (plate 84). As
compared with bachelor skins, the female skins were said to be more
elastic. During the period 4-8 September 1956, a tally was kept of
female pelts rejected from the kill as being commercially unattractive.
Out of 4,807 females killed, the pelts of 603, or 12.5 percent, were
rejected (Abegglen and others, 1956, tables S and T). All age-classes
from 2 to 10-plus were included, though about half of the seals killed
were in classes 2 to 5 years. While admitting that the skins of old
females killed in August may be difficult to process, I am inclined to
believe that part of the difficulty stems from the fact that routine
50 THE PELAGE
processing methods are being applied to a new and unusual class of
skin. (See also discussion of molt on page 26ff.)
The weights of tanned pelts in the National Museum collection —
3 adult males and 4 adult females — indicate that the male pelt
without flippers may weigh up to 10 pounds; the female pelt with-
out flippers, up to 4 pounds. These pelts were prepared for study,
not for commercial use.
STRENGTH AND DURABILITY OF SEALSKINS
Bowker (1931) measured the strength and thickness of commer-
cial sealskins dyed black or brown. Although not so specified, the
skins were certainly those of bachelors (3- or 4-year males), buffed
in the routine way. Kesults: thickness, 0.023 to 0.026 inches;
breaking strength of a half- inch strip, 37.5 to 46.0 pounds; tensile
strength, 3,150 to 3,680 pounds per square inch; percent stretch at
failure, 23.5 to 38.1 ; stitch-tear, 6.1 to 9.3 pounds. Sealskin leather,
though slightly weaker, compares favorably with the leather of
light calfskin and sheepskin.
Terao (1940) examined the leather of sharks, moray, California
sea lion, common dolphin, sperm whale, and blue whale.
The fibrous matter of the leather was found mostly running obliquely
longitudinally and united with transversely directed one so that it forms an
irregularly shaped rhombic network. The general feature of the network is
evident in the configuration of the upper-surface which is so characteristic to
each species as to aid its identification . . . The findings stand in harmony
with the fact that the leathers of aquatic animals are liable to be torn trans-
versely when used as boots, bags, etc.
L. A. Hausman, who studied for many years the microscopy of
hair, published (1939, p. 503) a table showing "durability" of com-
mercial furs. He ranked highest those species having fur hairs with
little or no medulla, as follows: Grade 100, otter and wolverine;
grade 90, beaver ; grade 80, fur seal ; grade 70, skunk and mink ; grade
65, raccoon (natural) ; grade 50, raccoon (dyed) ; grade 45, muskrat;
grade 40, fox (natural) ; grade 35, oppossum; grade 25, fox (dyed),
ermine, nutria, and lynx; grade 15, chinchilla and goat; grade 5,
rabbit, hare, and mole.
OTHER FEATURES OF THE
Features of the Head
NOSTRILS, MOUTH, AND LIPS
These features have been examined on four selected fetuses, and
on newborn and adult seals, as indicated below. ( "MNW" = mean
newborn weight; see page 10.)
Fetus of 23.7 g. (0.0049 MNW), female, 14 February
The nostrils are slightly open; mouth open and tongue showing.
Fetus of 103 g. (0.021 MNW), female, 20 January
Nostrils and mouth are open (plate 70-A) .
Fetus of 1.42 kg. (0.26 MNW), male, 22 March
Between the parted lips, 20 low, softly rounded bumps along the
gumline show where most of the teeth will appear. On each side of
the mouth there are 4 bumps above and 6 bumps below.
Fetus of 3.31 kg. (0.69 MNW), female, 6 July
On each side of the mouth the tips of the following teeth have
erupted: (above) 3 incisors, 1 canine, and 3 cheek teeth; (below)
2 incisors, 1 canine, and 2 cheek teeth; a total of 12. The third
lower cheek tooth, which will complete the deciduous set, has yet
On newborn and older seals, the rhinarium and nostrils are dark
gray, near black (plate 98-A). The dark color continues into the
tunnel of the nares as far as one can see, or 1-3 cm., depending on the
size of the seal. The upper and lower lips are medium gray. The
mouth and tongue are flesh pink, becoming red in an overheated indi-
vidual and fading to dirty grayish pink after death (plates 55 and
The tip of the tongue has a curious notch, 4 or 5 mm. dee]) in
adults — a feature of all pinnipeds except the walrus.
EYELIDS, EYE GLANDS, AND IRIS
The eyelids are open on a fetus of 822 g. (0.17 MNW), female, 9
March, and on all larger fetuses (plates 34, 36, 41-A, 52-A, and 55).
52 OTHER FEATURES OF THE SURFACE TOPOGRAPHY
The eyelids are closed on smaller specimens. On newborn to adult
seals, the eyelids are streamlined. Each is a low-relief extension of
the facial coat; thick, muscular, and hairy (plate 99). Wide open, it
frames a nearly circular aperture and is rimmed (in the newborn) by
a 2- to 4-mm. wide band of naked, black, thick, wrinkled skin. The
diameter of the eye opening is about 11 mm. in the newborn and 20
mm. in the adult.
Pinnipeds have tear glands but no ducts leading to the nasal pas-
sage. According to Rabsch (1953, p. 488) the lachrymal gland is
small, the Harderian gland large, and the individual fornix glands
especially well developed. Alaska fur seals "cry" freely in warm, dry
weather; the tears run down the cheeks (plate 100) .
The iris of the eye is dull bluish gray when the fetal eyelids open
for the first time. It is black or brownish black at birth, and there-
after. The eyeballs of two 4-year-old males are 43 mm. and 46 mm.
On a fetus as small as 23.7 g. (0.0049 MNW), female, 14 February,
the ears are well formed and nearly adult in shape. A groove or
flexure persists for 4 to 6 weeks around the base of each ear. In a
fetus of 1.11 kg. (0.23 MNW), female, 23 March, the groove is begin-
ning to disappear and the ear pinna is becoming more cylindroid and
stiffer (compare plate 101-A; also plates 34, 36 and 41-A). Thus,
the ear is becoming more like that of a pinniped and less like that of a
On an adult seal, the inside of the ear pinna, which can only be seen
when the furled edges are pried apart, is smoky grayish brown, smooth
and glossy (plates 52-A, 55, and 101-B). Externally, from the base
toward the tip, the fur disappears and the overhairs become shorter,
more slender, sparser, and lighter in color. The epidermis of the
outer surface of the ear is black. The blackness is conspicuous at the
tip and along the distal third of the ear, where the original fine hairs
have been lost through abrasion. The pelage beneath and just behind
the ear is paler than the surrounding hair. (Description of an old
female; additional notes on the pelage of the ear were given in the
On the evidence of 201 measurements (table 15), the growth in
length of the ear has virtually ceased by the eighth year of life.
Growth during postnatal life represents an increase of about 35 per-
cent in males and 30 percent in females.
FEATURES OF THE BELLY 53
Features of the Belly
MAMMARY GLAND COMPLEX
The teats or nipples on the skin of the female and male will be
described first, then the mammary glands of the female. On a female
fetus of 23.7 g. (0.0049 MNW), 14 February, the position of each of
the four mammary teats can clearly be seen as a white dot beneath
the surface of the skin. Each dot eventually becomes a pimple, then
a pimple within a dimple (plate 36). Vellus of the belly grows up
around the circular, naked, flesh pink dimple. On a living, full-term
fetus of 3.31 kg. (0.69 MNW), female, 6 July, the anterior teats are
70 mm. apart, on a line 58 mm. anterior to the navel ; the posterior
teats are 43 mm. apart on a line 26 mm. posterior to the navel. Each
teat is hidden in the pelage, though its location is marked by a light
gray dot of hair. None of the teats on the female has, at time of
birth, risen above the black hairy coat of the belly. The anterior and
posterior pairs of teats develop at the same rate and seem to be equally
important throughout life. On no fetus is there evidence of rudi-
mentary (vestigial) teats.
The teats become more conspicuous with advancing age. On a
silver pup as well as on older, but not yet parous, individuals, the
teat locations are indicated by faint brown spots. Occasionally they
can be found only after the guard hairs have been parted with one's
fingers. They are conspicuous, dark brown spots on the pelage of
parous females, both in and out of the nursing season (plates 102 and
103, A and B) . On a fully adult, lactating female, the loose, blackish,
wrinkled, naked teats can be stretched with one's fingers to a length
of 25 mm. On a large old female, the teats were arranged as follows :
2 lying 20 cm. apart on a line 25 cm. anterior to the navel and 2 lying
9 cm. apart on a line 6 cm. posterior to the navel. It has been found
that the measured distance between levels of anterior and posterior
teats on the tanned pelt is worthless as a criterion of age. For
example, this distance on a silver pup, length 76 cm., is the same as on
an 8-year-old, length 125 cm.
Of the tanned skins of 40 females examined with special attention
to the mammary teats, 2 have an extra (fifth) teat. On the pelt of a
5-year-old, there are 2 posterior teats on the left side, 10 cm. apart,
aligned with the long axis of the body. On a 10-year-old, there are
2 posterior teats on the right side, 11 cm. apart, similarly aligned. A
10-year-old examined in the field was noted as having "5 nipples in
On the male fur seal, the 4 teats are always hidden by the pelage.
They are arranged around the navel as on the female (plate 104).
On a fresh carcass of a 6-year-old, the teats were arranged as follows :
54 OTHER FEATURES OF THE SURFACE TOPOGRAPHY
2 lying 19 cm. apart on a line 20 cm. anterior to the navel and 2 lying
10 cm. apart on a line 4 cm. posterior to the navel, 12 cm. anterior
to the penial opening. One can occasionally locate the male teats
by finding faint brownish or blackish spots on the pelage, though
more often one must wait until the pelt has been removed and tanned ;
then search for scarlike marks on the leather side (plate 105).
On plucked pelts of both sexes, the location of the mammary teat
is marked by a slight break or depression in the fur surface. Here
the color is uniform light brown, like the surroundings.
With the hope of finding a relation between the underlying mam-
mary glands and the sparse, often patchy underfur of the belly,
in September 1958 I examined the glands on a number of fresh
carcasses. The gland-complex proves to be an extensive apron cover-
ing the lower thorax, abdomen, and sides of the body. The sketch
reproduced in figure 8 is based mainly on dissection, with photo-
graphs, of an old female, age over 10 years, not lactating, killed
on 9 September (plate 106-A). It is also based on cursory field dis-
section of 4 copiously lactating individuals. In the old female speci-
men, 2 liters of embalming fluid were introduced through the 4 teats.
Using a knife, one can easily separate the glandular tissue from
the overlying blubber. The glandular tissue is light brown and more
fibrous; the blubber is whitish and less fibrous (plate 106-B). The
blubber at the level of the anterior teats is 2 cm. thick ; the glandular
tissue is 1 to 2 cm. thick. These two layers are, at the level of the
posterior teats, 2 cm. and 1 to 1.5 cm., respectively. On the old female,
length 137 cm., the gland-complex is about 66 cm. long and 50 cm.
wide, along curves of the body. Posterior to the armpits the gland
bends rather abruptly upward along the sides; anterior to the heels
it bends less abruptly upward. It reaches forward about 21 cm.
beyond the level of the anterior teats or almost to the level of the
insertion of the fore flippers. It reaches hindward about 20 cm. be-
yond the posterior teats, or almost to the level of the heels. Its total
area is 2,189 sq. cm. (339 sq. in.). The gland-complex appears to be
one continuous sheet, though it probably consists of 4 anastomosing
units, 1 unit draining into each teat. (When embalming fluid was
injected, the region around each teat swelled independently.) The
main duct leading to the teat is thin-walled, about 5 mm. in diameter,
and is conspicuous for only 6 cm. of its length, the deeper portion
being buried in glandular tissue. The shape of the milk reservoir be-
neath each teat is suggested in plate 106-A. At its margin, the gland-
complex becomes very thin, not over 2 or 3 mm. A shipbuilder
would say that it is "faired" into the body. Carlisle (1954) believes
that mammary glands may have originated from sebaceous glands,
rather than sweat glands.
FEATURES OF THE BELLY
Figure 8. — Diagram of the mammary gland complex ; represented on a flat sur-
face with the side flaps lifted to the plane of the thorax and belly ; reservoir
beneath each teat swollen with embalming fluid ; distance between anterior
teats 24 cm. ; letters represent anterior mammary teats, navel, posterior mam-
mary teats, and vaginal opening. (4189)
56 OTHER FEATURES OF THE SURFACE TOPOGRAPHY
Milk capacity of the mammary gland is perhaps 2 or 3 liters.
Milk in the bulging stomach of a nursling has been found to vary
in amount from 1 liter in a newborn to 2.5 liters in a pup nearly
weaned (Scheffer, 1950 c, p. 7; and Ford Wilke, MS, 1941, based on
specimen BDM 6). To a limited extent, milk may flow spontane-
ously from the mother. On 27 September the writer saw a cow of
medium size scrambling over the rocks in alarm. Five to ten drops of
milk fell in rapid succession from her left anterior teat. Wilke col-
lected milk as it drained from the slashed mammary gland of a female
in estrus; he later reported (1959) that it contained 46 percent fat.
(The milk of the gray seal Halichoerus may contain up to 53 per-
cent fat, while the suckling elephant seal Mirounga may quadruple
in weight in 21 days ! )
PENIAL OPENING AND SCROTUM
On the smallest male fetus available for study, 131 g. (0.024 MNW),
25 January, the site of the future penial opening is a distinct dimple
about 0.5 mm. in diameter. On a fetus of 2.21 kg. (0.41 MNW),
2 May, the penial opening is a craterlike prominence surrounded by
long hairs, with a distinct opening 1 mm. in diameter. On the new-
born pup, the opening is usually marked by a fringe of white
hairs. On the adult, the skin of the penial opening is distinct,
naked, and flesh pink surrounded by black (plate 57).
The scrotum of the adult is dark gray, wrinkled, and virtually
hairless. The testes descend in the third or fourth year, though the
descent is less conspicuous than in land carnivores (plates 57 and
FEMALE EXTERNAL GENITALIA
Of the female external genitalia, Bartholomew and Hoel (1953,
p. 420) have written :
In the interval between parturition and the end of estrus [about 1 week]
the vulva is swollen and protruding and the vestibular mucosa and vaginal
orifice are a brilliant pink. By the time a female returns from her first trip
to sea, the swelling is completely gone, and neither vestibular mucosa nor
vaginal orifice are conspicuous. The entire vulva appears dark brown or black.
On an adult female shot 18 minutes after copulation, the pink
rosette of the vaginal opening was clearly visible from a distance of
100 meters. Ordinarily the vestibule appears black. (Plate 108.)
NAVEL AND TAIL
The navel can nearly always be seen in both sexes, regardless of
age, as a disturbance in the lay of the hair, without distinction in
color (plates 36, 44, and 102).
FEATURES OF THE LIMBS 57
On a fetus as small as 23.7 g. (0.0049 MNW), female, 14 February,
the tail is well formed and nearly adult in shape. The tail is dif-
ficult to measure; its free length is 15 to 20 mm. on the newborn
pup and 30 to 50 mm. on the adult (plates 44, 58, and 107-B). On
the field record of a 4-year-old male is noted "tail 32 mm. plus 4 mm.
hairs, though standard length is about 62 mm. when loose skin is
pushed toward the body." As the seal reaches old age, the tail
pelage becomes darker — at times almost black — and the underfur
becomes sparser. (For further description of tail pelage, see pre-
Features of the Limbs
FLIPPERS AND CLAWS
At birth, the flippers are brownish gray (Munsell 5 YR 4/1) and
naked, except for sparse vellus on the dorsal surface of the fore
flipper (plates 43 and 44). They soon turn almost black (plate 109).
When wet, they are intensely black ; when dry, dark grayish brown
(5 YR 2/1) ; when very dry, as on an old bull sleeping in the sun,
gray (plate 110). In a group color photograph, the flippers of cer-
tain individuals may catch and reflect the light of the sky, appearing
white or bluish.
Forty flippers from 10 subadult male seals were cured in salt on
St. Paul Island, 20 June 1949. (A set of 4 flippers weighs 2.5 to
3 lb. in fresh condition.) Half of the collection was sent to a large
national manufacturer of glues and half to a large national producer
of photographic gelatin. The former reported (personal correspond-
ence) that "the resulting glue liquors were dark in color and had
a characteristic 'fishy' odor. The glue was of low test and the per-
centage of glue obtained was much lower than for green salted stock
obtained from cattle or other skin trimmings." The gelatin manu-
facturer reported "we have conducted some extensive tests with this
material but our experiments disclose that it has no value in our
The National Bureau of Standards also examined a barrel of
flippers (U.S. Bureau of Fisheries, 1920) :
The experiments made by that bureau showed a yield of glue amounting to
G7 percent of the weight of the salted nippers. The viscosity at 40° C. of a
10 percent solution was . . . 1.20, a little below Peter Cooper's glue, grade 1%.
The only functional claws of the fur seal are those on the 3 inner
toes of each hind flipper. The seal uses its claws exclusively for
grooming the anterior parts of the body. The pup, especially,
scratches itself frequently and vigorously during the summer molt.
Development of the claws on five selected fetuses is described as
58 OTHER FEATURES OF THE SURFACE TOPOGRAPHY
Fetus of 23.7 g. (0.0049 MNW), female, 14 February
The sites of all 20 claws are visible. Each of the fore-claw sites
on digits 1 to 4 is visible as a soft, whitish disc or pad of skin with
a minute, teat-like projection. The outer hind claws are similar.
The 3 inner hind claws, destined to become the only functional claws,
are represented now by the largest of all the whitish pads. The claw
rudiment on digit 5 of the fore flipper is a roundish disc below the
surface of the skin and here it remains; it does not erupt with ad-
vancing age of the fetus.
Fetus of 103 g. (0.021 MNW), female, 20 January
On each fore flipper, the first claw rudiment is distinctly conical
and clawlike, though soft and white, 1 mm. in length. The second
to fourth rudiments decrease in size in this order. They are also
clawlike. The fifth is no more than a faint pimple. The hind claws
are well formed; the middle 3 robust and about 2 mm. in length.
(Compare plate 36.)
Fetus of 1.09 kg. (0.20 MNW), male, 25 March
The 3 middle claws on each hind flipper are becoming firm and
horny ; brown with lighter tips and under parts.
Fetus of 3.31 kg. (0.69 MNW), female, 6 July
A full-term fetus, delivered by caesarian section and killed 9 hours
later. The vestigial claw sites on each fore flipper are scar-like pits
with diameters as follows (first to fifth digits) : 1, 0.5, 0.5, 0.5, and less
than 0.5. On each hind flipper, the claws are grayish in color, with
distal one-third to one-half thin, flexible, and semicircular in cross
section. They may be described as follows: (first) vestigial, length
10 mm., basal 3 mm. stiffer, distal 7 mm. softer, paper-thin; (second)
length 20 mm.; (third) length 19 mm.; (fourth) length 18 mm.;
(fifth) vestigial, length 5 mm. After birth, the first and fifth claws
quickly become worn to nubbins.
Fetus of 5.79 kg. (1.07 MNW), male, 9 July
The hind claws on this full-term fetus are nearly as long as the
longest recorded for the newborn: 3, 26, 26, 25, 10 cm. The claws
dry out soon after birth, when they become brownish black along the
basal part and horn-brown toward the thinner tip.
On adults, the third (middle) hind claw is usually the longest.
On a 10-year-old male, the fore claws are rudiments hidden in skin
pits 1 to 2 mm. in diameter. The hind claws are 9, 29, 30, 26, and 4
mm. in length on the first to fifth digits, respectively. On a 10-year-
old female, the fore claws are also rudiments. The hind claws are 6,
23, 24, 19, and 7 mm. in length. I do not know whether the claws
continue to grow in later life, but I presume that they do not.
Their position on top of the hind flipper protects them from the
THE BLUBBER LAYER 59
sort of attrition to which the claws of a xiat or dog are exposed ; yet
the claws of the fur seal never exceed 30 mm. in length. (Plates 110
and 111, A and B.)
The Blubber Layer
The blubber on the belly of a newborn fur seal was 3 mm. thick;
on the belly of an old cow, 50 mm. ; and on the belly of an old bull,
On breeding bulls, some of them known to fast for at least 64
days in summer, the skin is loose and wrinkled by mid-August.
Clearly there has been a loss of subcutaneous fat, though no actual
measurements of the loss have been made. McLaren (1958, p. 63)
found in the ringed seal Pusa that blubber made up about 45 percent
of the body weight in winter, but only 20 percent in late June.
A reduction plant on St. Paul Island utilizes the byproducts of
the Pribilof sealskin industry. The skinned carcasses are reduced
to dry meal and "carcass oil", while the blubber scraped from the
skins is reduced to "blubber oil". The yield of both kinds of oil
over a 10-year period is shown in table 16. A subadult male seal
weighing about 30 kg. (66 lb.) yields roughly 0.6 gal. of blubber
oil. Apparent variation from year to year in yield of oil per skin
is believed to result, in a large part, from inconsistent handling of
materials in the plant. Additional data, from records kept from
1950 to 1952, are as follows: 1 subadult male sealskin yields about
0.13 cu. ft. of crude blubber, and 1 cu. ft. of crude blubber yields
4.3 gal. blubber oil. Crude blubber is the plumped-up mass of fat,
connective tissue, and muscle scraped from sealskins that have been
allowed to soak overnight in cold sea water. On 25 July 1947,
I weighed the crude blubber from 100 skins of "Group III"
seals (mostly 3-year males) and from 100 skins of "Group IV" seals
(mostly 4-year males). The average weights per skin were 11.7
lb. and 15.2 lb., respectively.
Thompson (1950, p. 726) gave an analysis of oil which had been
heat rendered on St. Paul Island in 1949 from blubber scraped from
Free fatty acids (as oleic) 1.05%
Moisture 0. 34%
Insoluble matter 0. 05%
Iodine number (Wijs) 132.5
Stearin at 70° F. (21.1° C.) 1.04%
Unsaponiflable matter 0. 49%
Titer 70. 2° F.
Lovibond color using a 1-inch column :
Red 3. 5
553006 O — 62 5
60 OTHER FEATURES OF THE SURFACE TOPOGRAPHY
Clegg (1951) reported on the characteristics of oil from cold-
rendered fur-seal blubber as follows :
Free fatty acid (AOAC) 1.58%
Moisture and other volatile matter (AOAG) not measurable
Iodine number (AOAC, Hanus) 108
Unsaponifiable matter (AOAC) 0.64%
Saponification number (AOAC) 196.3
Specific gravity 25° C./25° C 0. 917
Index of refraction at 25° C 1. 4743
Vitamin A content (1894XE3M) 1 306 units/g.
1 Determined on the whole oil without saponification.
Minato (1949) gave additional data on "body oil" of a fur seal
taken off Japan. Miyauchi and Sanford (1947) found little vitamin
A in two samples of fur-seal blubber oil : 490 and 493 units per gram.
In a sample of fresh seal blubber, Wilber (1952) found total
phospholipids 4.3 percent and total cholesterol 0.24 percent. The
phospholipid content is high — as in perhaps all marine mammal f ats —
and is conceivably "associated with a high rate of fat turnover at the
The sample analyzed by Wilber was reddish orange. The carcass
of a seal with orange blubber, called by natives of the Pribilof
Islands a "salmon-eater'', may occasionally be seen on the killing
field among carcasses with normal, creamy white blubber. Orange
individuals include fewer than 1 percent of the total. Wilber con-
cluded that the orange color is, in all probability, a carotenoid
pigment. It may, in fact, be astaxanthin, a pigment found by
Baalsrud (1956) in an abnormal, reddish-orange cod. Baalsrud
stated that "There is as yet no obvious explanation for this sporadic
appearance of astaxanthin in cod flesh, but somewhat similar ob-
servations have been made on whales. Occasionally red (asta-
xanthin-containing) whale-body oils and whale-liver oils are encoun-
tered; in this case pigmentation is taken to indicate an unspecified
Experts of the Fouke Fur Company say that an indistinct dark
band can be seen along the dorsal region of the finished, dyed
sealskin from old female animals. This is not present in male skins.
It is referred to as an "oily band," though its real nature is unknown.
Actually, it may be correlated with age rather than with sex; that
is, only younger males commonly enter the commercial kill, as against
females of all ages.
The midsummer population of northern fur seals Callorhinus
ursinus is estimated at 1,978,000. Of this number, 1,800,000, or 91
percent, originate on the Pribiliof Islands. The Pribilof herd is
capable of yielding 80,000 to 100,000 sealskins a year.
The epidermis of the sealskin has a cornified layer about 15 microns
thick and a generative layer about 25 microns thick. The dermis
or leather is 3 to 4 mm. thick, thickest on old males. Regardless
of age, the follicular (hair-rooot) stratum of the dermis does not
vary appreciably from 2.3 to 2.4 mm. in thickness. An apocrine
sweat gland is associated with each hair bundle, rising from depths
of 2 to 3 mm. Sweat glands are not functional in the black pup.
The skin is pigmented (dark gray) on the following naked parts:
nose, lips, rim of the eye, inside of the ear pinna, penial opening
scrotum, vestibular opening, teats, anus, and flippers. It is also
pigmented (light gray) beneath the pelage of the ear pinna and
The pelage consists of bundles, rather evenly distributed, about
15 per sq. mm., each bundle with a guard hair that slopes, rooflike,
above, and anterior to, a group of 35 to 40 underfur fibers. At the
skin surface, the bundle is surrounded by a thick sheath. The guard
hair is flanked by a pair of sebaceous glands seated 0.8 to 1.0 mm.
below the surface ; functional even in the black pup. There is no hair-
erecting muscle. The guard hair is most deeply rooted. Behind it,
the roots of the individual fur fibers are arranged in stairstep fashion,
the most posterior fibers nearest the surface. The total number of
hair and fur fibers per sq. mm. is about 570 (370,000 per sq. in.).
The pelage is highly efficient as a thermal insulator; the underfur is
water repellent. The haired surface of the body of the adult male has
an area about 2.5 times that of the female.
Guard hairs may attain a length of 33 mm. on the male (mane
hairs to 70 mm.) and 20 mm. on the female. Underfur hairs may
attain a length of 14 mm. on the male and 13 mm. on the female.
The pelage of the belly is shorter than that of the back. The individ-
ual guard hairs and underfur hairs resemble those of mink; less
closely, those of otter. The guard hair of the seal is stiff and flattened,
lanceolate, medullated, heavily pigmented as a rule, with diamond-
petal scale-pattern along most of the shaft. The underfur is much
553006 0—62 6 61
finer, distinctly wavy, without medulla, with very little pigment, and
with pectinate scale-pattern along most of the shaft.
The fur-seal embryo implants in early November. Hair primordia
are visible on a midwinter fetus of y 200 mean newborn weight, and
erupted hairs on a midwinter fetus of y 2 o mean newborn weight.
Finer, paler hairs erupt in advance of coarser, blacker ones; the
early fetus is gray. Heavy black guard hairs are aligned in a streak
along the back of the fetus of I/3 mean newborn weight. Waves
of hair-growth move backward and downward from the head and,
slightly later, forward and downward from the rump. The top of
the fetal flipper is covered with fine hairs which disappear at birth,
though sweat glands remain. A fetus of 2.7 kg. (y 2 mean newborn
weight) is well covered, except on the belly, with black hair.
The birthcoat is jet black, and its fibers are mature. It consists
of 75 to 80 percent underhairs and 20 to 25 percent guard hairs. The
arrangement of hair bundles is quite unlike that in the adult coat.
In the birthcoat, there are 40 to 45 small bundles per sq. mm., each
containing 1, 2, or 3 hairs. When the bundle includes 2 or 3 hairs,
the posterior ones are underhairs.
The pup guard hairs are about 15 to 20 mm. in length. To a
certain extent, they intergrade in size and structure with the under-
hairs. The largest ones resemble adult guard hairs. The pup un-
derhairs are 6 to 15 mm. in length. They differ from adult underfur
fibers in being shorter, coarser, less wavy, with more pigment, and
often with medulla. In the birthcoat, adult-type underfur follicles
are already taking form, deep in the dermis.
The height of the pupping season is 15 July. Two weeks later,
the black birthcoat has started visibly to molt and has taken on a
ragged appearance. By the end of September, it has largely been
replaced by the adult-type pelage of the silver pup. The silver
pelage persists for about 11 months, or until the end of August of
the second summer.
The annual molt of the seal is believed to be a prolonged affair,
4 to 5 months from start to finish. The first adult-type molt (to
silver pup) centers in September; the second in August (to yearling
of autumn) ; the third in September (to 2-year-old of autumn) ; the
fourth and subsequent molts in late September or October. The
fibers are shed individually, with the result that the pelage is always
intact and ready to meet the demands of an amphibious life. One
rarely sees a "molt line." Molting is not accompanied by sloughing
of the epidermis as in certain phocids. In autumn, the coat is duller
and browner; in spring (at sea) it is brighter and more silvery.
In late adolescence, ages 3 to 5 years, the whitish rump patches dis-
appear, mane and wig hairs of the male start to lengthen, and pig-
ment ceases to form at the roots of the whiskers (vibrissae) in both
At birth, there are 2 superciliary (above-the-eye) and 20 to 23
mystacial (snout) vibrissae on each side of the head. The number
does not vary with age or sex. Nearly all of the vibrissae have
erupted on a fetus of y 2 oo mean newborn weight, far in advance
of the body hairs. Like sheep-wool fibers, the vibrissae are ever-
growing, even in spring when the body-hair follicles are at rest.
They continue to grow, so far as we know, throughout life. On a
seal approaching the end of the first year of life, the longest vibrissa
is growing at the rate of 0.2 mm. per day. The vibrissae on the
adult are 4 to 5 times longer than those on the newborn. The longest
vibrissa of record has a maximum length on the male of 334 mm.
(13.1 in.), and on the female 220 mm. (8.66 in.). The vibrissae
are the only fur-seal hairs that taper all the way from base to tip.
The most commonly observed pelage anomalies are the following:
(1) Genetic color- freaks such as albino, piebald, and chocolate. (2)
"Rubbed" pelage with guard hair absent from extensive areas;
etiology unknown. (3) Naked, scabby patches on lousy pups. (4)
Thick-skin, or pachyderma; etiology unknown. (5) Warty nodules,
thus far seen only on the flippers; etiology unknown. (6) Female-
like pelage on males with infantile testes. (7) Algal and barnacle
growths on the pelage, especially in winter.
The Pribilof sealskin industry is now about 175 years old. "Island
operations" include killing, skinning, blubbering (flensing), and cur-
ing. "Factory operations" include unhairing, leathering, dyeing, and
finishing. The skins receive a chamois, rather than chemical tannage.
Field measurements of seals show that larger individuals tend to
arrive on land in summer slightly ahead of smaller seals of the same
age. However, as a result of selection by the killing crew, the com-
position of the take (by size of skin) remains constant throughout
the sealing season. The weight of the blubbered, subadult, male pelt
varies from 3.2 lb (on a seal of 38-inch field length) to 8.5 lb. (on a
49-inch seal). Commercial sealskins range in length and width as
follows (inches): Raw, salted: length 28^4.5, width 19-30. Fin-
ished, dyed: length 35.5-51.5, width 19-29. Thus, the finished skin
gains considerably in length. Raw, salted sealskins are graded in five
main categories, the smallest ("small medium") representing an area
of about 718 sq. in. and the largest ("extra extra large") 1,261 sq. in.
Breaking-strength tests applied by the Bureau of Standards reveal
that sealskin leather compares favorably with the leather of light
calfskin and sheepskin.
On the fetus, the ear pinna is flattened and somewhat flexible, like
that of many land carnivores; on the adult, it is more cylindroid,
stiffer, and more specialized for submarine life. It ceases to grow in
about the 8th year of life, with a length (from notch) of 50 mm. on
males and 45 mm. on females.
The 4 mammary teats (abnormally 5) are abdominal and equal in
importance. On males and young females, they are hidden beneath
the pelage. The mammary gland-complex is an extensive apron cov-
ering the lower thorax, abdomen, and sides of the body. It attains a
thickness of 2 cm. and an area of more than 2,000 sq. cm. (300 sq. in.).
It has a milk capacity of 2 to 3 liters. A sample of milk contained 46
The testes descend in the third or fourth year. The tail is insig-
nificant ; throughout life it scarcely doubles in length. On each fetal
nipper, five claw primordia are clearly visible. However, only the
three middle claws of each hind nipper become functional ; these are
used exclusively for scratching the body. On an adult male, the
middle claw (third digit) is about 30 mm. in length.
The blubber may attain a thickness of 6 cm., considerably less than
that of phocid seals of comparable size. The crude blubber on a sub-
adult male weighs 12 to 15 lb., and yields roughly 0.6 gal. of oil.
The free fatty acid component of blubber oil is high (1.05 to 1.58
percent), as is the phospholipid content (4.3 percent). Reddish-
orange blubber, occasionally seen, may contain astaxanthin.
In appendix A, Munsell colors are given for 8 seals of selected age
and sex. The middle value in an array of 39 colors recorded for
fur-seal pelage is light brown. Seals from American and Asian
waters are inseparable on the basis of color. Even to the trained ob-
server, there are no sex distinctions in color pattern up to age 2 or 3
years. By age 4, the male is beginning to show a grayish mane and
wig, and to lose his rump patches.
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Table 1. — Length and weight of male fetal seals collected off the North American
coast, by 10-day periods, 1951-52
[16-25 January 1951, oft Sitka, Alaska (Ford Wilke, MS); 15 February to 29 June 1952, California to Gulf
of Alaska (Taylor and others, 1955, table 27); summer, full-term fetal and newborn seals collected selec-
tively on Pribilof Islands, Alaska, 19 June to 11 August 1940-50 (Scheffer and Wilke, 1953, tables 1 and 2)]
Midpoint of 10-day period
Length in centimeters
Weight in kilograms
20 Jan. -.
0. 08-0. 39
1. 17-2. 04
1. 79-2. 89
1. 96-3. 35
4. 99-5. 10
4. 05-7. 03
4. 08-7. 14
Table 2. — Length and weight of female fetal seals collected oft the North
American coast, by 10-day periods, 1951-52
[16-25 January 1951, off Sitka, Alaska (Ford Wilke, MS); 15 February to 29 June 1952, California to Gulf
of Alaska (Taylor and others, 1955, table 27); summer, full-term fetal and newborn seals collected selec-
tively on Pribilof Islands, Alaska, 19 June to 11 August 1940-50 (Scheffer and Wilke, 1953, tables 1 and 2)]
Midpoint of 10-day period
Length in centimeters
Weight in kilograms
0. 08-0. 37
. 63-1. 25
1. 11-1. 28
3. 18-6. 12
3. 31-6. 01
Table 3. — Mean lengths of underfur and guard -hair fibers, by age and sex
[Measured on 114 tanned pelts at neck (10-25 cm. behind ears), back (mid-dorsum at level of fore flippers),
and belly (ahead of navel). Sexes are lumped through age 2. Figures in parentheses represent AT, or num-
ber in sample.]
Length In millimeters '
Age and sex
Black pup, newborn 2
Black pup, molting..
11 Aug.-25 Sept.
29 Sept.-17 Nov.
24 Sept.-5 Nov__
20 Aug.-21 Sept.
22 June-19 July.
23 Mar.-15 Sept.
2 Apr.-17 Aug...
28 June-2 July
13 June-5 July..
13 Mar.-3 Oct—
6 July (4)--
4 Sept. (4)...
25 Oct. (7) —
22 Apr. (4)..
26 Oct. (20)..
31 Aug. (7)-
5 July (10) —
8 July (3)...
4 July (12) —
2 July (9)...
1 July (6) ..
21 July (2)
21 June (2)..
2 July (2) -
25 June (9)..
10 July (13)-
Five-year-old male. .
Maximum length of
fibers on male
Youngest age group
in which maxi-
mum length is
Maximum length of
fibers on female
Youngest age group
in which maxi-
mum length is
1 "Length" is equivalent to "depth" of underfur or guard hair; with fibers in natural, slightly bent, or
2 The black pup has no underfur, only a sparse underhair coat. Members of all age classes have an inter-
mediate coat of short guard hairs, difficult to see without a lens, and ignored in the present table.
Table 4. — Length of longest vibrissa, by age and sex
[The longest mystacial vibrissa is normally the posterior bristle in row 4 or 5 (counting 6 horizontal rows
from top of snout to lip). Its length is measured from surface of skin to tip. Since the tip may be worn
or broken, maximum length is more important than minimum]
Number of specimens
7 years .
' Males, totaling 133, were taken June-August (except 1 yearling on 13 September) ; females, totaling 67,
were taken June-September.
Table 5. — Change in color of mystacial vibrissae with age, female seals
[Adapted from Abegglen and others (1957, p. 97; 1958, p. 186); based on 14.457 female seals]
Black and white
3 years ..
4 years. .
5 years. .
8 years ._
9 years ..
Estimated from tooth-ridge counts.
Table 6. — Sizes of grading boards for raw, salted skins
[Measured from outline tracings of boards provided by Fouke Fur Company in 1958; see figure 2]
Extra extra large
Table 7. — Sizes of male sealskins taken in early season
[Size classification of raw, salted skins at St. Louis factory; skins originally stripped and blubbered on
St. Paul Island from latter part of June through 15 July]
Extra extra large..
1 Including 4 wigs.
Table 8. — Sizes of male sealskins taken in late season
[Size classification of raw, salted skins at St. Louis factory; skins originally stripped and blubbered on St •
Paul Island from 16 July to end of July or early August]
Extra extra large. ..
1 Including 7 wigs.
Table 9. — Comparison of body weights of female seals arriving on land in early
summer and in late summer
[From a kill of approximately 500 seals, none with full-term fetus, on hauling grounds and rookeries of St.
Paul Island, 15 June-4 September 1953. (Ford Wilke, MS, 1953)]
4 years 2
1 Estimated from tooth-ridge counts.
2 Total sample 34, rather than 50, in this age class; thus, total number seals measured 184.
Table 10. — Weight of fresh male sealskin with relation to field length of seal
[Sample of 558 skins from subadult males, mostly ages 3 and 4 years, taken in regular commercial kill, St.
Paul Island, 17 June to 27 July 1949. Length is "field length" or approximate length from snout to tip
of tail on unskinned animal. Weight is of pelt, freshly blubbered and wrung, without mask and flippers.
Length of seal
Weight of pelt in pounds
3. 2-4. 2
3. 1-4. 6
3. 3-5. 8
3. 9-6. 1
4. 0-6. 7
4. 0-7. 5
4. 6-7. 2
5. 1-7. 3
5. 5-7. 7
5. 2-8. 5
6. 2-8. 5
42 inches ...
Table 11. — Trade classification of raw, salted, male sealskin with relation to
field length of seal
[Based on pelts of 523 subadult male seals sampled at random between 18 June and 20 July 1946, on St. Paul
Island; classified by Harry Gladson in 1947]
Table 11. — Trade classification of raw, salted, male sealskin with relation to
field length of seal — Continued
Table 12. — Trade classification of finished, dyed, male sealskin with relation to
field length of seal
[Based on pelts of 523 subadult male seals samnled at random between 18 June and 20 July 1946, on St.
Paul Island; classified by Harry Qladson in 1947]
Table 12. — Trade classification of finished, dyed, male sealskin with relation to
field length of seal — Continued
663006 O— 62-
Table 13. — Trade classification of raw, salted, male sealskin with relation to
[Based on pelts of 523 subadult male seals sampled at random between 18 June and 20 July 1946, on St. Paul
Island; classified by Harry Gladson in 1947. Dimensions are approximate]
Trade classification (size)
Length in inches
Width in inches
Table 14. — Trade classification of finished, dyed, male sealskin with relation
to over-all dimensions
[Based on pelts of 523 subadult male seals sampled at random between 18 June and 20 July 1946, on St. Paul
Island; classified by Harry Gladson in 1947. Dimensions are approximate]
Trade classification (size)
Length in inches
Width in inches
Extra extra large
Table 15. — Length of ear from notch, by age and sex
Number of specimens
Table 16. — Yield of oil from fur seals killed on St. Paul Island, Alaska, 1949
[Source: U.S. Fish and Wildlife Service (1952-57) and unpublished data]
APPENDIX A— COLOR NOTES
Reproductions of the natural colors of seals or their pelts have
rarely been published (Fortune, 1930; Schops and Fritzsche, 1938;
Scheffer and Kenyon, 1952). Thus, it seems desirable to place on
record the fresh colors of the fur-seal pelage. The simple black
pattern of the pup has already been described. In the following
pages, color notes will be given for males and females representing
the following classes: silver pup, yearling in autumn, 3-year-old
(adolescent) , and adult.
Colors were compared on St. Paul Island, unless otherwise noted,
from living or freshly killed seals, pelage clean and dry (or moist),
in sunlight whenever possible, with a Munsell Color Company (1954)
soil color chart as reference. Bowers (1956) and Miller (1958)
have pointed out the advantages of the Munsell system of color
notation. The names used in the present paper, however, are not
those given on the soil color chart, but rather the more widely used
ISCC-NBS names (National Bureau of Standards, 1955, p. 15-31).
The pelage hues of the northern fur seal range from 5 YR to 10
YR, with two exceptions : (1) On tanned pelts, a dark reddish brown
color (2.5 YR 2/4 or 3/4) may appear. This is the color labeled
by Maerz and Paul (1950, pi. 8) as "seal." It is next to "chocolate."
"Seal" as a color name probably originated in the fur market from
examination of tanned pelts. The color itself can often be seen in
life near the bases of the flippers and around the teats and vestib-
ular mucosa. As a matter of fact, the names "seal" and "seal brown"
have been applied by artists and professional colorists to at least
seven colors (National Bureau of Standards, 1955, p. 144-145).
These colors range from dark reddish gray through moderate brown
to dark olive brown. (2) The second exception is pale yellow (2.5
Y 8/4), seen on adult vibrissae and usually referred to as "white."
The middle value in an array of 39 colors recorded for fur-seal
pelage is light brown (7.5 YR 5/4) — an interesting but perhaps
As a result of contact with rookery soil as well as excrement,
urine, and regurgitated bile and milk, the coat of the seal invariably
becomes stained. (Colors imparted by algal growths have been
mentioned.) After patiently watching seals from a blind, Barthol-
omew (1951, p. 3) concluded:
When the pregnant females first arrive on the breeding grounds they are
pale silvery gray. Within 4 days of coming ashore they turn yellow-brown.
Each time they go to sea they regain some of their grayness, and females who
82 APPENDIX A — COLOR NOTES
have made three trips to sea cannot, on the basis of color, be definitely dis-
tinguished from females who have just come ashore for the first time.
Similar color changes take place in the males, although their coloration is
much more variable than that of the females. When they first come ashore,
individual males will vary from light gray to almost black, but with each
succeeding day ashore they become progressively more brown. One male, which
when it was marked [tagged] was almost black, with a virtually white mane,
after a week ashore became tan, with a yellow-brown mane.
In the present study, I have tried to select clean specimens for
observation, though for certain individuals, especially silver pups, it
has been difficult to distinguish between stain and true pelage color.
There is no strong evidence of graying (interference in the synthesis
of melanin) with increasing age, except in the vibrissae, which are
permanent hairs. As previously mentioned, these begin to turn white
at the base, near the time of sexual maturity or a little later.
Up to the time of writing (1959), no diagnostic features of pelage
or internal anatomy that might be used to identify American, as
against Asian, fur seals have been discovered. The three main popu-
lations of C allorhinus ursinus breed, respectively, in eastern Bering
Sea, western Bering Sea, and Sea of Okhotsk. (Perhaps 3,000 breed
in the northern Kuriles, on the rim of the North Pacific) Repro-
ductive isolation in the three groups is rather complete, as indicated by
the strong homing instinct of individual seals to the land of their
birth. However, important numbers of seals from each group are
known to mingle at sea in winter ; American seals have been recovered
on Soviet grounds, and vice versa. After careful study, Taylor and
others (1955, p. 61-65) could find no evidence of pelage differences
among the members of the three main populations.
Silver Pup, Male
I can distinguish a male from a female silver pup on the basis of
genitalia, less surely on the basis of size and shape of canine teeth,
and even less surely on the basis of body size. (In a sample of 173
pups weighed on 4 October 1947, the mean weight of males was 13.9
kg., the mean weight of females 12.0 kg.) I cannot see any differ-
ences in the color pattern of male and female silver pups, or even of
autumn yearlings, in the second adult-type pelage. Nevertheless, in
view of the possibility that slight differences do exist, I have
reported separately on the color pattern for each sex.
Top of snout light grayish brown (10 YR 7/3) ; upper lip also
light grayish brown; forehead brownish gray (10 YR 4/1) ; cheeks
light grayish brown (10 YR 7/3) ; region around eyes brownish gray
SILVER PUP, FEMALE 83
(10 YR 3/1), in strong contrast to paler cheek stripes; crown brown-
ish gray (10 YR 4/1) ; ears brownish gray (10 YR 3/1) with slightly
worn tips; neck, shoulders, back, rump, and tail brownish gray (10
YR 4/1) ; no mane; rump patches (prominent) and flanks brownish
pink (7.5 YR 7/2) ; bases of flippers, dorsal and ventral, dark grayish
brown (5 YR 2/2). Light-brown color of belly extends upward and
along sides into armpit, visible from dorsal aspect.
Lower lip and chin brownish pink (7.5 YR 7/2) ; lower lip stained
brownish, probably from bile; throat brownish gray (10 YR 4/1).
(Some silver pups have a continuous bright silver throat and anterior
chest region, without the dark band of the throat as in the present
specimen.) Chest, anterior region, brownish pink (7.5 YR 7/2) ;
chest, posterior region between flippers, and belly, anterior region,
brownish gray (10 YR 3/1) ; belly, posterior region, light brown (5
YR 6/3) ; around penial opening grayish brown (5 YR 4/2) ; armpits
very bright, brownish pink (5 YR 7/2) .
Specimens : Principal specimen, age 8-10 weeks ; killed 24 September
(24-9-58 B). Three others, killed 13 October-17 November; BDM
187, BDM 188, BDM 184.
Silver Pup, Female
Top of snout light yellowish brown (10 YR 6/3) ; upper lip dark
yellowish brown (10 YR 3/3), fading to color of cheeks, which are
light grayish brown (10 YR 7/3) ; region around eyes brownish gray
(10 YR 3/1) ; ears dark grayish yellowish brown (10 YR 3/2) , slight-
ly worn at tips; forehead, crown, back of neck, shoulders, back and
rump brownish gray (10 YR 4/1) ; rump patches prominent, light
brownish gray (10 YR 6/1) ; tail (dorsal) brownish gray (10 YR
4/1); flanks mostly like belly, light grayish brown (10 YR 7/3);
bases of flippers (dorsal and ventral) dark grayish yellowish brown
Lower lips and chin at corners of mouth like top of snout, slight
yellowish brown (10 YR 6/3), but at anterior tip stained darker,
grayish brown (7.5 YR 3/2) ; throat brownish gray (10 YR 4/1) ;
chest, anterior region, light grayish yellowish brown (10 YR 7/2) ;
chest, posterior region between flippers, grayish yellowish brown (10
YR 4/2) ; armpits brownish pink (7.5 YR 7/2), except for narrow
84 APPENDIX A — COLOR NOTES
zone near flippers, where moderate yellowish brown (10 YR 5/3) ;
belly, anterior region, light brown (5 YR 6/3) ; belly posterior region,
light grayish yellowish brown (10 YR 7/2) ; tail, ventral surface,
brownish gray (10 YR 4/1) ; location of mammary teats not visible.
Specimens : Principal specimen, age 8-10 weeks ; killed 28 September
(28-9-58 A). Three others, killed 13 October-17 November; BDM
Yearling, Autumn, Male
Top of snout light brownish gray (10 YR 6/1) ; upper lip light
grayish yellowish brown ( 10 YR 7/2) ; forehead light brownish gray
(10 YR 5/1) ; cheeks light grayish yellowish brown (10 YR 7/2) ;
region around eyes brownish gray (10 YR4/1) ; crown light brownish
gray (10 YR 5/1) ; ears grayish yellowish brown (10 YR 4/2) ; back
of neck (no mane), shoulders, back, and rump light brownish gray
(10 YR 5/1) ; rump patches not conspicuous (though conspicuous on
certain other yearling males), light yellowish brown (10 YR 6/2) ;
tail, dorsal, dark grayish yellowish brown (10 YR 2/1) ; flanks
shading into color of belly, visible well up along sides; bases of
flippers, dorsal and ventral, grayish brown (5 YR 3/2).
Lower lip and chin light yellowish brown (10 YR 6/3) ; throat
brownish gray (10 YR 4/1) ; chest, anterior region, light grayish
yellowish brown (10 YR 7/2) ; chest, posterior region between
flippers, grayish brown (7.5 YR 4/2) ; arm pits moderate brown (5
YR 4/3) ; belly, anterior region, grayish brown (7.5 YR 4/2) ; belly,
posterior region, light grayish yellowish brown (10 YR 7/2), stained
brownish posterior to penial opening; tail, ventral, grayish brown
(5 YR 3/2), with black margins.
Specimens: Principal specimen killed 26 September (26-9-58 A).
Sixteen others killed 13 September-5 November (27-9-58 B, BDM
nos. 7, 8, 14, 15, 21-24, 290, and 512-517) .
Yearling, Autumn, Female
Top of snout and upper lip light brown (7.5 YR 5/4) ; cheeks light
yellowish brown (7.5 YR 7/4) ; narrow region around eyes grayish
brown (7.5 YR 3/2) ; outward of this brownish gray (10 YR 3/1) ;
ears moderate brown (7.5 YR 4/4), rubbed bare at tip; forehead, a
circular region of grayish brown (7.5 YR 3/2) ; crown, back of neck,
THREE-YEAR-OLD, ADOLESCENT MALE (BACHELOR) 85
shoulders, back and rump brownish gray (10 YR 3/1) ; rump with
conspicuous patches of light brownish gray (10 YR 6/1) ; tail, dorsal,
dark grayish yellowish brown (10 YR 2/1) ; flanks intermediate color
between back and belly, appearing light-colored from above; bases
of flippers, dorsal and ventral, dark grayish yellowish brown (10
Lower lip light brown (7.5 YR 5/4) ; chin and throat brownish
gray (10 YR 4/1) ; chest light grayish yellowish brown (10 YR 7/2) ;
belly brownish pink (7.5 YR 7/2) ; tail, ventral, dark grayish yellow-
ish brown (10 YR2/1).
Specimens: Principal specimen killed 3 October (3-10-58 A).
Four others killed 27 October-23 November (BDM nos. 16, 25, 26,
Three-year-old, Adolescent Male (Bachelor)
Top of snout and upper lip light yellowish brown (10 YR 6/3) ;
upper lip palest at corner of mouth, under eye, and darker toward
muzzle ; cheeks also light yellowish brown ; region around eyes grayish
yellowish brown (10 YR 5/2) ; ears grayish yellowish brown (10
YR 4/2), not worn at tips, followed posteriorly by faded streak;
forehead to rump brownish gray (10 YR 4/1) ; crown with an area
about 6 cm. in diameter in which the guard hairs are longer (28 mm.)
than those surrounding (15 mm.) and are erect or slightly recurved;
rump patches faintly suggested; tail, dorsal, dark grayish yellowish
brown (10 YR 2/1) ; flanks, transition color between back and pos-
terior region of belly; bases of flippers, dorsal and ventral, dark
grayish yellowish brown ( 10 YR 2/2) .
Lower lip and chin moderate yellowish brown (10 YR 5/3);
throat brownish gray (10 YR 4/1) ; chest, anterior region, light
yellowish brown (10 YR 6/3) ; chest, posterior region between flip-
pers, grayish brown (7.5 YR 3/2) ; armpits moderate brown (5 YR
3/4); belly, anterior region, grayish brown (5 YR 3/2), shading
gradually into color of belly, posterior region, light yellowish brown
(10 YR 6/3) ; tail, ventral, brownish gray (5 YR 3/1).
Specimens: Principal specimen killed 27 September (27-9-58A).
Ten others killed 22 June-19 July (BDM nos. 60, 67, 70, 72, 73, 77-79,
83, and 87).
86 APPENDIX A — COLOR NOTES
Three-year-old, Adolescent Female (Young Cow)
Top of snout grayish brown (7.5 YR 4/2) ; upper lip light yellow-
ish brown (10 YR 6/3) ; forehead brownish gray (10 YR 4/1) ;
cheeks moderate yellowish brown (10 YR 5/3) ; region around eyes
brownish gray (10 YR 3/1); crown brownish gray (10 YR 4/1);
ears grayish yellowish brown (10 YR 4/2), worn and blackish at
tips; back of neck, shoulders, back and rump brownish gray (10 YR
4/1 ) . Flanks are colors in transition from back to belly. Tail, dorsal,
and bases of all flippers, all surfaces, dark grayish yellowish brown
Lower lip and chin moderate yellowish brown (10 YR 5/3) ;
throat brownish gray (10 YR 4/1) ; chest, anterior region, light
yellowish brown (10 YR 6/3) ; chest, posterior region between
flippers and belly, anterior region, grayish brown (7.5 YR 3/2) ;
belly, posterior region, moderate brown (7.5 YR 4/4) ; location of
mammary teats not visible ; vestibular mucosa dark brownish gray to
black, with narrow rim of dark reddish brown hair (2.5 YR 2/4) ;
tail, ventral, dark grayish yellowish brown (10 YR 2/2).
Specimens: Principal specimen killed 24 September (24-9-58 A).
Three others killed 23 March-15 September (NWC 52-3048, BDM
287, and BDM 410).
Adult Male (Bull)
Top of snout and upper lip grayish yellowish brown (10 YR 5/2) ;
forehead, cheeks, and region around eyes grayish yellowish brown
(10 YR 4/2) ; crown and ears dark grayish yellowish brown (10 YR
3/2) ; crown with longer hairs ("wig") same color as surroundings;
ear tips worn bare, nearly black; back of neck (mane) light yellowish
brown (10 YR 7/4), faintly parted (divergence line) into right and
left sides by the paired neck muscles, longest hairs 70 mm. ; shoulders
and back gradually changing from grayish yellowish brown (10 YR
4/2) to dark grayish yellowish brown (10 YR 3/2) ; rump and upper
surface of tail dark grayish brown (5 YR 2/2) ; flanks grayish yel-
lowish brown (10 YR 4/2) ; bases of all flippers, upper and lower
surfaces, dark reddish brown (2.5 YR 2/4) .
ADULT FEMALE (OLD COW) 87
Lower lip and chin grayish yellowish brown (10 YR 4/2) ; throat,
chest, and belly grayish brown (7.5 YR 3/2) ; penial opening not
marked by color change ; tail, ventral surface, nearly naked, grayish.
Specimens: Principal specimen at least 15 years old, teeth worn
or missing, killed 19 September (19-9-58 A) . Nine other bulls killed
25 June-5 July, all 7-year-olds or older (age 7, BDM nos. 251-255;
age 8, BDM nos. 302-303; age 9, BDM 319; "adult", BDM 75).
Many other known-age males between ages 3 and 7 have been
Adult Female (Old Cow)
Top of snout light brown (7.5 YR 5/4) ; upper lip moderate brown
(7.5 YR 4/4) ; forehead grayish brown (7.5 YR 3/2) ; cheeks moder-
ate brown (7.5 YR 4/4) ; region around eyes grayish brown (7.5 YR
3/2) ; crown grayish brown (7.5 YR 4/2) ; ears light brown (7.5 YR
5/4) along two-thirds of length, bare and blackish on tip; back of
neck grayish brown (7.5 YR 4/2) with a suggestion of a lighter,
grayer color on crown and mane; shoulders, back and rump grayish
brown (7.5 YR 3/2) ; tail, dorsal, dark grayish yellowish brown (10
YR 2/2) ; flanks light brown (7.5 YR 5/4), lightening toward armpit
and darkening toward hind flipper ; bases of flippers, dorsal and ven-
tral, dark grayish brown (5 YR 2/2) .
Lower lip, chin, and throat grayish brown (7.5 YR 3/2) ; chest,
anterior region, light grayish brown (7.5 YR 5/2) ; chest, posterior
region, grayish brown (7.5 YR 3/2) ; armpits moderate brown (5
YR 4/4) ; belly, grayish brown (5 YR 3/2) ; mammary teats not
visible, their location marked by a few gray hairs; vestibular mu-
cosa wrinkled, dark brownish black, surrounded by a thin line of
dark reddish brown (2.5 YR 2/4) ; tail, ventral, also dark reddish
Specimens: Principal specimen killed 25 September (25-9-58 B).
Eight others killed 13 March-11 September; all 7-year-olds or older
(age 7, BDM nos. 276, 279; age 8, BDM nos. 324 and 349; age 10,
BDM 404; age over 10, SITKA 50-25, SITKA 50-34, NWC 52-
3029). Many other females between ages 3 and 7 have been exam-
ined ; also many females recorded simply as "adult."
APPENDIX B— GLOSSARY
For textbook- style illustrations of the structure of hair and skin,
see Auber (1952), Chase (1954), Hamilton (1951), Hausman (1939,
1944), Miller (1952), Montagna (1956), Odland (1954), Parnell
(1951), and Wildman (1954).
Awn. — (See guard hair.)
Bachelor. — Colloquially, a male seal of any age between 2 and 6 years, In-
clusive. Thus, a pup born in summer 1950 became a "yearling" on 1 January
1951, a "bachelor" on 1 January 1952, and a "bull" on 1 January 1957.
Birthcoat. — Pelage of the black pup, newborn.
Blastocyst (blastula). — An early stage of the embryo when the cells are ar-
ranged in a single layer to form a hollow sphere, barely visible to the naked
Blubber (panniculus adiposus). — The thick stratum of yellowish or whitish,
fatty connective tissue which underlies the skin of most marine mammals.
Bulb. — Swollen base where hair root and hair follicle are indistinguishable.
Bull. — Colloquially, a male seal older than 6 years. ( See bachelor. )
Cast. — A negative impression, in a sheet of plastic film or gelatin, of part of
the surface of a fiber.
Club hair. — An inactive, mature hair with characteristic shrunken, rather
than bulbous, base.
Connective tissue sheath. — An especially heavy sheath surrounding the outer
root sheath of the vibrissa. The connective tissue sheath serves for attach-
ment of erectile muscles.
Cortex. — Main substance of the hair, situated between the outer cuticle and
the central medulla; usually pigmented; consisting of dead, keratinized cells.
Cow. — Colloquially, a female seal older than a yearling. Thus, a pup born in
summer 1950 became a "yearling" on 1 January 1951 and a "2-year-old cow"
on 1 January 1952.
Cuticle. — A single layer of translucent cells on the surface of the hair. The
cells are attached at one end, with their thin free margins pointing toward
the tip of the hair. In the fur seal, the cuticle is less than 1 micron thick.
Cuticular-scale pattern. — Various nomenclatures have been proposed, depend-
ing upon shape of the visible portion of the scale, degree of overlap, and form
of external margins. See Wildman (1954) for diagrams and photographs of
coronal, diamond-petal, and other patterns.
Dermis (derma, corium). — The thickest and most elaborate stratum of the
skin (representing, in the fur seal, about 99 percent of its thickness), lying
between the epidermis and the blubber, consisting largely of connective tissue
surrounding the hair roots and the sweat and sebaceous glands.
Epidermis. — The thin surface layer of skin, consisting of two main parts: a
superficial stratum corneum of dead, translucent cells and a deeper stratum
malpighii of active, deeply staining cells. At the site of each hair follicle, the
two layers dip deeply into the dermis.
90 APPENDIX B — GLOSSARY
Fiber. — As used in this work, a hair of any kind, including a vibrissa.
Follicle. — A cylindrical sleeve or pouch, representing an invagination of the
outer skin, in which the hair grows. It is swollen at the base into a bulb.
Follicular bundle (common follicular bundle, common hair bundle). — A group
of follicles, each distinct at its base (bulb) but coalescing near the surface of
the skin. Near the surface of the adult skin, the follicular bundle contains a
guard hair, 35-40 underfur fibers, sweat duct, and 2 sebaceous ducts, all sur-
rounded by a thick, conspicuous sheath (the outer root sheath).
Germ (germ plate, hair germ). — Matrix cells which remain below the hair
follicle, at the tip of the papilla, in the resting stage between molts. They
initiate growth of a new hair at regular intervals.
Guard hair (shield hair, awn hair, overhair). — A fiber of the outer coat of
the juvenile and adult ; largest, thickest, and most deeply rooted of the pelage
fibers ; distinctly pigmented and medullated along most of the shaft ; expanded
toward the tip into a blade. (Certain of the largest ones, appearing widely
spaced in longitudinal rows on the fetus, might be called guide hairs, or
Hair. — The hair is divided regionally into root and shaft; structurally into
cuticle, cortex, and medulla (which see). So far as known, all hairs of the
adult fur seal, except the vibrissae, are replaced annually by new hairs origi-
nating on the sites of their predecessors.
Horizontal section (tangential section). — A section cut in a plane parallel to
the surface of the skin. Since the pelage fibers emerge at a slant, they rarely
appear as true circles in a horizontal section of skin.
Lanugo. — The fine hair on the body of the fetus.
Matrix. — Base of the root bulb where the cells are most actively dividing to
form the hair.
Median section. — A section made in the plane which divides the body sym-
metrically into right and left halves. In a true median section of hair from
the middle of the back, for example, the entire length of the hair can be seen.
Medulla. — Pith of the hair; a series of gas-filled cells along the axis of the
shaft; present only in guard hairs and largest underhairs. See Wildman
(1954) for classification of medullary patterns.
Melanocyte. — A cell in the root of the hair follicle, or elsewhere, which manu-
factures a yellowish brown pigment; melanin. Concentrated melanin appears
Micron. — A unit of measurement : 0.001 mm. or 0.000039 inch.
Molt. — Replacement of an older crop by a newer crop of fur and hair fibers.
In the fur seal, the first molt (in late summer) results in a qualitatively
different population of fibers. Each subsequent annual molt, prolonged over
a period of 4-5 months in autumn, results in a similar, though newer, population.
Munsell color notation. — (See Appendix A and Literature Cited.)
Otariid (eared seal). — Anglicized name for any fur seal or sea lion of the
family Otariidae, including 7 genera (Scheffer, 1958).
Palmar. — Pertaining to the palm.
Panniculus adiposus. — (See blubber.)
Panniculus carnosus. — A discontinuous thin sheet of muscle underneath the
blubber. When a sealskin is stripped forcibly from the body, large patches of
the panniculus carnosus remain with the skin.
Papilla. — A cone of connective tissue, continuous with the dermis, which rises
into the bulb of the follicle.
Parchment cure. — Method, of preserving a sealskin by stretching it on a hoop
and allowing it to dry.
APPENDIX B — GLOSSARY 91
Parous. — Having borne one or more young.
Phocid (hair seal, earless seal, true seal). — Anglicized name for any seal
of the family Phocidae, including 13 genera.
Pilary system. — The pelage, including the hidden roots and nourishing struc-
tures of the fibers as well as their visible shafts.
Pilosebaceous. — Pertaining to the hair and its sebaceous gland or glands. In
the fur seal, the guard hair with follicle and pair of sebaceous glands compose
a pilosebaceous unit. The hair emerges through a pilosebaceous funnel and
orifice. A bundle of underfur fibers emerges through the same funnel and
Plantar. — Pertaining to the sole.
Pore. — On hairless skin, the opening of a sweat gland ; on unhaired skin or
leather, the pilosebaceous orifice.
Prime. — A pelt is prime when molt is complete, that is, when new fibers have
ceased to grow in length ; pigment is no longer being formed in the root ; and
old fibers have been pushed out or shed.
Primordium. — An embryonic hair follicle first visible as a thickening of the
Pup. — A young seal up to about age 6 months, or arbitrarily to 31 December of
the year of birth. In the present report, pups are classified as "black pup, new-
born" ; "black pup, molting" ; and "silver pup."
Rhinarium. — Naked area of roughened skin at the tip of the snout.
Roadskin. — Colloquial term applied on the Pribilof Islands to a seal in shock
from overheating or exhaustion ; also to its skin.
Root. — The basal (proximal) portion of the hair which is buried in the skin
and is surrounded by 1-3 sheaths. Near the deepest part of the root, the hair
matrix (living) becomes the hair (dead).
Root sheath. — The outer root sheath is a pouch-like continuation of the epi-
dermis which surrounds the follicle, except at its extreme base, where the
papilla enters. The inner root sheath originates in the bulb of the follicle and
extends part way up the root of the hair, interlocking with the cuticle of the
hair. ( See also connective tissue sheath. )
Scale. — (See cuticle.)
Sebaceous gland. — A gland secreting an oily hairdressing known as sebum.
Twin glands are associated with each follicular bundle in the juvenile as well
as in the adult pelage. Each gland secretes independently through an exit
near the base of the guard-hair shaft.
Shaft. — The free portion of the hair. At its basal (proximal end, the shaft
may free itself of the root sheath a short distance below the level of the
epidermis. At its terminal (distal) end, it tapers to a sharp tip.
Stage. — Colloquially, a pelt is said to be "stagy", or going through a stage,
when it is molting; especially when dark pigment flecks can be seen on the
buffed side of the pelt.
Stratum. — (See epidermis.)
Sweat gland. — A sweat gland of the apocrine type originates beneath and
beside each guard hair, and empties into the pilary funnel above the exit
of the sebaceous glands. See Woolard (1930) for distinction between the
small, ordinary, superficial eccrine glands of man and the large, deep apocrine
glands of man and lower animals.
Tela subcutanea. — A filmy layer of connective tissue, often difficult to dis-
tinguish, which binds the panniculus adiposus or panniculus carnosus to the
92 APPENDIX B GLOSSARY
Tooth ridge. — Dentin is deposited unequally in winter and summer on the
root of the fur-seal tooth. The result is a series of concentric, alternate,
ridges and valleys which may be counted on the surface of the root up to
about age 10 to 12 years.
Underfur fiber (underfur hair). — One of the fibers of the undercoat of the
adult-type pelage ; first seen in mature form when the pup has reached an age of
about 6 months ; always in bundles of 35 to 40 ; nonpigmented ; nonmedullated,
wavy ; varying but little in cross-section shape and diameter along its length.
Underhair. — A fiber of the undercoat of the pup; shortest, thinnest, and most
superficially rooted of the juvenile pelage fibers; faintly pigmented; usually
nonmedullated ; varying but little in cross-section shape and diameter along
Vellus. — A coating of fine, temporary hairs such as those on top of the flippers
of the fur-seal fetus.
Vibrissa (sinus hair, tactile hair, whisker). — An elaborate sensory bristle,
much larger than any body hair, situated on either side of the snout (mys-
tacial) and above each eye (superciliary).
Yearling. — ( See bachelor. )
Plate 1. — Wet pelage of subadult male in San Diego Zoo. Water parts the tips of
the guard hairs into silvery streaks but does not penetrate to the base of the
underfur. (San Diego Zoo photo by R. Van Nostrand)
Plate 2. — Cross section of subadult male showing pelage relations ; posterior face
of section at level of bronchi ; flesh frozen ; pelage damp; X x k (above) and X 2^
(below). GH — guard hairs; UF — underfur hairs; E — epidermis; D — dermis of
two indistinct zones, the darker one containing the hair roots ; PA — panniculus
adiposus; PC — panniculus carnosus ; TC — tela subcutanea. (3037-9)
Plate 3. — Tanned pelt of subadult male showing pepper-and-salt effect of white-
tipped guard hairs. (Above) Outer surface; anterior end at left: X 4. (Below)
Inner surface, with guard hairs extending beyond wooly underfur fibers : leather
at bottom of photo; X 4. (1285 and 1292 A)
Plate 4-A.— Strip of parchment-cured pelt from back of subadult male; 12 July;
Plate 4-B. — Freshly cut section of pelt of yearling with drop of water placed on
underfur to demonstrate its water-repellent nature; 7 September; X 4. (4063)
Plate 5.— Scaly appearance of epidermis from back of subadult male ; 12 July ; skin
sample parchment-cured; later macerated 20 days in warm water; plucked;
hardened in formalin; illuminated from anterior end (top) ; photographed in moist
condition: X 40. (4212)
Plate 6. — Surface of suede-tanned leather from back of neck of 5-year-old female,
showing distribution of pilosebaceous orifices, or "pores." A bundle including 1
guard hair and 35 to 40 underfur hairs was withdrawn in the tanning process
from each pore. Anterior end of body toward top of photo; X 40. (4075)
Plate 7-A.— Small square of parchment-cured pelt from back of subadult male.
Lateral view; X 4. (3913)
Plate 7-B. — Transverse section of pelt from rump of adult female showing natural
waves in underfur; fibers held together with tritolyl phosphate; anterodorsal view;
X 3. (3985)
Plate 8.— Silhouette of bit cut from tanned skin of neck of 9-year-old male, showing
underfur fibers, ordinary guard hairs, and long guard hairs (mane hairs) ; 1 July;
X 2. (4152)
- PF --,V^"--
/ 4 r...
y. • s-j--- *
sbg- ^^ v :
Plate 0. — Median section through skin of back of 7-year-old male; 30 September;
pelage oot fully prime; pigment cells still active in bulbs <>f underfur follicles and
guard-hair follicles: X •">•>. B — bundle of underfur hairs: E — epidermis ; GH —
guard-hair bulb : PF — pilosebaceous funnel ; SBG sebaceous gland; SWG- sweat
gland ; UP— underfur-hair bulb. I 4170)
Plate 10. — Median section through skin of back of 7-year-old female ; 30 September ;
X 30. (4171)
Plate 11. — (Left) Duct of sweat gland rising from secretory portion ; median section
of skin from back of 5-year-old female; 23 September; X 120. (Right) Similar;
secretory portion of sweat gland of 3-year-old female; 5 September X 400.
(41 70 and 4180)
Plate 12. — Sweat droplets appearing on palmar surface of fore flipper freshly
severed from body of 3-year-old female seal; exposed to heat lamp; X 4. (4055)
^M W lk< ' • V
> If \ *
Plate 13.— Horizontal section, at depth of about 0.1 mm., from back of neck of
3-year-old female ; pelage fully prime ; 7 February ; posterior end at top ; X 200.
X«»te 8 entire follicular bundles, each with a single, large, round, translucent
section of guard-hair root and 35 to 40 underfur roots. ' 1-09)
Plate 14. — A single follicular bundle; X 800. Note (above) bundle of 40 underfur
fibers, (left) sweat duct, and (below) guard nair flanked by 2 sebaceous ducts.
Plate 15.— (See pi. 13.) Section at depth of about 0.4 mm., where sebaceous glands
are largest in cross section; x 200. Note sweat duct between guard hair and fur
Plate 16. — (See pi. 13.) Section at depth of about 1.0 mm., near base of underfur
roots ; X 640. Note follicles of underfur fibers at various levels ; some being
more superficial, appearing as dark bulb-sections. At lower right, the sweat duct
rises through the base of a large sebaceous gland. (4215)
9?\ J ■■■■->' *J*/
Plate 17.— (See pi. 13.) Section at depth of about 1.2 mm., showing lumens of
sweat glands; x 200. Note (center) the dome of a gland, with its duct, beside
a guard-hair follicle. (On another section cut nearer the surface, a bundle of
underfur fibers is situated vertically above this dome.) (4216)
Plate 18. — Bundles of fibers rising from surface of skin of subadult male ; antero-
dorsal view. (Above) Parchment-cured skin. (Below) Plucked, chamois-tanned,
black-dyed skin. (39S6 and 3939)
Plate 19. — Bundles of fibers rising from surface of skin of subadult male; antero-
dorsal view: x 40. (Left) Ilyrax mount ; each prominent, white-dotted column
is the medulla of a guard hair. A tuft of underfill - fibers, Donmedullated, rises
from the pilosebaceous orifice behind the guard hair. ( Right i I'olyvinyl-acetate
mount, showing portion of root as well as shaft ; medulla here appearing black
rather than white. I :'.'.»li'.» and U14)
• » ' *■
Plate 20. — Root of guard-hair follicle in median section of skin from back of
4-year-old male: 2 September; X 80 (above) and X 400 (below). B — bulb;
IRS— inner root sheat; ORS — outer root sheat; P— papilla. (4182 and 4183)
Plate 21. — Vibrissa of 144 jr. fetus: 25 January: cross section of upper portion of
follicle: X 200. Primordia of nonspecialized body hairs appear at top of photo.
CTS — connective tissue sheath (much thicker around vibrissa than around guard
hair): IRS — inner rool sheat; <>KS -outer root sheath: V — vibrissa, mainly pig-
mented cortex with thin, dark cuticle and suggestion of central medulla. (4163)
i'L ' ft* t "■ ' '*nflr
Plate 22.— Stumps of underfur fibers and guard hairs from parchment-cured seal-
skin ; in tri-n-butyl phosphate ; fibers cut at approximately halfway point ; antero-
dorsal view showing flat side of each guard hair; mountant has partly invaded
medulla and has pushed original gas upward through cut tips of guard hair;
X 50. (4118)
Plate 23. — Cross sections (by Hardy device) of adult-type pelage; X 300. (Left)
Prime silver pup; 13 October; tanned skin. Smallest bodies are underfill- fibers;
largest are guard hairs of various sizes. (Right) Subadull male; L2 July;
parchment-cured skin. Note that guard hairs are Larger and darker h«re.
(4153 and 4112)
Plate 24. — Cross section of coarse mane hairs ; some white and some dark brown ;
cut about 1 cm. from surface of skin; 10-year-old male; (left) X 120; (right)
X 800. (4099 and 4098 A)
V * t' i MA
$?' N ^*M
«- vV 3 v^ "> -Air/
Plate lm. — Cross section of underfur fibers of finished, brown-dyed, subadult male
sealskin ; y 1000. <411h 0)
*^l* * *»PV
Plate 26-A. — Pigment granules in blade of large guard hair from mane of 10-year-old
male ; field includes about one-third of cross section ; medulla not open at this
level; X 1000. (4160)
Plate 26-B. — Underfur fibers from back of subadult male; parchment-cured skin;
thermoplastic cast ; X 100. Note smooth attenuated root of one liber. (4080 A)
I'i.aii; 1^7. — Guard bairs against background of fine underfur Qbers; first adult-type
pelage; silver pup; 13 October. (Only the medulla or pith of tbe hair stands out
in tbis niountant.) (Above) Hairs of various sizes; X 100. (Below) Portions
of two medium-size hairs: >< 500. I U02 A and 4102 B)
Plate 28. — Cuticular-scale pattern on basal region of shaft of guard hair ; parchment-
cured skin: thermoplastic casts; X 100 and X 500. (4092 O and 4094)
- '■'' V-
Plate 29. — Cuticular-scale pattern on blade of shaft of guard hair; parchment-cured
skin: thermoplastic cast ; x 500. (4091 B)
Plate 30. — Cuticular-scale patterns on underfur fibers from pelt of subadult male ;
parchment-eured ; gelatin casts; X 500. (Left to right) basal region, middle
region (3 fibers), and tip. (4088 A, B, C, D, F)
Plate 31. — Medulla of guard hair of albino in first adult-type pelage; 2 December;
basal region of shaft in benzol ; x 500. Gas-filled chambers of the medulla reflect
light and cause the pelage to appear white. (4185)
Plate 32-A. — Primordinin of hair follicle developing as thickening of epidermis in
skin of back of 23.7 g. fetus ; X 500. (4158)
Plate 32-B. — Three early follicles pushing downward into dermis of 161 g. fetns ;
X 500. (4162)
Pi.atk 33.— Surface of skin from back of 144 g. fetus; each bump the site of a hair
about to erupt ; specimen removed from formalin to alcohol ; now partly dried ;
posterior end of body at top of photo; X 40. (3910)
Plate 34. — Fetus of 260 g. ; 19 January ; when first, almost invisible, hairs are
appearing on face and head; superciliary and niystacial vibrissae well developed.
Plate 35.— Earliest pelage, on cheek-skin of 260 g. fetus. (Above) Median section
showing roots; X 100. (Below) Surface view showing Shafts Of several hairs
and many whitish humps indicating sites of other hairs about to erupt ; posterior
end at top; X 25. , ,|,; s and 4123)
Plate 36. — Body of fetus, weight 372 g. ; standard length 255 mm.; female; photo-
graphed in fresh condition out of mother killed 16 February and held on ice until
23 February. (1802 A)
w r ■ \ »f 'I
1 ' *'•
■"WW* A--- '
\\ • li ' •**• ft ft jfc
Aft, • iWr.'*' '77, ■ Jitfv
Plate 37.— Horizontal section, at depth of about 0.1 mm., from back of neck of
575 g. fetus; posterior end at top; X 200. The 5 large objects are hair follicles;
the numerous small dark ones may be (?) nnderhair primordia. (4191)
Plate 38-A. — Unclerhairs erupting on back of 660 g. fetus; X 25.
t fill 111 *
i ( i f * i u i I i
Plate 38-B. — Large, coarse guard hairs beginning to appear in field of smaller
guard-hair tips and underhairs ; on back of 1.93 kg. fetus; X 10. (4134)
Pi \n: 39.— Developing underhairs and guard hairs on back of neck of 1.45 kg. fetus;
earlier growth at anterior end (bottom of photo); X 10. (4139)
Plate 40. — Pelage developing on back of 2.21 kg. fetus ; 2 May ; anterodorsal view ;
X 50. (3931)
Plate 41-A. — Head of 1.7 kg. fetus ; natural size.
Plate 41-B. — Three male fetuses showing pelage development; 1.4 kg. (27 April) ;
2.7 kg. (28 April) ; 3.7 kg. (9 May). (KWK 50-630)
Plate 42. — Bases of developing underhairs and guard hairs on back of 2.44 kg.
fetus (0.5 mean newborn weight) ; fibers shaved; partly dried; X 40. (3974)
Plate 43. — Twin fetuses of 9 May; removed from uterus preserved in formalin;
X 0.33. Each is a female in nearly mature birthcoat ; one is 54 cm. and 3.43 kg. ;
the other 53 cm. and 3.49 kg. (4017)
Plate 44. — Full-term fetus ; female ; weight 3.3 kg., length 54 cm. ; 6 July ; pelage
glossy black. (1682 and 1683)
Plate 4.">. — Black pup, newborn female ; anterodorsal view of hair shafts rising from
skin ; formalin specimen : X 40. Xote coarse guard hairs and fine underhairs
rising more or less independently. (3937)
Plate 46. — Horizontal section, at depth of abont 0.1 mm., from back of neck of
full-term fetus (black pup); posterior end at top; X 200. Follicular bundles
include 1, 2, or 3 hairs; the anterior one a guard hair. (4193)
Plate 47-A. — (See pi. 46.) Section at depth of about 0.2 nun. ; through one follicular
bundle ; X 400. Note guard hair at right, underhair at left, and sebaceous glands
above and below. (4195)
mil "t^r^^5^r*. ^'ffrk * - v < *fe- » v
x., * —
Plate 47-B. — (See pi. 46.) Section ;tt depth of about 0.8 mm.; bulb of guard-hair
follicle at right; bulb of underhair follicle at left, surrounded by primordia of
adult-type underfur follicles ; X 400. (4196)
Plate 48. — Black pups, molting, on 29 July. Loose birthcoat fibers are blowing
about on the sandy rookeries at this time of year. (2250A)
Plate 49. — Black pup, molting; approaching silver stage; 15 September; wet pelage
of hack of neck; X 2.3. Pup had come out of ocean and shaken itself, and was
sprawled on a rock. Guard hairs 20 mm. in length: umlerhairs 11 mm. (See
plate .10.) (4036)
Plate 50. — Black pup, molting; 15 September; posteroventral view of fresh, dry
pelage from back ; X 8. ( Same specimen as shown in plate 49. ) Pigmented roots
of many adult-type guard hairs may be seen in the skin; adult-type underfur
fibers are beginning to dominate the surface pelage. (4142)
Plate 51. — Tanned pelts showing transition from birthcoat to first adult-type pelage.
A.— black pup; newborn female; 12 July; 4.42 kg. (9.75 lb.). B.— black pup;
molting female; 11 August; 9.30 kg. (20.5 lb.). C— black pup; molting male;
29 September; 14.7 kg. (32.5 lb.). U. — silver pup; autumn female; 13 October;
15.2 kg. (33.5 lb.). (4190)
Plate 52-A. — Head of silver pup; male; 24 September; entire weight of animal
12.7 kg. (28 lb.). (4056)
Plate 52-B.— Similar ; female; 28 September; weight 11.8 kg. (26 lb.). (4066)
Plate 53. — Tanned pelt of yearling, pelagic; male; 25 April; X 0.2. Compare
with silver pup in pi. 52-A. Dark streak along back is an artifact, a result of
folding. (4000 NWC 52-3656)
Plate 54.— Tanned pelt of yearling, autumn ; female ; 31 October ; in second adult-
type pelage; X 0.2. (4000 BDM 25)
Plate 55. — Head of yearling, autumn; male; 26 September.
Plate 56. — Four-year-old male on 26 July, entering its 5th year of life and its 5th
molt. This molt centers in October. Length 141 cm. (55.5 in.) ; weight 51.2 kg.
( 113 lb. ) ; scar on neck represents hot-iron brand applied in first summer ; dorsal
Plate 57. — Similar to preceding figure ; ventral view.
Plate 58. — Eight-year-old male on 2 July; length 191 cm. (75 in.) ; weight 184 kg.
( 405 lb. ) . Note metal tag, applied 8 years previously, on right fore flipper. ( 2571)
Plate 59. — Nine-year-old male on 27 June; length 106 cm. (77 in.) ; weight 188 kg.
(415 lb.). Note hot-iron brand, dark spot on lower edge of mane. (2564)
Plate 60.— Tanned pelt of adult female (age 10+) taken on breeding ground on
30 October ; in dingy old pelage ; X 0.14. Compare plates 61 and 62.
Plate 61. — Same pelt as in preceding figure; reverse side showing roots of replace-
ment guard hairs ; a typical unprime skin ; X 0.14. (4000 USNM 2S6032L)
Plate 62.— Tanned pelt of adult female (age 10+ ) taken at sea on 28 March ; in bright
new pelage; X 0.14. Compare plates 60 and 61. (4000 SITKA 50-25)
Plate 63. — Horizontal section, at depth of about 0.1 mm., from back of neck of
yearling during molt; 26 September; posterior cud at top; x 200. In two of the
larger follicular bundles the wide blade of a new guard hair is erupting. (4204)
Plate 64. — (See pi. 63.) One follicular bundle; X 600. Note (from top to bottom)
bundle of underfur fibers, with newer, strap-shaped fibers above and older, cylindri-
cal fibers below; sweat duct (left); wide, pigmented blade of erupting guard
hair; round, translucent root of old guard hair. (4207)
Plate 65. — Molt line on rump of yearling, autumn; female; 3 October; X 0.7.
Second adult-type pelage is progressing toward rear (toward bottom of figure).
Plate 66. — Tanned pelt of 2-year-old female; 21 September; in third molt; pelage
short and lacklustre; X 0.2. (4000 BDM 239)
Plate 67. — Reverse side of unprime pelt which was shown in plate C><; : anterior end
toward bottom of photo; X 40. Note black stumps of replacement guard hairs,
cut off on 21 September before they had reached the surface. Insert is X 4.
(4010 and 4008)
Plate 68-A.— Two niystacial vibrissae from 6-year-old female, showing massive
connective-tissue sheath around root; specimen cleaned by marine amphipods ;
X 6. ( 413 °)
Plate 68-B.— Vibrissa of 10-year-old male showing smooth surface; X 50. (3951)
Piate 69.— Cross section of vibrissa of black pup (full-term fetus) showing: open
medulla; broad cortex, pigmented excepl Eor narrow peripheral baud; thin cuticle
appearing dark under this illumination; X 400. (4157)
Plate 70-A.— Face of 103 g. fetus with full set of 20 mystacial vibrissae; X 6.
Plate 70-B. — Vibrissae of adult male turned outward and forward in threat reaction
during breeding season; 15 July; vibrissae white at this age. (2647)
Plate 71. — Vibrissas of subadult males, ages •". and 4 years, plucked on killing field by
small boy. in these year-classes the vibrissae are beginning to turn white at base,
and to present a mottled appearance. (2221 )
Plate 72.— Four pelage phases of the pup on 11 October (reading clockwise) : pup
born late in summer and termed "black pup, molting" ; pup in first adult-type pelage
termed "silver pup" ; and two freaks termed "chocolate" and "albino," respectively.
Plate 73-A. — Albino pup in first adult-type pelage, corresponding to "silver" pelage
of normal pup in autumn; male; 10 October. (2321)
Plate 73-B. — Head of female albino pup; Seattle Zoo; 2 December; dark areas are
Plate 74.— Albino adult female collected on rookery, 15 August, in stained coat which
she had been wearing for about 10 months. (2871)
Plate 75-A. — Piebald subadult male; 8 August.
Plate 7.">-P». — Partial albino pup in birthcoat (molting) ; 11 August : eyes and flippers
pinkish white; underhair white; guard hair grayish brown. (2436)
Plate 76-A.— Two adult bulls, exemplifying range in pelage color from light to dark ;
22 July. ( 2056 >
Plate 76-B — Pelt of subadult male; pale phase; 5 August. (4000 BDM 350)
Plate 77-A. — Adult cows with blotchy or "rubbed" pelage ; guard hair absent in
patches; 23 July. (1004)
"^t .^BH wlr^ sI^b^H^^Bjp ^* ^T^^^^H^^^k^
8-'S^.»^S*' *■ * ^
> ' 1
Plate 77-B. — Similar ; body of 6-year-old cow ; washed and nearly dried ; 12
September; dorsal view. (4031)
Plate 78. — Body of subadult male with "rubbed" back ; 26 July.
Plate 79. — Top of head of subadult male shown in preceding plate. (1872)
Plate 80. — Fresh, damp pelt of 2-year-old female lacking most of guard hair ; guard
hair present only in patches on face and on bases of flippers; 2 July. i 2*21 )
Plate 81. — Tuft of fur from "rubbed" area on back of subadult male, showing absence
<>f guard hairs but fairly normal appearance <>f onderfur fibers; 27 July; postero-
ventral view: X 15. ■'■'" I
Plate 82-A. — Bare, scabby areas on rump of black pup, molting
at right of center.
Plate 82-B. — About 130 lice feeding on penial opening of black pup, molting; 11
August; X 4. (1903)
Plate &3. — Pachyderma ; subadult male skin rejected from commercial take on St.
Paul Island ; 3 July ; anterior edge of section cut from back ; alcohol ; X 8. (4167)
Plate 84.— Pelt of old female exemplifying poor fur quality. Killed 10 August;
unhaired in St. Louis on 28 October of following year ; dried on hoop.
(3996 ex Harry May)
Plate 85. — Right fore flipper of subadult male, showing blisters on dorsal surface :
1G July; fresh; about X 0.6. On this individual, both surfaces of all flippers were
Plate 86.— Cryptorchid killed on 7 July ; length 188 cm. (74 in.) ; weight 101 kg. (222
lb. ) . Note slender, ungainly appearance of trunk and limbs ; absence of wig and
Plate 87-A. — Cryptorchid in right foreground, treated as "female" by harem bull at
left; 15 July. (1708)
Plate 87-B. — Tanned i«'lt of same cryptorchid, original body weight 101 kg. (222
lb.) ; length of tanned skin, snout to tip of tail, 200 cm. I 1000 BDM 86)
Plate 88. — Brown alga Ectocarpus on left flank and belly of subadult female shot at
s(>;i off central California; 12 December; (below) enlarged to natural size.
Platk 80. — Barnacles Lepas attached to (lamp pelage on rump <>f subadull male aboul
:: years of age; St. rani Island; 18 July; X %. Pell has been removed and blub-
bered; many barnacles have been crushed. < 1850)
Plate 90.— Blubbering or defatting a sealskin after it has been washed for 24 hours
in cold running sea water ; St. Paul Island; 16 July. (2031)
Plate 91. — Freshly blulibeivd sealskin.
Plate 92. — Commercial sealskin taken on 27 July from subadult male about 3 years
of age ; skin blubbered, wrung, shaken, and dried under fan for 2 hours ; weight
1.93 kg. (4.25 lb.) ; X %. (2420)
Platk 93.— Sealskin at processing plant, having been washed, hooped, and dried in
preparation for unhairing. (Fouke Fur Co.)
Plate 94-A. — Unhairing
(Fouke Fur Co.)
Plate 94-B. — Dyeing.
(Fouke Fur Co.)
-»■«■■■»•- £* ■> _*. - *~ . /em,
Plate 95-A. — Fragment of untannecl sealskin immediately after the unhairing
process; lateral view; anterior end toward viewer's left; X 7. (2923 A)
Plate 95-B. — Fragment of finished sealskin after all processing, including tanning.
dehairing, and brown-dyeing ; near posterolateral view; x 7. (2924)
fj~&z~ y %\|**
Plate 96. — Looking down on fragment of tanned, unhaired pelt from neck of 4-year-old
male : killed 22 July ; anterior end at top ; X 10. Insert is natural size.
(4006 and 4002)
Plate 97. — Demonstration pelt showing three stages of processing (from top to
bottom) : "tanned in the hair," with all fillers intact ; "unhaired." with guard hairs
removed; and "finished," with fur filters straightened and dyed brown. Specimen
courtesy Fouke Fur Co. | l'718)
. - N
W fir"' fH
l^»^ \ \
< / at * - If' d t ' i fl f l* tUiiJMiiSMUKk
Plate 98-A. — Snout of yearling male ; 26 September ; about X 1.8. The "cowlick"
above the rhinarium is double on certain individuals. (4062)
Plate 98-B. — Profile of head of yearling female showing mouth ; 3 October. (4067)
Plate 09.— Eye of 3-year-old female; Seattle Zoo; 20 December; X 2. (3SS4)
Plate 100. — "Tears" on the cheek of a female seal on a warm, quiet day ; 15 July.
Plate 101-A.— Left ear of 1.19 kg. fetus ; X 10.
Plate 101-B. — Ear of 0-year-old female ; edges held apart by a pin ; 17 September ; X 3.
Plate 102. — The four mammary teats and the navel (center) on an adult female;
20 July. (1848)
Plate 103-A. — Right anterior teat, forcibly extended and hardened in formalin, of
old, parous female; 2 September; natural size. (4218)
Plate 103-B. — Inside of two skins showing one posterior teat on a nulliparous (left)
and on a parous, laetating individual (right). Seals killed 27 September; skins
held in salt until 12 May ; blubbered and photographed. (2735 A)
Plate 104.— White discs show location of the navel and 4 rudimentary teats on a
6-year-old male; 9 September; about X Vi- (4028 A)
Plate 105. — Leather side of tanned, buffed pelt of yearling male killed about 1
November, showing location of four rudimentary teats; x %. (4000 RDM 516)
Plate 106-A. — Belly of adult female seal after 500 ml. embalming fluid has beeu
injected in each teat. (4025 and 4026)
J? Vftv t*
f vm f 1
Plate 106-B. — Portion of mammary gland peeled down (by knife) from smooth
tissue which connects it to body; X 3. (4034)
Plate 107-A. — Tail of 6-year-old male ; scrotum relaxed ; 9 September ; natural size.
Plate 107-B. — Tail of old bull ; scrotum pulled forward in order to reveal anus ; 20
September; natural size. (4049)
Plate 108. — Lower abdomen of female, weight 22.6 kg. (50 lb.) ; probably nulliparous ;
4 August. Light-colored region is vestibule, with clitoris in front and anal opening
behind and hidden. (1898)
Plate 109. — Surface of right heel of silver pup; 28 September; X 10. (4065)
Plate 110. — Right flippers of old male (above) and 7-year-old female (below) ; dorsal
view ; X 0.18. (2413 and 2425)
Plate 111-A. — Claws of 6-year-old male; digits 3 (in background) and 4 (in fore-
ground) of left hind flipper; X 1.3. (4030)
I'late 111-B. — Roentgenogram of hind flipper of 3-year-old male, showing 3 functional
claws; X 1.2. (4188)
Plate 112. — Adult female scratching herself. Only the three middle claws of the hind
flippers are functional. (4140 ex Karl W. Kenyon)
US GOVERNMENT PRINTING OFFICE : 1962 O — S53006
OCCIDENTAL COLLEGE LIBRARY
1 49.30:64 docus
Pelage and surface topography/Scheffer,
3 5043 00316 9017
Demco, Inc. 38-J