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Feathering and Characters Affecting Fecundity, Egg

Production, and Mortality Rate in Females.

Number of birds

Age at first egg Days

Weight at first egg Pounds

Winter pause Days

Winter clutch Eggs

Winter production Eggs

Egg weight to Jan. 1 Ounces per dozen

Persistency Days .

Annual production Eggs.

Laying house mortality Percent

si Group SI Group





















The two groups of females were almost identical in such fecundity characters
as age at first egg, weight at first egg, winter pause duration, winter clutch, and
annual persistency, as well as in winter and annual egg production. The mean
egg weights up to January first were not significantly different. Mortality rates
for 365 days in the laying houses were essentially the same. In general, these
data appear to indicate that the sex-linked gene for rapid chick feathering is
independent of genes associated with high fecundity in Rhode Island Reds.

Relation of Chick Feathering to Body Weight and Mortality Rate in Males

All males on which the feathering record was taken at 12 days were divided
into rapid and slow groups. All other males had their feathering record taken
at 8 weeks of age and are grouped as + or — for back feathering. The body
weight was taken on each individual at 5 months of age and the mortality rates
up to 5 months were recorded for each of the four groups.

The data on the sex-linked gene SI were secured in 1938, 1939, and 1941 and
only a very small number of the slsl cockerels was retained up to 5 months of
age. The data on back feathering were collected each year beginning in 1934.
In table 10 the records on back feathering for 1938, 1939, and 1941 were omitted
because all of these cockerels were included in the slSl classes for those years.

Unfortunately the number of males in the slsl class that were retained to 5
months of age was too small to permit an accurate evaluation of this class as
compared with the SI class. The data show, however, that the slsl cockerels
were of about the same body weight at 5 months of age as the SI cockerels


















Mortality rates were low in both groups, but the data are not adequate to show

A comparison of the + and — groups with respect to back feathering at 8
weeks shows the two groups to be very similar in body weight. In mortality
rate the + group was somewhat lower than the — group, although the rates
were low in both classes.

Table 10. — Relation of Chick Feathering to Body Weight and
Mortality Rate in Males. 1934 - 1941.

Number Body Number Mortality

Feathering Class of Weight at of Rate to

Birds 5 Months Birds 5 Months
Pounds Percent

Chick feathering at 12 days

Rapid (slsl)

Slow (SI)

Back feathering at 8 weeks

Feathered ( +)

Bare (-)

The data in table 10 do not in general indicate superior growth in rapid feather-
ing cockerels up to 5 months of age. There is some evidence, however, to indicate
a lower mortality rate in the rapid feathering groups.

Special Results of Matings in 1942

In addition to the regular complement of females from line 1, three females
from line 2 were mated to the line 1 sire to study the inheritance of the sex-linked
gene si and other genes affecting degree of back feathering. In these matings
each bird was classified for the recessive sex-linked gene si by the presence or
absence of tail growth at 12 days. All individuals were also graded for degree
of back feathering at 8 weeks of age into grades 0, 1,2, 3, and 4. For example,
slsl 4 means that the male had a tail when 12 days old and also had complete
back feathering at 8 weeks of age.

The first mating of the slsl 4 male and a si 3 female gave only slsl 3 sons and
daughters. A second mating of the slsl 4 male to a SI 1 female gave 2 SI sons,
3 SI 1 sons, 9 SI 2 sons, and 4 SI 3 sons. This is a ratio of 12 intermediate
(grades 1 and 2) to 4 grade 3 to 2 grade 0. It seems probable that the sire was
slslXx in genetic makeup and that the dam was SlXx. Such a mating should
give all male progeny heterozygous for gene si, of which 25 percent should be
SIslXX, 50 percent SlslXx, and 25 percent Slslxx. The actual proportions were
4-12-2. The 11 daughters were all placed in grade 3 (si 3). A third mating was
made between the slsl 4 male and a SI 2 female. This mating gave 14 sons, all
heterozygous for gene si. In back feathering there were 3 grade 3, 10 inter-
mediate, and 1 grade 0. The expectation was 1-2-1 or 4 2/3 to 7 to 4 2/3. From
this last mating there were 9 grade 3 daughters and 1 of grade 2, all carrying
recessive gene si.

A cross was also made between line 1 and line 2, using an si 3 dam from line
1 mated to the line 2 sire which was SlSl in makeup. This sire was homozy-
gous for gene SI and gave 13 sons, all graded SI 2. The 19 daughters were also all
graded as SI 2. As was to be expected on the basis of a smgle autosomal factor,
all sons and daughters were intermediate in back feathering. All 32 progeny failed
to exhibit the recessive sex-linked gene for rapid feathering.


Types of matings made in line 1 for 1942 may be briefly considered. Two
sires, both graded slsl 4, were used for breeding. These males were mated to
five dams graded si 3. The type of mating must have been slslXX sire and
slXX dam. From these matings 32 sons and 41 daughters were recorded. All
sons were graded slsl 4 as would be expected. All daughters were graded si 3,
except two which were graded si 2. It is very evident that these sires and dams
bred true for rapid back feathering as well as for the sex-linked gene si.

Types of matings in line 2 may also be examined. A single sire was mated to
a number of different dams. Mating the SlSlXx sire to SI 1 females gave 9 51
sons and no other types. There were 4 SI 1 daughters and 4 SI 2 daughters
from this mating. The dams were probably SlXx in genetic makeup. The
slow feathering sire of line 2 was mated to one dam graded SI 2. All sons pro-
duced were SI in grade. Out of 4 daughters, 3 were medium in back feather-
ing and 1 graded 0. All lacked the sex- linked gene si.

The mode of inheritance of rapid back feathering appears to be somewhat
involved. The sex-linked recessive gene si appears to play an important role
in relation to the degree of back feathering. Specific matings made in 1942 to
test the relation between the sex-linked gene for rapid feathering and possible
autosomal genes for rapid back feathering point definitely to the sex-linked gene
si as essential to secure complete back feathering at 8 weeks of age. This reces-
sive gene si need not be in homozygous condition to produce complete back
leathering in an individual male, but from the standpoint of his breeding ability
it is highly desirable that he be homozygous for gene si.

Evidence seems to point to a single dominant autosomal gene X which has a
cumulative effect and must be supplemented by recessive gene si to give complete
rapid back feathering. Sexual dimorphism in the rate of back feathering in
Rhode Island Reds renders the grading of females for back feathering an un-
certain procedure. On the basis of these studies, it seems evident that in breed-
ing for rapid back feathering two procedures will quickly accomplish the desired
end. (1) Both breeding males and females should be selected at 10 to 12 days
of age for the presence of the recessive sex-linked gene si. (2) The same birds that
showed tail development on the first examination should be graded for back
feathering at 8 weeks of age, and only those with complete back feathering should
be placed in the breeding pens.

Males of different grades with respect to back feathering at 8 weeks appear
to have the genetic composition indicated below:
















Representative photographs of the 1942 generation are shown in Plates I,
II, and III.


This report covers the period from 1931 to 1942 during which a study was
made on the mode of inheritance of rapid feathering in Rhode Island Red chicks.
Some of the more important deductions are:

1. Rhode Island Reds are normally sexually dimorphic with respect to rate
of feathering in chicks. Under continued selection for rapid feathering, this sex-
dimorphism almost completely disappears.


2. Rapid chick feathering was not consistently associated with greater weight
at sexual maturity.

3. There was some evidence that rapid feathering in males is associated with
a lower mortality rate to the age of 5 months.

4. The presence of the gene si for rapid feathering, at least in heterozygous
condition, in males is essential for the development of complete back feathering
at 8 weeks of age.

5. Complete feathering required a longer period for development in the back
region than in any of the other major body regions.

6. A dominant autosomal gene X exerts a cumulative effect with recessive
sex-linked gene si to produce complete feathering over the back at 8 weeks and
to essentially eliminate sex-dimorphism in rate of feathering.

7. Either gene X alone in homozygous condition or gene si alone in homozygous
condition may produce slight back feathering in males at 8 weeks.

8. Progress in breeding for rapid back feathering was slow when breeding males
were selected solely on the basis of feather development at 8 weeks of age.

9. No relation was found between the se ^-linked gene for rapid chick feather-
ing and several important inherited characters affecting egg production.

10. Results from a number of special matings indicate two procedures in select-
ing breeding stock that will establish gene si, the recessive sex-linked gene for
early tail growth, and gene X, the dominant autosomal gene for back feather-
ing, in a short period.

(A) Classify all prospective breeding males and females when 10 to 12
days of age for gene si.

(B) At 8 weeks of age definitely select both males and females that
showed gene si at 10 to 12 days and have complete back feathering
at 8 weeks of age.

12. There was no indication that selective breeding for rapid back feathering
will produce undesirable effects from the standpoint of egg production.


Danforth, C. H. 1929. Two factors influencing feathering in chickens.

Genetics 14:256-169.
Gericke, A. M. M., and C. S. Piatt. 1932. Feather development in Barred

Plymouth Rock chicks. N. J. Agr. Expt. Sta. Bui. 543.
Jaap, R. G., and L. Morris. 1937. Genetic differences in eight-week weight and

feathering. Poultry Sci. 16:44-48.
Kinugawa, Y. 1927. On the sex-linked inheritance of tail feathering in chicks

and their sex-identification. Proc. Fourth World's Poultry Cong. pp.

Lloyd, E. A. 1939. Breeding for meat and egg production. Proc. Seventh

World's Poultry Cong. pp. 483-487.
Martin, J. H. 1929. Rate of feather growth in Barred Plymouth Rock chicks.

Poultry Sci. 8:167-183.
Radi, M. H., and D. C. Warren. 1938. Studies on the physiology and inherit-
ance of feathering in the growing chick. Jour. Agr. Res. 56:679-705.
Saharova, L. N. 1926. Genetics of the rate of feathering. Mem. Anikowo Sta.

edited by Koltzoff p. 130.
Warren, D. C. 1925. Inheritance of rate of feathering in poultry. Jour. Hered.

Warren, D. C. 1933. Retarded feathering in the fowl. Jour. Hered. 24-431-434

Publication of this Document Approved by Commission of Administration and Finance
4M 10-42-10406P

agricultural experiment station

Bulletin No. 397 December 1942

A Civilian Program for
Tree Protection

By Malcolm A. McKenzie

Public appreciation of shade trees in Massachusetts is evidenced by the
extensive and varied planting throughout the State. This bulletin, prepared
primarily to promote municipal tree management, also suggests methods of
tree care in general.


View of Massachusetts State College campus taken about 1880, illustrating how starkly build-
ings stand out when tree cover is absent.

View of Massachusetts State College campus 1942. taken from approximately the same spot
as the earlier photograph and showing how tree cover obscures outlines of buildings and renders
target indistinct.


By Malcolm A. McKenzie, Research Professor of Botany i


The appreciation of shade trees, widespread in the life of the American people,
is of paramount importance in Massachusetts, and in the spring of 1942 there
was a marked increase in the number of requests for the investigation of tree
casualties. Trees were reported to be afflicted with diseases and other defects
and the urgency of the demand for the completion of field and laboratory studies
was promptly recognized.

Healthy trees should be highly prized by all communities, but seriously weak-
ened trees may be dangerous liabilities. A tree or limb which falls on a highway
(Fig. 1) may injure a pedestrian, delay the transportation of troops and war
materials, damage an automobile, or destroy electric light, telephone, fire alarm
and telegraph services. During normal times the temporary incapacity of the
injured person may not be a serious loss, damage to an automobile may be covered
by insurance, and the public utilities' supply of replacements may be ample for
all demands. During wartime, however, delay in movement of men and material
and the loss of man hours is tragic, a destroyed automobile is irreplaceable and
the loss of electric light, telephone, fire alarm and telegraph service may mean
failure in transmission of air-raid and fire alarms and in mobilization of aid. Air
bases, air fields, defense centers, and military or naval defense areas may be
isolated and unable to function. Therefore, these investigations were undertaken
with the twofold purpose of learning what significant defects were present in
trees and what treatment might be given to prevent damage to persons and
property. From one point of view the objectives are closely related. A tree
which is or can be made reasonably sound can be a reasonably safe tree. The
cruxes of the problem are the recognition of various tree defects and the timing
of their discovery and treatment.

The Massachusetts law (G. L. chap. 87) provides that each municipality be
officered by a person responsible for "all trees within a public way or on the
boundaries thereof"; in towns, a tree warden; in cities, a forester or corresponding
official. In section 1 of chapter 41 of the General Laws, the term of offic" for
tree wardens in towns was limited to one year. If, however, a town adopts the
amendment passed by the General Court in 1939, the tree warden may ha^■e a
term of three years, thereby providing for a measure of continuity for municipal
tree programs. Very serious consideration should be given to the matter of
providing adequate appropriations for tree work, and as an emergency measure
a supplementary program for tree protection under the direction of the tree war-
den or other responsible officer appears necessary and is recommended.

1 The writer is indebted to Professor A. Vincent Osmun, Head, Department of Botany for
valuable assistance, suggestions and criticisms during tlie preparation of this bulletin. Acknowl-
edgment is also made to Dr. S. J. Ewer, Technical Assistant in Botany, for criticism of the manu-
script and the preparation of certain of the illustrations. The helpful interest of the Massachusetts
Tree Wardens' and Foresters' Association, the Massachusetts Horticultural Society, the Massa-
chusetts Forest and Park Association, the New England Telephone and Telegraph Company the
Western Massachusetts Companies, the Boston Edison Company, the Municipal Lighting Associa-
tion of Massachusetts, the New England Power Association, the New England Gas and Electric
Association and the New England Section of the International Municipal Signal Association has
played an important part in completing this work; particular credit should be given to Mr A
Warren Stewart, President of the Massachusetts Tree Wardens' and Foresters' Association



In time of peace the annual value of the tree crop in the United States, prin-
cipally in manufactured forest products, approaches $800,000,000 and in war-
time this figure may be more than doubled. Therefore, the itrportance of wood
and other tree products is widely recognized. The essential value of shade tree
programs durmg wartime, however, has not been universally appreciated. The
use of trees and other plants has always been important for the concealment of
unsightly areas and for securing privacy about dwellings. Since the battleground
of modern war is limitless, including the homes in cities and towns throughout
the world, any increased obscurity associated with native tree plantings is of
significance as supplementary protection against aerial attack.

The decentralizing of municipalities or the expansion of communities into
subdivisions has been a matter of research involving many considerations, es-
pecially in recent years. When the decentralizing of C'ties began in the United
States it was not with any thought of making the communities less vulnerable as
targets, but rather for the constructive benefits of peaceful pursuits including
convenience, health, safety, and general welfare. Fortunately, civic planning,
perhaps unwittingly but nevertheless genuinely, anticipated the future and
materially contributed to the present-day war effort. Recently, R. P. Brecken-
ridge,2 Major, Corps of Engineers, Fort Belvoir, Virginia, published this hearten-
ing-descript'on under a photograph: "Aerial view of a well-planted city. Trees
screen this area and render it practically immune to aerial attack." A second
photograph bore this gloomy prediction: "A city where tree planting has not been
considered important. Note the vulnerability and visibility to aerial attack."
Major Breckenridge pointed out in particular that trees and natural foliage are
obviously of prime importance in any camouflage scheme.

The development of war housing projects has added heavy duties to some muni-
cipal tree. programs, and there is not time for all municipalities to provide addi-
tional tree canopies, but all towns and cities can make judicious use of the trees
already planted on streets and roadsides. Spraying for the prevention of attacks
by destructive pests will aid materially in enabling trees to render important ser-
vice and every community should provide for tree protection. The dangers of
the policy of "too little and too late" were never more clearly apparent than in
the war on plant pests. Let no one be lulled into complacency concerning the
imminence of attack by disease fungi and insects. Too often, ground lost to
these invaders can never be recaptured. The economic loss sustained by unwar-
ranted curtailment of pest control programs finally reaches every individual in
the nation. The danger of winning the war only to lose the peace was never more
real than in relation to the control of plant diseases and insect pests, and the
importance of unbroken continuity in a pest control program cannot be empha-
sized too strongly. The ample scientific basis for this statement, although some-
what involved, may be visualized as the pattern from which "blitzkrieg" tactics
were copied.

Trees protected from pests are in turn a safeguard to life and property. More-
over the sprayers, trucks, hose lines, and storage tanks employed in shade tree
protection may serve other use in an emergency. The tree wardens were among
the first public officers to make specific study and provisions for a revision of
local programs in cooperation with public service agencies. In fact, on November

2 The Use of Trees in Camouflage. Trees, Sept.— Oct., 1941. pp. 7 and 15.


15, 1941, they published recommendationsS which should materially facilitate
the operation of the war emergency work of tree programs.

In brief, then, in view of the camouflage value of shade trees (Frontispiece),
municipal tree planting and protection programs previously developed for the
promotion of peaceful pursuits may nOw enable communities which were inter-
ested in living better, also to live longer.


The present studies included forest and shade trees in all sections of the State,
with special attention to street plantings. The principal types of troubles found
are analyzed briefly.

Fungus Diseases and Insect Pests. Insects'* contributing to tree injuries have
been found to include insects causing initial injury to healthy tissues, insects
associated with secondary injury to tissues previously weakened, and insects
which serve as vectors or carriers of other pests. Fungi and bacteria related to
tree injury include organisms which may kill trees promptly, induce ch onic
disease, or cause disintegration of portions of weakened trees.

Dutch Elm Disease. The Dutch elm disease has been found in only seven trees
in Massachusetts, but mention of it is included here to call attention to the im-
portance of keeping this disease in check in any program concerned with the
elimination of hazardous trees. Extensive spread of the disease would doubtless
result in greatly increasing the number of dangerous street trees. (For additional
information see tailpiece.)

Wood-destroying Fungi. It often happens that a limb broken from a tree dur-
ing a wind storm had been previously weakened as a result of decay following
invasion by wood-destroying fungi (Fig. 2). Sometimes evidence of this weakness
prior to the break may be completely lacking, but in many instances it might
have been detected had the tree been inspected. If a tree shows extensive signs
of decay, limbs which may be broken by the wind should be removed, as in the
case of the tree shown in figure 3.

Physiological Disorders. Trees, like all other green plants, require water,
nutrients, sunlight, and air in order to function as living organisms. The lack
or excess of some of these essentials may result in injury or death. Thus, trees
sometimes suffer from drought, flood, alteration of water table, winter conditions,
shade, evaporation, non-availability of nutrients, and other inherent or induced
soil conditions.

Chemical Injury. Calcium chloride and other chemicals stored or applied in
locations which permit contact with the soil about trees may cause injury to
roots. In the atmosphere, some of these materials may cause the burning of

Smoke Injury. Smoke and fumes frequently contain sulphur compounds or
other toxic substances which may injure trees with which they come in contact.

^ Recommended Principles and Practices of Massachusetts Tree Wardens' and Foresters'
Association and Public Service Agencies.

■* Inquiries concerning specific insect pests or their control should be addressed to the De-
partment of Entomology, Massachusetts State College, Amherst, Massachusetts.


Similar injury^ was observed on foliage exposed to sulphur dioxide fumes from a
defective electric refrigerator.

Fire. The huge losses resulting annually from forest fires are already known
to most persons, but the knowledge of how a fire injures individual trees is ap-
parently not so well understood. Extensive injury to the trunk and branches of
shade and ornamental trees often results from the burning of rubbish nearby, and
scorching of the bark is sometimes the prelude to invasion by fungi.

Injury from Illuminating Gas. Many trees have been killed from the effects
of illuminating gas in the soil. Usually by the time the gas injury shows in a
tree, no remedial treatment is practical. In recent years considerable progress
has been made in detecting gas leaks by means of surveys conducted by gas
companies, and tree casualties have been reduced and human lives saved by the
prompt repair of leaks.

Site. Tree troubles maj' originate at the site in which the tree is growing. The
basic nature of a possible site may be such as to make the planting of a particular
type or individual tree unwarranted. After the selection of a suitable species or
specimen, planting should be done in such a way as to avoid air pockets in the

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