524 
AMERICAN AGRICULTURIST. 
[November, 
The Common Hydatid, or Tape Worm. 
11Y DR. K. W. SBISS. 
All the hydatids, no matter what species of ani¬ 
mal, wild or domestic, may be their bearer, be¬ 
long to one species of tape worm, being larval 
forms of the tape worm ( Tcenia echinococcus) which 
infests the dog and wolf.—The mature parasite 
(fig. 1) lias a length of from one-sixth to 
one-third inch; it is composed of four parts, 
of which the one called the “head” is armed 
with a pointed beak, around which is a dou¬ 
ble circle of hooks, usually 
about thirty-live in number. Im¬ 
mediately behind the beak are 
situated four prominent sucking 
disks. All these details are easily 
studied by means of a powerful 
hand-magnifier. The last division 
(called the proglottis) comprises 
half the length of the entire ani¬ 
mal. The reproductive portion is 
situated on this segment below its 
centre. When any animal swal¬ 
lows a mature proglottis, or the ripe 
eggs of this tcenia , the w^alls of the 
segment and the shells of the ova, 
of which it contains a large num¬ 
ber, are digested, and minute em¬ 
bryos of a spherical shape, being 
each provided with six hooks, es¬ 
cape. The larval parasites bore 
their way into the blood vessels, 
and are carried bv the blood cur¬ 
rent to various organs, but espe¬ 
cially to the liver and lungs ; here 
the young hydatid first becomes 
encysted, that is, surrounded by a 
sort of sack derived from the tis¬ 
sues of its host. Within this sack 
is found a thick membrane, called 
thecuticular layer, surrounding a 
central granular mass, which in 
the process of development is yet 
again surrounded with a delicate 
membrane. The contained hyda¬ 
tid is but half the diameter of its cyst, or sack. 
In about three months, “heads” of future tape 
worms develop, and rapidly arrive at maturity in the 
granular membrane, or the nucleus, by a process 
allied to “budding.” Many of the lowest animals 
reproduce by tbe growth of “ buds ” from the sur¬ 
face of their body; these have, more or less, the 
structure of the parent, and are finally thrown 
off and set free as perfect individuals ; this is re¬ 
production by “budding,” 
Hydatid bags vary in form according to the ani¬ 
mal and the organ containing them, but are usually 
found as masses, of the size of a hickory nut, em¬ 
bedded in the tissue of an organ, or projecting 
from its surface, and are filled with tiny bladders. 
The fluid contained in the bags is of a milky 
hue, and is heavier than water, having a spe¬ 
cific gravity of 1.010 ; it contains no albumen, but is 
rich in common salt, and may contain grape sugar. 
The “heads” above mentioned, when fully de¬ 
veloped (fig. 2), are about one-eighth of an inch in 
length, and separated by an hour-glass-like con¬ 
striction into an anterior and posterior portion. 
Each “head” is provided with a beak ( rostellum ), 
which is armed with a double crown of hooks. 
These “heads” need only to be devoured by 
some animal in order to develop into perfect 
specimens of the tape worm. 
The symptoms of hydatid disease in man or the 
lower animals are by no means distinctive, resem¬ 
bling those of various other diseases affecting the 
particular organ attacked. In the liver, the para¬ 
site produces enlargements that can often be felt 
externally ; jaundice maybe caused by pressure on 
the liver duct; the diaphragm may be so pressed 
upward as to embarrass respiration ; and dropsy of 
the lower extremities may result from pressure on 
the great veins. The cysts may rupture into the 
peritoneum, causing fatal peritonitis! into the 
pericardium, causing fatal pericarditis; into the 
lungs, or externally. Hydatids of the lung are al¬ 
most always fatal—the disease here presenting the 
appearance of pulmonary tuberculosis, or consump¬ 
tion. In the kidney, abscess or extensive disease 
may be produced by the presence of the parasite, 
or the tumor may burst into the pelvis of the kid¬ 
ney, and its contents be passed in the urine. 
Hydatid cysts, in any organ, may suppurate or 
undergo fatty and calcareous degenerations, that 
is, become converted into a chalky mass composed 
of lime salts, usually resulting in a cure. 
In order to show the immense importance of this 
parasite, it is only necessary to give some statistics 
by Dr. Cobbold: Out of a very large number of 
specimens examined, he found that of tbe cases 
occurring in man, six per cent had entered the 
brain and three and one-half per cent the heart, all 
proving fatal. He estimates that fully tweDty-five 
per cent of all human victims of the disease die 
from its effects. The number of sufferers is in 
some countries very large, especially in Iceland, 
where the disease is very prevalent, owing to the 
closeness of the relations between dogs and man. 
Concerning the number of domestic animals which 
die annually from the ravages of this tape worm, I 
know of no reliable statistics, but, certainly, the 
number must be immense, especially among horned 
cattle, which are the most frequent sufferers. 
The mature worm produces in the dog very ob¬ 
scure symptoms of intestinal irritation, and is not 
in this stage, so far as we are aware, ever danger¬ 
ous or fatal. If an animal is supposed to be in¬ 
fested, by examining a number of specimens of 
excreta the presence of terminal segments and ova 
will render the diagnosis certain. 
The manner in which hydatids are introduced 
into the bodies of meu and animals is usually 
through drinking water. A dog infested with this 
worm, is continually throwing off in the faeces 
great numbers of ova ; these float in tbe air, settle 
upon water, and are swallowed with it while drink¬ 
ing, with the results al¬ 
ready described. The 
ova are also taken in¬ 
to the body with 
food, being carried 
through the air by the 
wind, and falling up¬ 
on fruits, fodder, etc., 
are swallowed. The 
hygienic measures ca¬ 
pable of preventing 
hydatid disease need 
most careful atten¬ 
tion. All dogs known 
to be affected with 
this tape worm should 
either be killed or 
treated by a compe¬ 
tent veterinary sur¬ 
geon until all tbe par¬ 
asites are expelled, 
and all excreta should 
be either burned or 
flooded with hot water. Flesh containing hyda¬ 
tid cysts should never be thrown out to furnish 
fresh sources of infection, which may be devoured 
by dogs or other animals, but should be either 
burned or deeply buried in the ground. 
However, neither this nor any of the many kin¬ 
dred parasitic diseases which mfest our herds, 
and place our own lives in constant jeopardy, and 
are yet so easily controlled, can ever be eradicated 
until Government shall undertake to outroot it. If 
a very few of the many thousands of dollars an¬ 
nually squandered and pocketed by jobbers and 
lobbyists were devoted to the support of a coips 
of able students of these parasites, how perfectly 
enormous would be the saving of human suffering, 
animal life, and, what is far more important in the 
eyes of the present generation—money ! 
In this age of improved architecture in barns, 
there is danger of overlooking proper ventilation, 
which our domestic animals need quite as much as 
human beings. Tbe old style barn with cracks a 
half inch or more between every board of the sid¬ 
ing had too much ventilation. The wooden barn 
made of rabbeted boards well seasoned, with tight 
floors and doors, and windows, needs a complete 
system of ventilation as much as a dwelling house. 
The shoots sometimes provided to pass hay and 
other fodder from tbe bays and lofts to the stables 
below, will give sufficient circulation of air, if 
there is a good ventilator in the roof to permit a 
draft. The animal heat in a tight barn from a 
large stock of cattle is sufficient sometimes to pre¬ 
vent hard freezing, except in extreme zero weather. 
Foul air is damaging to health and thrift. The 
problem in barn building, where animals are to be 
sheltered, is to secure pure air without lowering 
the temperature below the freezing point, in win¬ 
ter. During the summer months, the windows and 
doors should, as a general thing, be left open. 
Eggs a Perfect Pood—Experiments, etc. 
Set an egg and hatch out a perfect chicken : it 
comes from the shell ready for vigorous action, 
having bones, muscles, nerves, feathers, etc., in 
short all the parts that are found in the human 
body, except feathers instead of hair. All inside 
the shell is used up in producing the perfect ani¬ 
mal, and little or nothing has been added or sub- 
stracted from the contents of the egg during incu¬ 
bation—possibly a little absorption of gases 
through the shell. Does not this show very con¬ 
clusively that an egg supplies all the elements for 
the nourishment of the human or other animal, 
and in the proper proportions ? Beiiur at a farm¬ 
house, to while away an invalid’s time, we made 
the following experiments with a dozen fresh eggs 
just brought in, which will doubtless interest as 
well as instruct many readers of the America i 
Agriculturist. Part of the eggs were below the 
average size. Carefully weighing them with scales 
turning to a one-fourth grain, the following was 
the result: (seven thousand grains make a common 
avoirdupois pound.) 
Number. 1 2 3 4 5 6 7 
Weight (grains)....650 TOO 726 756 762 767 794 
Eggs to 1 lb. 10% 10 0% 0% 9V 5 9>/ 5 8V 6 
Number. 8 9 1011 12 
Weight (grs).. .847 863 888 942 1014. .nv'ge 809 grains. 
Eggs to i lb.. ..8}^ 8 l /io 8 7j^ 7. .av’ge to lb. 8*/ & eggs 
Practical lessons are taught by these figures : 
First, how nonsensical is the custom of selling eggs 
by count instead of by weight. A dozen eggs like 
No. 12 would just about equal twenty of No. 1. 
Fifteen of No. 1 would only equal a dozen of No. 7. 
Second, we boiled No. 2 and No. 11 five minutes, 
and let them cool. They each lost only 4 grains in 
weight. No. 11 yielded ninety-two grains of shell, 
leaving eight hundred and forty-six grains of solid, 
hard boiled egg, of which two hundred and eighty- 
four grains were yolk, and five hundred and sixty- 
two white. No. 2 gave ninety grains of shell, and 
six hundred and six inside, viz : white four hundred 
and nine, yolk one hundred and ninety-seven grains, 
or just about one-tbird yolk. The two eggs which 
together averaged eight hundred and twenty-one 
grains, or about the average of the whole dozen, 
furnished an average of seven hundred and twenty- 
six grams of solid food, exclusive of the shell. A 
dozen eggs would, therefore, supply almost exactly 
one and a quarter pound of solid food, of a perfect 
composition as first above stated—or a little over 
ODe pound to ten eggs. Most eggs run to a larger 
size than these. If fresh beef, for ex ample, were 
as perfect a food as eggs, and if, including its 
large amount of water, it were as valuable pound 
for pound as eggs, beef at twenty cents a pound 
would be as costly as eggs of tbe above average 
at twenty-four cents a dozen. Third, eggs used 
in cake, in picked up fish, indeed, with any 
other food, add much nutriment to it. Soft boiled 
eggs (two and a half minutes quick boiling, and left 
to stand warm until a little thickened through by 
the heat),are much more digestible than hard boiled 
ones, unless the latter are grated or masticated 
very fine. Raw eggs are a very easily digested 
and highly nourishing food. 
