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Full text of "North American fauna"

BOSTON PUBLIC LIBRARY 



3 9999 06317 638 

PELAGE AND 
SURFACE TOPOGRAPHY 

OF THE 

NORTHERN FUR SEAL 



OCCIl 



DEPOSITORY 



t ft^HAfcEKfr^ 




NUMBER 64 



UNITED STATES 

DEPARTMENT OF THE INTERIOR 

FISH AND WILDLIFE SERVICE 



PELAGE AND 
SURFACE TOPOGRAPHY 



OF THE 



NORTHERN FUR SEAL 



By 

Victor B. Scheffer 

Biologist, Branch of Marine Mammals 
BUREAU OF COMMERCIAL FISHERIES 




NUMBER 64 



[_MAR 3 1 200 q 



UNITED STATES 
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 
February 1962 



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 



CONTENTS 



Page 

Abstract v 

Introduction 1 

Previous research 1 

Methods 2 

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 

Underhairs 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 

in 



IV CONTENTS 

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 

Ears 52 

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 

Summary 61 

Literature cited 65 

TABLES 

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 

APPENDIXES 

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 
Plates 1-112 95-206 



ABSTRACT 



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 
before September. 

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) 



INTRODUCTION 

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. 

Previous Research 

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, 



2 INTRODUCTION 

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. 

Methods 

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. 



METHODS 6 

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 
sheath. 

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 
glands. 

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 PELAGE 

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 
next chapter. 

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) : 

Approximate duration 
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- 
tember). 

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 

September. ) 

3-year-old, adolescent male (bachelor) 1 year (e.g., 1 October-30 Septem- 
ber). 

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- 

9 



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 
newborn weight. 

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 
November. 

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 
46.) 

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 
anus. 

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 
at all. 

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- 
ing amounts. 

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 
this kind. 

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 
hair. 

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. 

UNDERHAIRS 

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 
curly. 

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 
0.2 mm. 

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). 

UNDERFUR FIBERS 

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 
guard hairs. 

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 
diameter. 

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 
silhouette. 

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 
bubbles. 

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. ) 



PELAGE HAIRS 



25 






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." 

FIRST MOLT 

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. 

SECOND MOLT 

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 ? ) 

THIRD MOLT 

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 

8-year-olds 2 

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 
females. 

It has already been noted that the true cinnamon color of the adult 
underfur is first attained at the conclusion of the third molt. 

FOURTH 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 
is uncertain. 

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. 

Pelage Anomalies 

COLOR ANOMALIES 

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 
removed. 

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 
follows : 

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 
flipper : 

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. 

FOREIGN GROWTHS 

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, 
1916,1917,1922,1938). 

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 
and females. 

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 
products. 

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 



43 




Figure 2. — Outlines of the five boards used for size-grading raw, salted sealskins 
X y 8 (see table 6). 



553006 0—62- 



44 



THE PELAGE 




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 



46 



THE PELAGE 



PERCENT 
50 i- 



40 



30 



20 



10 







SM 



M 



XL 



XXL 



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 



47 



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 



POUNDS 

10 r- 



8 - 



6 - 



4 - 



2 - 







— 








Milt'' 

,,11111 


( 
> 


o - 


- 



38 40 42 44 46 48 50 
INCHES 



Figure 5. — Weight of fresh male sealskin with relation to field length of seal. 
(Data from table 10; vertical lines = range, circle = mean.) 



48 



THE PELAGE 



PERCENT 

100 i- 




-//- 



48 49 50 51 



M 



SIZE: SM 



M 



XL 



XXL 



D 



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 



49 



PERCENT 
100 p 

80 ■ 

60 

40 



20 








N'. 41 42 43 44 45 46 47 48 49 50 51 



SIZE-- SM 



M 



xl[] xxlQ 



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 
SURFACE TOPOGRAPHY 

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 
to appear. 

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 
98-B). 

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). 

51 



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. 
in diameter. 

EARS 

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 
land carnivore. 

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 
preceding chapter.) 

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 
use." 

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 



55 



AMT 



N 
PMT 




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 
107-A). 

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- 
ceding chapter.) 

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 
operations." 

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 
follows : 



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, 
60 mm. 

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 
sealskins : 

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. 

(21.2° C.) 
Lovibond color using a 1-inch column : 

Yellow 20 

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 
depots.*' 

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 
pathological condition." 

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. 



SUMMARY 

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 
tail. 

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 



62 SUMMARY 

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- 



SUMMARY 63 

ment ceases to form at the roots of the whiskers (vibrissae) in both 
sexes. 

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, 



64 SUMMARY 

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 
percent fat. 

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. 



LITERATURE CITED 

Abegglen, C. E., A. Y. Roppel, and F. Wilke. 

1956-1958. Alaska fur seal investigations, Pribilof Islands, Alaska. 

Report of field activities June-September . . . Published annually by U.S. 

Fish and Wildlife Service, Seattle. Processed. 
American Medical Association Journal. 

1943. Can hair turn white overnight? 121 : 161-162. 
Aoki, T., and M. Wad a. 

1951. Functional activity of the sweat glands in the hairy skin of the dog. 
Science, 114 : 123-124. 

AUBER, L. 

1952. The anatomy of follicles producing wool-fibres, with special reference 
to keratinization. Royal Society of Edinburgh, Transactions, 62 : 191-254, 
5 pis. (lin color). 

Baalsrtjd, K. 

1956. Astaxanthin in the muscle of cod. Nature, 178 : 1182-1183. 
Bachrach, M. 

1946. Fur ; a practical treatise. Rev. ed. Prentice-Hall, New York 672 p. 
Baker, R. C. 

1957. Fur seals of the Pribilof Islands. U.S. Fish and Wildlife Service, 
Conservation in Action No. 12. 24 p. 

Bartholomew, G. A., Jr. 

1951. Summary of observations made by . . . Bartholomew ... on the 
social and reproductive behavior of the Alaska fur seal during June, 
July, and August, 1951. U.S. Fish and Wildlife Service, Seattle, MS 
report, 4 September, 3 p. 

Bartholomew, G. A., Jr., and P. G. Hoel. 

1953. Reproductive behavior of the Alaska fur seal, Callorhinus ursinus. 
Journal of Mammalogy, 34 : 417-^436. 

Bassett, C. F., and L. M. Llewellyn. 

1948. The molting and fur growth pattern in the adult silver fox. Ameri- 
can Midland Naturalist, 39 : 597-601. 

1949. The molting and fur growth pattern in the adult mink. American 
Midland Naturalist, 42 : 751-756. 

Bassett, C. F., O. P. Pearson, and F. Wilke. 

1944. The effect of artificially increased length of day on molt, fur growth, 
and priming of silver fox pelts. Journal of Experimental Zoology, 96 : 77- 
83. 

Beroersen, B. 

1931. Beitrage zur Kenntnis der Haut einiger Pinnipedier . . . Skrifter 
Norske Videnskaps-Akademi i Oslo, Mat, -Naturvidensk. Klasse, 1931 : 
1-179, 22 pis. 

BlSSONNETTE, T. H. 

1935. Relations of hair cycles in ferrets to changes in the anterior hypo- 
physis and to light cycles. Anatomical Record, 63 : 159-168. 

1942. Anomalous seasonal coat-color-change in a small male Bonaparte's 
weasel . . . American Midland Naturalist, 28 : 327-333. 

65 



66 LITERATURE CITED 

Bissonnette, T. H., and E. E. Bailey. 

1944. Experimental modification and control of molts and changes in coat- 
color in weasels by controlled lighting. New York Academy of Sciences, 
Annals, 45 : 221-260. 
Bowers. D. E. 

1956. A study of methods of color determination. Systematic Zoology, 
5 : 147-160, 182. 
Bowkeb, R. C. 

1931. Some physical properties of fur-seal skins. Technical Association 
of the Fur Industry, Journal, 2 : 34-43. 
Bbondsted, H. V. 

1931. Bygninger af Snuden og Ansigtsmuskulaturen hos nogle Pinnipedier 
. . . K. Danske Vidensk. Selsk. Skrifter, Naturvidensk. og Mathem. Afd. 
9. Raekke, IV. 2, p. 41-55, 12 this. 

Carlisle. D. B. 

1954. On the relationship between mammary, sweat, and sebaceous glands. 
Quarterly Journal of Microscopical Science, 95 : 79-83. 
Carter. H. B. 

1939. A histological technique for the estimation of follicle population per 
unit area of skin in the sheep. Council for Scientific and Industrial 
Research. Australia. Journal, 12 : 250-258. 
Chase. H. B. 

1954. Growth of the hair. Physiological Reviews, 34: 113-126 (incl. bibl. 
of 78 titles). 
Clegg. W. 

1951. Characteristics of oil from cold-rendered fur seal blubber. U.S. Fish 
and Wildlife Service. Commercial Fisheries Review, February, p. 30-31. 
Danfobth, C. H. 

1925. Hair. Journal of the American Medical Association, Chicago, 152 p. 

FOBTUNE MAGAZINE. 

1930. The seal and the U.S. Treasury. November, p. 70-72, 122, 124. 
Fouke, P. B. 

1949. St. Louis : fur sealskin market of the world. American National 
Fur and Market Journal, 27 : 13, 76-77. 
Fouke Fub Company. 

1958. The romance of the Alaska fur seal. Published by the company, 
St. Louis. 48 p. 
Fub Tbade Review. 

1916. First batch of seals dyed in St. Louis. May, p. 80-81. 
Gbeen, D. D. 

1947. Albino coyotes are rare. Journal of Mammalogy, 28 : 63. 
Guxn, C. K. 

1932. Phenomena of primeness. Canadian Journal of Research, 6: 387- 
397, 2 pis. 

Hall, E. R. 

1951. American weasels. University of Kansas Publications, Museum of 
Natural History, 4 : 1-466, 41 pis. 
Hamilton, J. B. (Editor) 

1951. The growth, replacement, and types of hairs. Annals of the New 
York Academy of Sciences, 53 : 461-752 (27 articles, 27 authors) . 
Hardy, J. I. 

1935. A practical laboratory method of making thin cross sections of 
fibers. U.S. Department of Agriculture, Circular 378. 10 p. 



LITERATURE CITED 67 

Habdy, J. I., and Thoba M. Plot 

1940. An improved method for revealing the surface structure of fur fibers. 
U.S. Fish and Wildlife Service, Wildlife Circular 7. 10 p. 
Hausman, L. A. 

1939. Furs under the microscope. Nature Magazine, November, p. 501-503. 
1944. Applied microscopy of hair. Scientific Monthly, 59 : 195-202. 
Jobdan, D. S., and others 

1898. Observations on the fur seals of the Pribilof Islands, 1872-1897 . . . 
[part 2, p. 250-606]. In The fur seals and fur-seal islands of the North 
Pacific Ocean . . . edited by David Starr Jordan. Govt. Print. Off- 
Washington, Treasury Department Document 2017, 4 parts. 1898-99. 
Kbumbiegel, I. 

1954. Kbrperbedeckung [vol. 1, p. 39-68]. In Biologie der Saugetiere. Agis 
Verlag GmbH, Krefeld. 2 vols. 
Maebz, A., and M. R. Paul 

1950. A dictionary of color. Ed. 2, McGraw-Hill. New York. 208 p. Color 
plates. 
Mathiak, H. A. 

1938. A rapid method of cross-sectioning mammalian hairs. Journal of 
Wildlife Management, 2 : 162-164. 
Mathub, B. N. 

1927. Theory of oil tannage with special reference to seal oil. Journal of 
the American Leather Chemists' Association, 22 : 2—14. 
McLaben, I. A. 

1958. The economics of seals in the eastern Canadian arctic. Fishery 
Research Board of Canada. Circular 1. 94 p. 
Menges, R. W., and Lucille K. Geobg 

1957. Survey of animal ringworm in the United States. U.S. Public Health 
Service, Public Health Reports, 72 : 503-509. 

Mtt.leb, M. E. 

1952. Guide to the dissection of the dog. Ed. 3., reprinted 1955. Published 
by the author, Ithaca. NY. 427 p. 
Milleb, R. S. 

1958. The Munsell system of color notation. Journal of Mammalogy, 
39: 278-286. 

MlNATO, A. 

1949. Constituents of body oil from marine animals. Journal of the Phar- 
maceutical Society of Japan, 69 : 68-101. 
Miyauchl, D. T., and F. B. Sanfobd 

1947. Vitamin A content of fur seal oils. U.S. Fish and Wildlife Service, 
Commercial Fisheries Review. 9 : 5 B 
Montagna, W. 

1956. The structure and function of skin. Academic Press. New York, 356 p. 
Montagna, W., and R. J. Habbison. 

1957. Specializations in the skin of the seal (Phoca vitulina). American 
Journal of Anatomy. 100: 81-101, 6 plates. 

Munsell Colob Company 

1954. Munsell soil color charts. Pub. by the company, Baltimore, 6 p., 9 
color plates, all loose-leaf. 
Mubbat, M. D. 

1958. Ecology of the louse Lepidophthirus macrorhini Enderlein 1904, on 
the elephant seal Mirounga Iconina ( L) . Nature. 182 : 404—105. 



68 LITERATURE CITED 

Nakai, J., and T. Shida 

1948. Sinus-hairs of the sei-whale (Balaenoptera borealis). Scientific Re- 
ports, Whales Research Institute, Tokyo, No. 1, p. 41-47. 

National Bureau of Standards 

1955. The ISCC-NBO method of designating colors and a dictionary of 
color names. National Bureau of Standards Circular 553, 158 p. 

Noback, C. R. 

1951. Morphology and phylogeny of hair. Annals of the New York Academy 
of Sciences, 53 : 476-492. 
Odland, G. F. 

1954. Skin and epidermal derivatives [p. 428-457]. In Histology, edited 
by Roy O. Greep, with 13 contributors. Blakiston, New York, 12 + 953 p. 
Parnell, J. P. 

1951. Hair pattern and distribution in mammals. Annals of the New York 
Academy of Sciences, 53 : 493-497. 
Partridge, R. A. 

1938. A study of the lipids of fresh seal skin. Journal of the American 
Leather Chemists' Association, 33 : 144-156. 
Pearson, Anita K., and R. K. Enders 

1951. Further observations on the reproduction of the Alaskan fur seal. 
Anatomical Record, 111 : 695-712. 
Pocock, R. I. 

1914. On the facial vibrissae of Mammalia. Proceedings of the Zoological 
Society of London, 1914, p. 889-912. 
Poland, H. 

1892. Fur-bearing animals in nature and commerce. Gurney and Jackson, 
London, 66 + 392 p. 
Rabsch, B. 

1953. Die Tranendrusen der Saugetiere. Wiss. Z. Martin-Luther-Univ. 
Halle-Wittenberg, Jg. 2, Heft 8, Math.-natur. Reihe Nr. 4, p. 477-508. 
Rand, R. W. 

1956. The Cape fur seal Arctocephalus pusillus (Sehreber) : its general char- 
acteristics and moult. Union of South Africa, Depaftment of Commerce 
and Industries, Division of Fisheries, Investigational Report 21. 52 p. 

Roddy, W. T. 

1956. Histology of animal skins [p. 4-^0]. In The chemistry and tech- 
nology of leather. Vol. 1. Preparation for tannage. Edited by Fred 
O'Flaherty, William T. Roddy, and Robert M. Lollar. Reinhold, New 
York, 2 vols. 

Rothschild, Miriam, and C. Lane 

1957. Note on change of pelage in the stoat (Mustela erminea L.). Pro- 
ceedings of the Zoological Society of London, 128 : 602. 

Samet, A. 

1950. Pictorial encyclopedia of furs/from animal land to furtown. Pub- 
lished by the author, New York. 474 p. 
Scheffer, V. B. 

1949. The clitoris bone in two pinnipeds. Journal of Mammalogy, 30 : 269- 
270. 

1950a. Growth layers on the teeth of Pinnipedia as an indication of age. 

Science, 112:309-311. 
1950b. Experiments in the marking of seals and sea-lions. U.S. Fish 

and Wildlife Service, Special Scientific Reports — Wildlife, No. 4. 33 p. 



LITERATURE CITED 69 

1950c. The food of the Alaska fur seal. U.S. Fish and Wildlife Service, 

Wildlife Leaflet 329. 16 p. Processed. 
1950d. Growth of the testes and baculum in the fur seal, Callorhinm 

ursinus. Journal of Mammalogy, 31 : 384—394. 

1951. Cryptorchid fur seals. American Midland Naturalist, 46:646-648. 
1955. Body size with relation to population density in mammals. Journal 

of Mammalogy, 36 : 493-515. 
1958. Seals, sea lions, and walruses; a review of the Pinnipedia. Stan- 
ford University Press, 179 p., 32 plates. 
Scheffer, V. B., and K. W. Kenyon 

1952. The fur seal herd comes of age. National Geographic Magazine, 
101 :491-512 (10 color plates in text) . 

Scheffer, V. B., and F. Wilke 

1953. Relative growth in the northern fur seal. Growth, 17:129-145. 
Sohops, P. (In collaboration with Rudolf Fritzsche). 

1938. Pelze. J. J. Weber, Leipzig. 52 p. 16 color plates. 
Shanks, C. E. 

1948. The pelt-primeness method of aging muskrats. American Midland 
Naturalist, 39 :179-187. 
Stevenson, C. H. 

1904. The skins of fur-seals [p. 298-308, pi. 31]. In Utilization of the skins 
of aquatic animals. U.S. Fish Commission, Report of Commissioner for 
1902, p. 281-352, 13 plates. 
1905a. Leather from seal skins. Scientific American Supplement, 59: 

24334-24335. 
1905b. The skins of fur seals. Scientific American Supplement, 59 : 24502- 
24504. 
Stoves, J. L. 

1958. Fibre microscropy/its technique and application. D. Van Nostrand, 
Princeton, 286 p. 
Taylor, F. H. C, M. Fujinaga, and F. Wilke 

1955. Distribution and food habits of the fur seal of the North Pacific 
Ocean, U.S. Fish and Wildlife Service, Washington. 86 p. 
Terao, A. 

1940. Microscopical examination of the leather of aquatic animals. Jap- 
anese Society of Scientific Fisheries (Tokyo), Bulletin, vol. 8, No. 6, 
p. 343-346. 
Thompson, S. H. 

1950. Seal fisheries [p. 716-732]. In Marine products of commerce, by 
Donald K. Tressler and James McW. Lemon. Reinhold, New York, 782 p. 
U.S. Bureau of Fisheries 

1916. Dyeing and dressing Government fur-seal pelts. Fisheries Service 
Bulletin, No. 11 (April 1916), p. 4. 

1917. Alaska fisheries and fur industries in 1916. Bur. Fish. Doc. 838, 
118 p. 

1920. Fur-seal flippers as a source of glue. Fisheries Service Bulletin, 
No. 62 (July 1,1920), p. 2. 

1922. Alaska fishery and fur-seal industries in 1921. Document 933. 85 p. 

1923. Alaska fishery and fur-seal industries in 1922. Document 951. 118 p. 
1938. Preparation of Pribilof Islands fur-seal skins for market. 3 p. 

Processed. 



70 LITERATURE CITED 

U.S. Depabtment of Agriculture 

1954. Hyperkeratosis (X-disease) of cattle. Department Leaflet 355. 6 p. 
U.S. Fish and Wildlife Service 

1952-57. Alaska fishery and fur-seal industries . . . Fish and Wildlife 
Service, Statistical Digests, Nos. 23, 26 29, 31, 33, 35, 37, and 40 [annual 
reports for calendar years 1948-55]. 
Wilber, C. G. 

1952. Fur seal blubber. Journal of Mammalogy, 33 : 483-485. 

WlLDMAN, A. B. 

1954. The microscopy of animal textile fibres, including methods for the 
complete analysis of fibre blends. Wool Industries Research Association, 
Torridon, Headingley, Leeds, 209 p. Illustrations in text, 235 halftones, 
11 color photographs, 88 line drawings. 

WlLKE, F. 

1959. Fat content of fur-seal milk. Murrelet 39 :40. 
Woollard, H. H. 

1930. The cutaneous glands of man. Journal of Anatomy, 64 : 415-421. 
Zobell, C. E. 

1946. Marine microbiology. Chronica Botanica, Waltham, 240 p. 



TABLES 



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 




N 


Mean 


Range 


SD 


N 


Mean 


Range 


SD 


20 Jan. -. 


41 


19.3 


14-24 


2.5 


41 


0.21 


0. 08-0. 39 


0.08 


30 




9 Feb 


















19 
29 


11 


28.8 


25-34 


2.6 


11 


.58 


.43- .83 


.16 


10 Mar 


15 
14 
28 
14 
19 

1 

45 

3 


35.6 
36.2 
42.4 
47.6 
50.1 

60.5 
64.4 
64.7 


27-42 
33-45 
37-48 
44-53 
46-57 


3.6 
2.9 
2.7 
2.7 
3.0 


15 
14 
28 
14 
19 

2 
61 
4 


1.01 
1.31 
1.59 
2.20 
2.42 

5.05 
4.89 
5.61 


.53-1.37 
.80-1.65 
1. 17-2. 04 
1. 79-2. 89 
1. 96-3. 35 

4. 99-5. 10 
4. 05-7. 03 
4.54-6.80 


.72 


20 
30 
9 Apr 


.67 
.90 
.95 


19 
8 June 


.36 


18 
28 


60-72 
59-69 


2.4 
5.1 


.67 
.83 


Total 


191 








209 






















Summer 


23 


65.9 


54-75 


4.6 


23 


5.4 


4. 08-7. 14 


.9 







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 




N 


Mean 


Range 


8D 


N 


Mean 


Range 


SD 


20 Jan 


37 


18.7 


14-25 


2.5 


38 


0.19 


0. 08-0. 37 


0.07 


30 




9 Feb 


















19 

29 


12 


27.3 


22-33 


3.3 


12 


.46 


.29- .79 


.52 


10 Mar 


15 
6 

22 
9 

20 
1 

1 

45 
7 


34.1 
38.7 
40.4 
43.1 
47.3 
48.7 

56.6 
61.9 
63.4 


30-39 
37-40 
31-45 
40-45 
43-54 


2.7 
1.2 
3.5 
1.9 
2.7 


15 
6 

22 
9 

20 
1 

1 
58 
7 


.88 
1.21 
1.40 
1.66 
2.15 
2.30 

3.66 

4.87 
5.55 


. 63-1. 25 
1. 11-1. 28 

.68-1.90 
1.39-1.96 
1.81-2.64 


.54 


20 
30 
9 Apr 


.06 
.89 
.62 


19 
29 


.89 


8 June 










18 


57-67 
54-69 


2.6 
5.0 


3. 18-6. 12 
4.99-6.80 


.60 


28 


.97 






Total 


175 








189 






















Summer 


16 


63.1 


54-69 


4.4 


16 


4.8 


3. 31-6. 01 


.7 







71 



72 



TABLES 



Table 3. — Mean lengths of underfur and guard -hair fibers, by age and sex 

of seal 

[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.] 





Dates taken 


Mean date 


Length In millimeters ' 


Age and sex 


Neck 


Back 


Belly 




Under- 
fur 


Guard 
hairs 


Under- 
fur 


Guard 
hairs 


Under- 
fur 


Guard 
hairs 


Black pup, newborn 2 
Black pup, molting.. 
Silver pup.. 


11 June-22July_. 

11 Aug.-25 Sept. 

29 Sept.-17 Nov. 

16-25 Apr 

24 Sept.-5 Nov__ 
20 Aug.-21 Sept. 

22 June-19 July. 

23 Mar.-15 Sept. 

16June-22 July.. 
2 Apr.-17 Aug... 
28 June-2 July 

14-24 July 

18-24 June 

17June-16July_. 
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)- 


8.5 

(2) 

9.7 

(3) 
11.8 

(5) 
12.7 
12.8 
12.0 
13.2 
12.7 

13.1 
12.6 
14.3 
12.3 
15.0 
12.0 
14.7 

12.0 

16 

5 yr. 
14 

10+ 


19.0 

(2) 
18.7 

(3) 
18.2 

(5) 
18.3 
19.4 
16.3 
20.2 
18.3 

20.1 
18.9 
21.0 
19.0 
26.5 
18.5 
46.8 

18.5 

70 

8yr. 
22 

4 yr. 


8.5 

(4) 

8.7 

(3) 

11.3 

(7) 

11.5 

11.3 

11.3 

11.4 

10.7 

11.9 
10.9 
11.8 
11.0 
11.5 
11.0 
12.7 

11.0 

14 

7 yr. 
13 

Syr. 


17.3 

(4) 

18.7 

(3) 

17.3 

(7) 

17.7 

17.5 

15.3 

16.9 

16.0 

17.9 
16.3 
17.8 
17.3 
18.5 
18.0 
23.0 

17.0 

33 

8yr. 
20 

/ yr. 


6.0 
(2) 
5.5 

(2) 
7.0 
(5) 
7.7 
8.0 
6.3 
7.2 
7.7 

7.1 
7.2 
7.5 
7.3 
7.5 
7.0 
7.0 

7.0 

9 

/ yr. 
10 

Adult 


12.5 
(2) 

11.0 
(2) 

10.6 


Yearling, pelagic 

Yearling, autumn 

Two-year-old 

Three-year-old male. 
Three-year-old 

female. 
Four-year-old male.. 
Four-year-old female. 
Five-year-old male. . 
Five-year-old female. 

Six-year-old male 

Six-year-old female.. 
Seven-year-and- 

older males. 
Seven-year-and- 

older females. 

Maximum length of 
fibers on male 


(5) 
12.3 
12.8 

9.4 
11.5 
12.0 

11.3 
11.3 
11.8 
12.3 
12.0 
12.0 
13.1 

10.9 
15 


Youngest age group 
in which maxi- 
mum length is 
attained. 






8 yr. 


Maximum length of 
fibers on female 






15 


Youngest age group 
in which maxi- 
mum length is 
attained 

















1 "Length" is equivalent to "depth" of underfur or guard hair; with fibers in natural, slightly bent, or 
wavy attitude. 

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] 



Age' 



Number of specimens 



Male 



Female 



Range 



Male 



Female 



Mean 



Male 



Female 



years. 

1 year.. 

2 years. 

3 years. 

4 years. 

5 years. 

6 years. 

7 years . 

8 years. 

9 years. 

10 years 
"adult" 



52- 63 



95-134 


77-120 


111-144 


80-115 


96-155 


95-142 


110-222 


79-141 


115-212 


106-127 


148-204 


124-164 


132-255 


118-168 







217-334 



104-220 



63 
104 
118 
124 
133 
149 
163 
185 
199 
306 
286 
259 



94 
HI 
113 
117 
150 
143 
120 
120 
145 



' Males, totaling 133, were taken June-August (except 1 yearling on 13 September) ; females, totaling 67, 
were taken June-September. 



TABLES 



73 



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] 



Age 1 



Black 



Number Percent 



Black and white 



Number Percent 



White 



Number Percent 



3 years .. 

4 years. . 

5 years. . 

6 years.. 

7 years.. 

8 years ._ 

9 years .. 

10 years. 
10+..... 



1,753 

1,067 

394 

57 

6 

2 



282 

1,329 

1,901 

886 

234 

92 

26 

7 

27 



14 


6 


54 


74 


67 


531 


44 


1,072 


20 


919 


11 


747 


4 


657 


2 


428 


2 


1,960 



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] 



Size classification 


Length 


Width 


Area 


Small medium 


Inches 
30 
34H 
35 H 

39 
39% 


Inches 

21 U 
24 \i 
26 
27 
30 


Square inches 
718 




877 


Large 


946 


Extra large 


1,039 


Extra extra large 


1,261 







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] 





1938 


1939 


1940 


1941 


4 years 


Size classification 










Total 
number 


Mean 




Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Small medium 

Medium 


6,507 

10, 971 

2,308 

163 

7 


32.6 

54.9 

11.6 

.9 


13,818 

11,450 

1,636 

287 

21 


50.8 

42.1 

6.0 

1.0 

.1 


8,919 

14,058 

3,294 

155 

10 


33.7 

53.2 

12.5 

.6 


9,342 
15,368 
5,553 
1,258 
' 124 


29.5 

48.7 

17.5 

3.9 

.4 


38,586 

51,847 

12, 791 

1,863 

162 


9,646 

12,962 

3,198 

466 

40 


36.7 
49.3 


Large 


12.1 


Extra large 


1.8 


Extra extra large.. 


.1 


Total.. 


19, 956 


100.0 


27, 212 


100.0 


26, 436 


100.0 


31,645 


100.0 


105, 249 


26, 312 


100.0 







1 Including 4 wigs. 



74 



TABLES 



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] 





1938 


1939 


1940 


1941 


4 years 


Size classification 










Total 
number 


Mean 




Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Small medium 


5,897 

9 139 

2,088 

120 

3 


34.1 

53.1 

12.1 

.7 


8,457 

8,529 

1.170 

106 

2 


46.3 

46.7 

6.4 

.6 


5,774 

8, 558 

2,038 

167 

9 


34.9 

51.7 

12.3 

1.1 


13, 893 

13,551 

3,750 

910 

i 116 


43.1 

42.1 

11.6 

2.8 

.4 


34, 021 

39, 777 

9,046 

1,303 

130 


8,505 

9,944 

2,261 

326 

32 


40.4 
47.2 
10.7 


Extra large 


1.6 


Extra extra large. .. 


.1 


Total 


17, 247 


100.0 


18, 264 


100.0 


16, 546 


100.0 


32. 220 


100.0 


84,277 121,069 


100.0 



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)] 



Age 



4 years 2 

5 years.. 

6 years.. 

7 years.. 



Earliest 25 

seals, mean 

weight in 

pounds 



62.9 
71.9 

77.7 
78.6 



Latest 25 

seals, mean 

weight in 

pounds 



55.2 
62.1 
70.8 
71.2 



Percent 
difference 



13.9 
15.8 
9.7 
10.4 



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 


N 


Weight of pelt in pounds 


V 




Range 


Mean 


SD 




38 inches 


8 
48 
49 
54 
46 
54 
44 
45 
49 
48 
46 
41 
15 
11 


3. 2-4. 2 
3. 1-4. 6 
3. 3-5. 8 
3. 7-5. 
3. 9-6. 1 
4. 0-6. 7 
4. 0-7. 5 
4. 6-7. 2 
5. 1-7. 3 
5.4-7.1 
5. 5-7. 7 
5. 2-8. 5 
6. 0-8. 
6. 2-8. 5 


3.7 
3.9 
4.3 

4.4 
4.7 
5.0 
5.5 
5.7 
6.0 
6.2 
6.4 
6.7 
7.0 
7.3 


0.33 
.33 
.48 
.31 
.50 
.62 
.75 
.59 
.50 
.40 
.51 
.62 
.63 
.69 


Percent 
9 1 


39 inches 


8 6 


40 inches 


11 3 


41 inches 


7.0 


42 inches ... 


10 7 


43 inches 


12.4 


44 inches 


13.6 


45 inches 


10.3 


46 inches 


8.3 


47 inches 


6.5 


48 Inches 


8.0 


49 inches 


9.3 


50 inches 


9.0 


51 inches 


9.5 







TABLES 



75 



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] 



Field length 


Small 
medium 


Medium 


Large 


Extra large 


Extra extra 
large 


All classes 


and quarter 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


41 inches: 
First 


2 
9 
10 
11 




2 
2 
10 
6 




1 




1 








6 
11 
22 
17 














Third 




2 














Fourth 


































32 


57.1 


20 


35.7 


3 


5.4 


1 


1.8 






56 


100 










42 inches: 
First 


1 

5 
6 
10 




4 
6 
11 
9 




1 












6 
11 
19 
19 


















Third 




2 














Fourth 


































22 


40.0 


30 


54.5 


3 


5.5 










55 


100 














43 inches: 
First 


1 
1 




3 

8 
19 
5 








1 








5 
12 
22 
14 








3 

2 
1 












Third 




1 










Fourth 


8 




























10 


18.9 


35 


66.0 


6 


11.3 


2 


3.8 






53 


100 










44 inches: 
First 






2 
7 
13 

17 




1 




2 








5 

10 
16 
21 






3 

1 
2 












Third 




2 
2 














Fourth 






























6 


11.6 


39 


75.0 


5 


9.6 


2 


3.8 






52 


100 










45 inches: 
First 






3 
3 
10 

7 




2 
6 
5 
3 












5 
11 
20 
16 






1 

1 
6 






1 
4 










Third 










Fourth 


























8 


15.4 


23 


44.2 


16 


30.8 


5 


9.6 






52 


100 










46 inches: 
First 






3 

5 
2 
2 




11 
8 

11 
4 




5 
8 
2 
1 








19 
21 
16 

7 


















Third 


1 












Fourth 


























1 


1.6 


12 


19.0 


34 


54.0 


16 


25.4 






63 


100 










47 inches: 
First 






3 

8 
2 
2 




6 
7 
9 
4 




6 
6 
2 








15 
21 
15 

6 


















Third 

Fourth 


1 






1 
























Season 


1 


1.7 


15 


26.3 


26 


45.6 


14 


24.6 


1 


1.8 


57 


100 


48 inches: 
First 






2 
1 
4 
3 




6 
7 
5 
3 




7 
15 
3 




2 
1 




17 

24 

12 

6 












Third 








Fourth 
































Season ... 






10 


16.9 


21 


35.6 


25 


42.4 


3 


5.1 


59 


100 


49 inches: 
First 






1 
1 

1 




5 
7 




8 
8 




3 




17 
16 

1 
5 












Third 














Fourth 








3 




2 




























Season 




J 3 


7.7 


15 


38.5 


18 


46.1 


3 


7.7 


39 


100 





























76 



TABLES 



Table 11. — Trade classification of raw, salted, male sealskin with relation to 
field length of seal — Continued 



Field length 


Small 
medium 


Medium 


Large 


Extra large 


Extra extra 
large 


All classes 


and quarter 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


50 inches: 
First 






1 




6 




7 
5 
2 




3 

1 




17 
6 
2 




Second 








Third 
















Fourth 
















































Season 






1 


4.0 


6 


24.0 


14 


56.0 


4 


16.0 


25 


100 










51 inches: 
First 










2 




3 

3 
1 
1 




1 




6 
3 
2 
1 




Second 












Third 










1 












Fourth 








































Season 










3 


25.0 


8 


66.7 


1 


8.3 


12 


100 














All lengths: 

First 

Second 

Third 

Fourth 


4 
19 
20 
37 




24 
41 
72 
51 




41 
38 
39 

20 




40 

46 

15 

4 




9 
2 
1 




118 
146 
147 
112 














Season 


80 


15.3 


188 


35.9 


138 


26.4 


105 


20.1 


12 


2.3 


523 


100 



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] 



Field length 


Small 
medium 


Medium 


Large 


Extra large 


Extra extra 
large 


All classes 


and quarter 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


41 inches: 
First 






3 
7 
16 
13 




2 
3 
2 




1 








6 
11 
22 
17 




Second 


1 
4 

4 












Third 














Fourth 
































Season 


9 


16.1 


39 


69.6 


7 


12.5 


1 


1.8 






56 


100 










42 inches: 
First 






3 
9 
11 

18 




3 
2 
6 
1 












6 

11 
19 
19 




Second 


















Third ._ 


2 
















Fourth 
































Season 


2 


3.6 


41 


74.6 


12 


21.8 










55 


100 














43 inches: 
First 




2 
6 
17 
11 




3 

5 
5 
3 












5 
12 
22 
14 




Second 








1 










Third 














Fourth 




































Season 






36 


67.9 


16 


30.2 


1 


1.9 






53 


100 














44 inches: 
First 










2 
7 
9 
9 




3 








5 
10 
16 
21 




Second 






3 

7 
12 












Third 


















Fourth 




































Season 






22 


42.3 


27 


51.9 


3 


5.8 






52 


100 




— 


_ 









TABLES 



77 



Table 12. — Trade classification of finished, dyed, male sealskin with relation to 
field length of seal — Continued 



Field length 


Small 
medium 


Medium 


Large 


Extra large 


Extra extra 
large 


All classes 


and quarter 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


Num- 
ber 


Per- 
cent 


15 inches: 
First 










3 

6 
10 

5 




2 
3 
3 








5 
11 
20 
16 










2 
6 
11 












Third . 








1 






Fourth 
































19 


36.5 


24 


46.2 


8 


15.4 


1 


1.9 


52 


100 










46 inches: 
First 






2 
1 

4 




11 
10 
9 

5 




6 
10 
3 

2 








19 
21 
16 

7 


















Third 














Fourth I 






































7 


11.1 


35 


55.6 


21 


33.3 






63 


100 














47 inches: 
First 










8 
13 

7 
5 




7 
7 
5 

1 








15 
21 
15 

6 
















1 
1 






Third 






2 






Fourth 


























Season 






2 


3.5 


33 


57.9 


20 


35.1 


2 


3.5 


57 


100 


48 inches: 
First 










6 

13 

1 

5 




10 
10 

9 
1 




1 
1 

1 




17 

24 

12 

6 
















Third 






1 






Fourth 
































1 


1.7 


25 


42.4 


30 


50.8 


3 


5.1 


59 


100 










49 inches: 
First.. 










6 
5 
1 




10 
9 




1 

1 




17 
16 

1 
5 










1 






Third 








Fourth 












3 




2 






















Season .*, 






1 


2.6 


12 


30.7 


22 


56.4 


4 


10.3 


39 


100 


50 inches: 
First 










4 




10 

5 
2 




3 

1 




17 
6 
2 
















Third 
































































Season 










4 


16.0 


17 


68.0 


4 


16.0 


25 


100 


51 inches: 
First. ... 










1 




4 
3 

1 
1 




1 




6 
3 
2 
1 
















Third 
















1 












































Season 










1 


8.3 


9 


75.0 


2 


16.7 


12 


100 


All lengths: 
First 






10 
29 
64 
65 




49 
64 
50 
33 




53 
48 
23 

8 




6 
4 
4 
2 




118 
146 
147 
112 




Second 

Third 

Fourth 


1 
6 
4 






Season 


11 


2.1 


168 


32.1 


196 


37.5 


132 


25.2 


16 


3.1 


523 


100 



663006 O— 62- 



78 



TABLES 



Table 13. — Trade classification of raw, salted, 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 




Minimum 


Maximum 


Minimum 


Maximum 




28 

304 

33 

354 

38 


344 
37 

394 
42 

444 


19 

204 

22 

234 

25 


24 


Medium 


254 




27 




284 




30 







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 



Minimum Maximum 



Width in inches 



Minimum Maximum 



Small medium... 

Medium 

Large 

Extra large 

Extra extra large 



354 
384 
414 
44,4 
474 



394 
424 
454 
484 
514 



19 

204 
22 

234 
25 



23 

244 
26 
274 
29 



Table 15. — Length of ear from notch, by age and sex 



Age 



Number of specimens 



Male 



Female 



Range 



Male 



Female 



Mean 



Male 



Female 



years 

1 year 

2 years 

3 years 

4 years 

5 years 

6 years 

7 years 

8 years 

9 years 

10 years 

"adult" 

Total 



134 



Mm. 
33-41 



Mm. 
32-37 



Mm. 



36-45 


35-42 


40-46 


35-45 


40-49 


37-46 


42-49 


37-45 


42-51 


38-41 


45-50 


39-46 


49-57 


44-46 







48-53 



42-46 



67 



Mm. 



36 



TABLES 



79 



Table 16. — Yield of oil from fur seals killed on St. Paul Island, Alaska, 1949 

to 1958 

[Source: U.S. Fish and Wildlife Service (1952-57) and unpublished data] 





From carcasses 


From skins 


Year 


Number 
of car- 
casses 

handled 


Yield of 

carcass 

oil 


Yield of 

carcass 
oil per 
carcass 


Number 

of sealskins 

handled 


Yield of 

blubber 

oil 


Yield of 

blubber 

oil per 

skin 


1958 


59, 570 
57, 315 
93,300 
49,700 
49,850 
54,297 
50,935 
49, 565 
47,800 
55, 232 


Gallons 
18, 035 
i 18,000 
27, 813 
12, 771 
11, 352 
15, 180 
8,267 
12, 165 
10, 056 
14, 830 


Gallons 
0.33 
.31 
.30 
.26 
.23 
.28 
.16 
.25 
.21 
.27 


60,080 
61,244 
93, 966 
50,803 
50,239 
54,995 
51,560 
50,573 
48, 696 
57,445 


Gallons 
33,400 
132,000 
60,464 
29, 821 
30, 044 
31, 620 
28, 138 
28,000 
31, 957 
34, 420 


Gallons 
0.56 


1957 


.52 


1956 


.64 


1955 


.59 


1954 


.60 


1953 


.57 


1952 


.55 


1951 - 


.55 


1950 - 


.65 


1949 


.60 







i Estimated. 



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 
unimportant fact. 

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 

81 



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. 

DORSAL ASPECT 

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. 

VENTRAL 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 

DORSAL ASPECT 

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 
(10 YR2/2). 

VENTRAL ASPECT 

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 
185;BDM186;BDM189. 

Yearling, Autumn, Male 

DORSAL ASPECT 

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). 

VENTRAL ASPECT 

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 

DORSAL ASPECT 

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 
YR3/2). 

VENTRAL ASPECT 

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, 
and 29). 

Three-year-old, Adolescent Male (Bachelor) 

DORSAL ASPECT 

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) . 

VENTRAL ASPECT 

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) 

DORSAL ASPECT 

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 
(10 YR2/2). 

VENTRAL ASPECT 

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) 



DORSAL ASPECT 



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 

VENTRAL ASPECT 

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 
examined. 

Adult Female (Old Cow) 

DORSAL ASPECT 

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) . 

VENTRAL ASPECT 

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 
brown. 

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 
eye. 

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. 

89 



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 
"Leithaare".) 

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 
black. 

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 
orifice. 

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 
epidermis. 

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 
body t 



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 
its length. 

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. ) 



PLATES 





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) 



5^3006 0-62-8 



95 




*+*UjKM 










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) 



96 




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) 



97 




Plate 4-A.— Strip of parchment-cured pelt from back of subadult male; 12 July; 



natural size. 



(3978) 




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) 



98 




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) 



99 










» *■ 






/« 



* 




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) 



100 





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) 



101 




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) 



102 



- PF --,V^"-- 






i B 



/ 4 r... 
y. • s-j--- * 

/ > 



sbg- ^^ v : 





i 







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) 



103 




Plate 10. — Median section through skin of back of 7-year-old female ; 30 September ; 
X 30. (4171) 



104 



























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it 



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. 4 



• 



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• i 



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) 



105 




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) 



106 



U' 



PUB 




<K 






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^M W lk< ' • V 



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»- 



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) 

107 




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. 

(4213) 



108 




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 
bundle. (4214) 



10!) 




•- 






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) 



110 



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) 



553006 0-62-9 



111 




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) 



112 







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) 



113 



■ 










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% 






• » ' *■ 



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) 



114 




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) 



115 









a , 



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) 

116 




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) 



117 




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) 



118 




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r.fe ! 



$?' N ^*M 



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/ 



/ 



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v^.yiVr^v** 



iSs 



Plate lm. — Cross section of underfur fibers of finished, brown-dyed, subadult male 
sealskin ; y 1000. <411h 0) 

119 







*^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) 



120 



mmmmmm 



mm 






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) 



121 




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) 



122 




t33"~ 




- '■'' V- 



Plate 29. — Cuticular-scale pattern on blade of shaft of guard hair; parchment-cured 
skin: thermoplastic cast ; x 500. (4091 B) 



123 



A 



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) 



124 




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) 



125 







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) 



126 



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4 



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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) 



553006O-62-10 



127 



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. 

(3859) 



128 



£ 



1 9 






M 













< 




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) 



129 










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) 



130 



w r ■ \ »f 'I 



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I 



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I 



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- 



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i 



\\ • li ' •**• ft ft jfc 



i 



Aft, • iWr.'*' '77, ■ Jitfv 



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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) 

131 




Plate 38-A. — Unclerhairs erupting on back of 660 g. fetus; X 25. 



(3926) 



t fill 111 * 



A 






1 






i» 



I 



i 






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) 



132 



MlMlli 




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) 

133 




Plate 40. — Pelage developing on back of 2.21 kg. fetus ; 2 May ; anterodorsal view ; 
X 50. (3931) 



134 




Plate 41-A. — Head of 1.7 kg. fetus ; natural size. 



(4132) 




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) 



135 




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) 



136 




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) 



137 




Plate 44. — Full-term fetus ; female ; weight 3.3 kg., length 54 cm. ; 6 July ; pelage 
glossy black. (1682 and 1683) 



138 




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) 



139 




3®«£Sf£S 



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) 



140 




v it*si 



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 



WKk 



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) 



141 




Plate 48. — Black pups, molting, on 29 July. Loose birthcoat fibers are blowing 
about on the sandy rookeries at this time of year. (2250A) 



142 




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) 



553006 O-62-U 



143 




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) 



144 





B 





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) 



1 IS 




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) 



146 




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) 



147 




Plate 54.— Tanned pelt of yearling, autumn ; female ; 31 October ; in second adult- 
type pelage; X 0.2. (4000 BDM 25) 



148 



*Sfe 



>**: 




Plate 55. — Head of yearling, autumn; male; 26 September. 



(4060) 



149 




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 
view. (1721) 



150 





Plate 57. — Similar to preceding figure ; ventral view. 



(1722) 



151 




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) 



152 




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) 



153 




St;."" 



¥■ V 








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. 

(4000 USNM28603F) 



154 



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) 



1 55 




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) 



156 




w 






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) 



157 




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) 



158 




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). 

(4070) 



553006O-62-12 



159 




Plate 66. — Tanned pelt of 2-year-old female; 21 September; in third molt; pelage 
short and lacklustre; X 0.2. (4000 BDM 239) 



160 




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) 



161 




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) 



162 




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) 



163 




Plate 70-A.— Face of 103 g. fetus with full set of 20 mystacial vibrissae; X 6. 

(4126) 




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) 



164 




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 ) 



165 




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. 

(2323) 



166 




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 
stained. (4131) 



167 




Plate 74.— Albino adult female collected on rookery, 15 August, in stained coat which 
she had been wearing for about 10 months. (2871) 



168 




Plate 75-A. — Piebald subadult male; 8 August. 



(1044) 




Plate 7.">-P». — Partial albino pup in birthcoat (molting) ; 11 August : eyes and flippers 
pinkish white; underhair white; guard hair grayish brown. (2436) 



169 




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) 



170 




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^ 


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Plate 77-B. — Similar ; body of 6-year-old cow ; washed and nearly dried ; 12 
September; dorsal view. (4031) 



171 




Plate 78. — Body of subadult male with "rubbed" back ; 26 July. 



(1871) 



172 




Plate 79. — Top of head of subadult male shown in preceding plate. (1872) 



173 




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 ) 



174 




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 



553006O-62-13 



175 




Plate 82-A. — Bare, scabby areas on rump of black pup, molting 
at right of center. 



16 July. 



Note louse 
(1832) 




Plate 82-B. — About 130 lice feeding on penial opening of black pup, molting; 11 
August; X 4. (1903) 



176 




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) 



177 




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) 



178 




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 
affected. (2859) 



179 




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 
mane. (2000) 



180 



^ 




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) 



181 




£'f+ 




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. 

(2464) 



182 



^ Mm 



fl {#' 



- 



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m 



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) 

183 




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) 



184 




Plate 91. — Freshly blulibeivd sealskin. 



(2828) 
185 




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) 



186 




Platk 93.— Sealskin at processing plant, having been washed, hooped, and dried in 
preparation for unhairing. (Fouke Fur Co.) 



187 




Plate 94-A. — Unhairing 



(Fouke Fur Co.) 




Plate 94-B. — Dyeing. 



(Fouke Fur Co.) 



188 






-»■«■■■»•- £* ■> _*. - *~ . /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) 



189 








k*F 



■■„■■ 



fj~&z~ y %\|** 



l/«!^\ 



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) 

190 




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) 



553006O-62-14 



191 











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Ki 








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< / 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) 



192 






^^Xis^e^ 



Plate 09.— Eye of 3-year-old female; Seattle Zoo; 20 December; X 2. (3SS4) 



193 




Plate 100. — "Tears" on the cheek of a female seal on a warm, quiet day ; 15 July. 

(2625) 



194 




*** 







Plate 101-A.— Left ear of 1.19 kg. fetus ; X 10. 



(4137) 




Plate 101-B. — Ear of 0-year-old female ; edges held apart by a pin ; 17 September ; X 3. 

(4048) 



105 




Plate 102. — The four mammary teats and the navel (center) on an adult female; 
20 July. (1848) 



196 




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) 



197 




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) 



198 



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) 



100 




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) 



200 




Plate 107-A. — Tail of 6-year-old male ; scrotum relaxed ; 9 September ; natural size. 

(4029) 




Plate 107-B. — Tail of old bull ; scrotum pulled forward in order to reveal anus ; 20 
September; natural size. (4049) 



201 




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) 



202 




Plate 109. — Surface of right heel of silver pup; 28 September; X 10. (4065) 



203 





Plate 110. — Right flippers of old male (above) and 7-year-old female (below) ; dorsal 
view ; X 0.18. (2413 and 2425) 



204 




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 








I'late 111-B. — Roentgenogram of hind flipper of 3-year-old male, showing 3 functional 
claws; X 1.2. (4188) 



206 




Plate 112. — Adult female scratching herself. Only the three middle claws of the hind 
flippers are functional. (4140 ex Karl W. Kenyon) 



206 



US GOVERNMENT PRINTING OFFICE : 1962 O — S53006 



OCCIDENTAL COLLEGE LIBRARY 

1 49.30:64 docus 

Pelage and surface topography/Scheffer, 




3 5043 00316 9017 



DATE DUE 










































































































































Demco, Inc. 38-J 


93