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The External and Internal Parasites of 
Ven and Domestic Animals, 

Rept. Conn. Board of Agriculture for 1870, 
ppe 1-140. Text figs. 1-84, 


Additional observations on the Parasites of 
Mien and Domestic Animals, 

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BNTERNAL AND INTERNAL PARASITES 


OF 
MAN AND DOMESTIC ANIMALS. / 


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PROFESSOR OF ZOOLOGY IN YALE COLLEGE, NEW HAVEN, CONNECTICUT. 


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[From the Report of the Connecticut Roard of Agriculture for 1870.] 


The External Parasites of Domestic Animals, 


THEIR EFFECTS AND REMEDIES.* 
BY A. E. VERRILL. 


The external parasites of our domestic animals nearly all 
belong to the great class of animals which we call Insects, but 
the internal parasites are, with few exceptions, representatives 
of the classof Worms. The division of the subjects of these 
lectures is, therefore, both convenient and natural. 

The class of Insects includes a far greater number of spe- 
cies than any other class of animals, the number actually 
amounting to several hundred thousands, each country having 
a vast number peculiar to itself. They are also exceedingly 
diverse in habits, as well as in form and structure. 

In order to show the affinities of the insect-parasites and 
their position among other insects, it will be necessary to give 
a brief sketch of the whole class, with a few remarks on the 
more important peculiarities of their anatomy. 

All insects, like the other articulated animals (worms and 
crustacea), have a body composed of a series of segments or 
rings, placed one behind the other, and together forming a 
sort of irregular tube, which incloses in one cavity all the in- 


* In the preparation of the reports of these lectures on the parasites of domes- 
tic animals, we are greatly indebted to Dr. A. S. Packard for the use of many 
cuts of insects from his excellent ‘Guide to the Study of Insects” and the 
“American Naturalist,” published at Salem, Mass.; and to Donald G. Mitchell, 
Esq., editor of the “Hearth and Home,” published by Pettingill, Bates & Co., New 
York, for the use of several excellent cuts of parasitic worms, prepared to illus- 
trate a series of articles on parasites of man and domestic animals by the writer. 
Without this assistance the lectures could have been illustrated only imperfectly. 
In addition to these we have added, so far as the available funds would admit, fig- 
ures of the more important parasitic insects and worms, copied from Cuvier, Gue- 
rin, Clark, Leuckart, Cobbold, and others.—A. FH. Verrill. 


2 BOARD OF AGRICULTURE. 


ternal organs. The nervous system consists of 
- a double nerve-centre or ganglion in the upper 
part of the head, connected with another below 
by nerves that pass around the gullet on each 
side, so as to enclose it as in a ring, and this 
lower double ganglion is connected by a double 
nervous cord with a series of similar ganglions 
or nerve-masses, which are arranged along the 
lower side of the body, below the intestine, each 
ganglion sending off small nerves to the adja- 
cent organs (figure 2). The rings of the body 
are thickened in certain parts, and in the head 
and middle region of the body are more or less 
consolidated. They thus form a somewhat firm 
external skeleton, composed of 
a peculiar substance, called 
chitin. When the rings are 
movable this outer covering, 
where it connects the rings to- 
gether, is thinner and flexible, 
and often folded inward so as 
to form peculiar joints. The 
legs, jaws, and other external 
organs, are merely hollow out- 
foldings of the outer covering, 
and contain, like the body, the 
muscles that move the various 
parts, while their cavities com- 
municate freely with that of 
the body, and thus receive their 
supply of blood, nerves, ete. 
Kach joint of the legs and other 
appendages is also formed by 
a thinner portion of the outer 
covering, which is folded in 
upon itself in various ways. 
The wings, when present, are 
also outfoldings of the integu- 


For description of Figures see next page. 


PARASITES OF ANIMALS. 3 


ment, which appear at first in the form of 
little sacks containing fluid, but finally ex- 
pand into broad membranes and the sides 
of the sack unite so as to appear like a 
simple membrane, supported by little 
@ branching, hollow rods, or tubes, which 
" communicate with the cavity of the body, 
and also form the joints of the wings. The 
legs and jaws originate from the lower part 
of the sides of each ring that bears such 
appendages, so that there must be as many rings or segments 
in any part of the body as there are pairs of such organs, but 


Fig. 4. 


Figure 1.— Hundred-legs,” (:Scolopocryptops sexspinosa Say ), natural size; color 
deep orange, with yellow feet. From Packard’s Guide. 

Figure 2.—Nervous system of Corydalus eornutas, a large neuropterous insect ; 
a and b, ganglions of the head; ¢, the three ganglions of the thorax, which send 
nerves to the three pairs of legs; d, d, the eight double ganglions of the abdomen. 
From Packard's Guide, after Leidy. 

Figure 3.—Portion of one of the trachez or breathing tubes, prepared so as 
to show the spiral fibre a, a part of which has been unwound; c, a secondary 
branch. From Packard’s Guide. 

Figure 4.—Transverse section of the thorax of a bee; a, one of the nervous 
ganglions; b, breathing pore or spiracle, opening into the trachez, which branch 
in the interior, and send small tubes into the legs and wings; c, the dorsal vessel 
or pulsating organ, which circulates the blood; d, the intestine. From Packard’s 
Guide. 


4 BOARD OF AGRICULTURE. 


the wings originate from the upper part of the same rings that 
bear legs below (fig. 4). Most insects breathe air by means of 
a complicated system of finely branched air tubes, having a 
sort of spiral spring to keep them open.(fig. 3), which are con- 
nected with valvular openings, called spiracles, along each side 
of the body. Some species of spiders have respiratory cavities 
that somewhat resemble lungs, and contain numerous thin 
membranes, arranged like the leaves of a book. These are, 
however, connected with openings in the lower side of the 
body, and may be regarded as a peculiar modification of the 
air tubes or trachee found in other insects. In many flying 
insects the air tubes expand in certain parts into large hollow 
vesicles, which give greater lightness to their bodies. In all — 
insects we can distinguish three regions of the body: the 
head, composed of several rings closely united together, and 
bearing the organs of the mouth and senses—as many pairs 
as there are rings; the thorax, composed of either three or 
four rings, which bear as many pairs of legs, and sometimes 
one or two pairs of wings above; the abdomen, composed of 
numerous rings, which are not consolidated, and generally bear 
only the external reproductive organs; but in the spiders they 
bear the spinnerets, in many larve several pairs of fleshy legs, 
in centipeds, etc., numerous legs, (figures 1 and 6), and in 
some insects long, slender, feeler-like organs (figure 5). 
Insects are naturally divided into three great Fig. 5. 
groups or sub-classes,* founded on important — 
differences in their internal anatomy and the 
arrangement of their external parts. 


I.—HeExapop INSECTS. 


The highest sub-class contains the Hexapod . 
or six-legged insects, including all the flying 
insects, and many that are destitute of wings. f 
In these the head, thorax, and abdomen, are 
distinctly separated as three regions of the body. 


* According to some writers these divisions are called orders. 

Figure 5.—‘Furniture-bug,” or Shiner, (Zepisma), natural size. A smooth, 
shining, neuropterous insect, covered with minute silvery scales, but destitute of 
wings. It lives in houses among books, papers, clothing, or in furniture, etc., 
eating them in various ways; it is very fond of the paste of books, and will often 
loosen wall-paper. ; 


PARASITES OF ANIMALS. ee 


The head appears to be composed of seven rings, and there 
are three pairs of mouth organs. They all breathe by means 
of air tubes or trachee. 


JI.—ARACHNIDS. 


The next sub-division, called Arachnida, includes the spi- 
ders, scorpions, ‘ daddy-long-legs,”’ or harvest men, mites, etc. 
In these the head is generally more or less united to, or sunken 
in, the thorax, as in the spiders, which have the abdomen very 
distinct; or the abdomen may be closely united to the thorax, 

Fig.6. asin the mites (figure 48). When mature they 
have eight legs. The head bears but few organs. 
There are no antenne. The eyes are simple, but 
often numerous. Many breathe by tracheex, but 
some spiders by lung-like organs, and others by 
both combined. 


IIJ.—Myriapops. 

The lowest sub-class, called Myriapoda, includes 
the centipeds, ‘“‘thousand-legs,” etc., (figures 1 
| and 6.) These have the rings of the thorax and 
abdomen all very similar, and the rings of the ab- 
domen in some become very numerous, sometimes amounting 
to several hundred. Hach ring usually bears a pair of legs, 
and contains anerve ganglion. The head is similar to that of 
the six-legged insects, and bears antennz, and sometimes com- 
pound eyes. They breathe by air tubes or trachee. This 
last sub-class contains no parasites, but in both the others 
there are numerous examples. Yet in those they are confined 
to particular orders and families. 

Among the Arachnids we find parasites only in the tweet 
order, which includes the mites, the true ticks, the itch-insect, 
etc., but among the Hexapod insects we find that the parasites 
belong mostly to two of the seven orders into which they are 
naturally divided. 

The seven orders of six-legged insects are based on many 
anatomical differences, but they are characterized, also, by 


Ape 
Figure 6.—Lithobius Americanus Newport, natural size; color yellowish brown. 
-From Packard’s Guide. 


6 BOARD OF AGRICULTURE. 


differences in their transformations, and peculiarities in their 
habits. The most obvious distinctions are found in the 
structure of the organs composing the mouth, and in the 
wings, when these exist. Their names are derived from the 
character of their wings. The orders are as follows: 

I. Hymenoptera, (membrane-winged). This order includes 
the bees, wasps, ichneumon-flies, saw-flies (figures 7, Ta), etc. 


Fig. 7 a. 
Fig. 7. 


They have four small but strong membranous wings, the front 
pair largest. The body is compact, the head large, and the 
three regions of the body very distinct. The head (figure 8) 
usually has three simple eyes Fig. 8. 

in front, forming a triangle ; a 
pair of slender antenne or 
feelers, and a pair of very large 
compound eyes; connected 
with the mouth we find a pair 
of powerful, often toothed, 
mandibles or jaws; a pair of 
orceps-like mazille, bearing 
near the base a jointed palpus 
or smail feeler ; and finally the 
labiwm or lower-lip, which bears 
a pair of palpi or feelers, and 
the ligula or tongue, which is 
long and highly developed and 
covered with hairs in the bees. 
They have, therefore, all the 
parts of the mouth symmetri- 


Ficure 7.—The Pear-slug or Saw-fly (Selandria cerasi Peck), enlarged. Color 
black, with white spots on four anterior legs and feet. 

Figure 7a.—Larvex of the same on leaf of pear, natural size ; and a, enlarged. 
It is covered with sticky slime. Both from Packard’s Guide. 

Figure 8.—Head of wild Bee (Anthophora), much enlarged; a, compound 


PARASITES OF ANIMALS. 7 


cally developed. The jaws are used for biting and cutting the 
materials used in constructing their nests; the maxille are 
used in manipulating and arranging; the tongue is used for 
lapping up honey and other liquid food. The larve are gen- 
erally soft, footless, and white, but those of the saw flies re- 
semble caterpillars, and have numerous abdominal legs. 

II. Diptera (two-winged). Insects belonging to this order 
have but one pair of wings. The three regions of the body 
are very distinct. The common house-fly, meat-flies, mos- 
quito, Hessian-fly, wheat-midge, onion-fly (figure 9), bot-fly, 
Fig. 9. horse-fly, and the fleas 

: are examples. The 
mouth organs corres- 
pond in number with 
those of the Hymen- 
optera, but the mandi- 
bles and mazille are 
usually formed like 
long sharp lancets, as 
in the horse-fly (fig. 
10), or have the shape of slender and 
sharp piercing organs, as in the mosquito. 
The labium and tongue together generally 
form a long proboscis, often with the 
tongue curiously bilobed and expanded at 
the end as in the horse-fly and house-fly. 
The sharp mandibles and maxillz are used 
to penetrate the skin of animals, or the 
bark of plants, and rind of fruits, and the fleshy tongue is 
used to suck up the blood or other liquid food. The larvee 


eyes; 6, clypeus; c, the three simple eyes or ocelli; d, the antennz; e, labrum or 
upper lip ; f, mandibles ; A, maxillary palpi, borne upon the base of the maxillz 
zi, which are slender and hairy; j, labial palpi; &, ligula or tongue; J, palpifer ; 
m, paraglossze or lateral lobes of the ligula. From Packard’s Guide, after New - 
ort. 
: Figure 9.—Onion-fly (Anthomyia ceparum), considerably enlarged, with larvee, 
aandb. From Packard’s Guide. : 
Figure 10.—Head of Green-head fly or Horse-fly ( Tabanus lineola Fabr.), much 
enlarged ; a, antenne; m, mandibles; mz, maxille; mp, the large, two-jointed 
maxillary palpi; /, the ligula or tongue; 1b, the labrum. From Packard’s Guide. 


8 BOARD OF AGRICULTURE. 


are usually soft, white, and footless, and generally pass under 
the name of maggots. In this order we find many parasites, 
of which the fleas, sheep-tick, bat-ticks, horse-tick, forest-flies, 
bot-flies, etc., are examples. This order contains some bene- 
ficial and very many injurious insects. 

Ili. Lepidoptera (scaly wings). This order includes the 
butterflies, moths, millers, army worm (figure 11), canker- 
worms, cut-worms, silk-worms, etc. 
The wings are four in number, usually 
broad, and covered with minute scales, 
looking somewhat like beautiful feath- 
ers under the microscope, but appear- 
ing like fine dust to the naked eye. 
The mandibles are nearly abortive, but 
the maxille are usually very long, slen- 
der, and hollowed out on the inside, so that inthe 
gether they form a long hollow tube or proboscis, through 
which they suck up their liquid food. The proboscis can be 
rolled np beneath the head when not in use. The larve 
mostly feed upon plants, and are generally known as cater- 
pillars. They are often bright colored, sometimes hairy, and 
usually have, in addition to three pair of small true legs, two 
or more pairs of fleshy legs under the abdomen. Most of the 
insects of this order are injurious to vegetation. 

IV. Coleoptera (shield-wings). Insects of this order are 
known as beetles, weevils, etc. The front wings are thick- 
ened and stiff, not used in flight, but serve to protect the 
hinder wings, which are larger and thin, and can be folded up 
and tucked away under them. ‘The mandibles and maxille 
are both used as jaws for biting and chewing. The larvee 
have usually three pair of legs, and many are well known as 
grubs and borers in wood. ‘The apple-tree borer (figure 12), 
isan example. This great order includes many beneficial 
carnivorous insects, as well as many that are injurious to 
vegetation. | | 

V. Hemiptera (half-wings). This order embraces those 


Figure 11.—Southern Army-worm (Leucania) imago; and larva, a, natural 
size. From Packard’s Guide, after Glover. 


PARASITES OF ANIMALS. 9 


_ insects properly called bugs, such as the squash-bug (figure 
13), strawberry-bug, bed-bug, and also the cicada or “seven- 


Fig. 12. 
4 Fig. 13 


teen-year locust,” the plant-lice, bark-lice, cuckoo-spits, the 
true lice, bird-lice, etc. In this order we find, therefore, the 
greatest number of external parasites: The wings, when 
present, are often crossed upon the back, and the front wings 
are often thickened toward the base, but in other cases, as in 
the cicada and plant-lice, the wings are transparent and not 
crossed. The mouth organs form a sharp hollow proboscis, 
for piercing the bark of plants or skin of animals, in order to 
suck up the blood or sap. When not in use the proboscis can, 
be folded down upon the breast, by means of three joints. 
The mandibles and maxille are four, long, slender, very 
sharp, piercing organs, often barbed near the points. These 
are enclosed in the jointed proboscis, as in a sheath, but can 
be thrust out through the opening in the end. The proboscis 
is formed mostly by the lower lip or labium, but the opening 
in the upper side is covered by the shorter upper lip. The 
larvee of many Hemiptera resemble the adults from the first, 
except that they lack wings; the pupz are also active and 
have the same habits. They therefore undergo less remark-- 
able transformations than those of the preceding orders.. 
Many of these insects are beneficial by destroying other in- 
sects, but most are injurious to vegetation by sucking sap. 


Figure 12.—Apple-tree Borer (Saperda candida Fabr.), natural size. Color 
light brown with two white stripes; the lower figure represents the larve. From 
Packard’s Guide. 


FIGURE 13.—Squash-bug (Coreus tristis DeGeer.), natural size. Color dark. 
brown. From Packard’s Guide. 


2 


10 BOARD OF AGRICULTURE. 


VI. Orthoptera (straight-wings). This order includes the 
grasshoppers, true locusts, katydid, crickets, cockroaches, etc. 
Fig. 14. The front wings are generally 
“long and straight, somewhat 
thickened, and in the male often 
have some sort of musical ap- 
paratus, as in crickets, katydids, 
etc. The hind wings are broad, 
fan shaped, and can be folded 
up like a fan beneath the front 
wings, which when folded gen- 
erally lie lengthwise of the body, 
forming a sort of roof. 

The mandibles and maxille 
are chewing organs. The larve 
have nearly the same form as the 
adults, but lack wings; they have 
similar habits; the pupe are also active. Most of these 
insects, except the Mantis, are injurious to vegetation by eat- 
ing the leaves. 

VII. Neuroptera (nerve-winged). The dragon-flies, lace- 
‘winged flies(Figure 15), May Fig. 15. 
flies, Lepisma (Figure 3), and 
white ants, belong to this order. 
‘The wings, when present, are 
thin, membranous, and subdivided by very numerous rods or 
nervures into small spaces, which are often squarish. The 
mandibles and maxille are chewing organs. The abdomen 
is generally long. The larve are of many forms, often 
aquatic, generally carnivorous and predacious in habits, and 
usually undergo a complete metamorphosis; the pup are 
mostly inactive. Most insects of this order, excepting the 


Figure 14.—Katydid (Cyrtophyllum concavum Say), male, natural szie. Color 
bright green. From Packard’s Guide. 

Figure 15.—The Lace-wing Fly (Chrysopa oculata Say), natural size, with the 
eges attached to the tips of slender pedicels. Body light green. This insect 
lays its eggs among plant-lice (Ap/és), which the larve, when hatched, destroy. 
From Packard’s Guide. 


PARASITES OF ANIMALS. 11 


white ants and Lepisma, are beneficial by destroying noxious 
insects. 

To those who desire more information upon the struc- 
ture, habits, and classification of insects generally, we would 
especially recommend Packard’s Guide to the Study of In- 
sects, Salem, Mass., 1869, and Harris’ Treatise on Insects 
Injurious to Vegetation (illustrated edition), Boston, 1862. 


PARASITES BELONGING TO THE DIPTERA. 


The Fleas. 


PULICIDA. 


It is somewhat singular that parasites are almost always 
degraded species of the orders and families to which they 
belong. This is very evident in the case of parasitic insects, 

for they are mostly destitute of wings, and are imperfectly 
organized in other respects when contrasted with their self- 
supporting allies. The fleas furnish us with examples of 
degraded diptera, and the sheep-tick is even more degraded 
than the fleas. Of fleas there are several species that attack 
man and domestic animals ; but the species do not appear to 
be so strictly limited to particular animals as are the lice and 
some other parasites; for the common dog-flea and cat-flea 
will attack man without hesitation, and in New England ap- 
pear to be far more troublesome to the human race than is 
the species commonly regarded as the real human flea (Pulezx 
irritans), which so far as I have observed, is comparatively 
rare, though in some localities it may be sufficiently common, 
as it is in parts of Kurope. 

In the genus Pulez, which includes the common species of 
fleas, the body is compressed and the integument is very firm, 
so that they are well adapted for gliding among hairs or 
feathers, and are not liable to be injured by any ordinary 
pressure. The wings are represented only by two pairs of 
short, stiff scales, which have little or no power of motion. 
The posterior legs are large and powerful, enabling them to 
leap with remarkable agility. The head is small; the eyes 


12 BOARD OF AGRICULTURE. 


are simple, in some species very minute ; the antennz are curi- 
ously constructed with three broad, flat, singularly lobed 
joints, and are, in nearly all species, closely folded away out 
of sight, in a socket or cavity behind the eyes; though in 
the males of .the mouse-flea and pigeon-fiea they are exposed 
and carried erect. The mouth organs are peculiarly con- 
structed and well adapted for piercing the skin and sucking 
the blood. The maxilla (Figure 16, a), are a pair of broad, 
flat, thin, somewhat lance-shaped organs, bearing at base the 
long, four-jointed feelers or palpi (6). The, mandibles (¢) 
are slender, flattened, sharp, piercing organs, finely serrated 
along their sides, like a minute saw. The Figure 16. 
labium (d) is a round, slender, piercing 
organ, forming the central lancet. The 
lower lip and labial’ palpi (¢) form to- 
gether a sort of sheath, with a groove on 
the inside, which receives the mandibles 
and labium, when in their natural posi- 
tion; the labial palpi are four-jointed in the cat and dog . 
fleas, if not in all, though some writers say they are three- 
jointed. The mandibles (¢) and labium (d) form together 
three slender lancets, and it is by means o€ these that the 
flea perforates the skin. The blood is then drawn up through 
the channels or spaces between these organs and the labial 
palpi and lower lip, by means of a sucking stomach. 


The Cat-flea (Pulex felis Bouché). Figures 17, 18. 


This species of flea is perhaps the best known and most 
common kind in New England. It not only infests nearly all 
cats and the places where they sleep, but is also more or less 
common in dwellings of all classes, especially when cats are 
allowed to roam about over the carpets. It often becomes | 
exceedingly troublesome in sleeping rooms, for it prefers to 
spend the day about the floor, in and beneath the carpet, 
or in some similar place of concealment; but when oppor- 


RS) 


7 Te ain nn oe ei Rea Laie na re 

Figure 16.—Head of the dog-flea (Pulex canis Curtis), highly magnified; a, 
the broad, thin maxille; 0, their four-jointed palpi; c, the mandibles; d, ‘in 
labrum or central seta of the proboscis; e, the labium and labial palpi. From 


Duges. 


PARASITES OF ANIMALS. 13 


tunities offer it is always ready to jump upon the naked feet 
or ankles, and may thus gain entrance to the bed. Many 
persons, especially ladies and children, are badly poisoned by 


Figure 17. Figure 18. 


them, and may suffer severely for several days from the bite 
of asingle flea; for, unlike the mosquito and other blood- 
sucking insects, they are never satisfied with a single bite, or 
with one spot, but must travel about and bite as they go, 
literally ‘‘ biting on the run.” In these respects, however, it 
agrees closely with the so-called human flea (Pulez irritans). 

The cat-flea (Figure 17) is dark chestnut-brown in color, 
and is stouter and thicker in the thoracic region than Pulex 
arritans, which has a rather slender waist and darker color. 
There is a row of sharp spines along the lower side of the 
head on each side, and another row of similar spines on the 
posterior edge of the first segment of the thorax; but the 
human flea lacks both these sets of spines. Other good dis- 
tinctions are found in the joints of the feet or tarsi, and in 
the mouth organs.’ In all fleas the males and females differ 
considerably in form and size, the males being smaller and 
shorter. 

The female cat-flea lays her eggs among the fur of the cat, 
to which they are but slightly attached ; these eggs are very 
small, white, and long-oval. As the cat walks or runs about, 
the eggs are constantly being scattered around, often in great 
numbers. On one occasion I was able to collect fully a tea- 
spoonful of these eggs from the dress of a lady in whose lap a 
half-grown kitten had been held for a short time. The plaves 


14 BOARD OF AGRICULTURE. 


where cats sleep become well filled with the eggs. These 
hatch in about two weeks into little, white, footless, maggot-. 
like larve (Figure 18), which have small tufts of hairs along 
the sides. They are at first about one-sixteenth of an inch 
long. The head is pale yellow, and the posterior end of the 
body bears two spines. These larve feed upon the decaying 
particles of animal and vegetable matter always to be found 
in the dirt in which they live. They move about by means of 
their hairs and spines. They grow rapidly in warm weather, 
and in about twelve days, when they mature, spin a slight 
silken cocoon and change to a pupa, which is inactive. 
This looks more like the mature flea and has the legs free. 
In a short time, varying from ten to sixteen days or more, 
according to temperature, the pupa matures, and the full 
formed flea comes forth from the cocoon, ready and willing 
to take care of itself. This it does by leaping upon the first 
living creature that comes within range ; but no doubt it is 
better suited with the cat than with other animals. This 
mode of increase and the habits of the young will explain the 
reason why fleas are often obtained out of doors, especially in 
gardens frequented by cats or dogs. Such fleas are often 
called “sand-fleas,” but they are simply the progeny from eggs 
of cat or dog fleas that have been hatched and lived in the 
dirt or soil. They pass the winter both in the mature and 
larval states, and perhaps also as eggs and pups. There are 
several broods each season. 


The Dog-Flea (Pulex canis Curtis). Figure 19. 


This species is very similar to the last, and is considered 
the same by several writers. It has the same form and color, 
and the same rows of spines below the sides of the head and 
on the thorax. But there appears to be some difference in 
the mouth organs. The posterior tarsi in this species are 


Figure 17.—Cat-flea (Pulex felis Bouché), much enlarged; a, the maxillary 
palpi arising from the bases of the maxillx, b; c, the labial palpi; d@, the slender 
mandibles. The labrum is not shown. From Packard’s Guide. 


Figure 18.—Larva of Cat-flea (Puler felis Bouché), much enlarged; a, one of 
the antenne more highly magnified; }, posterior end of the body, showing the 
two spines. From Packard’s Guide. 


' PARASITES OF ANIMALS. 15 


said to have the fifth joint longer than Figure 19. 
the second, while in the cat-flea the second 
is longer than the fifth. The habits are 
essentially the same, except that this one 
seems to prefer the dog’s blood. It will 
also attack human beings when oppor- 3 
tunities offer. — 

The Hen-Flea (Pulex galline Schank) lives upon the hen 
and about poultry-houses and yards. 

The Pigeon-Flea (Pulex columbe Gervais) lives upon do- 
mestic pigeons and in pigeon-houses. 

Other species infest rats, mice, bats, rabbits, swallows, and 
various other wild animals and birds. 

Remedies for Fleas. 


From the description of the habits of the larvae given above, 
it is evident that dirt and filth of all kinds afford facilities for 
the increase of fleas, and that dogs and cats are the means of 
diffusing their own peculiar species, and also, no doubt, the 
true human flea. The first care, therefore, should be to see 
that the dogs and cats, if such are kept, are freed from their 
parasites. ‘To this end they should be made to sleep on some 
material like shavings or chips, that can be easily burned, 
and their sleeping places should be often cleaned and their 
beds renewed. ‘To remove the fleas themselves from the 
animals a wash of water containing 6 to 10 per cent. of petro- 
leum, naphtha, or benzine, well shaken together, may be used. 
A weak solution of carbolic acid in water, about 2 or 3 parts 
of the acid to 100 of water, will also be efficacious for fleas 
and other parasites. Decoctions of tobacco and strong soap 
suds are also recommended. 

When fleas are troublesome in dwelling houses, a thorough 
cleaning of the floors and an equally thorough beating and 
cleaning of the carpets, rugs, etc., will generally be effectual. 
When cracks or crevices exist in the floors, a thorough wash- 
ing with the petroleum, naphtha, or carbolic acid water, will 
be useful to destroy the eggs and young. Persian Insect 


Figure 19.—Head of Dog-flea (Pulex canis Curtis), much enlarged. The parts 
are the same as in Figure 16. From Duges. 


16 [BOARD OF AGRICULTURE. 


Powder, which is a preparation from the flowers of a plant, is 
often used to expel fleas both from carpets and the fur or 
hair of animals. It appears to be particularly obnoxious to 
them. But after applying the powder to an animal it should 
soon after be thoroughly washed off. 

It often happens that there are really but few fleas, perhaps 
less than a half dozen, in a room that is supposed to be over- 
run by them; for owing to their habit of biting repeatedly, a 
single one may do the mischief attributed to a large number. 
In such cases a careful search for and capture of the of 
fenders will soon remedy the evil. When caught, a drop or 
two of benzine will kill them instantly. 


The Sheep-Tick, Forest-Flies or Horse-Ticks, ete. 


HIPPOBOSCIDA. 


These are degraded Dipterous parasites, and must not be 
confounded with the true ticks, which have eight legs. Some 
of them are destitute of wings, like the sheep-tick; others 
have long, narrow, simple wings, like the species infesting the 
horse, and those of the swallow and other birds, bats, ete. 
The body is flattened from above, and is hard and firm, with 
a horn-like or leathery texture. The head is somewhat 
sunken into the front edge of the thorax, without a distinct 
neck. The antenne or feelers are very small and near to-— 
gether. The eyes are large and often occupy most of the 
sides of the head. The proboscis consists of two lateral, nar- 
row, elongated, bristly plates (regarded as maxille by some 
authors), which project in front of the head. Below and 
between the bases of these there is a small orifice from which, 
when about to draw blood, three, long, slender, piercing 
organs are protruded; but these can be withdrawn when not 
in use. These are unequal in size, but equal in length. The 
lower one, which is largest and channeled along the upper 
side and dilated at base, receives the two smaller ones into 
its groove. These organs penetrate deeply into the skin, 
and through the channel formed by the setz the blood is 
sucked up. 

They live like lice among the feathers of birds or hairs of 


PARASITES OF ANIMALS. 17 


animals, and run with agility either forward, sideways, or 
backward, somewhat like a crab. Their feet or tarsi are fur- 
nished with powerful denticulated claws, with which they 
cling. securely. Their most remarkable peculiarity is their. 
mode of reproduction. Each female produces but one or two 
young at a time, but these are born as living, fully developed 
larve, which are enclosed in a smooth oval skin, notched at 
one end, within which they change to pup immediately 
after birth, the enclosing case becoming dark colored. The 
female has an uterus-like enlargement of the oviduct, in which 
the eggs hatch, and this organ has the power of secreting a 
milk-like substance for the nourishment of the larve until 
full grown. 


The Horse-tick or Forest-fly (Hippobosca equina). Figure 20. 


This species is almost as large as the house-fly, nearly black, 
with conspicuous yellow markings on the thorax. It some- 
a times infests the horse 

4, to such an extent as to 


ence those parts where 
the hair is thinnest 
and the skin softest, 
especially under the 
belly and between the 
hind-legs. Their bites - 
cause severe pain, and. will irritate the gentlest horses, often 
rendering them almost unmanageable, and causing them to 
kick dangerously. When found they cling so firmly as to be 
removed with some difficulty, and they are so tough as not to 
be readily crushed. If one escapes when captured, it will in- 
stantly return to the horse, or perchance to the head of its 
captor, where it is an undesirable guest. Another species 
sometimes infests the ox. 


Figure 20.— The Horse-tick (Hippobosca equina Linn.), enlarged. From 
Cuvier. 


18 BOARD OF AGRICULTURE. 


The Sheep-tick (Melophagus ovinus Linneus). Figure 21. 

This insect never acquires wings. It has a broad head, 
wider than the thorax. The abdomen is roundish and hairy, 
not showing distinct rings, and in the gravid female becomes 
much enlarged. The legs are short and stout, and the claws 
very strong. The proboscis is as long as the head. Like the 
horse-tick, it is viviparous, producing a full-grown larva, en- 
closed in an oval case, as shown in Figure 21. 

It is often very troublesome to sheep, especially lambs. 
There have been numerous remedies proposed. In general, 
when there are but few, they can easily Figure 21. 
be removed by hand when the sheep are 
sheared; but when numerous on lambs, 
they may be destroyed by various washes 
or baths. Snuff, or sulphur in powder, 
rubbed thoroughly into the wool, is some- 
times used with good results. A bath 
made by steeping tobacco in water, about 
2 pounds to 10 gallons of water, in which the lambs are 
entirely immersed, with the exception of the face, is said to 
be effectual, but in some cases, has proved injurious to the 
health of the lambs. Probably the same solutions recom- 
mended for fleas would be equally effectual for these; but 
the strength of petroleum water, or naphtha water, or car- 
bolic acid water, ought to be adapted to the age and strength 
of the animals to which it is applied, young lambs having a 
much more tender skin than dogs or old sheep. 


The Bot-flies of Horses, Cattle, and Sheep. 
CHsTRID A. 


The insects belonging to this family are much less degraded 
than the other parasitic Diptera. But in reality these are not 
parasites, except in the larval state. They pass the pupa state 
in the soil, and in the winged state are powerful fliers, seek- 
ing the quadrupeds only for the purpose of depositing their 


Figure 21.—Sheep-tick (Melophagus ovinus Linnweus), enlarged. The figure on 
the left represents the puparium when first born. From Packard’s Guide. 


"PARASITES OF ANIMALS. 19 


egos. There are numerous genera and species, each of which 
lives, in the larval state, upon some particular species of 
mammalia, and usually in some particular part of the ani- 
mal. In the tropical parts of America there are species which 
live beneath the human skin, in tumors that they cause. The 
larve are usually thick, fleshy grubs, destitute of feet, but 
generally provided with rows of hooks or spines, by means of 
which they move about in their burrows. The breathing 
pores are in one or two scaly plates at the thick posterior end 
of the body. In those that are parasitic in the stomac)), the 
mouth has horny hooks by means of which they cling to the 
lining membrane ; but in those that live in tumors under the 
skin, there are no hooks to the mouth, but only fleshy 
tubercles. ‘They live on the matter, or pus, which is caused 
by the irritation that they produce. 

The flies generally have a stout, hairy body, sometimes 
looking somewhat like humble-bees. The female has a more 
pointed abdomen, with an extensible ovipositor. The an- 
tenne are very-small, and placed in little pits. The mouth 
organs are almost abortive, and the mouth very small, for 
these flies take little or no food in their winged state, this 
period of their lives being wholly devoted to the reproduction 
of their kind. The species that infest cattle, sheep, and 
horses have been transported to nearly all parts of the world 
where these animals are reared; but there are many native 
species that are found only in the wild animals. * 


The Bot-fly of Cattle (Hypoderma bovis Latr). Figures 22, 23. 


This fly is densely covered with hairs, except upon the 
thorax, which is partially naked and black, broadly banded 
with white and yellow. The abdomen is banded alternately 
with yellowish white and black, and with reddish orange at 
the end. The front of the head is dirty ashen, with yellowish 
white hairs. They appear from June to September, and the 
females lay their eggs on the backs of cattle. According to 


SBS SA eh NI cS eT 


-  * One species, Cuterebra emasculator, described by Fitch, lives in the scrotum of 
squirrels, and destroys one or both testicles. In some parts of the country it is 
often quite common, and doubtless greatly diminishes the number of squirrels. 


20 BOARD OF AGRICULTURE. 


some writers, they pierce the skin, by means of their peculiar 
gimlet-like ovipositor; but others deny this, and say that the 
eges are merely attached to the skin, and that the young 
larvee, which very soon hatch, eat their way in. At any rate 


Figure 22. Figure 23. 


the cattle are often greatly alarmed by their attacks, and run 
frantically about, sometimes even taking to the water for 
safety, which would hardly be the case unless they had suf- 
fered pain from their attacks. Working oxen, when thus 
attacked, sometimes cause serious trouble. 

The larvee having entered the skin increase the size and 
depth of their burrows as they grow larger, but always keep 
up an opening with the exterior, and keep the posterior end 
of the body, in which the breathing pores are situated, near 
this opening to get air. In this way they cause, by the irrita- 
tion and inflammation that they produce, tumors or abscesses 
of considerable size beneath the skin, and live upon the 
matter formed by the inflammatory action. When young, 
they are white, but afterwards become brownish; when ma- 
ture, deep brown. fr | 

They have transverse rows of minute hooks; the narrower 
rows are on the posterior part of each segment, and the hooks 
point backward ; those of the wider rows, point forward. These 


Figure 22.—The Bot-fly of Cattle(Hypoderma bovis Latreille), considerably en- 
larged. 


Figure 23.—The full grown larva, enlarged. Both from Packard’s Guide. 


PARASITES OF ANIMALS. ; 21 


hooks are used in moving about, and no doubt cause consid- 
erable irritation. The mouth is small and inconspicuous, 
with small papillz. The posterior end of the body bears two 
small plates in which the spiracles or breathing pores are 
situated ; and this end of the body is kept next to the external 
orifice of the tumor. When the larva is mature, which hap- 
pens from May to July, it is about an inch long (igure 23). 
It then works its way out of the opening backward, and falls 
to the earth, where, in a day or two, it changes to a pupa, 
the dried-up skin of the larva serving as a covering for the 
pupa. They remain in the pupa state from four to six weeks 
during summer, when the end of the pupa-case comes off, 
like a lid or cap, and the mature fly comes forth. The sores 
caused by them heal very soon after the larve leave. 
Although these insects probably cause some pain, especially 
at first, they do not appear to cause any permanent injury, 
and but little inconvenience, unless in large numbers. They 
can usually be pressed out of their burrows with the thumb; 
but care should be taken not to crush or burst them in the 
burrows. Or the openings of the tumors may be enlarged with 
a sharp knife or lancet, and then they can be easily removed 
and the wounds will soon heal. They attack by preference 
young and healthy or fat animals, perhaps because the skin 
is softer and thinner in these. They frequent chiefly the 
uplands, and especially the vicinity of trees, and seem to 
particularly avoid water or damp localities —a fact that cattle 
‘seem to learn by experience. Owing to this habit, cattle that 
graze upon meadows are generally free from them, or nearly 
so, although those upon the neighboring hills may be at- 
tacked. The eggs are laid soon after the flies emerge from 
the pupa; but as there is considerable variation in the time 
when the larvae mature, the flies may occur from June to 
September. The larve live during the entire winter in the 
tumors, and perhaps some of the pup remain over winter. 


The Sheep Bot-fly (Gstrus ovis Linn.). Figure 24. 


This species somewhat. resembles the preceding in form, 
but is considerably smaller, with a rounder abdomen in the 


22 BOARD OF AGRICULTURE. 


male, and the color is lighter. The thorax is ash-colored, 
with four black lines and small black spots. The abdomen is 
light ash, more or less spotted with blackish. The female has 
a tapering abdomen, with a long ovipositor, which is curved 
forward when about to deposit the eggs. 

The flies appear during the whole summer, and according 
to Mr. Riley, deposit the young larve previously hatched in 
the oviduct, on the margins of the nostrils of 
sheep. “‘ The moment the fly touches this part of 
the sheep, they shake their heads and strike the 
ground violently with their fore-feet ; at the same 
time holding their noses close to the earth, they 
run away, looking about them on every side to 
see if the fly pursues. They also “smell to the 
grass” as they go, lest one should be lying in 
wait for them. If they observe one, they gallop back, or take 
some other direction. As they cannot, like the horses, take 
refuge in the water,.they have recourse to a rut or dry, 
dusty road, or gravel pits, where they crowd close together 
during the heat of the day, with their noses close to the 
ground, which renders it difficult for the fly conveniently to 
get at the nostril.” (Clark, 1796). This description, al- 
though written long ago, applies equally well to the habits 
both of the fly and sheep, as observed at the present day. 
The young larvee at once proceed to ascend into the nostrils 
by means of their hooks and writhing motions, thus causing 
great irritation and an increased secretion of mucus, upon ° 
which they feed. They finally reach the frontal and maxil- 
lary sinuses and other cavities, connected with the nose, and 
attach themselves securely to the mucus membranes by means 
of the two sharp hooks upon their heads. They thus cause 
great inflammation, if in cousiderable numbers, and severe 
illness, or even at times convulsions and death result. This 
disease is often known as “ grub in the head”? among farm- 
ers. The disease is indicated by loss of appetite, frequent 
coughing or sneezing, unusual discharge of matter from the 
nose, slow and weak gait, dullness, inability to stand, tossing 


Fig. 24. 


Figure 24.—Larva of the Sheep-bot (@strus ovis), natural size. From Clark. 


5 


PARASITES OF ANIMALS, 23 


or turning of the head, inclination to butt and push with the 
head, fits of frenzy, and general appearance of suffering and 
weakness, which sometimes goes so far as to render the animal 
unable to rise, when death generally results. The gums, back 
part of mouth, and lining of the nasal cavities are often red and 
inflamed. Sometimes the larve even force their way, by the 
openings through which the nerves pass, into the brain, when 
death quickly follows. 

These larve, when full grown (Figure 24) are about an 
inch long, and have lost more or less of the white color which 
they had when younger, and each ring is crossed above by two 
dark brown bands; there are also small, round, raised brown 
spots on the sides of each segment. The small end, or head, 
has two sharp hooks and two papilla; but the posterior seg- 
rent bears two small brown plates, in which the spiracles 
are placed, and this segment can be drawn into and con- 
cealed by the next, which give a truncated appearance to 
the posterior end. The under side is flattish, and each seg- 
ment has a median row of minute brown spines, which are 
directed backward. 

When full grown, they descend from the nostrils and fall 
to the earth, where, in the soil or among the roots of grass, 
they change to pupz in about two days. They remain in 
this state from six weeks to two months, when a sort of lid is 
forced off from one end of the pupe cases, and the mature 
flies come forth, pair, and immediately proceed with the work ° 
of perpetuating the race, for in the winged state they seem to 
have no other instinct; and not having any mouth, they take 
no food. When not engaged in depositing the eggs, they 
seem sluggish and lazy. The flies appear irregularly in June, 
July, and August, and larve of all sizes may be found at one 
time in the same sheep. Hach female produces several hun- 
dreds of young. According to Mr. Riley, * over 300 living 
larvee have been taken from one female fly, by Mr. Cockrill. 

The amount of injury which these insects do to the sheep 
has long been a matter of discussion among veterinary sur- 
geons and others; but it appears to be the universal testi- 


* First Annual Report on the Noxious Insects of Missonri, p. 164, in Report of 
Roard of Agriculture, 1868. 


24. BOARD OF AGRICULTURE. 


mony of those who are most immediately interested — the 
_ breeders of sheep —that their effects are evil, and evil only, 
and that the amount of injury is in direct proportion to their 
numbers, as is the case with all other parasites. That, when 
as abundant as they often are, they are capable of causing 
death, seems to be well established. As a preventive, it 
has been recommended to move the sheep to distant pastures 
after most of the grubs or larve have left the sheep and are 
in the earth in the pupe state, which happens during June or 
July, according to locality. In this State probably the latter 
half of June would be the best time for this. Others smear the 
noses of the sheep with tar, or make them do so themselves 
by boring large augur holes in logs to contain salt, and fre- 
quently smearing the adjacent wood with tar. Many provide 
spots of light, dry soil into which the sheep may thrust their 
noses when pursued by the fly. When the larve have ac- 
tually entered the nostrils in large numbers, they may be 
removed to a considerable extent by a feather wet with oil of 
turpentine, camphor, or a weak solution of carbolic acid, or 
of creosote. Lime, in fine powder, is sometimes used; for 
by sniffing it, they sneeze, and thus expel the larve. Salt 
water or diluted carbolic acid solution may also be injected 
into the nose with a syringe. It is doubtful, however, 
whether any remedies will reach the larvee which have taken 
up their abode in the more remote cavities in the bones of the 
-forehead and beneath the bases of the horns. Therefore it is 
better to apply these remedies early and often, if necessary. 
Another species of bot-fly (Hypoderma lineata Brauer), 
lays its eggs upon the backs of sheep and cattle, and the 
larve live in tumors beneath the skin, like the more com- 
mon Hypoderma bovis of cattle. It appears to be rare in this 
country, but has been observed in Kentucky. This fly may 
be known by three, longitudinal, naked, black stripes on the 
thorax. The abdomen is very hairy, blackish, with three 
bands, the base whitish or yellowish, the middle black, the 
apex orange-red. The wings are transparent, somewhat 
brownish, unspotted. In New Grenada another species, the 
Dermatobia noxialis Goud., has the same habits, and also at- 


C3 


PARASITES OF ANIMALS. 25 


tacks men in the same way, forming painful tumors beneath 
the skin. The same or a similar species also infests the dogs 
in the tropical parts of America. 

Several peculiar species of Hypoderma live beneath the skin 
of the moose, elk, and other species of the deer family. These 
anitnals are also infested by several species of the genus 
Cephenomya, which live in the larval state in the throat, or at 
the root of the tongue. 

The goat is attacked by a species of Hypoderma, which 
makes tumors under the skin, and by a species of Wstrus, 
that enters the frontal sinuses, and has the same habits as the 
common species of the sheep; but these two species have not 
been determined and are little known. The camel is infested 
by the larvee of Cephalomya maculata Wd., which lives in the 
nasal cavities, like the larve of the sheep-bot. Even the ele- 
phant and rhinoceros have their peculiar parasites of this 
kind. The latter is attacked by a bot-fly, allied to that of the 
horse, which lives in the stomach in its larval state. 

Bot-fly of the Horse ( Gastrophilus equi). Figures 25, 26. 

The “bots” of horses are the larve of several species of 
flies, belonging to the genus called Gastrophilus. The largest 
and most common kind is G. equi, the female of which is 
represented in Figure 25. This species is very hairy, and has 
dark spots on the wings. The eyes are black and distant; the 
top of the head is brown, the front whitish ; the thorax is brown, 
with a darker brown or blackish central spot; the abdomen is 
brown with the transverse divisions and spots blackish. The 
male has a rounder or broad-oval abdomen, which is browner. 
This fly lays its eggs by preference upon the hairs about the 
knees of horses, especially on the inside ; it also frequently at- 
taches them to the hairs of the side and back part of the shoul- 
der, and occasionally to the tips of the hairs of the mane. These 
eggs are of considerable size, of a long oval form, pointed at 
one end and blunt at the other, and adhere firmly by one 
side. They may easily be seen and can be removed either 
by thorough washing and brushing, or by cutting the hairs 
off with scissors. A wash of carbolic acid soap has been re- 


commended to destroy them. Sometimes 500 or more may 
4 


> 


26 BOARD OF AGRICULTURE. 


be found on one horse. In depositing the eggs, the female 
fly hovers around the horse, and as each egg is ready to be 
deposited, she quickly advances and bends the abdomen for- 
ward, with the egg at the end, and applies it to the hair, to 


Figure 26. 


Figure 25. 


which it instantly adheres by the glutinous ‘secretion which 
covers it. She then retreats and prepares another egg for 
the same operation. This does not disturb the horse, unless 
by a tickling sensation, causing the muscles of the skin to 
contract with a tremulous‘motion. The eggs contain more 
or less perfectly developed larvee when laid ; and when they 
are mature, or have been a few days attached to the hair, 
they burst open and allow the young to escape almost instan- 
taneously, when moistened. Thus, when the horse licks itself 
or its companions, the moisture hatches the eggs, and the 
young larve are transferred to the mouth by the tongue or 
lips, and thence to the stomach, where they fasten themselves 
to the lining membrane by their two hooks. They generally 
occur in clusters, and are most common in the vicinity of the 
pylorus, but are found attached to all parts of the stomach. 
In this situation they slowly grow to be large fleshy larve, 
with a round body, about an inch long (Figure 25). The 
segments of the body are provided with double rows of spines, 
pointing backward. These are reddish with black tips. The 


Figure 25.—Bot-fly of the horse (Gastrophilus equi Leach), female, natural 
size. 


Figure 26.—Larva of the same, enlarged. From Packard’s Guide. 


PARASITES OF ANIMALS. OG 


two last segments do not show the spines, and the posterior 
end of the body is rather truncate, with two fleshy lobes, 
which cover, more or less completely, a chitinous plate, in 
which the spiracles are situated. The mouth is at the small 
end, between the hooks, which represent the maxille; the 
mandibles, above and between these, are small and slender. 
At the places where they attach themselves there are found 
small pits or depressions; but they do not appear to cause 
ordinarily much irritation or inflammation, unless in great 
numbers, as they sometimes are. They have been accused of 
perforating the walls of the stomach, and this may possibly 
be the case in very rare instances; but the perforations of 
the stomach, so often found in post-mortem examinations, 
are generally caused by the digestive action of the gastric 
juice after the death of the animal; for after death this fluid 
will attack the stomach as quickly as any other flesh. 

When full grown they loosen their hold, and passing 
through the intestine, fall to the earth. But they often fix 
themselves for a few days upon the lining of the intestine, 
and then cause considerable irritation and pain. Probably 
most of the acute symptoms of “ bots” in horses are caused 
in this way. They often attach themselves in and about the 
anal orifice, and in that situation cause much suffering and 
trouble to the horses, which under these circumstances, re- 
fuse to travel rapidly, and even after whipping, soon relapse” 
into a slow walk, as if lazy. But the bots can be easily re- 
moved from this location, much to the relief of the horse. 
The bot-larve get their growth and leave the horses from the 
latter part of May to July, or even later. They enter the 
surface of the soil and change to pupx within the shrunken 
skins of the larve. They remain in the pupa state forty or 
fifty days, and emerge in the same way as the preceding spe- 
cies; consequently the flies may occur from the last of June 
till September, or later. 

The amount of injury caused by the bots of horses has long 
been a matter of dispute, many writers claiming that they are 
very injurious, and even at times, fatal ; while others deny this, 
and consider them as harmless, or even beneficial. This can 


28 BOARD OF AGRICULTURE. 


be definitely settled only by experiment; but most reasonable 
men would be content to forego any possible benefit, and be 
satisfied with a healthy horse destitute of bots. No doubt 
many diseases due to other causes are commonly attributed 
to these insects, but that they are frequently the cause of 
serious trouble is generally believed and admitted. In this 
instance prevention is comparatively easy, while all writers 
admit that there is no reliable cure, no mattter how much 
they may differ in other respects. The means of prevention 
consist chiefly in frequently removing or destroying the eggs, 
as mentioned above, and also in removing and destroying the 
full-grown larve when observed attached to the rectum. In 
some countries the grooms frequently wash out the mouths 
of the horses with a suitable brush in order to remove the 
young larve. Many drugs have been recommended to re- 
move bots from the stomach, but none that do not endanger 
the life of the horse can be relied upon; and in cases where 
they bring away the larve, it is possible that those that are 
already in the intestines are the only ones affected. Spirits 
(or oil) of turpentine is a remedy in common use, but should 
be used with caution, if at all. A better plan, under ordi- 
nary circumstances, is to keep the horses in good health in 
other respects, so that they can the better sustain the attacks 
of the larvee until they naturally pass away, which will usually 
take place without serious injury. In exceptional and severe 
cases only, resort should be had to special medicines of a dan- 
serous or doubtful character; and then they should be given, 
if possible, in accordance with the advice of a competent phy- 
sician. There are several other species of bot-flies of the 
horse, which are less known, however, in this country. 

The Gastrophilus nasalis is a smaller species, densely 
hairy, with the thorax yellowish red or rust-colored. The 
abdomen is either whitish at base, with the middle black and 
the apex yellowish-brown and hairy; or the base is whitish 
and all the rest brown; or the middle is black, with the base 
and apex whitish, with grayish hairs. The wings are un- 
spotted. ‘The larvae are much like those of the preceding, 
except that they are smaller, and also live in the stomach of 


PARASITES OF ANIMALS. 29 


horses. They change to pups beneath the manure, and the 
flies appear from June to September. It also infests the ass 
and mule, and some authors say that it lives even in cattle. 

The Gastrophilus pecorum is densely covered with yellow 
hairs, with a band of black hairs on the thorax behind the 
suture, in the male. The female is yellowish brown, the 
abdomen black, with yellowish hairs at its base, as well as 
on the thorax. The wings are grayish or light brownish, 
clouded with yellowish brown. The larve are similar to 
those of the more common G. equz, and have similar habits. 
The flies appear at the same time. 

The Gastrophilus hemorrhoidalis, or red-tailed bot-fly, is 
a small species, easily distinguished by the bright orange-red 
tip of the abdomen. The thorax above is olive-gray and hairy, 
-with a black band behind the suture. The base of the abdo- 
men is whitish and the middle blackish, in strange contrast- 
with the orange-red of the end. The larve have the same 
habits and are found in the same situations with those of 
the common bot-fly, which they much resemble, except that 
they are whiter and smaller, their length not exceeding one- 
half or five-cighths of an inch. They change to pup within 
two days after leaving the horse, and the pupe are deep red. 
They remain in the pupa state about two months, and the flies 
appear from the last of June till the cool weather of autumn. 
In depositing the eggs, the female fly differs in habit from 
the common bot-fly, for she selects the lips and nose of the 
horse as the most suitable place for this purpose. In deposit- 
ing her eggs she therefore causes the horse much trouble and 
uneasiness. Mr. Clark described the operation as follows: 
““ At the sight of this fly the horse appears much agitated, 
and moves his head backwards and forwards in the air to 
baulk its touch and prevent its darting on the lips; but the 
fly, waiting for a favorable opportunity, continues to repeat 
the operation from time to time; till at length, finding this 
mode of defence insufficient, the enraged animal endeavors 
to avoid it by galloping away to a distant part of the field. If 
it still continues to follow and tease him, his last resource is 
in the water, where the @strus is never observed to follow 


30 BOARD OF AGRICULTURE. 


him. At other times, this Gstrus gets between the fore-legs 
of the horse whilst he is grazing, and thus makes its attack on 
the lower lip. The titillation occasions the horse to stamp vio- 
lently with his fore-foot against the ground, and often strike 
with his foot, as if aiming a blow at the fly. They also some- 
times hide themselves in the grass, and as the horse stoops to 
graze, they dart on the mouth or lips, and are always observed 
to poise themselves during a few seconds in the air, while the 
egg is preparing on the point of the abdomen.” The eggs are 
darker colored than those of the common bot-fly, and contain 
a nearly developed embryo, so that they very soon hatch, and 
the young larve are transferred to the mouth by the tongue, 
and thence get into the stomach. 

In other countries there are still other species of bot-flies 
that infest the horse, ass, and mule; among them Gast- 
rophilus inermis Br., which lives in the horse; G. flavipes 
Oliv., which inhabits the stomach of the ass and mule; and a 
species of Hypoderma, which lives beneath the skin of all three. 
But I am not aware that either of these has been observed in 
this country. 


The Meat-fly, Blowflies, etc. Figure 27. 


These flies are not true parasites, but naturally feed, while 
in the larval state, upon decaying flesh and other animal 
matter. Their larve are, however, frequently 
found in wounds and sores, both of animals 
and men, feeding upon the purulent matter, 
and when allowed to live undisturbed, not un- 
unfrequently attack the living flesh, when 
their food becomes exhausted ; and in this wa, 
if they gain access to wounds in large numbers, 
they will not only greatly aggravate and enlarge 
them, but in many cases, when neglected for a 
short time, they have caused the death of men 
and animals by actually eating away living tis- 
sues. The females in this group of flies are 
viviparous, the eggs being retained in capa- 


Figure 27.—Larva or maggot of the Blue-bottle fly (AZusca Cesar Linn.), en- 
larged. From Packard’s Guide. 


— 


PARASITES OF ANIMALS. 31 


cious spiral dilations of the oviducts, until hatched into small 
larvee or maggots, when they are deposited by the mother, with 
almost unerring instinct, upon or near decaying flesh. The 
female flesh-fly (Sarcophaga carnaria Linn.), is said to de- 
posit at least 20,000 of these young larve. They are ready 
to commence feeding at once, and grow with remarkable 
rapidity, often becoming half an inch long in two or three 
days. When mature, they crawl out of the flesh and change 
to long-oval, brown pup, in the earth or any other conven- 
ient place, and the mature flies come forth in a few days. 
By this rapid increase the progeny of a few pairs would in a 
short time devour the carcass of a large animal.. The blue- 
bottle fly (Musca Cesar Linn.), the meat-fly (Musca vomi- 
toria Linn.), and others allied to them, are common and well 
known species, having similar habits. The larve of all these 
are long, soft-bodied, footless maggots, smaller toward the 
head, thicker and blunt behind. The larva of the blue-bottle 
fly is represented in Figure 27. The eggs or larve and 
those of other similar flies are not rarely swallowed with 
food by men and animals, and are capable of living, for a 
time at least, in the stomach and intestine, sometimes giving 
serious trouble. To keep them out of wounds or sores, the 
old females should be kept away. If this cannot be done by 
bandages, frequently washing the wounds with a weak solu- 
tion of carvolic acid will be an effectual remedy and pre- 
ventive. 


PARASITES BELONGING TO THE HEMIPTERA. 


The parasitic Hemiptera are all degraded, and mostly 
wingless forms, belonging to three very different families: 
the Cimicide, including the bed-bug; Pediculide, including 
the true lice; and the Mallophagide, including bird-lice, ete. 


CIMICIDA. 


This family, as restricted by Westwood, includes only the 
genus Cimex, or the bed-bug and its allies. These have a 
smoothish, oval, flat body, with a broad metathorax; a small 
head ; a slender, three-jointed proboscis or beak, which reaches 
as far as the front legs when folded down, and slender, four- 


a BOARD OF AGRICULTURE. 


jointed antenne, the last joint not enlarged or clavate. They 
seldom, if ever, have wings. In addition to the common bed- 
bug, there are species infesting pigeons (C. columbarius 
Jenyns) ; swallows (C-. hirundinis J.) ; and bats (C. pipistrelli 
J.). It is doubtful, however, whether all these be not identical 
with the common species. At any rate, it appears that the 
common bed-bug will attach itself to bats and various birds, 
when opportunities occur. 
The Bed-Bug, (Cimex lectularius Linn.). Figure 28. 


This species has long been notorious. - It was mentioned 
by Pliny, Aristophanes, Aristotle, Dioscorides, and other an- 
cient writers. Yet English writers have argued that it was 
first carried to that country from America, and thence to 
the continent of Europe. Moffitt mentions it, however, as 
having been seen in England as early as 1503, though it does 
not appear to have been common there until a century later, 
Its early English name was ‘“ wall louse”’; the term ‘ bug” 
was applied to it much later, its original meaning having been 
nearly synonymous with “ bug-bear.” 

At the present day this insect is sufficiently common 
throughout the civilized world, if not among the barbarians 
also. Its form and general appearance are well shown in Fig- 
ure 28, which represents it considerably larger than ordinary 
specimens. Its size varies greatly, however, according to its 
locality and the amount of blood it has been able to imbibe. 
Its color, when young, is pale yellowish, the blood in the in- 
testine showing through; as it grows older it becomes darker, 
until, when full grown, it is reddish brown, the color being 
darker when filled with blood. The eyes are small and bright 
red; the proboscis is much like that of the ordinary blood- 
sucking Hemiptera, which prey on other insects; the labium 
forms a three-jointed sheath or tube, the middle joint being 
broadest, the last one sharply pointed; the labrum is broader 
than the basal joint, which it overlaps. According to Dr. 
Packard, the internal structure is as follows: ‘“¢‘ The mandibles 
and maxille arise near each other, in the middle of the head, 
opposite the eyes, their bases slightly diverging. Thence they 
converge to the mouth, over which they meet, and beyond are 


PARASITES OF ANIMALS. 33 


free, being hollow, thin bands of chitine, meeting like the 
maxille, or tongue, of butterflies, to form a hollow tube for suc- 
tion. The mandibles each suddenly end in a curved, slender 
filament, which is probably used as a tactile organ to explore 
the best sites in the flesh of their victim for 
drawing blood. On the other hand, the 
maxille, which are much narrower than the 
mandibles, become rounded toward the end, 
bristle-like, and tipped with numerous ex- 
ceedingly fine barbs, by which the bug 
anchors itself in the flesh, while the blood is 
pumped through the mandibles. The base 
of the large, tubular labium, or beak, which ensheathes the 
mandibles and maxille, is opposite the end of the clypeus, or 
front edge of the upper side of the head, and at a distance 
beyond the mouth equal to the breadth of the labium itself. 
The labium, which is divided into three joints, becomes flat- 
tened toward the tip, which is square, and ends in two thin 
membranous lobes, probably endowed with a slight sense of 
touch.’ At the same time that the blood is sucked up, some 
poisonous secretion or saliva is introduced into the wound, 
perhaps to render the blood more liquid. ‘I'o some persons 
these bites are extremely poisonous and cause large inflamed 
swellings and violent itching, while in other persons no such 
effects occur, and the bites are scarcely noticed. 

These insects are inclined to be gregarious in their habits, 
and are fond of herding together, a dozen or more in aplace, 
whether in a crack, knot-hole, chink in the walls of houses, or 
any snug corners about a bedstead. They are also fond of 
returning constantly to the same hiding-place, morning after 
morning, after their nocturnal raids, just as many birds re- 
turn regularly to their roosts. On this account their retreats 
become discolored by dark spots of excrement. When 
much disturbed, or when food fails, they will disperse, how- 
ever, and each one will migrate on its own account. In the 
night they are quite lively and nimble, and run about with 


Figure 28. 


Figure 28.—Bed-bug (Cimex lectularius Linn.), enlarged. The straight line 
shows the ordinary length. From Packard’s Guide. 
5 


34 BOARD OF AGRICULTURE. 


ereat rapidity, and can then evidently see better than by day. 
They are capable of making long journeys even during the day, 
and may thus migrate from house to house. They are, how- 
ever, not restricted to human dwellings or to human blood, 
for they often take up their residences in poultry houses and 
yards, at times completely swarming in-such piaces. They 
will also attack dogs and cats, and may live about the places 
where those animals sleep. They have even been found in 
the woods under the bark of dead trees. The same species, 
apparently, also attacks bats, and may thus enter houses. In 
fact, there are a great many ways in which they may get into 
the best of houses, besides the well known method of adhering 
to clothing, etc. It is, therefore, no disgrace to any house- 
keeper that a bug should now and then be detected in the 
house ; but the disgrace consists in allowing them to remain 
undisturbed until their numbers increase to a great extent, as 
they will most surely do if neglected. Many kinds of Hem- 
iptera, like the squash-bug, etc., have the power of forming a 
peculiar odorous secretion, which, from the similarity of the 
odor, probably consists in part of formate of amylic ether ; 
but in the bed-bug this odor is combined with others that 
are far more disagreeable. 

The eggs are long-oval and white, and are laid in clusters 
in the cracks, etc., about bedsteads and other places that they 
frequent. The young hatch by forcing off one end of the egg- 
shell like a lid. The young, when first hatched, are whitish 
and translucent, and although having three legs and the gen- 
eral features and habits of the old ones, they differ considerably 
in form, being more louse-shaped. They have a broader and - 
more triangular head, and shorter and thicker antenne. 
They cast their skins several times during growth, each time 
looking a little more like’the adult than before. It is said 
that they require eleven weeks to mature, but this probably 
differs according to the temperature and food. They are, 
however, lively and blood-thirsty from the first, and are well 
able to look out for themselves. Their skill in finding a 
sleeping person and reaching him is marvelous indeed. 

In ordinary cases there is no great difficulty in eradicating 


PARASITES OF ANIMA.LS 35 


these insects completely, if.a proper amount of care is be- 
stowed in the way of keeping the house and beds clean and 
neat. The principal trouble arises from neglect on the part 
of housekeepers to examine the beds frequently, for, as al- 
ready intimated, no bed is sure to escape their attentions for 
any great length of time, especially in cities, where they may 
at any time walk in from some neighbor’s house oe a friendly 
visit or morning call. 

When they are merely located in bedsteads, or bedding, there 
is no better way than to makea careful and thorough examina- 
tion of all cracks and corners, and when any are seen, a little 
benzine poured upon them will kill them instantly, and the 
benzine should be poured into all suspicious cracks, which 
cannot otherwise be reached. Scalding hot water thoroughly 
applied is also effectual, but is liable to injure the varnish of 
furniture. One examination of a bed is seldom sufficient, for 
egos that have escaped observation, may subsequently hatch. 
Therefore two or three searches, with benzine in hand, should 
be made at intervals of a week or ten days. The use of cor- 
rosive sublimate and similar poisons is unnecessary and 
objectionable, for such preparations are not more dangerous 
to the bugs than to the persons who occupy the beds, and are 
less fatal, even when applied directly to the bugs, than ben- 
zine. When the bugs have also taken up their residence in 
the cracks and crevices in the walls of old houses, it is much 
more difficult to destroy them. If very bad, the house, when 
empty, may receive a thorough fumigation with burning sul- 
phur, which will generally prove very effectual. Hen-houses 
and other out-buildings may be thoroughly drenched with a 
mixture of crude petroleum and water, or with the solution 
of carbolic acid. 

Bed-bugs are extremely tenacious of life and have wonder- 
ful powers of fasting. They have been kept hermetically 
sealed in glass bottles for more than a year without any food, 
and were still lively and had a good appetite. 


PEDICULIDA. 


This family includes the ordinary lice of man and quadru- 
peds, which are furnished with a sucking mouth. They are 


36 BOARD OF AGRICULTURE. 


_yery low, degraded Hemiptera, destitute of wings. The head 
is small, conical, and narrow; the thorax is small and in-— 
distinctly separated into segments ; the 
abdomen is large, flattish, rounded or 
oval, with nine segments. The antenne 
are very slender and five-jointed. The | 
eyes are simple and very minute. The 
feet, or tarsi, have two joints, the 
last joint forming a strong hook for 
grasping the hairs firmly while crawling 
and climbing among it. The mouth- 
parts form a long and extremely slender 
fleshy tube, which is retracted when not 
in use, and is capable of being intro- 
duced into the skin, for the purpose of 
sucking blood. The structure of the 
mouth is as follows, according to 
Schiddte: ‘The peculiar attenuation of 
the head in front of the antenne at once 
suggests to the practised eye the exist- 
ence of a mouth adapted for suction. 
This mouth differs from that of Rhyn- 
chota [Hemiptera, bed-bug, etc.] gen- 
erally, in the circumstance that the 
labium is capable of being retracted into 
the upper part of the head, which there- 
fore presents a little fold, which is ex- 
tended when the labium is protruded. 
In order to strengthen this part, a flat 
band of chitine is placed on the under 
surface, just as the shoemaker puts a 


| 
‘ 
Figure 29. | 


Figure 29.—Probosejs of body-louse (Pediculus corporis DeGéer), entirely pro- 
truded and seen from above, magnified one hundred and sixty times; aa, the 
summit of the head, with four bristles on each side; 6b, the chitinous band, and 
c, the hind part of the lower lip—such as they appear through the skin by strong 
transmitted light; dd, the foremost protruding part of the lower lip (the haus- 
tellum) ; ee, the hooks turned outwards; jf, the inner tube of suction, slightly 
bent and twisted; the two pairs of jaws are perceived on the outside as thin 
lines; a few blood globules are seen in the interior of the tube-—F’rom American 
Naturalist. 


PARASITES OF ANIMALS.: 37 


small piece of gutta-percha into the back of an India-rubber_ 
shoe; as, however, the chitine is not very elastic, this band is 

rather thinner in the middle, in order that it may bend and 

fold a little when the skin is not extended by the lower lip. 

The latter consists, as usual, of two hard lateral pieces, of 
which the fore ends are united by a membrane so that they 

form a tube, of which the interior covering is a continuation 

of the elastic membrane in the top of the head; inside its 

orifice there are a number of small hooks, which assume 

different positions according to the degree of protrusion; if 
this is at its highest point the orifice is turned inside out, like 

a collar, whereby the small hooks are directed backward, so 
that they can serve as barbs. These are the movements 

which the animal executes after having first inserted the 

labium through a sweat-pore. When the hooks have got a 

firm hold, the first pair of sete (the real mandibles trans- 

formed) are protruded ; these are, towards their points, united 
by a membrane so as to form a closed tube, from which, 

again, is exserted the second pair of sete, or maxilla, which 
in the same manner are transformed into a tube ending in 
four small lobes placed crosswise. It follows that when the 

whole instrument is exserted, we perceive a long membranous 

flexible tube hanging down from the labium, and along the 

walls of this tube the setiform mandibles and maxille in the 

shape of long narrow bands of chitine. In this way the tube 

of suction can be made longer or shorter as required, and 

easily adjusted to the thickness of the skin in the particular 

place where the animal is sucking, whereby access to the 

capillary system is secured at any part of the body. It is 

apparent, from the whole structure of the instrument, that it 

is by no means calculated for being used as a sting, but is 

rather to be compared to a delicate elastic probe, in the use of 
which the terminal lobes probably serve as feelers. As soon 

as the capillary system is reached, the blood will at once 

ascend into the narrow tube, after which the current is con- 

tinued with increasing rapidity by means of the pulsation of 
the pumping ventricle and the powerful peristaltic movement 

of the digestive tube.” 


38 BOARD OF AGRICULTURE. 


The various species of these lice have similar habits, and all are 
blood suckers, but each species inhabits only certain kinds of 
animals, and some are restricted to particular parts of the 
skin. Many animals have two or more species of these para- 
sites. Five species have been described as parasitic upon man, 
though but three are common. 

When they become very abundant, as they soon will if the 
animals upon which they once get well established be neg- 
lected, they cause great irritation of the skin and nervous 
system, and the itching that they produce causes the animals 
to rub themselves against buildings, fences, etc., and thus the 
hair is often worn off and the skin abraded. Such animals 
generally soon become weak and emaciated, and are, there- 
fore, more liable to be attacked by other diseases. 

There are various washes which, if properly applied, will 
very rapidly destroy all species of lice, without much trouble. 
The use of preparations of mercury and arsenic, and all similar 
poisons, should be avoided, for they often poison the animals, 
as well as the persons who use them, and thus the remedy 
may be worse than the disease. 

A strong solution of tobacco, made by boiling cheap tobacco 
in water, is an effectual remedy, in common use. Snuff 
rubbed into the hair isalso used. Ordinary whale-oil, such as 
was formerly used in lamps, poured upon the skin along the 
back of an ox, cow, calf, or sheep, will diffuse itself over the 
skin and kill the lice. Weak petroleum water, or carbolic 
acid solution, or carbolic soap, may be used as a wash, or 
small animals may be immersed in a bath, taking care to 
keep the nose, mouth, and eyes outof it. But perhaps one of 
the best and simplest, as well as safest, washes for this pur- 
pose, as well as to destroy fleas, mites, itch-insects, mange- 
acari, and all other external parasites of man and animals, is 
a solution of sulphuret of potassium in water,—two to four 
ounces to the gallon of cold water, varying the strength ac- 
cording to the age and tenderness of the skin of the animal, 
for the solution will contain some free potash, which, if too 
strong, might irritate a delicate skin. There is otherwise no 
danger from its use, though its odor, like sulphuretted hydro- 


PARASITES OF ANIMALS. 39 


gen, is disagreeable, and it should be used, therefore, where 
there is plenty of ventilation. This is an exceedingly valua- 
ble remedy, also, for the itch of man, as well as the “mange” 
of animals. The sulphuret of potassium comes in the form 
of grayish or greenish lumps, put up in tight bottles. It is 
used in photography and can usually be bought at the princi- 
pal drug stores. 

An equally useful preparation, having the same properties, 
may be easily made by taking fresh quick-lime, slacking it 
gradually with water, and forming a milky solution by the 
addition of more water, as in the preparation of white-wash. 
Into this put as much flowers of sulphur as will dissolve by 
boiling for some time. This will produce a deep yellow solu- 
tion like that of the sulphuret of potassium in odor and 
effects. It may be diluted if too strong. It contains swl- 
phuret of calcium, upon which its usefulness depends. Sul- 
phur may also be boiled in potash lye, to produce a similar 
preparation, and to this, while boiling, tobacco is sometimes 
added, but the sulphur is, no doubt, sufficient for all practical 
purposes. But in no case can we be certain of destroying all 
the eges of these parasites by any wash whatever, that would 
not be dangerous to the animal. Therefore the treatment 
should be repeated two or three times, at intervals of ten or 
twelve days, in order to destroy any young that may have 
hatched in the meantime. 


The Head-louse of man (Pediculus capitis DeGéer). Fig. 30. 


This is, probably, the best known species of the genus 
Pediculus. It is still sufficiently common among persons who 
neglect personal cleanliness, though much less 
so than it is said tohave been formerly, when it 
was thought no disgrace in some parts of the 
old world, but was regarded as fashionable, 
rather than otherwise. This insect is almost 
exclusively confined to the human head. It 
attaches its eggs firmly to the hair, near the 
roots. These eggs are long-oval, with several 
little conical prominences at the large end, 


Figure 30. 


Figure 30.—Head-louse (Pediculus capitis DeGéer), greatly magnified. 
From Packard’s Guide.* 


40 : BOARD OF AGRICULTURE. 


which are open at the top, while the small end pears a cluster 
of bristles. The habits and treatment are too well known to 
need further description. 


The Body-louse of Man (Pedicutus corporis DeGéer). 
Figure 31. 

This species very closely resembles the last, but is usually 
larger. It attaches itself especially to the clothing, and at- 
tacks various parts of the body. It attaches its eggs chiefly 
to the clothing which it frequents, especially Heme 31. 
along the seams, and when the clothing is sel- eY 
dom changed, as often necessarily happens in 
time of war, it increases rapidly and becomes 
a great source of annoyance. Many unfortu- 
nate soldiers, who were confined in the south- 
ern prisons and prison-pens during the late 
war, can testify to the abundance of this par- 
asite under such circumstances. Nor were 
the ordinary camps free from them, especially during active 
campaigns. 

The Crab-louse (Phthirius pubis Leach). Figure 32. 


In the genus Phthirius the thorax is broad and not distinct 

from the abdomen, which is flatand has eight segments, the 
first one being composed of two united. Figure 32. 
The first pair of legs are terminated by 
slender tarsi, not changed to grasping 
claws, but the claws of the other two 
pairs are large and strong. 

This species lives among the hairs of 
the pubic regions of man, and also, 
though much less commonly, upon the breast, arm-pits, in the 
beard, eye-brows, and also upon the head. It sometimes also 
clings to linen and clothing, and, not unfrequently, may be 
found in the beds of those persons harboring them. They 
may be destroyed by simple ointments and unguents, or by 
the sulphuret washes described above. 


Figure 31.—Body-louse (Pediculus corporis DeGé _), greatly magnified. From 
Packard’s Guide. 

Figure 32.—Crab-louse (Phthirius pubis Leach), much enlarged. From Pack 
ard’s Guide. ‘ 


PARASITES OF ANIMALS. 41 


The Cattle-louse (Hematopinus vituli Denny). Figure 33- 


In the genus Hematopinus, which includes a large number 
of species, the head is obtuse or truncated in front, the middle 
segments of the abdomen well separated, and the posterior 
legs much the longest. The eyes are very minute. They are 


all small and some are minute species. 
Figure 33. 


Hf. vituli is brownish, with a pale 
abdomen, the abdominal segments 
bearing lateral chitinous pieces, in 
which the spiracles are situated. The 
head is elongated with a constriction 
behind the antenne. It is about 7, 
of an inch in length, ora little more. 
It is parasitic both on cattle and horses, 
and sometimes becomes very abun- 
dant. 


Another species (H. ewrysternus 
Denny), also infests both cattle and 
horses. In this the head, thorax, and feet are horn-colored. 
The thorax is very broad. The length is abouty, of an 
inch. 

The Hog-louse (Hematopinus suis Leach). Figure 34. 
Figure 34. . This species is brown, with a white 
abdomen. The spiracles are placed in 
blackish, horny plates along each 
side of the abdomen. Length ¢ of an 
inch. 

H. stenopsis infests the goat. It is 
a. horn-colored species, with a long oval 
hairy abdomen. 

H. asini Denny is parasitic on the 
cae ass. 

H. piliferus Denny lives upon the dog. It is uniformly 
horn-colored. The body is slender and covered with pale 
hairs. Length yy of an inch. 


Figure 33.—Cattle-louse (Hematopinus vituli Denny), much enlarged. From 
American Naturalist. 
Figure 34.—Hog-louse (H. suis Leach), much enlarged. From Cuvier. 


6 


42 BOARD OF AGRICULTURE. 


MALLOPHAGA (Bird-lice). 

These insects live both among the feathers of birds and hair 
of mammals. They are peculiar in having distinct jaws (Figure 
36), instead of a sucking tube. The body is flat, corneous, 
and firm above. The head is horizontal and generally broad. 
The antennez have three to five joints. The mandibles are 
small and hook-like. The maxillary palpi, when present, are 
four-jointed ; and the labial palpi two-jointed. The legs are 
short and stout, with one or two strong claws. There are sev- 
eral hundreds of species already described, nearly every bird 
having one or several peculiar species. They produce nearly 
the same effects as the true lice, and may be destroyed by the 
same remedies. : 


Figure 35. 


a Figure 36. 


The Turkey-louse (Goniodes  stylifer Denny). 


This is a large species, conspicuously marked with transverse 
black bands. It is very common both on the domestic and 
wild turkey, together with three or more other species, one of 
which is much longer and nearly black. Some of the other 
species parasitic on the turkey are Liothewm stramineum 
Nitzsch, Philoplerus polytrapezius Nitzsch. 

The Hen-lice (Liotheum pallidum Nitzsch, Philopterus 
variabilis N., P. heterographus N., P. dissimilis N., and P. 


Figure 35.—Turkey-louse ( Goniodes stylifer Denny), much enlarged. 
Figure 36.—Head of same, seen from below, more magnified ; a, mouth organs ; 
b, antenna. Both from Cuvier. 


PARASITES. OF ANIMALS. 43 


hologaster N., Goniocotes Burnettii Packard, Figure 37) are 
common enemies of domestic fowls. 


Figure 37. Figure 38. 


The Pigeon-lice (Liotheum giganteum Denny, Philopterus 
baculus Nitzsch, Mirmus clavicornis, Goniodes compar N.) 
infest domestic pigeons. 


Figure 39. Figure 40. 


The Goose-louse ( Trinotum squalidum Denny) is found with 
other species on the goose. 


The Duck-lice (Philopterus squalidus Nitzsch), Figure 38, 
with other species, inhabit the common duck. 


Figure 37.—Hen-louse (Gfoniocotes Burnettii Pack.). American Naturalist. 
Figure 38.—Duck-louse (Philopterus squalidus N.) From Gervais. 

Figure 39.—Cat-louse ( Trichodectes subrostratus N.) From American * Naturalist. 
Figure 40.—Goat-louse (Z. capre Packard). From American Naturalist 


44 BOARD OF AGRICULTURE. 


The Peacock-lice ( Philopterus falcicornis N., P. reclanguia- 
tus N.) are very common on the peacock. 

The Cat-louse (Zrichodectes subrostratus Nitzsch), Figure 
39, is one of the parasites of the house cat. This species is 
whitish, with the head and thorax pale honey-vellow. 

The Goat-louse ( Trichodectes capre Packard, probably the 
same as 7’. limbalus Gervais), Figure 40, lives with other 
species upon the domestic goat. It is reddish yellow, trans- 
versely barred with reddish brown, the abdomen edged with 
red. ne 

SUB-CLASS, ARACHNIDA. 
ACARINA (Mites). 


These are characterized by their simple, usually rounded or 
oval bodies, in which there is no distinct separation into 
thorax and abdomen. They have eight legs, which are gen- 
erally short, but when young many of them are six-legged. 
The species are numerous. Their habits are very 
diverse ; many are parasitic upon man, various quadrupeds, 
birds, reptiles, insects, etc., some externally and others in- 
ternally. Species have even been found within the abdc- 
minal cavity and skull. Other species live under the water, 
and are parasitic on mollusca. Many attack plants and prove 
very injurious. Others are carnivorous and prey on small 
insects. Some, like the meal-mite, sugar-mite, cheese-mite, 
fic-mite, and many others attack and greatly injure articles of 
food. Many lead a solitary, wandering life, others occur 
together in vast numbers at certain times. 


DERMANYSSUS Dugés. » 


The insects of this genus are small, soft-bodied parasites, 
which infest various birds, bats, insects, and some of them 
are at times parasitic upon man. 

The fifth joint of the palpi is smallest. The lip is sharp. 


The mandibles of the male are forceps-like, with long hooks ; 
those of the female ensiform. ‘The anterior feet are the 


- longest. Young with six legs. 
Dermanyssus galling is fouud among the feathers of the 
domestic fowl, and lives by sucking the blood. 


PARASITES OF ANIMALS. 45 


D. Gallopavonis infests the turkey. The body is marked 
by peculiar, delicate, transverse strize, and with numerous 
small circular impressions on the back. ~ 

D. avium torments small cage birds, like the canary. It 
often takes refuge in cracks about the perches, which should 
therefore be kept clean. 


ARGAS Latreille. 


This genus includes the famous Argas Persicus, which 
infests old dwellings in Persia, especially at Miana, and is 
said to be so poisonous that its bite produces convulsions and 
speedy death ; or even its juices, if crushed upon the skin, 
may produce the same results. 

These are larger than most of the mites, and somewhat 
resemble the ticks. The body is broad-oval or roundish. 
The upper side of the head so projects as to conceal the mouth 
parts. The jaws are suctorial. The lower side of the body 
is granulous, not scaly, and covered by a single piece. 

Argas reflexus Latreille lives upon pigeons and sucks their 
blood. It especially infests the young, upon which there are 
sometimes great numbers. The body is marked with curious 
tortuous grooves and.pits. The color is yellowish, but when 
filled with blood violaceous. 


1xopEs Latreille. (Ticks). 


These are the largest of the Acarians, and all are parasitic, 
chiefly upon quadrupeds and reptiles, but sometimes on birds. 
The body is broad-oval or round, and when not swollen with 
blood is flatish, and the integument is firmand tough. Their 
mandibles (Figure 43,b,) are covered with teeth and have ter- 
minal hooks ; their maxille are small, not reaching beyond the 
beak, but bear a peculiar organ called the glossoid (Figure 
43,a,) also covered with hook-like teeth. The legs are slender 
and have two claws, and in the young have pads or suckers 
(d). The young are six-legged (Figure 42). The ovarial 
opening is near the mouth, between the first pair of legs. 
These parasites, when young, cling in large clusters to the 
tips of leaves and twigs of herbs and shrubs, with part of 
their six slender legs extended. When brushed by a passing 


46, BOARD OF AGRICULTURE. 


animal, they instantly leave the plant and quickly disperse © 
over their host. They insert their glossoidsand mandibles into 
the skin, where they cling firmly by means of the numerous 
hooks, and live by sucking the blood. The abdomen soon be- 
comes very much swollen, and sometimes grows so large as to 
resemble a tumor. They attack various animals and even man, 
indiscriminately. In many parts of the Southern States the 
‘6 wood ticks ”’ are extremely troublesome to persons who have 
occasion to go into the forests, as well as to animals. The 
eges of Zxodes albipictus are laid in large masses, from the 
first of May until the last of June. arly in July the eggs 
hatch out simultaneously, “the shell opening like a clam.” 


The young when first hatched have six slender legs. 
Figure 41. Figure 42. 


Figure 44. Figure 43. 
The Cattle- tick (Ixodes bovis). Figure 41. 


This is a flattened, leathery, reddish, seed-like species, with 
an oblong-oval body. It sometimes grows to be nearly half 
an inch long. It infests cattle, and is very troublesome in the 
Western and Southern States, but is far less common in the 
North. It also attacks the horseand many other quadrupeds, 
as well as reptiles, including the rattle-snake. 


Figure 41.—Cattle-tick (Ixodes bovis Riley), enlarged. 

Figure 42 —Ixodes albiptetus Packard; six-legged young, much enlarged; d, 
foot with sucker. 

Figure 43.—Head of the same, more enlarged; a, glossoid; b, mandibles; € 
maxillary palpi. 

Figure 44.—Adult of bee same, gorged with blood, natural size. All from 
Packard’s Guide. 


PARASITES OF ANIMALS. 47 


Ixodes albipiclus Packard. Figures 42, 43,44. | 


This was originally found upon a tame moose by Mr. W. 

G. Hays, but doubtless infests other animals. 
Ixodes unipictus Packard. 

This is about a quarter of an inch long and has an oval 
form. Isis reddish brown, or mahogany-color, with a central 
silvery spot upon the back. It often attacks men and vari- 
ous animals. It has been found in New England, but is more 
common southward. 

In Europe, numerous species have been found. 

Ixodes vicinus is very troublesome to dogs. It is of a brown- 

ish violet color, crenulated posteriorly. It has five radiating. 
- brown spots and some brown dots. 

Ixodes reduvius infest sheep and dogs. It has a pale red or 
yellowish color, and becomes more than a quarter of an inch 
long. It must not be confounded with the ordinary “ sheep- 
tick” (see page 89). : 

Mites, acarus Linn. 

This genus, which originally included all the mites, is now 
restricted to those that are allied to the cheese-mite. The 
mouth parts are prolonged into a rostrum or beak. There is 
a constriction of the body between the second and third pair 
of legs, dividing it somewhat into two parts. 


The Cheese-mite (Acarus stro Linn.). 
This species ordinarily lives in cheese and other articles of 
food; but has sometimes been observed parasitic upon man, in 
certain diseased conditions. 


The Meal-mite (Acarus farine De Géer). 

This species, found in meal and flour that has been in- 
jured is sometimes accidentally swallowed while living. 

Acarus dysenteric Linn. was found living in the excreta of 
a person attacked by violent dysentery. It also sometimes oc- 
cursin large numbers about wine and beer casks, and may 
therefore be swallowed accidentally. 

Glyciphagus hippopodos has been found inthe ulcerated feet 
of horses. A species of mite also occurs in the diseased 
feet of sheep. 


48 BOARD OF AGRICULTURE. 


Mange-insect of the Horse (Psoroptes equi Gervais). 


This insect is readily visible to the naked eye and swarms 
on horses afflicted with the mange, which is a disease anala- 
gous to the itch inman. It has a soft, depressed body, spiny 
beneath at the base of the legs and on the thorax. One or 
both of the two posterior pairs of feet bear suckers, and all 
are more or less covered with long slender hairs. 


Figure 45. 
Fig. 46. 


This insect may be destroyed by the same remedies used for 
lice and for the human itch. The best remedy is probably the 
solution of sulphuret of potassium, described on page 109. 


The Itch-insect (Sarcoptes scabiei Latr.). Figure 47. 


This is a very minute, whitish species, barely visible to the 
naked eye, unless on a dark surface. It has been, in former 
times, the subject of many lengthy discussions, in reference 
to its causing the itch. It is, however, at the present time 
fully ascertained to be the sole cause of the ordinary itch, 
though other species of similar parasites may cause different 
varieties of itch. The body is rounded and soft, with small 
round pustules on the middle of the back, and with radiating 
lines or ridges, the sides of the body and legs bearing long 
bristle-like hairs. The mandibles are needle-like. The 
female is largest and has the two pairs of hind legs but little 
developed, ending a bristle ; in the male they are well devel- 
oped and terminate inaslender sucker. These creatures, as 
seen under the microscope, have something of the unwieldy 


Figure 45.—Psoroptes equi Gervais, female ; ventral side, much enlarged. 
Figure 46.—Head of the same, more magnified. Both from Cuvier. 


PARASITES OF ANIMALS. 49 


appearance of a tortoise, and are ordinarily sluggish, yet they 
are capable of ieaping to a considerable distance. They bury 
themselves in the human skin, especially in the more delicate 
and less exposed parts, and excavate minute galleries for them- 
selves, in a manner something like that 
Figure 47. in which moles excavate galleries in 
the soil. These galleries are at first 
perpendicular, and then go off horizon- 
tally to some distance. The females 
lay their eggs in these galleries as 
they progress. 

These mining and boring operations 
cause much irritation of the nerves of 
the skin and induce an intolerable itch- 
ing, and the inflammation that they 
cause produces pustules, filled with a 
watery exudation. The insects them- 
selves are not found in the pustules but 
in their minute galleries, off to one 
side, the pustule generally marking the place where they en- 
tered. The itch is contagious, simply because the insects, 
especially in their young and more active state, pass from one 
person to another, or are transmitted by clothing. They are 
most active at night and, therefore, sleeping with an infested 
person is pretty sure to be attended by the transfer of the 
insects. The longer the parasites are neglected, the more 
numerous they become. The increase is, however, quite slow 
at first, owing to the small number of eggs. There are 
various remedies for this disease, but the different preparation 
of sulphur are no doubt the best and safest. The solutions 
of sulphuret of potassium, described on page 109, is probably 
the simplest and most efficacious preparation for this purpose. 
Its use should be accompanied by a thorough change of gar- 
ments and bedding, and it should be used by all the members 
of an infected family simultaneously. It should be appliedat 


Figure 47.—Itch-insect (Sarcoptes scabiet Latreille), female, upper side, much 
enlarged. From Guerin. ; 


T 


0S BOARD OF AGRICULTURE. 


least three times, at intervals of three or four days, to destroy 
the young as fast as they hatch. 

Species of Sarcoptes, closely allied to the itch-insect, have 
been found on the domestic animals, causing diseases analo- 
gous to the itch in man. Such diseases, caused by quite a 
number of distinct parasites, are called “mange.” They 
have been observed on the cat, dog, camel,* and hog. 

The genus Dermatodectes is closely allied to Sarcoples, and 
the species likewise live on animals, burrowing in the skin. 
D. bovis infests cattle, and D. ovis lives in the skin of sheep. 
The genus Dermaleichus infests birds in a similar manner. 

All these parasites should be treated like the itch-insect of 
man. The sulphuret of potassium solution, applied with a 
brush that has long bristles, ike a white-wash brush, is 
probably the best and simplest remedy. 


The Face-mite (Demodex folliculorum Owen). Figure 48. 


This singular but minute parasite lives in the discased and 
enlarged follicles in the skin of the human face, especially in 
those about the nose and chin. The follicles, when thus dis- 
eased, are enlarged and filled with a thickened 
sebaceous matter, the orifice being usually ob- 
structed by a hardened, blackish substance. If 
these be pressed, and the matter which is forced out 
be carefully examined with a microscope, it will often 
be found to contain numerous specimens of this minute 
creature, in all stages of development. A drop of 
oil or ether applied to the sebaceous matter, to 
dissolve the fatty parts, will render them more 
readily visible. The young ones have but six short 
legs; the adults have eight legs and a worm-like 
body, as represented in Figure 48. It has been thought that 
the “‘ barber’s itch” is caused by this parasite, but I do not 
know that this has been fully established. 


Figure 48. 


*S. dromedarii, of the camel, is sometimes communicated to man, causing a 
form of itch worse than the ordinary, owing to its great size and numerous spines. 

Figure 48.—Face-mite (Demodex folliculorum Owen, or Simonea folliculorum of 
some authors), much enlarged. From Packard’s Guide. 


PARASITES OF ANIMALS. ‘61 


The same species, or one very closely allied to it, occurs in 
the skin of the dog and other domestic animals, producing 
some forms of the “mange.” These parasites will probably 
be destroyed by the same remedies that are effective against 
the itch-insect. 


» HCO ONDE WC Ar Ey luk. 


The Internal Parasites of Domestic Animals; 


THEIR EFFECTS AND REMEDIES. 


The parasites of man are so intimately connected with those 
of his domesticated animals, that it is impossible to discuss 
them separately. Indeed, many of the human parasites in- 
habit also the hog, cattle, sheep, and the dog, in certain stages 
of their development, and nearly all the most dangerous kinds 
are derived, either directly or indirectly, from those animals. 
While in return mankind furnish to them the eggs of several 


52 BOARD OF AGRICULTURE. 


of their worst parasites. Thus some of these creatures are 
kept in existence solely by reason of the peculiar relations ex- 
isting between man and his brute dependents. This is partic- 
ularly the case in respect to the two most common tape-worms 
of man, derived respectively from the flesh of cattle and hogs, 
in which the young worms live. These two worms appear to 
be capable of coming to maturity only in the human in- 
testine. 

Most of these internal parasites belong to the great class of 
articulated animals known as Worms, constituting, however, 
several distinct orders, which are often collectively called 
Helminths. The orders of parasitic worms are much lower 
in rank than those that include the independent kinds, like 
the numerous species of free marine worms, or Annelids, 
many of which have beautiful gills and locomotive organs, a 
very complex circulation, red blood, and a well-organized head, 
eyes, mouth, and intestine ; to such worms the common earth- 
worms, or angler-worms, are also allied, although destitute of 
gills. But the parasitic worms never have red blood nor 
special organs for breathing, and rarely for locomotion ; most 
have no distinct organs of sense, and many have no head and 
no intestine. The reproductive system is, however, always 
very highly developed, and most of them are exceedingly 
prolific. This is essential to their existence, for it is often only 
by mere chance that any of the eggs or young reach the 
peculiar habitats in which alone they can grow to maturity. 

The internal parasites of animals have long been the sub- 
ject of laborious and careful research by many of the ablest 
naturalists and physiologists,* owing to the remarkable 


*The following are some of the more important and useful of the recent gen- 
eral works on parasitic worms: 

Félix Dujardin, Histoire naturelle des Helminthes au vers intestinaux, 8vo, 
with plates, Paris, 1845. (Suites a Button.) / 

C. M. Diesing, Systema Helminthum. Two volumes, 8vo. Vindobone, 1850. 

J. Leidy. A Flora and Fauna within living animals. Smithsonian contribu 
tions, 1852. 

C. Davaine, Traité des Entozoaires et des maladies vermineuses de l’homme et 
des animaux domestiques, 8vo, 930 pages, with 88 figures. Paris, 1860. 

D. F. Weinland. An Essay on the tape-worms of man; 8vo pamphlet, with 
figures. Cambridge, Mass., 1858. 

T. S. Cobbold. Entozoa ; an Introduction to the study of Helminthology, with 


PARASITES OF ANIMALS. 58 


peculiarities of their structure, habits, andmodes of reproduc- 
tion, as well as to their great practical importance with refer- 
ence to human health and property. 

The total number of species hitherto described, from all 
animals, is more than 2,000. Of these upwards of 100 species 
are found in domestic animals and man. 

The parasitic worms of man and domestic animals are nat- 
urally divided into four principal orders, which are character- 
ized by important anatomical and physiological peculiarities. 

I. CestopEs. (Tape-worms). 

This order includes the numerous kinds of tape-worms and 
their young, the ‘“ measles,” hydatids, and bladder-worms, 
found in more or less abundance in all classes of vertebrate 
animals, as well as in insects, mollusca, ete. These tape- 
worms helong to three very distinct families and to numerous 
genera. About 250 species have been hitherto described. 

These worms in the sexually mature condition have a more 
or less enlarged roundish, oval, angular, or lobed head, desti- 
tute of a mouth, but provided with two or four suckers, or 
pits, and often with one or four proboscis-like organs, sur- 
rounded by hooks, by means of which they fasten themselves. 
securely to the mucous membrane of the intestine of the 
animal in which they live. There is no intestine or other di- 
gestive system. The head is followed by a series of many 
flattish joints or segments, those near the head being small 
and short, while those that are more distant are larger and 
usually oblong or squarish. These joints, as they mature, are 
spontaneously detached and may enjoy a short independent 
existence, and are then called proglottides. Hach joint con- 
tains distinct male and female reproductive organs, and 
matures a vast number of eggs, which are generally liberated 


reference more particularly to the internal parasites of man. Large 8vo, 480 
pages, with numerous figures and 21 plates. London, 1864. 

J. L. W. Thudichum. On the Parasitic Diseases of Quadrupeds used for food. 
In the Seventh Report of the medical officer of the Privy Council, p. 303. Lon- 
don, 1865. 

T. S. Cobbold. Tape-worms (Human Entozoa), their sources, nature, and treat- 
ment; 12mo, 83 pages, with figures. London, 1866. 

R. Leuckart, Die Menschlichen Parasiten, und die von ihnen herriihrenden 
Krankheiten. Two volumes, 8vo, with numerous figures. Leipzig and Heidel- 
berg, 1862 to 1868. 


54 BOARD OF AGRICULTURE. 


from the enclosing. proglottid after the latter has been dis- 
charged from the animal that nourishes the parent tape-worm. 
The eggs usually escape by the bursting of the integument of 
the proglottid, owing to their increase in size, as the embryos 
develop within them. While attached to the tape-worm the 
successive joints are connected together by longitudinal tubes 
or ducts that pass through the entire length of the worm, gen- 
erally one near each edge of the joints. These are connected 
together by transverse tubes in each end of the successive 
joints (Figure 54). 

The reproductive organs occupy variously branched and 
ramified cavities in the interior of the joints, communicating 
by ducts with the external male and female organs, which are 
placed side by side, either on the edge of each joint, as in 
Tenia, or in the middle of one side, as in Bothriocephalus. 
The remainder of the joint is composed of a 2 more or 
less solid tissue. 

All the species of this order undergo remarkable metamor- 
phoses; the larva living in one animal must be swallowed by 
another before it can become mature. 


. IJ. Trematopes. (Flukes). 

This order includes a great number of more or less flattened 
worms, of which the “ fluke,” frequently found in the liver of 
sheep, causing the “ rot,” isan example (Figure 75). 

The body is generally broad and more or less oval, some- 
times elongated, but never divided into distinct joints. On 
the lower side there is usually: one or two prominent suckers, 
and sometimes several. There is a small mouth on the lower 
side, usually near one end, but no head. The mouth com- 
municates with a small, dilated cesophagus or stomach, and 
this with a more or less branched and subdivided, sometimes 
arborescent, intestine, the branches ending in closed tubes or 
blind-sacs. Another system of branched and often much sub- 
divided tubes arises in the more or less solid tissues of the 
body. These tubes are at first small, like rootlets, but grad- 
ually uniting into larger and larger branches, finally empty 
their contents into one or two main trunks, which open ex- 
ternally by one, or sometimes two orifices, near the posterior 
end of the body. This is called the water-vascular system, 


PARASITES OF ANIMALS. 55 


and is supposed to perform the office of excretory organs, 
analogous to the kidneys and liver of vertebrate animals. In 
the central region of the body there is a well developed repro- 
ductive system, both male and female organs being generally 
contained in the same individual worm; but in some species 
the sexes are separate. All the rest of the body, around these 
organs, is composed of a rather firm and solid tissue, the or- 
gans not being contained in a distinct cavity. 

The species constituting this order are very numerous, be- 
longing to several distinct families and many genera. About 
400 species have been described. They are found in all classes 
of vertebrate animals, and are numerous in their larval states 
in many invertebrates, especially in fresh-water snails. They 
particularly abound in fishes, frogs, and aquatic birds. Nearly 
all the species undergo very remarkable transformations, with 
alternate generations, some of them passing different stages of 
their lives free in water, and then in two or more distinct an- 
imals, as parasites. So that the adult forms, found in the 
higher animals, are generally derived from larve swallowed 
in small mollusks, like the river snails, and perhaps in insects. 


TI. AcantrHocersaLa. (Thorn-headed worms.) 


This order includes elongated, more or less cylindrical 
worms, usually with the body encircled by distinct transverse 
ridges and wrinkles, and which have at the anterior end a 
prominent, elongated or conical, retractile proboscis, covered 
. with numerous recurved hooks, by means of which they at- 
tach themselves to the mucous membrane in the intestine of the 
animals that they inhabit. The body contains a large cavity, 
in which the reproductive organs are contained. The sexes are 
distinct. The ovary, situated in the anterior part of the body, 
sets free large roundish masses of cells from which the ova are 
afterward developed, while these masses, or “cocoons,” are 
free in the abdominal cavity, each mass containing a large 
number of eggs, often several hundred. In the male the two 
testicles are attached to the lower closed end of the digestive 
sac, and are connected by ducts with the intromittent organ, 
which is a slender spiculum, enclosed in a sheath, situated at 
the posterior end of the body. 


56 BOARD OF AGRICULTURE. 


Many observers state that these worms have no mouth and 
no digestive organs whatever, but obtain their nutriment by 
absorbing the nutritive materials by which they are surrounded 
in the intestine of their host directly into their own tissues, 
after the manner of the tape-worms. M. Lespes* states, how- 
ever, that Echinorhynchus claveceps, found in the minnow, etc., 
has a complete alimentary system. The mouth is very small, in 
form of a pore, opening at the end of the proboscis and raised 
upon a small mobile papilla. This mouth communicates with 
a short digestive cavity, in the form ofa blindsac. He states 
that he has seen the refuse of the food ejected from the mouth. 

Upwards of 100 species of these worms have been described, 
nearly all of which are referred to the genus Hehinorhynchus. 

- They are especially abundant in birds and fishes. 

Those species in which the development has been studied, 
have a kind of alternate generation, the young embryo be- 
ing very different from the parent, and afterward developing 
in its interior another form, which in turn becomes like the 
erandparent. M. Lespes states that H. claveceps produces 
‘¢ cocoons” containing 150 to 200 eggs. The embryos devel- 
oped in the eggs are capable of moving while still in the shell, 
and remain alive fora year. On feeding a snail with food 
containing these eggs, they hatched in his intestine, and the 
free embryos were quite lively and active, and furnished with 
two pairs of hooks for boring purposes. They had consider- 
able resemblance to the free embryos of tape-worms and no 
doubt have similar habits, but they failed to undergo their 
transformations in the snail. 

_ Leuckart fed the eggs of E. proteus, found in the trout and 
other fishes, toasmall crustacean, Gammarus pulex. ‘The eggs 
hatched in a few days and the young embryos bored their way 
through the intestine into the general cavity of the body, some 
of them penetrating into the limbs. In the course of three 
weeks they grew larger and the granular mass still in the inte- 
rior of the body of these embryos developed into a distinet or- 
ganism, which afterwards developed a proboscis, muscles, and 
the other peculiar organs of an Echinorhynchus becoming gradu- 


* Journal del’ Anatomie, 1864, p. 683 ; Gunther’s Zoological Record, 1865, p. 747. 


PARASITES OF ANIMALS. 57 


ally more and more like its grandparent. It finally fills up 
the whole interior of the body of the enclosing embryo, sexual 
organs appear, and then the outer skin of the latter is cast off. 
Thus the young Echinorhynchus is formed, but in order to be- 
come mature it must be swallowed, with its crustacean host, 
by some fish. In the intestine of the fish it becomes sexually 
mature in about a week. 

The giant Echinorhynchus of the hog (E. gigas), Figure 74, 
is the only species known to infest domestic quadrupeds. 

TV. NemarTopes. (Round-worms). 


This order includes a great number of worms, which occur 
in all classes of animals, both vertebrates and invertebrates, 
together with some that are not parasitic, but live in water, 
moist earth, or decaying animal or vegetable matters. They 
are much more highly organized than those of the preceding 
orders. The pin-worms of children, the common round-worms 
of man and domestic animals, and the notorious Trichina spi 
ralis are examples of this order. (See figures 76 to 83.) 

These worms are almost without exception long, round, and 
rather slender, varying in length from a tenth of an inch or 
less to three feet, or even more, and usually tapering to one or 
both ends. The external surface of the body is generally 
smooth and uniform, without suckers or other appendages. In 
the interior of the body there is a continuous visceral cavity, 
containing a distinct digestive system, theintestine generally 
extending from one end of the body to the other, and well de- 
veloped reproductive organs, the sexes being separated. The 
mouth is usually at the smaller end of the body and is often 
surrounded by papillz or other organs. Some of the species 
are viviparous, like Zrichina; others produce eggs, like the com- 
mon round-worms and pin-worms. ‘There is great diversity 
in their habits and modes of development. Some of them 
pass through alternate generations and remarkable trans- 
formations, living in some cases, like Trichina, in two different 
animals in the larval and adult states, in other cases pass- 
ing the young states in the water, as free worms, and after- 
wards becoming parasitic, when swallowed by the proper ani- 
mal,in which alone they develop their reproductive organs 


58 BOARD OF AGRICULTURE. 


and become mature. Some species seem to have a much 
more simple history during development. There are but few 
species, however, of which the complete history is known. 
The Trichina spiralis is, perhaps, better understood in all 
stages of its life than any other species. Important discov- 
eries remain to be made, without doubt, concerning other 
species that infest our own bodies, as well as those of our 
domestic animals. At present the complete histories of the 
two commonest human parasites, the round-worm and _ pin- 
worm, are still unknown, although they have been most care- 
fully investigated and experimented upon by many able nat- 
uralists. 

Of this order about 1,000 species have been already described, 
but it is probable that a considerable number of these will event- 
ually prove to be only the young of others. They particu- 
larly abound in mammals, birds, and fishes, inhabiting the in- 
testine, stomach, windpipe, lungs, kidneys, muscles, brain, and 
various other parts of the body. Twelve species or more are 
liable to infest human beings. 


ACARINA. 


In addition to the internal parasitic worms, there are certain 
parasites which belong to other groups, Among these are 
certain forms of acarina, or mites, some of which are, perhaps, 
only accidentally parasitic, like the Acarus dysenterie mentioned 
in our previous lecture. But the genus Pentastoma includes 
species which are true parasites and have nearly the same 
habits as some of the parasitic worms, which, indeed, they 
closely resemble in general appearance. Formerly these par- 
asites were regarded as worms by all authors, but they are 
now generally referred to the Acarina, although they differ 
greatly from the more typical forms. One of these species 
is represented in Figure 84. 


PROTOZOA. 


Several genera and species of infusoria have been found liy- 
ing in the human body, or in the excreta, especially of pa- 
tients attacked with certain contagious diseases. The effects 
of these parasites and their relations to diseases are not weH 
understood. 


PARASITES OF ANIMALS. 59 


Lists of the Parasites of Man and Domestic Animals. 


The number of species of these internal parasites now 
known is upwards of 100. Therefore it will be impossible, at 
this time, to do more than enumerate the species, with their 
principal modes of occurrence, and then describe more fully 
some of the most important kinds, with their effects and rem- 
edies, so far as space will admit. It is hoped that the lists 
will serve as a key or index for those who wish to pursue the 
subject further, in the more extensive works upon this subject. 


INTERNAL PARASITES OF MAN. 
CESTODES. 


Tenia solium Linneus. Intestine, young in hog; common. 
T. mediocanellata Kuch. Intestine, young in beef; common. 
T. flavopunctata Weinland. Intestine; one case only, in the 
United States. 
T. lophosoma Cobbold. Intestine, larva unknown; one 
Case. 
T. elliptica Batsch. Intestine ; rare, common in cats. 
T. nana Siebold. Intestine ; only observed in Egypt. 
Bothriocephalus latus Bremser. Intestine, larva in fish (?); 
Kurope, rare in America. 
B. cordatus Leuckart. Intestine ; common in Greenland. 
In the larval state. 


Tenia solium Linn. In muscles, brain, eye, etc.; not rare. 

T. marginata Batsch. Abdominal viscera; very rare. 

T. acanthotrias Weinland. In muscles, mature worm un- 
known ; observed once only, in Virginia. 

T. echinococcus Siebold. Tumors in liver, brain, lungs, ab- 
domen, muscles, etc., adult in dog ; common. 


TREMATODES. 


Bilharzia hematobia Cobbold. Inhabits the blood-vessels, es- 
pecially the portal veins and those of the kidneys and blad- 
der ; very common in Africa, producing a very serious disease. 

Fasciola hepatica Linneus. Gall-bladder and ducts, and 
sometimes beneath the skin ; common in sheep, rare in 
man. 


60 BOARD OF AGRICULTURE. 


Distoma lanceolatum Mehlis. Gall-ducts ; rare. 

D. crassum Busk. Duodenum; one case. 

D. heterophyes Siebold and Bilharz. Small intestine, in large 
numbers ; two cases, in Hgypt. 

D. ophthalmobium Diesing, (perhaps young of D. lanceola- 
tum). Hye, several together ; two cases. 

Tetrastoma renale Delle Chiage. Kidney; one case. 

-Hexanthyridium Brsele Treutler. In an ovarian tumor ; 
one case. 

H. nena um Treutler, (probably young). Veins; rare. 


NEMATODES. 


Trichina spiralis Owen. Adult in intestine, young in muscles ; 
common. 

Trichocephalus dispar Rudolphi. Small intestine. 

Filaria trachealis Cobbold. Trachea and larynx ; one case. 

F. lentis Diesing, (larval form). Hye; very rare. 

Dracunculus medinensis Gmelin, (Guinea-worm). In the 
connective tissue beneath the skin and among the muscles. 
Very common in Arabia, Guinea, Upper Hgypt, and other 
parts of tropical Asia and Africa ; also in some parts of the 
West Indies. 

D. oculi Diesing, (loa). Orbit of the eye, in the conjunctiva, 
etc. Not uncommon in tropical Africa and America, chief- 
ly in the African races. 

Oxyuris vermicularis Bremser, (pin-worm). In the large in- 
testine, chiefly in the rectum and near the anus, sometimes 
in the genital passage ; very common, especially in chil- 
dren. 

Ascaris lumbricoides Linn., (round-worm). Intestine, some- 
times ascending into the stomach, rarely passing into the 
abdominal cavity by perforating the intestine ; very com- 
mon. 

A. mystax Rud. (round-worm of cats). Intestine ; rare in 
man, common in the cat. 

Eustrongylus gigas Diesing, (kidney-worm). Kidney ; rare 
in man. 

Strongylus bronchialis Cobbold.. Bronchial tubes ; very rare. 


PARASITES OF ANIMALS. 61 


Dochmius duodenalis Leuckart. Small intestine; Italy, 
much more common in Heypt, causing very serious disease. 


ACARINA. 


Pentastoma denticulatum Rud. (Probably the young of P. 
tenioides of the dog.) In cysts on the liver, etc. ; not very 
rare. 

P. constrictum Siebold. Liver and lungs; common in Egypt. 


PROTOZOA. 
Paramecium coli Malmstein. Colon, excreta. 
Cercomonas intestinalis Lambl. (C. hominis Davaine). Intes- 
tine; from a cholera patient. 
Variety B. From a typhoid fever patient. 
C. urinarius Hassal. In urine. 
C’. saltans Ehrenberg. 
Trichomonas vaginalis Donné. Vagina, in mucus. 
Psorosperms, (perhaps the eggs of Distoma). 


In addition to the preceding species of true parasites, 
various kinds of insect larvee have been known to live for a 
time in the human stomach and intestine, from which they 
have been discharged either by vomiting or purging. 

Among the most common larve that may thus live in the 
human body are those of the various species of meat-flies, blue- 
bottle-flies, blow-flies, or flesh-flies (see page 101), and those 
of the house-fly. Several species of the genus Homalomyia 
have also been known to occur in this way, the eggs or larve 
having been swallowed with fruit, and more especially in de- 
eayed fruit, in which they naturally live.*. Such larve often 
cause considerable irritation of the intestine, and diarrhea, 
but as their life in the larval state is very short, they must 
soon pass from the intestine or perish in it. 


INTERNAL PARASITES OF THE DOG. 
CESTODES. 


Tenia echinococcus Siebold. Intestine, many together ; larvee 
in sheep, cattle, and man; common. 


*These insects are well described by Mr. B. D. Walsh in the American En- 
tomologist, vol. II, page 137, 1870. 


62 BOARD OF AGRICULTURE. 


T. cenurus Kuch. Intestine, many together; not rare. 
Larve in sheep. . 
T. marginata Batsch. Intestine, few or singly; common. 
Larve in sheep and cattle. 
T. serrata Goeze. Intestine; common. Larve in rabbits. 
T. canis-lagopodis Rud. Intestine ; in Iceland common. Lar- 
ve unknown. Perhaps same as Z” litterata Batsch. 
T. cucumerina Bloch. Intestine; very common. Larve un- 
known. 
T. solium Linn., (in cysticercus state). Muscles, brain, ete. 
Bothriocephalus latus Bremser. Intestine ; not common. 
B. cordatus Leuckart. Intestine; very common in Green- 
land. 
B. fuscus Krabbe. Intestine; not rare in Iceland. 
See OUT; WELVCULOLIS: Karenco eis be 
6 yar. dubius Kr. eo ate % 
Dibothrium serratum Diesing. Intestine ; very rare. 


TREMATODES. 


Holostoma alatum Nitzsch. Intestine; less common than in 
the fox. 


NEMATODES. 


Trichina spiralis Owen. Intestine (mature); larve in 
muscles. 

Spiroptera sanguinolenta Rudolphi. Gisophagus, stomach, and 
heart, larva in blood; very common in China. 

Trichosoma plica Rudolphi. Bladder ; rare. 

Trichocephalus depressiusculus Rud. Ccecum; not common. 

Ascaris marginata Rud. Small intestine ; very common. 

Pseudalius filum Duj.(?). Heart and pulmonary artery, 
recorded by Collas ; originally from porpoise. 

Hustrongylus gigas Diesing. Kidney; rare. 

Dochmius trigonocephalus Duj. Intestine, larve in water ; 
rare. 

Filaria trispinulosa (larval form). Hye. 

F. sanguinis (larval form). In blood. 

F. mmitis Leidy. Heart. 


PARASITES OF ANIMALS. 63 


Dracuneculus medinensis Cobbold. Sub-cutaneous tissues ; in 
tropical Asia, Africa, and America. 


ACARINA. 


Pentastoma tenoides Rudolphi. Nostrils; not rare. Larve 
in man and cattle. 


That thousands of lambs and sheep are annually killed by 
dogs that have a taste for mutton of their own procuring is 
unfortunately too well known to most of the farmers in this 
country, especially in those States where neither stringent 
laws nor severe taxes have diminished the numbers of these 
useless curs. 

That the number of dogs in every part of the country is by 
far too great, and even dangerously so, is generally admitted, 
especially during the summer, when mad dogs and hydropho- 
bia are the constant theme of conversation in our cities. That 
the laws of every State ought to impose restrictions, or, at 
least, very high taxes upon the owners of dogs is evident and 
advocated by many legislators. Yet it is not, by any means, 
generally known to what an alarming extent our flocks are in- 
jured in health and depreciated in value by the parasites de- 
rived directly from dogs. Still less is it known to what an 
extent human lives and health are sacrificed on account of 
these animals. 

There are three principal and very important parasites of 
sheep derived jfrom tape-worms of dogs. These are: 1. The 
“‘water-brain” of sheep, which is produced by the young or 
larve of a small tape-worm (Tenia cenurus); 2. The ech- 
inococcus, or hydatid tumors of sheep, of cattle, and of man, 
found in various organs, but most commonly in the liver, 
brain, and kidneys, which are caused by the young of a very 
small dog tape-worm (Tenia echinococcus) ; 8. The diving 
bladder-worm, or ‘* water-bladder,”’ often found in the abdo- 
men of sheep, cattle, and pigs, frequently forming tumors as 
large as a hen’s-egg, or even a goose-egg, which is the young 
of a larger tape-worm of the dog (Tenia marginata). There 
are, also, others of less importance obtained by sheep from 
dogs, as indicated in the lists. 


64 BOARD OF AGRICULTURE. 


It is perfectly safe to say that at least twenty-five sheep are 
killed by parasites derived from dogs, for every one killed by 
the teeth of dogs! It is also safe to say that more than fifty 
persons die from the same parasites, for every one that dies of 
hydrophobia! And yet this work of destruction goes on 
silently and almost unobserved, except by professional men 
week after week and year after year. Theloss of human life 
every year more than counterbalances all the good that all the 
dogs in the civilized world can possibly do. In Iceland it is 
stated that one-sixth of all the deaths are caused by one of 
the dog-parasites (Echinococcus). The same parasite occurs 
also, not unfrequently, in all other parts of the world where 
dogs are kept, and causes most horrible disease and death. 
To this we may add the Pentastoma, which man also derives 

from dogs, and in all probability several other parasites, in- 
ternal and external. 


INTERNAL PARASITES OF THE CAT. 


CESTODES. 
Tenia crassicollis Rud. Intestine, young in rats and mice. 
T. elliptica Batsch. Small intestine ; common. ; 
T. canis-lagopodis Rud. Intestine ; common in Iceland. 
Dibothriwm decipiens Diesing. Intestine, also in leopard, 
ounce, etc. Perhaps Bothriocephalus felis Creplin. 


TREMATODES. 
Amphistoma truncatum Rud. 
Distoma lanceolatum Melilis. Bile ducts; rare. 
NEMATODES. 


Trichina spiralis Owen. Intestine, young in muscles. 
Dochmius tubeformis Dujadin. Duodenum. 

Ollulanus tricuspis Leuck. Intestine, and young in muscles. 
Ascaris mystax Rud. Small intestine ; common. 


ACARINA. 


Pentastoma denticulatum Rud. Cysts on liver, ete. 


This list includes all those that I have found recorded from 
the house cat, but doubtless many others may occur. 


PARASITES OF ANIMALS. 65 


INTERNAL PARASITES OF SHEEP. 


CESTODES. 

Tenia expansa Rud. Mature, in small intestine. 

Tenia. (Undetermined species with hooks.) In cystecercus 
state in muscles. 

T. marginata Batsch. Young or cysticercus state in viscera, 
adult in dog; common. 

T. ceenurus Kuch. Young or encysted state in large tumors 
in the brain, adult in dog; common. 

T. echinococcus Siebold. Young or hydatid condition in liv- 
er, lungs, brain, and other organs, adult in dog ; common. 


TREMATODES. 
Fasciola hepatica Linn. Liver and bile ducts. 
Distomalanceolatum Mehlis. Bile ducts. 
-Amphistoma conicum Rud. First stomach. 


NEMATODES. 

Ascaris ovis Rudolphi. Intestine ; rare. 
Trichocephalus ovis (affinis?). Large intestine ; common. 
Sclerostoma hypostomum Dujadin. Intestine. 
- Strongylus contortus Rud. Small intestine. 
S. filicollis Rud. Small intestine. Perhaps same as last. 
S. filaria Rud. Trachea and bronchial tubes; common ; also 

in the goat. 


ACARINA. 
Pentastoma tenioides Rud. Larynx, nostrils, etc. 
The goat is infested by many of the parasites found in 
sheep. Besides these, there are a few peculiar species; 


among them are Tenia capre and Strongylus venulosus Ru- 
dolphi, both found in the intestine. 


INTERNAL PARASITES OF CATTLE. 
CESTODES. 
Teenia expansa Rudolphi. Intestine, mature ; not common. 
T. denticulata Rud. Intestine, mature ; rare. 


T. mediocanellata Kiich. Young or eysticercus state in mus- 
cles, adult in man ; common. 


66 BOARD OF AGRICULTURB. 


T. marginata Batsch. Young or cysticercus state in viscera, 
adult in dog; common. 

T. echinococcus Siebold. Young or hydatid state in liver, 
brain, and various other organs, adult in dog ; common. 
T.cenurus Kiich. Young state in brain, adult in dog; rare. 

TREMATODES. 
Fasciola hepatica Linn. Liver, gall-ducts, etc.; not rare. 
Distoma lanceolatum Mehlis. Liver ; not uncommon. 
Amphistoma conicum Rud. First stomach ; common. 
A. crumeniferum Creplin. Stomach. 
A. explanatum Creplin. Bile ducts. 


NEMATODES. 

Trichina spiralis Owen. Observed only in experimental an- 

imals. 
‘Trichocephalus affinis Rud. Large intestine ; frequent. 
Strongylus radiatus Rud. Duodenum, colon, small intestine. 
SS micrurus Mehlis. Trachea and bronchial tubes. 
Eustrongylus gigas Diesing. Kidney ; rare. 
Filaria lachrymalis Gurlt. Lachrymal ducts, ete. 
F. papillosa Rudolphi. Abdominal cavity, etc.; rare. 


ACARINA. 


Pentastoma tenioides Rud. Nasal cavaties, larynx, etc. 
P. denticulatum Rud. (Young of preceding.) In cysts on 
liver, etc. 


INTERNAL PARASITES OF THE HORSE. 


CESTODES. 

Tenia perfoliata Goeze. Swell intestine, colon, coecum; 
common, and sometimes in vast numbers. 

T. plicata Rud. Stomach and small intestine ; common. 

T.mamillana Mehlis. Large intestine ; common. 

Tenia, (species undetermined). Young state (cysticercus 
jistularis) in peritoneum. 

T. cenurus Kuch. Young or encysted state in brain ; rare. 

T. echinococcus Siebold. Hydatid state in liver, ete.; not 
common. 


TEMATODES. 
Fasciola hepatica Linn. Liver, gall-bladder, ete. 


PARASITES OF ANIMALS. 67 


NEMATODES. 


Ascaris megalocephala Cloquet. Small intestine ; common. — 
Oxyuris curvula Rudolphi.. Colon, ccecum, rectum ; common. 
Eustrongylus gigas Diesing. Kidney, etc. 

Sclerostoma equinum Blainv..Duodenum, colon, ccecum, pan- 
creas, sometimes very numerous, and in enlargements of 
the arteries; common. 

S. tetracanthum Diesing. Duodenum, ececum, colon. 

Strongylus micrurus Mehlis. Trachea and bronchial tubes. 

Filaria microstoma Schneider. 

F. papillosa Rud. Abdomen, thorax, brain, eye, intestine. 

F. lachrymalis Gurlt. About the eyes, in lachrymal ducts, etc. 

Spiroptera megastoma Rud. Tubercles in stomach. 

Dracunculus medinensis Cobbold. (Guinea-worm). Subcu- 
taneous tissues ; only in tropical parts of Africa, Asia, and 
America. 

ACARINA. 

Pentastoma tenioides Rud. Nasal cavities, larynx, ete. 

The mule and ass are subject to the same parasites as the 


horse, but not to the same extent. The number of species 
hitherto observed is less, and they are far less common. 


INTERNAL PARASITES OF THE HOG. 
CESTODES. 


Tenia solium Linn. In the larval or cysticurcus state in the 
abdominal viscera. 
T. marginata Kiich. Cysticercus state inthe abdominal viscera. 
ZT’. echinococcus Siebold. Hydatid state.in liver, ete.; not 
common. 
TREMATODES. 
Fasciola hepatica Linn. Liver and bile ducts. 
Distoma lanceolatum Mehlis. Bile ducts. 


ACANTHOCEPHALA. 
Echinorhynchus gigas Goeze. Small intestine ; common. 
NEMATODES. 


Trichina spiralis Owen. Mature in intestine, young in mus- 
cles ; common. 


68 BOARD OF AGRICULTURE. 


Ascaris suilla Dujardin. Small intestine ; common. 
Spiroptera strongylina Rud. Stomach. 
Simondsia paradoxa Cobbold. Stomach, in cysts ; one case. 
Trichocephalus crenatus Rud. Large intestine. 
Strongylus dentatus Rud. Ccecum, colon. 
S. elongatus Dujardin. Bronchial tubes. 
8. paradoxus Mehlis. Trachea and bronchial tubes. 
Hustrongylus gigas Diesing. Kidneys, ete. 
Sclerostoma pinguicola Verrill. In fat about kidneys and ‘“‘spare- 
ribs,” in large numbers; probably common. 
ACARINA. 
Pentastoma denticulatum Rud. Cysts on liver, ete. 
INTERNAL PARASITES OF POULTRY. 
CESTODES. 


Tenia infundibuliformis Goeze. Intestine of hens, ducks, 
geese, etc. 

T. proglottina Davaine. Duodenum of hens ; common. 

T. crassula Rud. Intestine of pigeons, hens, and geese. 

T. malleus Goeze. Intestine of geese and ducks, etc. 

T. lanceolata Goeze. Intestine of geese and ducks, etc. 

T. setigera Froh. Intestine of geese ; common. 

T. sinuosa Rud. Intestine of geese and ducks. 

T. fasciata Rud. Intestine of geese ; common. 

TREMATODES. 

Monostoma mutabile Zeder. Sub-orbital cavities of geese, etc. 

M. variabile. Geese. 

MM. triseriale. Geese. Perhaps same as the next. 

M. verrucosum Zeder. Ducks, in coecum. 

M. caryophyllinum Bremser. Ducks. Originally described 
from fish. 

Distoma ovatum Rud. Oviducts, etc., of geese and ducks. 

D.lineare Zeder, Large intestine of hens. 

D. dilitatum Miram. With last. 

D. echinatum Zeder. Intestine of ducks and geese. 

D. oxycephalum Rud. Same habits as last. 


ACANTHOCEPHALA. 
Echinorhynchus polymorphus Bremser. Intestine of ducks. 


PARASITES OF ANIMALS. 69 


NEMATODES. 


Heterakis compressa Schneider. Intestine of chicken. 

H. vesicularis Duj. Intestine of hens and turkeys. 

Hf. dispar Duj. Intestine of geese. 

Ascaris crassa Desl. Intestine of ducks. 

A. infleca Rud. Intestine of hens. 

A. perspicillum Rud. Intestine of turkey. 

A. maculosa Rud. Intestine of pigeon. 

Spirotera hamulosa. Gizzard of hens. 

S. uncinata Rud. Tubercles in cesophagus of geese. 

Syngamus trachealis Siebold. Windpipe, causing “ gapes.” 

Strongylus nodularis Rud. Gizzard and intestine of ducks 
and geese. 


In the preceding lists we have brought together most of the 
parasites hitherto discovered in our more common domestic 
animals. There can be no doubt but that many more will 
hereafter be discovered. In the rabbit, Guinea-pig, parrots, 
singing birds, and other animals often domesticated, many 
additional species occur. 

In the following pages only the more common and impor- 
tant species will be described. 


The Armed Tape-worm or Pork Tape-worm of Man (Tenia 
solium Linn.) ; andits young, the ** measles” of pork and hu- 
man flesh. 

This is perhaps the best known of all the numerous kinds of 
tape-worms. Its young or larye are common in the muscles 
and other organs of hogs, and not very rare in man. (See 
Figures 49-51.) In the adult state it is, so far as known, pe- 
culiar to the human intestine, where it is unnecessarily com- 
mon. It grows toa great length, frequently ten to fifteen 
feet, or even more, and is then composed of upwards of 800 
joints, those that are sexually mature commencing at about the 
450th segment. The head is small, about the size of a pin- 
head, roundish, with four prominent suckers on the sides, and 
a conical, proboscis-like top, around which there are two cir- 
cles of sharp hooks, 22 to 28 in each circle (Figure 53). 
The neck portion is slender, crossed by fine lines, which are 
wider apart as they recede from the head, finally forming dis- 


70 BOARD OF AGRICULTURE. 


tinct joints. These are at first very smalland short, gradually 
becoming broader and squarish, then oblong. The largest 
are about a third of an inch in breadth and quite thin and flat 
(Figure 52). The sexually mature joints or proglottides are 
twice as long as broad, and contain the ovaries and a long 
central egg cavity or uterus, with T to 12 lateral branches, 
which are irregularly lobed and divided (Figure 54) ; and also 
the male organ, or testicle, in the form of branched tubes, 
communicating with a penis, which is situated on one edge 
of the joint, in front of the female genital orifice, and has a 
curved or sickle-shaped form. The genital openings are either 


on the right or left edge indifferently, in the successive joints. 
Figure 49. Figure 52. 


Fig. 50. 


Wsile 
ye ¢ 
Cine Gs ahs 


The young or larval state produces the white spots known as 


f} 

ely a 

ee la CO()) | 
4449 a8 eades 5} 
dis SEE ep 


Figure 49.—Pork “ measles” ; natural size; Hearth and Home, after Owen- 

Figure 50.—Young tape worm from measles of pork; and Fig. 51, head of same, 
more enlarged ; Hearth and Home, after Owen. 

Figure 52.—Pork tape-worm (Zenia so’ium), less than natural size; Hearth and 
Home, after Owen. 


ee 


PARASITES OF ANIMALS. T1 


,‘ measles” in pork (Figure 49). These are cavities or cysts 
produced by inflammation, containing whitish fluid and enclos- 
ing small, bladder-like, translucent, vesicles, filled with a watery 
fluid, and which contain the proper head and neck of the young 
worm coiled up spirally in the interior in an inverted position. 
By gentle pressure the head and neck may be made to protrude 
by inversion, like the finger of a glove, and will then present 
the appearance shown in figure 50, the vesicle of fluid now 
forming the flask-like caudal portion of the worm. The head 
may now be seen to have four suckers anda central promi- 
nence surrounded by two circles of hooks, as in the adult. In 
this condition, enclosed in the cysts, they will remain living 


Figure 53. 3 Figure 54. 


for a long time in the hog, even surviving the death of their 
host for a considerable period. If one or more of these young 
worms or measles be swallowed by a human being, the mus- 
cular fibres and the cysts will be digested, and each young 
worm thus liberated will evert its head, and losing its bladder- 
like portion, will pass into the intestine. There it will fasten 
itself to the inner membrane by its suckers and hooks, and 
grow rapidly by absorbing the digested food by which it is 
surrounded. New joints will be rapidly formed as the older 
ones grow larger, until it becomes a mature tape-worm, with 
joints ready to be cast off. There may be but one tape-worm in 


Figure 53. Head of Tenia solium, magnified. From Cobbold. 
Figure 54.—A joint or proglottis of Tcenia solium, magnified ; a, branches of the 
“uterus ; 0, external orifice; c, male organ. From Cobbold. 


~ 


2 BOARD OF AGRICULTURE. 


the human intestine, or there may be several together, the 
number depending only upon the number of living young 
swallowed. ; 

It is, therefore, obvious that this tape-worm can be acquired 
only by eating raw or under-done pork. In this country the 
principal kinds of food serving as sources of this tape-worm 
are raw smoked ham and raw sausages, but soldiers and others 
are often obliged to eat their pork-rations uncooked, and thus 
obtain the parasites. Our recent war was the means of greatly 
increasing the numbers of this and other parasites, both in- 
ternal and external. 

Persons harboring the mature tape-worms become in their 
turn the means of diffusing the race. Each mature joint cast 
off contains several thousands of: eges, each of which encloses 
an embryo, nearly ready to hatch, and as these joints are con- 
tinually being discharged during the whole life of the worm, 
which may be ten or twelve years, it is evident that one per- 
son may thus be the means of diffusing many millions of eggs, 
most of which will no doubt perish, but the chances are good 
that some of them wil] find their way into the stomachs of 
hogs, either with their food or in water. 

The free joints or proglottides have an independent life for 
a few days and are capable of moving and crawling about to 
a considerable extent. In a short time, however, the myriads 
of embryos in the interior so increase in size that the walls of 
the proglottis burst open and thus liberate the eggs. The 
eggs are globular and very small, their average diameter 
being about g}z of an inch; the shell is comparatively 
thick} being z¢55 of an inch. They are so small that they 
may be blown about by the winds, carried on the feet of in- 
sects, or may be suspended in unfiltered waters. They may, 
therefore, also readily adhere to lettuce, celery, and other 
garden plants, or to fallen fruit, especially when night-soil is 
used as manure, and unless such food be carefully and 
thoroughly washed, there is always more or less danger of 
eating the eges of this and other parasites. When these eggs 
are swallowed, either by hogs or human beings, they hatch as 
soon as acted upon by the gastric juice, and disclose their con- 


PARASITES OF ANIMALS. 73 


tained embryos, which are very different from both the old 
worm and the measle-worm. They are provided with six 
hooks or spines, placed in three pairs upon the head. By 
means of these they quickly bore their way through the walls 
of the intestine into the blood-vessels, and are thus carried to 
all parts of the body. They finally lodge in various organs, 
but especially in the muscles, liver, brain, eyes, lungs, and 
heart. They then excavate galleries for themselves in these 
situations, causing, if in large numbers, a great amount of 
inflammation and disease, which in some cases proves fatal. 
The inflammation soon causes cysts to be formed around the 
intruders, by which they are enclosed and restricted in their 
motions. Thus the ‘‘ measles” in the muscles of hogs and 
man are formed. After this the patient may recover, unless 
these parasites have lodged in the brain or other vital organs, so 
as to produce serious symptoms subsequently. In the human 
subject more than 100 cases have been recorded in which 
these parasites have taken up their abode in the brain, causing 
epilepsy, insanity, and sometimes sudden death. In such 
cases, which are probably more common than is generally im- 
agined, there can be norelief. There have also been recorded 
quite as many instances in which these cysticerci or larval tape- 
worms have been situated within the ball of the eye, causing 
a partial or total loss of sight, and sometimes great inflamma- 
tion. Many of these have been successfully removed. In 
other important organs they are liable to produce serious 
trouble. But when in the subcutaneous, areolar, or inter- 
muscular tissues, they may often be easily removed by the 
surgeon. In hogs they are much more liable to produce these 
results, because hogs are likely to swallow whole joints, or 
even entire tape-worms, while human beings seldom swallow 
more than a few dozens of eggs. 

The effects and symptoms caused by the adult tape-worms 
are discussed under the next species, together with the 
remedies. 

As means of prevention every one should avoid eating pork, 
in any form, that has not been thoroughly cooked. In this 


way it is easy to avoid the mature tape-worm of this species. 
10 


74 BOARD OF AGRICULTURE. 


To prevent measles in hogs they should not be allowed to have 
access to human excrement, the reverse of which is too often 
specially provided for by farmers. To avoid the same para- 
sites in our own flesh we must take care to have all fruit and 
other uncooked vegetable food well washed and our drinking 
water pure. 


The Beef Tape-worm of Man (Tenia mediocanellata Kuch.) ; 
and its young’, the ‘ measles”’ of veal and beef. 


This is a very large species, which was formerly generally 
known as the unarmed variety of the human tape-worm. It 
is known to occur among all beef-eating people, and is the 
common species in Africa, Western Asia, and several Huropean 
countries, especially in Austria, Turkey, and certain parts of 
Russia. 

It haslong been known that Jews, Mohammedans, and other 
people who never eat pork, are nevertheless liable to be in- 
fested by tape-worms. It was also observed, many years ago, 
that infants fed upon dried beef—a custom much practised at 
St. Petersburg—were liable to have the same parasites ; and 
these facts were formerly brought forward as arguments 
against the doctrine that the common tape-worm is derived 
from eating the larval form contained in measly pork. But 
it was soon discovered that nearly all the tape-worms obtained © 
from patients in Mohammedan countries, as well as in Austria, 
and some other parts of Europe where pork is little used, were 
destitute of the two circles of peculiar hooks around the cen- 
tral, proboscis-like prominence of the head, as well as the 
prominence itself, which are very conspicuous features in the 
common tape-worm of pork-eating people. Owing to these 
peculiarities, naturalists began to consider the two forms 
either as different varieties or different species. The source 
of the unarmed tape-worm remained uncertain, however, until 
direct experiments were undertaken by Leuckart, Mosler, and 
others to settle this question. Thus it was discovered that 
when the joints or eggs of the unarmed tape-worm (¢ Tenia 
mediocanellata) were given to calves, the eggs hatched in the 
stomach, and the young embryos worked their way, by means 


+ 


PARASITES OF ANIMALS. 715 


of their six boring hooks, through the intestine into the cir- 
culation and, lodging in the muscles, caused serious disease 
or death, if in too large numbers, and after a time became 
enclosed in little capsules, producing, in fact, “measly” veal 
or beef, as shown in Figure 55, which represents part of a 
muscle of the hind leg from a calf that had been fed by Drs. 
Cobbold and Simonds upon the eggs of this tape-worm, and 
killed three months afterward. The flesh of this calf was 
estimated to contain over eight thousand measles, and yet, 
although at first it had been scriously ill from the effects of 
the parasites, it was at the time when slaughtered perfectly 


Figure 55. Figure 56. 


healthy and fat. The measles of veal or beef are much 
smaller than those of pork, and if they existed only in 
moderate numbers, would scarcely be detected either by the 
butchers or consumers. They are seldom larger than a small 
pea. One of these ‘measles,’ when examined with the 
microscope, is found to consist of an outer oval cyst or mem- 
branous sac, enclosing loosely in its cavity a more delicate 
vesicle filled with fluid and containing the inverted head of 
the young tape-worm, as represented in Figure 56. The head 
has four well-marked suckers, but has no central proboscis 
and no circle of hooks—differing therefore from the pork- 
measle, or cysticercus, in just the same way that the heads of 
the mature tape-worms differ from each other. Thus it was 
definitely settled that the unarmed or hookless tape-worm of 


Figure 55.—Measles in veal, reduced. Hearth and Home, after Cobbold. 
Figure 56.—One of the measles magnified. Hearth and Home, after Cobbold. 


76 BOARD OF AGRICULTURE. 


man ( Tenia mediocanellata) is obtained by eating the young, 
in the shape of “ measles,” in raw or slightly cooked beef and 


Figure 58. 


VA say 
io 
a “i 


ay EZ 
A 
SSS) 
SS 


veal. And thus the presence of tape-worms in infants fed on 
dried beef, as well as in Jews and others not guilty of eating 


Figure 57.—Tcenia mediocanellata, natural size. Hearth and Home, after 
Leuckart. : 

Figure 58.—Head of beef tape-worm, magnified. Hearth and Home, after 
Leuckart. 

Figure 59.—A joint of the beef tape-worm, showing the ovaries, enlarged. Hearth 
and Home, after Leuckart. 


a a a re 


PARASITES OF ANIMALS. 17 


pork, is fully explained. Since these facts have been ascer- 
tained, search has been made for ‘‘measles” in beef from 
animals not experimented upon, and they have been found in 
several instances. 

When such beef is swallowed by man, without cooking, the 
young tape-worms are liberated from their capsules or cysts 
by the process of digestion ; the head becomes protruded, and, 
passing into the intestine, it fastens upon the lining mem- 
brane by its suckers. There it rapidly grows larger, new 
joints are developed, and the body grows longer and longer; 
the form of the joints changing as they grow, until those that 
are most mature become square, and finally oblong, as shown 
in Figure 57, which represents a beef tape-worm, of natural 
size, in several sections, the intermediate joints being omitted. 
When full grown, which requires three or four months, one of 
these tape-worms may contain over 800 joints, of which 360 
to 400 of the last ones will be sexually mature, cach one con- 
taining 5000 or more eggs. This species is much larger than 
the pork tape-worm (T. soliwm), as well as longer, its length 
being sometimes twenty feet, and its greatest breadth half an 
inch, while the joints are thicker and stouter, or have a plump 
look, instead of being thin and flat, as in the other. The 
head, as already intimated, is quite different in the two species 
—that of the beef-worm being larger aud flat, or even concave, 
at the end, with four large suckers on the sides, as shown, 
greatly magnified, in Figure 58. The joints themselves are 
very different internally, the egg-masses or uteri being very 
numerous, and crowded together in a more parallel manner 
(Figure 59) in this than in the pork tape-worm, in which 
they are fewer and more aborescently branched. ‘The mature 
joints, filled with eggs, are cast off, as in other tape-worms, 
and leaving the intestine, have an independent existence for 
a few days, when they burst by the enlargement of the embryos 
in the eggs. The eggs are thus scattered about in manure, in 
water, in the drainage of cess-pools and sewers, by the winds, 
and by insects. Itis not strange, therefore, that cattle should 
occasionally swallow such eggs with their food and drink, 
especially if we reflect that one man, harboring only one of 


78 BOARD OF AGRICULTURE. 


these worms, may thus scatter about, during a single year, 
more than a thousand joints, and if each of these contains but 
5000 eggs, he would thus diffuse 5,000,000 eggs, each con- 
taining an active embryo, ready to leave its shell the moment 
that it enters the stomach of a calf, cow, or ox. Young ani- 
mals seem to be more liable to be infected by them ‘than old 
ones. Fortunately these young worms retain their vitality 
for but one year when enclosed in the flesh, and after that 
die and, withering away, leave only a very small yellowish 
spot, containing calcareous particles. The adult worm, if 
left undisturbed, will live in a person ten or twelve years, 
constantly dropping its joints. Among the Burates, or Cos- 
sacks of the Baikal region, this species is very abundant. 
Their habits of eating chiefly the raw or slightly cooked flesh 
of cattle, sheep, camels, horses, and goats, while they devour 
the liver, kidneys, and fat quite raw, would lead us to expect 
that this and other parasites might abound in their bodies, 
which proves to be the case. According to Dr. Kaschin in 130 
post mortem examinations only two bodies were found with 
out this tape-worm, and among 500 hospital patients every 
one had it. Sometimes as many as fifteen specimens were 
found in one person. 

It has been supposed until within a short time that the 
beef tape-worm (Tenia mediocanellata) was very rare in 
Great Britain and the United States, where the pork tape- 
worm was thought to be the only one that was at all common 
in man. Dr. Cobbold has shown, however, in his late works 
on parasitic worms, that the beef tape-worm is really quite as 
common in England as the pork tape worm, the wealthier 
classes generally harboring the former, and the poorer people 
the latter. Jam convinced that, even if not so common as 
the pork tape-worm, the beef tape-worm is by no means so 
rare in America as is generally supposed. The Museum of 
Yale College possesses one large specimen, raised by a citizen 
of New Haven, and many other museums in the United States 
no doubt contain them, labelled, however, ‘‘ Teenia solium.”’ In 
fact, probably not one physician in a thousand, in the country 
at large, possesses the knowledge of the subject requisite for 


PARASITES OF ANIMALS. ~ RD 


distinguishing the two species and, therefore, both are con- 
founded together as “ the common tape-worm.”’ 

In this country persons generally obtain this parasite by 
eating dried beef and Bologna sausages uncooked. In the lat- 
ter, there may be not only the young of this tape-worm, but 
also those of the pork tape-worm and Trichina, since there is 
also an admixture of pork. It is therefore evident that it is 
unsafe for the individual, and even a wrong to the community 
for persons to indulge in eating raw meats of any kind, for 
we find that pork, beef, and mutton may each contain the 
young of different tape-worms and other parasites, and per- 
sons who harbor these worms in their own bodies become, in 
one sense, a nuisance, since they thus serve as the propaga- 
tors and disseminators of parasites. And although one or 
two of these tape-worms may not cause any serious trouble in 
the bowels of one man, in another they may produce very 
erave consequences, and still more so, if, as often happens, 
several live together in one person. 

Symptoms. 

The symptoms and treatment are the same for both species 
of human tape-worms, but the species now under considera- 
tion is said tobe more easily destroyed than 7. soliwm, per- 
haps because it does not have so secure an anchorage as the 
latter has, with its hooks well imbedded in the membranes. 

The symptoms vary greatly, according to the temperament 
and other peculiarities of the person affected. Sometimes it 
causes little or no marked disturbance of the health, though 
causing perhaps more or less weakness, lassitude, and sense of 
weariness, often accompanied by restlessness, nervous irritabil- 
ity, and headache, which are nearly always attributed to other 
causes. In more severe cases, these symptoms become much 
increased, the headache especially, which is often accompa- 
nied by giddiness. “The sight and hearing may be affected ; 
noises in the head, itchings at the nose and anus, obscure 
pains about the body and limbs, loss of appetite, and other 
dyspeptic symptoms, show themselves in greater or less de- 
gree in different cases. One of the most common symptoms, 
however, which I have noticed, is the tendency to faintness. 
This is sometimes so marked as to create much alarm, and a 


80 BOARD OF AGRICULTURE. 


person uninformed as to the true cause of the disorder might 
be led to treat the symptom as arising from a totally different 
source. In female patients the nervous symptoms display 
features more or less peculiar to the sex. _ The restlessness 
-and anxiety are excessive, and at times accompanied by cho- 
rea and fits of hysteria. In the worst cases, in both sexes, 
the cerebral disturbance may show itself in convulsions and 
epileptiform seizures. I regret tohave to add that in nota 
few instances even mania itself has been entirely attributable 
to the presence of tape-worms in the intestinal canal.” Such 
are the usual symptoms, according to Dr. Cobbold. Many un- 
usual and remarkable cases are on record. In one instance, 
mania of eight years duration was completely cured by the 
removal of the parasite. In another, hysteria was caused by 
eighteen tape-worms in one patient. Many cases of insanity, 
due to this cause, are also on record. The best and perhaps 
only sure evidence of tape-worms is the passage of the joints 
from the intestine. 
Remedies. 

The remedies for tape-worms are numerous and, if fresh 
and pure drugs be used, there are several that appear to be 
perfectly reliable in most cases. These remedies should, how- 
ever, beadministered with proper precautions. Therefore, pa- 
tients afflicted in this way should immediately place them- 
selves under the care of a reliable and competent physician. 

The remedies chiefly used are the oil or root of male-fern, 
kousso, kamala, oil of turpentine, panna, pumpkin-seeds, and 
pomegranate-root bark. These are generally administered 
while the patient fasts. The pumpkin-seeds are perhaps the 
most domestic remedy, as well as one of the best, and safest in 
the hands of inexperienced persons. The fresh seeds may be 
bruised or pounded in a mortar, and mixed with water into a 
paste, of which the patient may eat freely, morning and even- 
ing, at the same time fasting, or eating sparingly soups or similar 
food. The root of the male-fern (Aspidium filiz mas) is gen- 
erally regarded as the most certain remedy, if fresh and pure. 
The dose for an adult is ten to fifteen grammes of the powder, 
morning and evening, followed by a purgative. The etherial 


PARASITES OF ANIMALS. 81 


extract is generally more effectual, however. The patient 
should have a sparing diet of soup, etc., for twelve or fifteen 
hours before taking the medicine, and the second dose should 
be followed, after an hour or two, by a purgative like castor- 
oil. These remedies are mentioned here not to encourage 
self-treatment, but for the benefit of those who may not be 
within reach of a reliable physician. 


The margined Tape-worm of the Dog (Tenia marginata 
Batsch) ; and tts young, the “‘ diving bladder-worm” of 
Sheep and Cattle. 


The young of this parasite are very frequently found in the 
abdominal cavity of sheep, either attached to various parts of 
the viscera, especially the liver and mesentery, or else nearly 
or quite free among the organs, so that when the sheep are 
opened, the bladder-like sacs fall out, of their own accord. 
These are usually known to butchers as ‘“ water-bladders.” 
When attached to the organs, these bladders or sacs are usu- 
ally enclosed in a cyst or membrane, formed by the inflamma- 
tory action that they cause. The sac issoft and whitish, en- 
closing a watery fluid, and varies in size from that of a pig- 
eon’s egg, or less, to that of a child’s head; but it is rather un- 
common to find them larger thana hen’s egg. In form they 
are often globular, but more frequently pear-shaped, as repre- 
sented in Figure 60. Ifone cf these bladders, while still en- 
closed in its cyst, be placed in a plate of warm water and care- 
fully examined in a good light, there may be dimly seen in the 
interior, near the upper end, the outlines of the head and neck, 
which are turned inward, as usual in most young tape-worms ; 
but what is singular in this case, the head and neck alternately 
rise and sink in the fluid of the interior, with remarkable reg- 
ularity. From this peculiarity it has received the name of 
“diving bladder-worm.” This motion is produced by a pe- 
culiar arrangement of muscular fibres in the interior, which 
are attached to the neck. At the top of the little knob onthe 
upper end of the bladder there is a small slit, from which, by 
gentle pressure, the neck may be gradually forced out, so as 
to project externally, and finally the head also appears. In 


82 BOARD OF AGRICULTURE. 


this condition the creature has a flask-shaped form. The neck 
tapers gradually from the bladder to the head, and is divided 
transversely into a series of many short joints. The head is 
but little enlarged, bearing four suckers, as usual, and in the 


Figure 60. 


center has a proboscis, surrounded by two rows of hooks, con- 
taining from sixteen to twenty-four pairs. Sometimes there 
are found in large bladders of this kind a few secondary blad- 
ders attached to the inside of the large one, produced by a 
process of budding, somewhat as in the water-brain, or cenu- 
rus. This parasite, as thus characterized, was formerly sup- 
posed to be a distinct and peculiar species, and received the 
name of “ Oysticereus tenuicollis,” or slender necked bladder- 
worm. Recent investigation and experiments have, however, 
proved it to be only the young or larval condition of one of the 
common tape-worms of the dog (Tenia marginata). Blad- 
der-worms of the same kind are found, though less commonly, in 
cattle and horses, as well as in pigs, monkeys, and many other 
animals, and very rarelyin man. Owing to the large size to 


Figure 60. Diving bladder-worm, from a sheep; natural size. Hearth and 
Home, after Thudichum. 


Figure 61. Head of Tenia marginata, enlarged. - Hearth and Home, after 
Thudichum. 


PARASITES OF ANIMALS. 83 


which this parasite grows, it is always liable to produce se- 
rious disease, or even death; but the symptoms thatit causes 
and the danger will depend very much upon the situation of the 
tumors. In some districts it is extremely common. According 
to Dr. Thudichum, it occursin nearly every sheep slaughtered 
in London ; and the dogs that feed upon the offal of slaughter- 
houses nearly always have the mature tape-worms in abun- 
dance. 

When a dog swallows one of these bladders, either free or 
in its cyst, the bladder portion is digested, and the head be- 
comes protruded ; on reaching the intestine, it fastens itself to 
the membrane by means of its suckers and hooks. In this 
situation, it rapidly develops new joints, and in the course of 
three or four months becomes a mature tape-worm, about 
three feet in length, and begins to discharge its ripe joints 
filled with eggs. A dozen or more of these tape-worms may 
exist together in the intestine of one dog. - In general appear- 
ance, this tape-worm (Tenia marginata) resembles the pork 
tape-worm of man (Zenda soliwm), but never grows so large, 
and its neck portion is much thicker, compared with the size 
of the head as shown in Figure 61. 

The first hundred joints are very short ; the mature joints are 
squarish, the posterior end of one somewhat overlapping the 
anterior end of the next. These joints contain a very much 
branched and subdivided female organ, with an oviduct ter- 
minating on one edge in a bell-shaped orifice ; and an arbor- 
escently branched male organ or spermary, with small, round 
dilations connected with the small branches. Dogs harbor- 
ing these tape-worms scatter the mature joints and thousands 
of eggs everywhere over the fields, and. in the water of 
streams and ponds. .The sheep and cattle swallow the eggs, 
either with their food. or water or both. The eggs are hatched 
in the stomach of the sheep, and liberate minute worms, 
which are armed with three pairs of hooks for boring their 
way through the tissues, like the embryos of other tape-worms. 
By this means, these embryos force their way through the 
lining membrane of the intestine into the blood-vessels, and 
are carried to various parts of the body. Many lodge in the 


84 BOARD OF AGRICULTURE. 


lungs, heart, and other organs, and cause for a time great irri- 
tation and inflammation of these and other parts by their move- 
ments in forcing and boring passages for themselves in the 
tissues ; but they all eventually perish, while still small, in 
such localities, and those that get into the liver and. abdomi- 
nal viscera are the only ones that survive and develop to their 
full size, becoming the water-bladders, or “‘ Cysticercus tenu- 
icollis,” first described. 

The complete history of this, like the other tape-worms, 
previously described, has been ascertained beyond doubt by 
direct experiment. In this case the water-bladders have been 
given to dogs, and at the proper time the dogs have been killed, 
when the mature tape-worms have always been found corres- 
ponding in number to the number of water-bladders eaten, 
and in size to the length of time. And then the eggs or joints 
of the tape-worms have been given to lambs; and although 
such lambs generally die in the course of five or six days, 
when they swallow large numbers, yet even in that short time 
the young worms have been found in vast numbers already 
distributed in the system; but when only a few eggs are em- 
ployed, they do not cause immediate death. And in this way 
Prof. Leuckart has studied their complete development. This 
tape-worm, in its mature state, does not inhabit the human 
body. Dr. Méller even swallowed several of the living blad- 
der-worms without any result. 

When these young worms have once got into the system of 
a sheep, there is noremedy. In this case, prevention is our 
only hope; and to this end the same means should be used as 
against the Tenia cenurus and T. echinococcus, to be de- 
scribed farther on. Especial care should always be taken to 
destroy the water-bladders and all other parasites observed in 
slaughtering animals, as well as those removed from living 
animals by medicines or surgical operations ; for in many cases 
the eggs are capable of retaining their vitality for many weeks 
or months. They should never be thrown aside as harmless, 
or even buried, but should be destroyed by scalding hot water 
or fire. Much may be done, also, in diminishing the numbers 
of this and other parasites by frequently doctoring those dogs 


PARASITES OF ANIMALS. 85 


that are worth keeping, or are necessary, in order to expel 
their parasitic worms, of which there are generally many 
kinds. There are numerous drugs that are efficacious for this 
purpose, some of which are mentioned under the beef tape- 
worm (page 191). But the principal difficulty is this—those 
who keep the most dogs, the worst dogs, and the dogs most 
likely to harbor parasites in abundance, are the very persons 
who are least likely to adopt such measures, either not know- 
ing or not caring for the consequences. 


Tenia cenurus Kuch., of the Dog; andits young, the “water- 
brain” of Sheep. 

In the substance of the brain of sheep there is often found 

a soft tumor, often as large as a pigeon’s egg, and sometimes 

- larger than a hen’s ege, which is filled with a watery fluid. 

Such tumors would go on increasing in size indefinitely, until 


Figure 62. 


death ensues. But even long before the result becomes fatal, 
the health is seriously impaired. The brain is often found 
much diseased, and in part quite disorganized—a state of 
things which in man would produce incurable insanity. In 
sheep, it causes “‘ staggers,” “ gid,’ “vertigo,” or “ sturdy,” 
and other cerebral derangements. This disease is, in most 


Figure 62.—Cenurus or water-brain of sheep. Natural size. Hearth and 
Home, after Thudichum. 


86 BOARD OF AGRICULTURE. 


cases, incurable, and such diseased sheep are too often sent 
to the market. Fortunately, man cannot be infected with 
this parasite. 

When one of these tumors is removed with care, it will be 
found to consist of a thin, white, translucent cyst or sac, 
roundish, oval, or irregular in shape. On one side may be 


Figure 63. Figure 64. 


seen clusters of little white spots (Figure 62). If the spots 
be examined with a lens, each one will be found to consist of 
the minute head and neck of a young tape-worm, projecting 
from the surface, and provided with four suckers and a circle of 


Figure 65. 


hooks, as usual in young tape-worms in this stage of their 
growth (Figure 63). Or else the heads will be found to be 
withdrawn into the sac, each in its own capsule, and then 
the spots are made by small depressions or pits, with a slit- 
like opening at the bottom. If the interior of the sac-mem- 
brane be examined with a microscope, each pit will be found 


Figure 63.—Portion of the outer membrane, with the heads of Canurus. En- 
larged four diameters. From Dayaine. 

Figure 64.—Inner surface of the membrane of the cyst, with inverted heads, 
magnified. Hearth and Home, after Thudichum. : 

Figure 65.—Brain of sheep in which the young embryos of Cenurus have ex- 
cavated galleries. Davyaine, after Van Benedeu. 


PARASITES OF ANIMALS. 87 


to correspond to one of the withdrawn and inverted worms, 
as represented in Figure 64. 

Each little worm has a head with a circle of hooks in the 
middle, surrounded by four suckers, just as in the measle- 
worm of pork. In this case, each little worm with a head is 
the larva of- one of the dog tape-worms ( Tenia cenurus), 
but in this the young worms have the power of propagating 
themselves by a kind of budding, in a manner similar to that 
by which the coral-animals bud from each other and_ so 
build great colonies. Thus it is that one of these little 
worms, lodged in the brain, by budding produces hundreds of 
others like itself, all connected together by the membrane of 
the sac; and thus the tumor constantly grows larger, instead 
of always remaining small, as does the measle-worm. 

Effects. 

Now, if a dog gnaws a skull containing such a tumor, and 
swallows the whole cyst, or any part of the membrane that 
has heads on it, the heads will be liberated from the mem- 
brane, and each one will fasten to the lining of the dog’s 
intestine by means of its suckers and hooks. There they will 
rapidly grow larger and larger ; new joints will be formed for 
the body, and in the course of three months each one will become 
a small tape-worm, with many joints, and each of the larger 
joints will have both male and female organs, and will be 
capable of propagating the race by itself. The female organs 
of each joint contain thousands of eggs, which are discharged 
when mature, and passing from the intestine of the dog in 
large numbers, they will be scattered about freely over the 
pastures and fields wherever the dogs go. Ifa lamb or sheep 
accidentally swallows some of the eges with grass or in water, 
the eggs will hatch in the stomach intominute worms. These 
force their way, by means of their six little hooks, through 
the lining of the intestine into the blood-vessels, and are thus 
carried to different parts of the system; but usually only 
those that lodge in the brain live, and there excavate galleries 
(Figure 65) and grow, and bud, thus forming the ‘“ water- 
brain,” and finally kill the sheep. Cenurus cysts have been 
observed, however, beneath the skin of sheep, in the cellular 
tissue. Similar cysts have, also, been found in the liver 


88 BOARD OF AGRICULTURE. 


of rabbits, and in squirrels, and other animals, so that dogs 
may perhaps obtain the same tape-worms by eating rabbits, and 
then give the ‘ water-brain’” in turn to lambs. But the 
ceenurus-like cysts of rabbits, etc., may prove to be a distinct 
species, which does not produce the same dog tape-worm, as 
several writers suppose. Young lambs are more liable to be 
infected by this parasite than sheep, the lability decreasing 
with age. This parasite is by no means uncommon, and is 
always abundant in proportion to the number of dogs in any 
country. Thus, in Iceland, where both dogs and sheep are 
kept in large numbers, Dr. Krabbe found this tape-worm in 
eighteen per cent. of the dogs, while the two other tape-worms 
dangerous to sheep were found even in much greater num= 
bers. ‘‘ Giddy” sheep are, of course, very abundant in that 
unfortunate country. In this country the disease is far more 
common than most persons suppose. 

That this disease is caused in the manner described above, 
has been repeatedly proved by direct experiments made by a 
number of naturalists. The following by Dr. Ktichenmeister, 
was one of the earliest: ‘‘ On the 6th of January, 1854, at 8 
o’clock in the evening, and on the 7th of January, at 11 o’clock 
in the forenoon, I gave some mature proglottides (joints) of the 
Teenia cenurus of the dog to six lambs of from six to nine 
months old, taken from three different flocks, which were not 
subject to vertigo. On the 20th of January the animals exhibit- 
ed the first symptoms of vertigo. They were then successive- 
ly killed, and presented the following phcoenomena on exami- 
nation. 

On the seventeenth day after the introduction, from twenty 
to thirty vesicles (Coenuri) inhabited the surface of the brain ; 
the substance of the brain was hollowed into galleries as though 
a Sarcoptes had been formingits passages (see Figure 65) ; the 
vesicles were still free and without envelopes, and of the size 
of a grain of millet. 

- On the twenty-fifth day the vesicles were larger. On the 
twenty-sixth day they were of the size of a lentil; the envel- 
opes began to be formed, and the first traces of heads appear- 
ed. On the thirtieth day, the heads, under the form of tuber- 


PARASITES OF ANIMALS. 89 


cles, were visible to the naked eye. On the thirty-eighth day, 
the eminences appeared more distinctly on the surface, and. - 
the heads exhibited signs of their suckers and _ hooks. 
Toward the forty-fifth day the Cwnuri were of the size of a 
bean, and the cavities in which the heads are lodged were 
formed.” LEncysted vesicles, containing strayed and aborted 
worms, were also found in the heart, the diaphragm, and the 
cesophagus. Some of the “ water-brains’’ obtained in this ex- 
periment were given to a dog early in March, and in due time 
a good crop of the mature tape-worm (Tenia cenurus) was 
obtained by killing the dog, which was done May 24th. These 
were immersed in white of eggs, in which some of them were 
kept alive, by changing it daily, for eight days, and sent to 
several other naturalists residing in other parts of Europe, at 
Louvain, Copenhagen, and Giessen. Prof. Von Beneden re- 
ceived his at Louvain, May 27th, and tried the following ex- 
periments: ‘‘ On the day of their arrival, at 9 o’clock a. m., 
half a proglottis was given to each of two young sheep, about 
two months old, and in the afternoon each of them took an 
entire proglottis. On the 3d of June, one of them, marked 
No. 1, swallowed another proglottis. The first symptoms of 
vertigo made their appearance on the 13th of June; on the 
morning of the 15th, I was told that the one marked No. 2 
was dying. Its head was burning hot, its eyes red, its legs 
bent under its body ; it beat with its head against the railings, 
and turned it constantly in one direction. It was then killed. 
The upper and lower surfaces of the two hemispheres of the 
brain presented irregular grooves which might be taken for 
the deserted tubes of certain annelids (Figure 65) ; these have 
been already mentioned by M. Kiichenmeister. There were 
about a dozen of them. At the end of these tubes there were 
the same number of Cenuri, almost all lodged in the cortical 
substance of the brain. Some of them were removed with the 
membranes of the brain. They were of nearly the same size, 
about three or four millimetres in diameter. These Cenuri 
as yet only consisted of a simple milk-white vesicle filled with 
fluid. The heads were not yet tobeseen. * * #* 

i hy The second sheep (No 1), was killed on the 

12 


90 BOARD OF AGRICULTURE. 


29th of June. It presented nearly the same symptoms as the 
former. For the last few days of its existence the right fore- 
leg was always bent, and in walking it could not support it- 
self upon its hoofs. In removing the brain from the cranium, 
a Coenurus of the size of a small nut fell upon the dissecting 
table. Two other Cenuri, of the same size, were found in 
the right hemisphere, one above. the other behind; and in 
separating the hemispheres of the cerebellum, I found two 
others touching the quadrigeminal tubercles. The left lobe 
of the cerebellum also contained one. Hight were found in 
all. These Coenuri were nearly all of the same size, except 
two or three, which were scarcely larger than a cherry-stone. 
Through the walls of the larger ones the naked eye could dis- 
tinguish some little whitish flakes, the indications ofso many 
heads (scolices). The smaller ones had no appearance of 
heads, nor of the place where they were to rise. The Cenuri 
were enclosed in a membrane of recent formation, produced 
by the inflammation of the neighboring surfaces.” 

Similar experiments, with the same results, were tried by 
Kschricht at Copenhagen, and Leuckart at Giessen, to whom 
tape-worms from the same dog were sent. Three sheep were 
fed by Dr. Eschricht. Of these one was not affected, but the 
other two became ill on the 15th and 16th days and died four 
days afterward with the symptoms already described, and in 
their brains the samekind of young Cenuri were found. 

In these experimental cases, where large numbers of eggs 
are given, the symptoms come on violently and death takes 
place at an early stage in the development of the worms, but 
under ordinary circumstances only a few eggs are swallowed 
and then the sheep may live long enough to allow the cysts to 
become much larger, with more numerous heads. The num- 
ber of the heads is often 300 or more on a large cyst, and each 
head is eapable of forming a complete tape-worm, with many 
joints. Allowing 500 sexual joints to each tape-worm, and 
each joint to contain 5000 eggs, there might result, as the pro- 
geny of one egg in a single generation, 150,000 joints, con- 
taining 750,000,000 eggs ! 

Remedies.—The only remedy for sheep with this parasite at 


PARASITES OF ANIMALS. 91 


work in the brain, would be trepanning, and that can seldom 
be effectual, unless the cysts be small and favorably situated, 
which is not often the case. As with most internal parasites, 
instead of remedies, we must seek means of prevention. It is 
very apparent that, in this case, prevention simply demands 
the absence of dogs that harbor the tape-worms, from all 
places where the sheep feed or drink. Prevention on the 
part of dogs can be secured by not allowing them to feed on 
the offal of slaughter-houses, and especially the heads of sheep. 
The mature tape-worms can be expelled from dogs by the or- 
dinary remedies for other tape-worms, some of which are men- 
tioned under Tenia mediocanellata. 

Perhaps the most effectual of these remedies is oil or spir- 
its of turpentine mixed with castor oil. 


Tenia echinococcus Siebold, of the Dog; and its young, the 
hydatid tumors of Man, Sheep, and Cattle. 


This is by far the most important and dangerous of all ces- 
tode worms. In the mature state it lives in the intestine of 
dogs and wolves in great numbers, as a very small tape-worm, 
about an eighth of an inch long, with only three sexual joints 
or proglottides (Figure 70). Inits larval state it forms com- 
pound cysts and tumors in a great variety of animals. 

Not unfrequently there may be found imbedded in the sub- 
stance of the liver and lungs of sheep, watery tumors of con- 
siderable size, sometimes becoming several inches in diameter 
and causing serious disease, and even the death of the ani- 
mal. Similar tumors occur, though less frequently, in the 
brain, kidneys, ovaries, among the muscles, and in various 
other situations in sheep. They occur also in pigs, horses, and 
cattle, though lesscommonly thanin sheep, but unlike the Can- 
urus, or “ water-brain,” these tumors are not confined to the 
lower animals. They are also found in the human body, and 
give rise to incurable and mosthorrible diseases, to which per- 
sons of all classes are liable,no matter how wealthy or refined. 
That large numbers of human beings of all ages and condi- 
tions die annually from diseases caused by this parasite is es- 
tablished beyond a doubt. And although such diseases are 


99 BOARD OF AGRICULTURE. 


most common among the poorer classes of society, and espec- 
ially among those who associate most familiarly with dogs, 
ee 66. 


Figure 67. 


oe 


L. | tt \ 
a i KAY a a 
“wy 
{ Uy Y/ AW 
uy wd 


they are by no means confined to them. Many men of great 
eminence and talent have likewise perished from. the same 
cause. And, unfortunately, society is so constituted that no 
one can be certain of escaping so long .as the parasites that 
produce the eggs exist in the dogs of every country. It is 
estimated that 500 persons die annually by this parasite in 
Great Britain. 

These tumors, in their simplest form, or when young, con- 
tain a roundish cyst or membranous sac, enclosing a watery 
fluid, as shown in Figure 66, which represents of natural size 
a parasite of this kind from the human kidney. More fre- 
quently the cysts become compound by a process of budding, 
either upon the outside or inside, or both without and within 
the membrane of the original cyst, so that its size goes on in- 
creasing indefinitely, sometimes becoming as large as a child’s 
head, and often completely permeating and destroying the 
liver, luhgs, or other organs. Thus the danger becomes con- 
stantly greater and greater by reason of the pressure upon 
and destruction of the adjacent organs. When the budding 
is external, it results in a cluster of secondary: cysts, often a 
dozen or more, and sometimes hundreds, all more or less con- 
nected together (Figure 67). And each of the external second- 
ary or daughter cysts, may increase and multiply itself in the 
same way, thus, at times, producing many hundreds of other 
tertiary cysts or “‘ grand-daughter cysts.”” By internal budding, 


Figure 66—Hydatid or echinococcus cyst, natural size. Hearth and Home, 


after Thudichum. 
Figure 67.—Secondary cysts from a tumor in the liver, natural size. From 


Cobbold. 


PARASITES OF ANIMALS. 93 


secondary or daughter cysts are formed inside the primary 
ones, and then others inside the secondary ones, within which 
the heads of the future tape-worms are formed by a peculiar 
budding process. If the inner membrane of one of the small 
eysts be examined when quite fresh with a good microscope, 
’ there will be seen attached to it by means of slender stalks, 
numbers of small oval or rounded heads, looking erica 
like fruit on a miniature plant, as shown in Figure 68, which 
shows a few of these heads attached to the inner mem- 
brane of a cyst from an echinococcus tumor of asheep. The 
heads may also bud forth from the outer as well as the inner 
surface of the cysts, or brood-capsules, as they arecalled. And 
these heads, either external or internal, may become changed 
by an enlargement of their bladder-like portion into new 
brood-capsules or cysts, and by budding produce other heads 
in their interior, as shown in Figure 69. The heads are found 
attached to the inner membrane of the. primary cyst, together 
with secondary cysts or brood-capsules ; they occur in the same 
way in the interior of the secondary cysts, sometimes associ- 
ated with tertiary cysts, or grand-daughter vesicles ; and also 
on the interior of the tertiary cysts. They sometimes appear 
even on the exterior surface of the secondary and tertiary 
vesicles. In all these situations they are similar in appear- 
ance and structure, and all are equally capable of developing 
into tape-worms in the intestine of a dog. Many of the 
smaller secondary and tertiary brood-capsules or cysts are not 
more than ;1, of an inch in diamter, and then generally con- 
tain only three or four heads. 

Each of the oval heads is a hollow sac, which contains the 
real head of the young tape-worm turned in like the finger of 
a glove, just as the heads are turned inward in the cenurus 
. and in the measles of pork, or the young of any other tape- 
worm. Often the head is turned outward, as is seen in one 
case in Figure 68, which shows well the four suckers around 
the head and the proboscis in the middle with its circle 
of hooks. ‘These same organs can be seen indistinctly even 
when in their inverted position, as in the other heads shown 
in Figure 68, owing to the partial transparency of the mem- 


94 BOARD OF AGRICULTURE. 


branes. As long as these cysts remain in a living animal, 
new heads are constantly formed, by their peculiar methods 
of budding, and when new cysts are formed either within or 
outside of the older ones, they develop on their inner mem- 
branes other heads in the same way,so that if the sheep or 
other animal lives long enough to develop a large tumor, it will 
finally contain many thousands of these minute tape-worm 
heads. In examining one of these tumors taken from a dead 
animal, most of the heads and also the internal secondary cysts 
are usually found floating freely in the watery fluid in great 
numbers, giving it a turbid appearance, and on standing they 
settle to the bottom as a granular sediment. This is 
due to changes after the death of the parasite, though some 
of the secondary cysts may be free during life. 
Development. 

Now, if a dog eats the liver, lungs, kidney, or other parts 
containing such tumors, and swallows either the cysts or the 
detached heads, these will lose the enclosing membrane, stems, 
and other parts that are no longer useful, the heads with their 
suckers and hooks will be protruded, and, passing into the 
dog’s intestine, each one will fasten itself by means of the 
hooks and suckers to the soft membrane lining the intestine. 
In this situation they remain and soon develop a small body, 
having only three separable sexual joints, as shown in Figure 
70, which represents the mature tape-worm (Tvenia echinococ- 

cus) greatly magnified. This tape-worm never becomes long, 
with hundreds of joints, as do the pork and beef tape-worms of 
man. It is only about an eighth of an inch long when ma- 
ture. The last joint, which is much the largest, contains both 
male and female organs, and is perhaps capable of selfimpreg- 
nation ; itis therefore a complete hermaphrodite. After this 
has matured and discharged its eggs, the two next in turn de- 
velop their sexual organs and take its place. In Figure 70 
the male organ may be seen projecting from one side, and the 
ovaries, containing many eggs, occupy the bulk of the 
joint. The eggs pass out through a duct that opens by 
the side of the male organ, and each egg is fertilized 
before being discharged. Thousands of these little tape- 
worms, derived from one large cyst, often live together in 


PARASITES OF ANIMALS. ' 95: 


the intestine of one dog, so that they make up by numbers 
what they lackin size. Suchadog is constantly discharging 
and scattering thousands or millions of the extremely mi- 
nute eggs of this tape-worm wherever he goes. 


Figure 68. 


Figure 69. 


\ 
ri 
ANUS \VHD SY iy 


ay 
y 


They are scattered among the grass in fields and pas- 
tures; they get into the water of brooks and springs ; they 
are liable to adhere to fruit that has fallen, or to lettuce 
and other garden vegetables. 

Dr. Cobbold has calculated the number of progeny that 
might proceed from one egg during a single generative cycle. 
Allowing 500 secondary cysts to be formed and 10,000 
heads or scolices to be developed by each hydatid cyst of 
average size, these might produce 5,000,000 tape-worms, 
each of which having three joints that become free, would 
give 15,000,000 joints or proglottides, and if each of these 
contains 10,000 eggs, the whole number of eggs in one gen- 
eration, would be 150,000,000,000! 


Figure 68.—Echinococcus heads attached to inside of brood-capsule, greatly 
magnified. Hearth and Home, after Thudichum. 
Figure 69.—A head or scolex, becoming a brood-capsule. From Leuckart. 


96 BOARD OF AGRICULTURE. 


Effects and Remedies. 

These eggs are well protected by a shell, but when taken 
into the human stomach, or into the stomach of sheep, cattle, 
or pigs, they are acted upon by the gastric-juice and then im- 
mediately hatch. The embryo is a very minute worm, very 
different from the parent, and provided with six little hooks, 
by means of which it digs its way through the lining of the 
intestine into the blood-vessels, and entering the circulation 
they are carried to the various organs of the body, where they 
develop into the peculiar cysts first described, and thus cause 
disease and death. When lodged in the brain, they are most 
dangerous, soon causing insanity and death by their rapid 
growth and consequent pressure. In the lungs they are also 
very dangerous and often fatal ; in the liver they cause severe 
disease, often terminating fatally; and in other organs the 
effects differ according to the nature of the organ. When 
the lodgment is among the muscles, or near the exterior of 
the body, the tumors may be removed by a surgical operation, 
or even by simple puncture, they may bedestroyed. The dis- 
charge of the contents is fatal to the life of the hydatid 
‘opened, but there may-be many others adjacent that will not 
be affected. Injections of iodine, etc., after opening, are un- 
necessary. When in the internal organs there is generally 
no remedy, though by chance the cyst may of itself burst, as 
sometimes happens, when, if the discharge takes place through 
some natural channel, recovery is possible, but such cases are 
of very rare occurrence. In the majority of cases the true 
nature of the disease is not suspected until a post mortem 
examination reveals it, or until the tumors burst or are 
opened, when a microscopic examination of the matters dis- 
charged gives reliable evidence; but many of these hydatid 
tumors are no doubt observed and treated by physicians, who 
do not even suspect what their real character may be, because 
they have neither suitable instruments nor sufficient knowl 
edge to make the requisite examinations. Chemical tests 
may be applied to the liquid discharged, it is said, with satis- 
factory results. The properties of the fluid are described as 
follows: “If the sac be not inflamed, it is limpid, has a 
specific gravity of 1007 or 1009, and contains no albumen, 


ee a 


PARASITES OF ANIMALS. 97 


but throws down a copious precipitate with a solution of 
nitrate of silver, owing to its strong impregnation with com- 


mon salt. 


Figure 70. 


Boney 


B=) AO 
eae as 
4S 


at fo 
> 
= 

vA 

ee) 
cz 


s 


These characters apply to no other fluid in the 


body, whether healthy or morbid.”—Dr. 
Murchison. In some cases hydatid tumors 
situated in the liver and other internal organs 
have been opened from the exterior, with suc- 
cess, by skillful surgeons, but these operations 
are always dangerous and often immediately 
fatal. The escape of the fluid, with the 
minute cysts aud heads contained in it, into 
the abdominal cavity, will give rise to other 
tumors, and thus increase the disease, even if 
death does not immediately result. 

This is eminently a case where ‘‘an ounce 
of prevention is worth a pound of cure.” The 
means of prevention are simple, though not 
easy of application inallcases. The first and 
most important rule is to diminish the num- 
ber of dogs to the utmost possible extent, and 
then to keep them at the minimum number ; 
second, avoid as much as possible the prox- 
imity of dogs and sheep; third, avoid feeding 
dogs with uncooked livers or other offal of 
sheep containing these parasites, or never give 
them such raw food without careful exami- 
nation ; fourth, avoid too much familiarity 
with dogs, and especially between children 
and dogs; fifth, be careful not to eat lettuce, 
fallen fruit, or other raw food that has not 
been thoroughly washed, both on account of 
this and other parasites; sixth, avoid by all 


means possible the use of impure water, or water liable to 
be contaminated by eggs of parasites and excreta of animals, 
both for household purposes and to supply sheep, cattle, and 
horses, for such water is not only liablesto contain echino- 


Figure 70.—Mature Tenia echinococcus, much enlarged. Hearth and Home, 


after Leuckart. 


18 


98 : BOARD UF AGRICULTURE. 


coceus eggs, but those of several other tape-worms, round- 
worms, and many other parasites, and is of itself unhealthy 
and often the prolific cause of disease. If water from a good 
well, or a well protected spring, cannot be had, the water 
should be carefully filtered, and by preference through char- 
coal. Most of thé water consumed in our cities, both from 
wells and the water-works, is wholly unfit to drink without 
filtering. In cities with loose sandy soils the well-water is 
the worst possible. 

Finally, dog-kennels and other places much frequented by 
dogs, should be frequently cleaned and the litter burned, 
while frequent sprinklings with strong petroleum water or a 
solution of carbolic acid in water should be used to destroy 
the eggs that may have escaped from the intestine. By these 
precautions the numbers of this and several other dog-parasites 
might be much diminished. Dogs might also receive a 
thorough course of medical treatment, once in three months 
to expel all their intestinal worms, with great advantage, and 
this might, with propriety, be made obligatory by law. In 
this case the dogs should be confined while treated and all 
excreta should be burned. 

The frequency of this parasite is in direct proportion to the 
extent to which the precautions are neglected in different 
countries. In Iceland, the conditions for its rapid increase 
and perpetuation have been favorable, and in that unfortunate 
country, Dr. Krabbe states that there are at all times about 
eighteen hundred patients suffering with severe forms of this 
parasitic disease—-a number equal to about one-fortieth of all 
the inhabitants. In some districts, the proportion is said to 
be one in every seven, and scarcely a family can be found 

without two or more cases! It is also stated that one-sixth 
of all the deaths are due to diseases caused by this parasite! 
The number both of dogs and sheep in Iceland is very large, 
and the dogs mingle with the natives and live with them in 
their rude dwellings, and are used in bringing the sheep to- 
gether, so that abundant opportunities occur for propagating 
the parasite. According to Dr. Krabbe, there is one dog for 
every three to five inhabitants in Iceland, while in Great 


a Lae 


PARASITES OF ANIMALS. . 99 


Britain, with a high tax on dogs, there is only one to fifty. 
Doctor Krabbe found the echinococcus tape-worms in twenty- 
eight out of one hundred Icelandic dogs examined, while in 
Denmark he found them in less than one per cent. of the 
three hundred and seventeen dogs examined for this purpose. 


Tape-worm of the Horse (Tenia perfoliata Goeze). 


This is a small species, seldom becoming more than three 
inches long and a third of aninch broad. The head is rather 
square, with four prominent suckers, but without a proboscis 
and hooks. There is no distinct neck, the first joints behind 


Ficure 72. 


the head being broad, but short. There are about 45 joints 
in full-grown specimens. The reproductive organs open on 
one edge of the joints, the first 22 segments having both male 
and female organs, the rest only female. 

It occurs quite frequently, in considerable numbers, in the 
coecum and colon of the horse, and more rarely in the small 
intestine. The development and the source from which 
horses derive them are unknown. The larve may, perhaps, 
live in insects accidentally swallowed with grass. It does not 
appear to produce any serious disease, unless in great num- 
bers, and may be expelled by the same medicines used against 
the human tape-worms. | 

A still smaller species, 7. mamillana Mebhlis, only about 
half an inch long, and also without a distinct neck, but with 
wedge-shaped joints, lives in the large intestine of the horse. 
A much larger species than either of these (7. plicata Rud.) 
lives in the small intestine and sometimes in the stomach of 
the horse. It grows to the length of three feet or more, and 
has a remarkably large head, with four suckers, but no hooks 


Figure 71.—Young Yeenia perfoliata, natural size. From Cuvier. 
Figure 72.—Head of YT. perfoliata, magnified. From Cuvier. 


100 BOARD OF AGRICULTURE. 


or proboscis. The neck is short and thick, transversely 
plicated, and the reproductive organs are in a single series on 
one edge. If in considerable numbers, this species may pro- 
duce serious symptoms, such as loss of flesh, tight skin, loss 
of strength and spirit, and general debility. 


The Sheep Tape-worm (Tenia expansa Rudolphi). 

This species, which is found both in sheep and cattle, grows 
to the length of eight or ten feet, varying in breadth from a 
quarter of an inch to upward of an inch, in large specimens. 
The head is very small with four suckers directed forward, 
and close together. The neck is scarcely distinct, or very 
short. The posterior border of the joints are uneven, divided 
up into rounded lobes and notches, or wavy. The reproduc- 
tive organs are double, opening on each edge of every joint. 
Its young stage is unknown, and consequently the source 
from which the sheep obtain it. It does not appear to be very 
common in this country, judging from the few cases recorded. 
In Germany it is very common in sheep. It does, without 
doubt, produce effects in sheep similar to those caused by the 
tape-worms in man. 

Tenia cucumerina Bloch, of the Dog. 

This species is very common in the small intestine of the 
dog. It grows to the length of ten or fifteen inches up to 
nearly ten feet, with a width of one-twelfth to one-eighth of 
aninch. The head issomewhat rhomboidal, with four suckers 
and a central proboscis, which is surrounded by three circles 
of claw-shaped hooks, the whole number being about 48. 
The mature joints are elliptical, or shaped somewhat like the 
seed of a melon or cucumber. From this peculiarity it takes 
its name. There are two genital orifices to each joint, one 
in the middle of each edge. The eggs are much fewer in 
each joint than in most other tape-worms. Its development 
is unknown. It has been supposed that the larvee live in flies 
or other insects. 

When in large numbers in a dog, it occasions more or less 
severe ‘symptoms, especially if associated, as it usually is, 
with several other species of tape-worms and round-worms. 
It can be expelled by the same remedies mentioned under 
some of the previous species. 


PARASITES OF. ANIMALS. 101 


Tenia elliptica Batsch is a similar species living in the cat, 
and by some is thought to be the same. 

Several tape-worms of the dog have already been de 
scribed (Tenia echinococeus, T. cenurus, T. marginata), 
but there is another that is equally common in some districts. 

Tenia serrata Goeze closely resembles T. cenurus and T. 
marginata. 'The larve live among the viscera of rabbits and 
hares, producing small round cysts, and the dogs get this tape- 
worm by eating rabbits or the refuse thrown aside in dressing 
them. The young state or larva was formerly named Cysti- 
cercus pisiformis, in allusion to the pea-shaped cysts. 

The Broad Tape-worm of Man (Bothriocephalus latus 

Bremser ). 

The genus Bothriocephalus differs greatly from the true 
tape-worms ( 7enia) in many anatomical characters, but has 
a similar form of body, divided into many flat joints. The 
head has no suckers, but is long-oval in shape, with a long 
and deep groove on each side. It has no proboscis and no 
hooks. The reproductive organs open at the mzddle of the 
side of each joint, instead of the edge. 

There are numerous species living in fishes and quite a 
number in birds. The present species grows to an enormous 
size—probably larger than any other known tape-worm. It 
grows to the length of 25 or 30 feet, and according to some 
authors to 50 or 60 feet. It is sometimes an inch wide. The 
joints seldom. break off, either singly or in chains, but the 
eges are discharged by the bursting of the joints while still 
attached within the body of the infested person. The male 
and female organs open separately, the male organ being a 
little in advance of the female orifice. The female uterine 
organ forms a sort of rosette, with eight or ten lobes, around” 
the external orifice. 

Its fertility is remarkable, even for a tape-worm. Prof. 
Eschricht found in one specimen 10,000 joints ; allowing each 
of these to contain only a thousand eggs, this worm would 
have produced 10,000,000 young. The full history of this 
parasite is not yet known. The eggs, however, will hatch in 
water, producing curious embryos, which are provided with 
vibrating cilia by means of which they swim around for a 


102 BOARD OF AGRICULTURE. 


few days. The external skin, with the cilia, is then cast off, 
liberating a very different looking embryo or larva, which is 
provided with six boring hooks, similar to those of the em- 
bryos of ordinary tape-worms. Their subsequent history has 
not been ascertained, but it is probable that they enter some 
fish Gmost likely trout and salmon) and become encysted 
among the muscles, and that persons who eat imperfectly 
cooked or raw dried fish get the parasite in that way. 

It is remarkable that this species is not known to be indig- 
enous in any but European countries, and even in Europe it 
is peculiar to certain districts. It is particularly common in 
certain parts of Switzerland. In Geneva it is said that about 
one-fourth of all the inhabitants are afflicted with this worm. 
It occurs also in some parts of Russia, Poland, and Prussia. 
In America it has only been observed in emigrants from 
Europe, and in persons who have traveled in the Huropean 
countries where it naturally. occurs. It causes similar symp- 
toms and is removed by the same remedies as the common 
tape-worms. 


TREMATODE WORMS. 


The Liver-fluke of Sheep and Cattle ( Fasciola hepatica Linn.). 


This common and notorious parasite has a very flat body, 
different on the two sides, and more or less oval in form, the 
anterior end suddenly narrowing to a sort of neck, which 
tapers off to the mouth end, where it is either rounded or 
pointed. The posterior end of the body is _ fFieure 7s. 
somewhat tapering, but blunt. Ordinary speci- ‘ 
mens are about three-quarters of an inch long 
and half an inch wide, but large ones become 
an inch and a quarter long and three-quarters 
broad. While living they often curl up the ends {; 
of the body, toward the lower side. The color \ 
is pale brownish or greenish yellow, sometimes 
with a faint rosy tint. At the anterior end of 
the body there is a small, cup-shaped sucker, at 
the bottom of which the mouth is situated 
(Figure 73, a); near the origin of the neck- 
like portion, on the middle line of the lower side, there is 


PARASITES OF ANIMALS. 103 


another larger sucker (0), with no opening at its bottom ; 
just in advance of this there are situated, side by side, the 
male and female genital orifices (¢). The external male 
organ is long, slender, and when protruded is curved in a 
spiral. It can be retracted into a small cavity. 


Anatomy. 


The reproductive system is very largely developed and com- 
plicated. The male organs, or testicles, consist of large 
clusters of vermiform, convoluted, yellowish tubes, situated 
in the middle region of the body, and filling up about one- 
half of the whole interior. The female organs, for they are 
hermaphrodites, are also largely developed and complicated. 
The lateral and hinder parts of the body are filled with in- 
numerable, very small, yolk-sacks, which communicate, by a 
complicated system of branched ducts, with a heart-shaped 
ovary, and this in turn has a short duct leading to the uterus- 
like organ, which consists of a convoluted, wide tube, forming 
a sort of rosette behind and around the ventral sucker. The 
uterine tubes show through the skin and are brownish yellow, 
owing to the numerous minute eggs with which they are filled. 
These eggs are discharged, one by one, from the small ex- 
ternal orifice as fast as they become mature. The mouth 
communicates with a small dilated cesophagus, and this gives 
rise to two large intestinal tubes, which diverge in advance of 
the genital orifice and extend backward, along each side, to 
near the posterior end, sending off numerous lateral branches, 
which again subdivide into many short divergent branchlets, 
as shown in Figure 73,d. The branches of these digestive 
tubes are all closed at the ends, and they communicate with 
the exterior only through the mouth. In life these tubes are 
all filled with food, consisting chiefly of bile, with some blood- 
corpuscles, etc. Another system of numerous, arborescently 
branched tubes is found nearer the dorsal surface, and as they 
show through the skin, on that side, they may be examined 


Figure 73.—Masciola hepatica, natural size, seert from below; a, mouth and 


oral sucker; , ventral sucker; c, genital orifice ; d, branches of intestine. From 
Cuvier. 


104 BOARD OF AGRICULTURE. 


with an ordinary lens. These tubes commence in fine, rootlet- 
like branches, with rounded and closed ends, but the small 
branches constantly unite into larger trunks, which in turn 
all unite into one main trunk, running along the middle line 
of the body, and this terminates in an external orifice at the 
posterior end. The use of this system of tubes is to remove 
the waste materials from the body. It may therefore take 
the place both of the kidneys and liver of the higher animals. 
There is no blood circulation and no true blood in these 
animals. 
Development. 

The fluke is avery prolific creature. Prof. Leuckart esti- 
mates that the ovaries may at any one time contain 45,000 
egos. The number of broods that they produce is not known. 
The eggs that are discharged pass out of the intestine of the 
sheep, or other animal in which they live, with the excre- 
ment. Those that get into water or moist places hatch after 
several weeks, producing minute conical embryos, which are 
covered with vibrating cilia or lashes, by means of which 
they swim freely about in the water. In this state the em- 
bryo is ;4, of an inch long and s$5 of an inch broad at the 
larger end. The cilia are ;z3'5g of an inch long. 

In a few days the external skin, with the cilia, is cast off, 
and after that the embryos are obliged to creep about, instead 
of swimming. Its farther development has not been traced, 
but it probably has a history similar to that of other species 
of flukes of which the entire history isknown. Therefore it 
is supposed that the young embryos, above described, attach 
themselves to the bodies or enter the tissues of the fresh- 
water spiral .snails, such as Limnea and Physa. In this 
situation the form probably changes, and they become the so- 
called “ nurses,’’ and then a brood of larve of another form 
is developed in their interior, by a process of internal budding. 
These larve are provided with a tail and have a form some- 
what resembling minute tad-poles. In this state they are 
known as cercari@. They are finally discharged from the - 
body of the ‘nurses,’ and escaping from the snails, may 
again swim actively about in the water, by means of 


PARASITES OF ANIMALS. 105 


their tails, but eventually they, in all probability, again enter 
the bodies of other small snails, and losing their tails, become 
encysted in ‘ttle capsules. Finally these snails, with their 
parasites, are swallowed by sheep and cattle, while adhering 
to the herbage growing on moist land or near the water, 
or when adhering to water-cresses they might be swallowed 
by mankind. In the stomach and intestine of these higher 
animals they are again liberated from their cysts. They then 
gain access to the liver, where they rapidly develop their 
sexual organs and become mature. Eventually, after they 
have matured and perhaps discharged a large part of their 
- eges, they themselves, or at least a part of them, enter the 
intestine and are discharged, while still living, in company 
with innumerable eggs. The eggs that they still contain may 
be laid after they reach the earth or water. These eggs are 
exceedingly minute and may be diffused in various ways, as 
by rains, winds, insects, and the feet of animals, and getting 
into water, or moist situations, they are ready to hatch and 
commence another series of transformations. 

The history of most of the flukes, which have hitherto been 
fully investigated, agrees in the main with that above given, 
and there can be little doubt but that this will prove to be the 
case with the common fluke, when its full history shall have 
been ascertained. At any rate it is certain that the eges can 
hatch only in water, or in moist places. Therefore it is evi- 
dent that sheep and cattle will be much more liable to the 
disease when kept in low wet pastures, than in dryer and 
more elevated situations ; and also that wet seasons will be 
favorable for the parasites and dry ones unfavorable. These 
conclusions have been fully sustained by the experience of 
sheep-owners in all countries. 


Modes of Occurrence. 


The liver-fluke is one of the few internal parasites that is 
capable of living in several very different animals. It is most 
common in sheep; less so in cattle, goats, horses, and the 
ass; and quite rarein man. It has also been found in the 
hog, elephant, camel, beaver, squirrels, rabbit, hare, deer, 
and antelopes of several kinds, and in the great kangaroo. 

14 


106 BOARD OF AGRICULTURE. 


It is chiefly found in the gall-bladder and bile ducts, but 
occurs also in the intestine, and sometimes in blood vessels. 
In the human subject it has, in some instances, been found in 
tumors beneath the skin. In these cases it is supposed that 
the larve entered from the exterior by boring through the 
skin. 


Effects. 


The injurious effect of this parasite is best known in the 
case of sheep. In these animals it produces the fatal disease 
generally known as “ rot,’’* “ water-rot,”’ or “ fluke-rot.”’ In 
severe cases of this disease there are always large numbers of 
flukes in the bile-ducts and gall-bladder,—often several dozens 
and sometimes several hundreds, or even a thousand in some 
fatal cases. A few may exist in a sheep without causing any 
marked disease ; in proportion to the number, the symptoms 
become more marked and the disease more fatal. In some 
wet seasons, and in certain districts, these parasites have 
destroyed immense numbers of sheep. Thus in 1830-1 it is 
estimated that between one and two million sheep died of 
this disease in Great Britain. If the number was but 1,500,- 
000, it would represent a loss equal to about $20,000,000. In 
a single year, in England, individual farmers have lost from 
300 to 800 sheep in the same way. In France, during the 
year 1812, according to Davaine, 300,000 sheep died by the 
same cause in the vicinity of Arles, and 90,000 at Nimes 
and Montpellier. In Germany, Holland, and most other 
European countries similar disastrous outbreaks of the dis- 
ease have occurred every few years, while during the most 
favorable years the aggregate annual loss is far greater than 
is generally supposed. In this country there are no reliable 
statistics by which the losses from this cause can be estimated. 
Yet there can be no doubt but that it amounts in reality to a 
large sum annually. Even those sheep that have the disease 
in a milder form and are sent to the market before they be- 
come too sick to be moved, lose very much in value, and are 


*This must not be confounded with an entirely different disease, known as 
“ foot-rot.”” 


PARASITES OF ANIMALS. 107 


really unfit for food, though it is to be feared that farmers, as 
well as butchers, are not always over scrupulous in such.cases. 


Symptoms. 


In severe cases any one at all familiar with sheep can 
readily detect the disease even by the general looks of the 
animal. They also show a peculiar weakness in the loins 
when the hand is pressed along the back over that region. . 
In very bad cases the back becomes hollow and the belly 
hangs down, while the sheep become more and more 
emaciated and weak, dull, and dejected, with a feeble gait. 
The skin loses its natural color and becomes dry, while the 
wool is also harsh and dry, and comes off easily. 

The skin on the inner parts of the thigh, especially where it 
is naked, becomes dry or scaly early in the progress of the dis- 
ease. The eye affords very certain evidence, even at an early 
stage, so that even shepherd boys are able to select from a 
flock those that are diseased, by this symptom alone. If the 
lids be turned back and the membrane at the corner of the eye 
be pushed away, the conjunctiva and other parts will present 
an unnatural watery appearance, the vessels being swollen 
and filled with pale or yellowish colored blood. When the 
disease is farther advanced the blood-vessels lose their color 
and are scarcely distinguishable, though a few of them may 
be swollen and filled with dark, unhealthy looking blood. 


Remedjes. 


It can be safely stated that when these parasites have once 
entered the liver in considerable numbers there is no known 
specific remedy. All that can be done is to keep up the 
general health and strength of the animal until nature effects 
a cure, or until the parasites complete the natural course of 
their lives and voluntarily leave the sheep. To this end the 
afflicted animals should be removed to a dry pasture or good 
shelter, and be liberally fed with a variety of nutritious and 
palatable food, while they should be freely supplied with salt. 

This is another of those instances where prevention is far 
easier and better than cure. From what we already know of 
the history of the parasite it is evident that sheep will be 


108 BOARD OF AGRICULTURE. 


little liable to get it if pastured on uplands, or other dry 
places, and supplied with pure spring water, by preference 
from a trough or other similar arrangement. On the other 
hand, sheep pastured on meadows, or swampy lands, or in 
places where they have access to the marshy banks of streams, 
ponds, and swamps, will be far more liable to get this and 
several other parasites. 

An exception should, however, be made in the case of salt 
marshes and meadows, for sheep pastured in such places sel- 
dom get the disease. This is probably owing to the fact that 
the fresh water snails, that harbor the young flukes, cannot 
live in salt or brackish water. 


Smaller Liver-fluke (Distoma lanceolatum Mehlis). 


This species is also found in the bile-duct and gall-bladder - 
of sheep and cattle, and occasionally inman. It is sometimes 
associated with the common fluke. It is much smaller, the 
length being about one-third of an inch and the breadth an 
eighth. It has a smooth, flat, lance-shaped body, broadest 
behind the middle, narrowing to each end, the mouth-end 
being most pointed. There are two suckers, as in the com- 
mon fluke, the one at the front end having the mouth at the 
bottom. 

The anatomy is quite different, for in this, as in all other 
true Distomas, the digestive tube only forks once, each branch 
remaining a simple, closed tube, running down on each side 
of the middle region of tlfe body. ‘The testicles are two 
large, roundish, but somewhat lobed organs, just below and 
near the ventral sucker. The uterine tube has numerous 
branches arranged on each side of a main central trunk, in the 
hinder part of the body. The ovaries are comparatively 
small and situated on each side of the middle region of the 
body. 

Development. 


The eggs hatch in water, after several weeks, producing 
very small, nearly round embryos, which have the vibrating 
cilia only on the head end, which is a little smaller than the 
other end. ‘They are not such lively swimmers as the em- 


PARASITES OF ANIMALS. 08 


bryos of the common fluke. They are about 345 to 54 of an 
inch long, and +35 of an inch broad. The head end is pro- 
vided with a dagger-like boring spine, which can be alternate- 
ly thrust out and withdrawn. It is supposed that these em- 
bryos become parasitic in fresh-water snails, for a time, and 
undergo transformations like those described under the pre- 
ceding species. Their effects and remedies are the same as 
for the common fluke, though owing to their small size they 
would be less injurious, unless in much greater numbers. 


The Stomach-flukes of Cattle (Amphistoma conicum Rud. and. 
A. crumeniferum Creplin). 


The flukes belonging to the genus Amphistoma, which in- 
cludes, besides the two indicated, A. explanatum from the 
bile-ducts of cattle and A. truncatum from the cat, have a 
small, rather thick, and somewhat conical body, the mouth- 
sucker being at the small end. The large end is rounded and 
bears the other sucker, which is always much larger, near the 
posterior end. The stomach and reproductive organs are 
nearly like those of Distoma. The eggs also produce ciliated 
embryos in the water, and they are supposed to go through 
similar transformations. I do not know that either of them 
have been observed in sufficient numbers to produce serious 
diseases in cattle. 


ACANTHOCEPHALA. 
(Thorn-headed worms.) 
Echinorhynchus gigas Goeze. Figures 74, 75. 


This, which is the only representative of the order hitherto 
found in our domestic mammals, is quite frequent in the intes- 
tine of hogs. It may at once be known by the peculiar pro- 
boscis, which bears several circles of small but sharp hooks, 
which are arranged alternately, in quincunx, mostly toward 
the end of the proboscis (Figure 75). These worms have a 
long roundish body, tapering to the posterior end. The skin 
is generally crossed by numerous transverse wrinkles, but is 
sometimes smoothish. The color is whitish or a little bluish. 
The males grow to the length of three or four inches, with a 


gC) ae BOARD OF AGRICULTURE. 


diameter of one-eighth to one-fifth of an inch. The females 
may become six inches, or even a foot in length, and some- 
times one-quarter of an inch in diameter, though generally 


Figure 74. 


smaller. The female is very prolific, producing an immense 
number of somewhat oblong-oval eggs. 

The history of its development and transformations has 
not yet been made out. There can be little or no doubt, 
however, that the young worms are parasitic in some other 
animals,—most likely in insects, worms, or snails,—and that 
the hogs get them by devouring the embryos included in 
some such small animals. 


Hffecis and Symptoms. 


This is the commonest and most injurious intestinal worm 
found in swine. ‘These parasites live in the small intestine, 
and more rarely in the large intestine. They usually adhere 
to the lining, or mucus membrane, by means 
of the hooks on the proboscis, which is thrust 
into the substance of the membrane. Not 
unfrequently they perforate the walls of the 
intestine and stray into other parts of the 
viscera, producing serious disease. Some- 
times the intestine of a hog is found per- 
forated by so many of these holes that it can- 
not be used in the manufacture of sausages ! 

In severe cases, hogs afflicted with this parasite are weak 
in the loins, and have the membranes in the corners of the 
eyes swollen, watery, and lighter colored than usual. The 
excrement is hardened and highly colored, and the animal 
often keeps up a continual squealing and grunting, especially 
in the morning. Such hogs are generally cross and morose, 


Figure 75. 


Figure 74.—Echinorhynchus gigas, natural size. From Cuvier. 
Figure 75.—Head of £. gigas, enlarged showing the reticulated vessels in the 
skin. From Cuyier. 


ape 


PARASITES OF ANIMALS. Ah 


biting and snarling at its companions, but is usually too weak 
to defend himself, if attacked in return, and is easily thrown 
down. Finally the weakness increases until the poor crea- 
ture is unable to walk about, or to stand. This parasite will 
probably yield to the same remedies used for tape-worms, or 
those employed against the common round-worms of man (As- 
caris lumbricoides ), to which, therefore, the reader should refer. 


NEMATODES. 


. 


(Round-worms and Thread-worms.) 
The Flesh-worm (Trichina spiralis Owen). Figure 76. 


This mostimportant and most dangerous of all human para- 
sites, is a very minute round worm, which in the larval state 
lives in the muscles of man, swine, dogs, cats, rats, mice, 
rabbits, Guinea-pigs, and many other animals, and in the ma- 
ture state inhabits the intestines of the same animals. The 
body is slender, smooth, and round. The intestine is com- 
posed of a series of small, bead-like swellings, separated by 
constrictions. The male is much smaller than the female, 
when mature measuring only 7; of an inch ; its bodyis filiform, 
pointed at the head, enlarged at the opposite end, generally 
somewhat bent or curved upon itself; the head. is very small 
and pointed, unarmed, but with a minute central mouth ; the 
posterior end of the body is furnished with a bilobed ap- 
pendage, the anal opening being between the lobes; the penis 
is a single spiculum, cleft above so as to have a V-shaped out- 
line. The female is stouter than the male and longer, meas- 
uring about ¢ of-an inch, when mature ; the posterior end is 
bluntly rounded; the genital orifice is at about a fifth of the 
length from the anterior end of the body. They are viviparous 
and the uterus occupies most of the body, in the form of along 
and wide tube, in which the embryos are closely packed. The 
eggs are yz'75 Of an inchlong. The young Trichine, like young 
tape-worms, occur imbedded in the muscles of the hog and 
various other animals, and man. ‘But unlike the young tape- 
worms or ‘‘ measles,” the young 7richine are so smail as to be 
quite invisible to the eye, and millions of them may ex- 
ist in the flesh of a pig without producing any unusual appear- 
ance in the meat sufficient to attract the attention even of an 


112 BOARD OF AGRICULTURE. 


expert, unless examined with a powerful microscope. This is 
one reason why deaths so frequently occur from eating pork 
filled with this parasite. When recently introduced into pork 
or human flesh, the little worms are free and coiled up among 
the muscular fibres, but after four or five weeks they become 
enclosed in minute, whitish, elongated, oval or roundish cysts 
or capsules, due to the irritation and inflammation that they 
cause by feeding and moving (Fig. 76). After ayear or more 
these cysts become calcified by a deposit of carbonate of lime 
in the membrane, and at this time are visible to the 
eye as minute specks, about the size of hemp-seed, scattered 
through the muscles. When enclosed in the cyst, the worms 
become dormant, and though they may live for years, and 
even some weeks after the death of their host, they can do no 
further harm unless swallowed by man or some animal. Hach 
cyst contains a little slender worm about one twenty-fifth or 
one thirtieth of an inch long, and one seven hundredth thick, 
coiled up in two or three 

turns. The cysts average gms 

about one eightieth of an 
inch long and a hundred 
and thirtieth thick. 

If pork or other flesh 
containing these worms, 
either free or enclosed in 
cysts, be eaten by man, 
they become liberated in 
the stomach, and, en- 
tering the intestine at- 
tach themselves to its soft 
lining, and there, sur- 
rounded with abundant 
food, they grow very rap- 
idly and become mature, 
with fully developed sex- 
ual organs, in two days. 


Figure 76.—A small piece of human muscle containing encysted young of 
Trichina spiralis Owen, enlarged forty-five diameters. From Hearth and Home, 
after Leuckart. 


eae ee pre nail 


PARASITES OF ANIMALS. 113 


The females are larger and more numerous than the males, 
and become about one-eighth ofan inch long when full grown. 
They pair as soon as mature, and the males soon die; 
but the females begin to give birth to living young in five 
or six days from the time when they enter the stomach, 
and they live long enough to produce a brood of from five hun- 
dred to one thousand young worms each. As one ounce of pork 
sometimes contains a quarter of a million or more of the worms, 
it is not surprising that the millions of adult worms and their 
offspring, sometimes resulting from a single meal of raw 
pork, should, by their presence, produce great irritation and 
inflammation of the intestine and violent diarrhoea and vomit- 
ing, which are often the first symptoms in severe cases. But 
the young worms, almost as soon as born, begin to eat or 
force their way through the membranes of the intestine into 
the minute blood-vessels and other organs, thus vastly in- 
creasing the irritation. Entering the circulation they 
are carried by the .blood to the heart, thence to the lungs, 
and then become diffused through the whole system. Accord- 
ing to other observers, the young worms force their way di- 
rectly through the intestine and all other intervening organs, 
until they finally reach a suitable habitation in the voluntary 
muscles. It is, however, difficult to understand how they can 
become so evenly and generally distributed through the whole 
muscular system as they often are, if this be their only mode 
of diffusing themselves. It is, therefore, not improbable that 
they migrate by both these methods, part entering the circu- 
lation and part going directly through the tissues, while in 
either case, if they find themselves in an unfavorable locality, 
they have the power of changing their position while still in 
the free state. According to Dr. Leuckart, they travel by the 
way of the intermuscular connective tissues, and are found 
most abundantly in the groups of muscles nearest the abdomi- 
nal cavity, especially in those that are smallest and have the 
most connective tissue. 


Effects. 


Large numbers often lodge in the heart, lungs, and various 
other organs, producing great irritation and various danger- 


114. BOARD OF AGRICULTURE. 


ous symptoms, but the majority finally reach and remain in 
the voluntary muscles, where they live and thrive for some 
weeks, making for themselves passages, and even entering and 
destroying the fibres themselves. All these operations cause, 
of course, an immense amount of inflammation and irritation, 
if, as often happens, millions of these flesh-worms are at work 
at the same time in all parts of the system ; and itis no won- 
der that many violent symptoms and high fever result, or that 
there should be intense soreness and pain or paralysis of the 
muscles, and dropsical swellings. Death in severe cases may 
occur at any time from the fifth to the fiftieth day. The du- 
ration of the disease, like its severity, is in direct proportion to 
the number of living Trichine swallowed, and varies from two 
weeks to three or four months. Even in many comparatively 
mild cases, the suffering is intense and the recovery slow and 
tedious, while many secondary diseases, like pneumonia,etc., are 
liable to ensue. When all the worms have become lodged in 
the muscles and enclosed in cysts, the direct symptoms cease, 
and, if the strength of the patient has been kept up, recovery 
is probable. Some persons, especially females, are much more 
severely affected than others, by the same number of the para- 
sites. 

Persons in robust health may be able to survive the attack 
of half a million or more of these flesh-worms and recover, 
but there is a limit to all human endurance, and the numbers 
often contained in the muscles of animals or persons who 
have been killed by them, are almost incredible. In a cat fed 
with trichinous flesh by Leuckart, they were so numerous that 
he estimated that one ounce of the flesh contained at least 
525,000 worms. Microscopic preparations, not much larger 
than a pin’s head, often contain from ten to forty worms, and 
one bit of muscle, weighing about one-fifth of a grain, from a 
child that died on the seventy-ninth day, contained fifty- 
eight. Allowing only one hundred worms to a grain of mus- 
cle, a man weighing 150 pounds might contain over forty 
millions of the parasites, and the length of the muscular 
fibres actively inflamed by such a number, if placed ina line, 
would amount to more than 120 miles. 


PARASITES OF ANIMALS. 115 


In some very severe cases the numbers contained in human 
bodies have been estimated, by reliable authorities, as 
high as forty and sixty millions. 

The cysts containing Trichine were first observed in human 
muscles in 1822, but the worms from similar cysts were first 
named and described by Owen, in 1835, but were only regarded 
as anatomical curiosities of no practical importance, until 1860, 
when Zenker proved that they are capable of producing the 
severe and often fatal disease now well known under the name 
of Trichiniasis, but which had been previously (as it often is 
still) confounded with typhoid fever, inflammatory rheuma- 
tism or rheumatic fever, poisoning, and various other 
diseases. 


Symptoms and treatment of the disease. 


The disease caused by this parasite has three more or less 
distinct phases : ; 

First. While the mature worms and young remain in the 
intestine, and while passing through its walls. In this stage 
the symptoms are derangement and inflammation of the in- 
testine, often resulting in severe diarrhoea, nausea and vomit- 
ing, swelling and pain, and sometimes peritonitis, due to the 
perforations of the intestinal walls. These symptoms ensue 
in two or three days after swallowing the trichinous flesh, and 
may lastafortnight or more. Animals experimented upon often 
die in this stage. Purgatives and anthelmintics are used in 
this stage to expel the mature and pregnant females, but after 
three or four weeks have passed this will be useless. Castor- 
oil and calomel have been used with success for this purpose. 

Second. While the young worms are migrating and work- 
ing in the muscles, a variety of symptoms are developed, 
varying in different persons, and depending, also, upon the 
number of worms. ‘This stage commences in ten to fourteen 
days, and generally lasts four or five weeks. The principal 
symptoms are lassitude and swelling of the muscles, with 
soreness, or intolerable pains, resembling rheumatic pains but 
not affecting the joints; profuse sweating sometimes occurs ; 
the pulse is very rapid, but the heat of the body is usually 


AGE BOARD OF AGRICULTURE. 


low, often never exceeding 102° Fahr.; the face frequently 
becomes suddenly and greatly swollen, and sometimes the 
whole body is affected in the same way. In certain cases, a 
peculiar congestion of the eyes has been observed. In general, 
many of the symptoms in this stage resemble those of typhoid 
fever. 

In very severe cases the patient is unable to use the mus- 
cles or move the limbs without the most intense agony, and 
finally is obliged to lie passively, flat upon the back, with the 
arms and legs somewhat bent, in the position that gives the 
least pain; and later the limbs are rigidly stretched out, some- 
what apart, the body stiff, and the muscular system in a state 
of more or less complete paralysis. Children generally lie 
on the side, with the body bent and the legs drawn up. The 
jaws are sometimes closed as in lock-jaw. The breathing is 
difficult, shallow, and rapid. The lungs are often affected, 
and frequently, also, the heart; and many secondary diseases 
are liable to ensue. 

The most that can be done in this stage of the disease by 
the physician relates to the relief of special symptoms and 
secondary diseases, and sustaining the strength of the system 
until nature may in time effect a cure. Most experimental 
animals die in this stage, and human patients, also, frequently 
perish even during the early part of this period. 

’ Third. In case the patient survives the two first stages, the 
inflammation gradually ceases, breathing becomes more 
natural, and recovery generally commences, but in very severe 
cases the muscles and other organs have been so much in- 
jured as not to perform their proper functions, and general de- 
bility often results, ending in a kind of consumption that finally 
proves fatal. In many cases of recovery, lameness lasts for 
several months. In many cases, however, the final recovery 
is complete and may be followed by robust health, although 
tens of thousands of living worms may be still enclosed in 
the capsules in the muscles. 

From this it is obvious that a hog may be fat and appear in 
every respect healthy, and yet his flesh may contain such im- 
mense numbers of the parasites as to be capable of killing a 


‘PARASITES OF ANIMALS. 117 


hundred or more persons, should they eat it raw or but slightly 
cooked. 
Cases of Trichiniasis. 

Since 1860 thousands of cases have been observed and hun- 
dreds of deaths are known to have occurred, especially in 
Germany, where the custom of eating various forms of raw 
or imperfectly cooked pork is much more common than in 
this country. At Hettstadt, in 1863, the flesh of one pig in- 
fected one hundred and thirty-five persons, of whom twenty 
died. Several other similar “‘ epidemics” have also occurred 
in the same country. In the United States, many sad cases 
have also been recorded, as the following instances will show: 

At Marion, lowa, May, 1866, Mr. Bemis and eight mem- 
bers of his family ate rare-done and raw ham, and were im- 
mediately taken sick. Up to June 5d, three had died, and 
others were considered critical. A post-mortem examination 
showed about two hundred thousand worms to a cubic inch of 
muscle in one of those who died. 

At Dubuque, lowa, according to Dr. Asa Horr, two families 
were attacked. In one five persons died ; in the other, five 
or six. Through him we also learn of a case where the 
mother of a family ate of the interior, rare-done part of a 
ham and took the disease, while those who ate the outside 
escaped. 

At Springfield, Mass., February, 1867, Mr. Ransley Hall 
and family ate of raw ham, and all seven were attacked in 
various degrees, according to the amount eaten. A daughter, 
aged seventeen, died, and the father had along and very 
dangerous illness. 

At Albany, N. Y., January, 1869, two boys ate of raw ham 
and were infected; the rest of the family ate of the same 
ham, when cooked, and escaped. 

At Rome, Oneida County, N. Y., December, 1868, Mr. 
John Wilbrecht and family, nine persons in all, ate raw 
smoked and dried sausages. All were dangerously sick, and. 
four adults, the father, son, and two daughters died before 
January 15th. Their sausages and salt pork were examined 
and found to be full of Trichine, as were also the muscles of 
those who died. 


118 BOARD OF AGRICULTURE. 


In New York City, January, 1869, eight cases occurred in 
a boarding-house in Carlisle Street, from eating sausages. 
Two of the victims: died in the New York Hospital, and others 
were dangerously sick. It is a significant fact that the physi- 
cians in two hospitals mistook these cases at first for typhoid 
fever, and only discovered the mistake after one death had 
occurred. 

In Bridgeport, Conn., January 30th, 1870, raw smoked | 
ham was eaten by five persons. Of these Mrs. Koch died of 
acute Trichiniasis, February 15th ; Mrs. Winter died February 
16th ; Mr. Winter died March 1st ; adaughter of Mrs. Koch, 
aged two and a half years, died March 7th. Mr. Strasburg 
was for a long time very dangerously ill, and was left in a very 
feeble condition. Another person who ate some of the same 
ham fried, escaped entirely. Mr. Winter thought himself not 
seriously ill when his wife died. Some portions of his pec- 
toral muscles, which I have had an opportunity to examine, 
were filled with Trichine, not yet encysted. There were 
perhaps 100,000 to the cubic inch. 


Prevention. 


Experiments have fully shown that nothing less than the 
most thorough. cooking, so prolonged as to destroy all redness 
of the juices even in the interior of the meat, is capable of 
destroying these parasites and rendering pork a safe article 
of food. Cases, some of them fatal, have occurred from eat- 
ing ordinary fried sausages, roast pork, and pork that had 
boiled two hours. But the majority of severe and fatal cases 
have happened from eating smoked ham, raw or partly cooked, 
and various kinds of smoked and dried sausages, which are 
often eaten raw, or but slightly cooked. 

Therefore, if people will eat pork at all, they should make 
it a fixed rule never to eat it unless thoroughly cooked, if 
they would avoid one of the most painful and dangerous dis- 
eases known. 

There appears to be no certain way of preventing the 
disease in hogs, for it is probable that in most cases they get 
it by eating rats or mice, which are often full of Trichine, 
but it is quite probable that they may often be infected by. 


PARASITES OF ANIMALS. 119 


eating slaughter-house offal. It is possible, also, to infect 
hogs and other animals by means of the mature female 
Trichine that have been discharged from the intestines of 
men or animals, before all the young worms contained in their 
uteri have been born. Therefore hogs may obtain this, as 
well as the larvee of the tape-worm of man and many other 
parasites, by being kept in places where they have access to 
manure, as is too often the case. Cats, rats, mice, rabbits, 
Guinea-pigs, young dogs, and various other animals may be 
infected, but adult dogs, like old hogs, are not nearly so likely 
to become infected as the young. Although lambs, calves, 
and horses may be infected by forcing them to eat trichinous 
meat, it is probable that they seldom or never become infected 
naturally. 
Trichocephalus dispar Rudolphi. Figure 77. 
This.is a small round-worm, living in the human intestine, 
and remarkable for its long, very slender, filiform neck, which 
Figure 77. 18 about two-thirds of the entire length. The 
male grows to the length of one inch and a 
half, aud the female to two inches. The sur- 
face of the body appears smooth to the naked 
eye, but when magnified, a longitudinal band of 
minute, wart-like papilla is seen on one side. 
The male has the posterior end of the body 
spirally curved, with a single spicule, which is 
emitted from the extremity of the body, and is 
enclosed in a short, tubular sheath, that is cov- 
ered with minute recurved spinules. The female 
*, has the posterior end of the body nearly straight 
and bluntly pointed (Figure 77). The genital 
orifice is situated at the origin of the neck. The eggs are 
elliptical, with a small projection at each end, and are z1, to 
gt Of aninchlong. They are discharged from the human in- 
testine before the contained embryos are fully developed. If 
kept in water for six months or more they hatch, liberat- 
ing a minute embryo 333 of an inch long, which tapers 
from behind toward the head. 


a 


Figure 77.—-T’richocephalus dispar ; a, female, natural size; 6, posterior end, en- 
larged. From Guerin. 


4 


120 BOARD OF AGRICULTURE. 


It is therefore probable that they are taken into the 
human system in impure water. In some regions it is very 
common. Davaine estimates that one-half of the inhabitants 
of Paris entertain this parasite. Its effects are not well made 
out, but it does not seem to cause, ordinarily, any marked in- 
convenience. It lives in the ececum and small intestine. 

Trichocephalus affinis Rud. 

This species lives in the coecum of cattle, sheep, deer, and 
anteiopes. It closely resembles the preceding, but the neck 
part is still longer and more slender. The posterior end of 
the male is curved in a close, conical spiral, and the spicule, 
like its sheath, is much longer, being equal to about a third of 
the length of the body. The genital orifice of the female is 
situated at the summit of a prominent, hour-glass shaped 
papilla, which is obliquely truncated at the summit and 
covered with minute spinules, like those of the spicule-sheath 
in the male. The eggs are similar to those of the preceding 
species and, without doubt, develop in the same way. It is 
not known to cause any serious disease. 

Spiroptera strongylina Rud., from the Hog. Figure 78. 

The genus Sproptera includes numerous species of small, 
whitish or reddish,.slender, round worms, which taper some- 
what toward the anterior end, or toward both Figure 78. 
ends. The head is small, and either naked, or 
with small papilla. The male has the posterior “~ 
end curved in a spiral, with membranous expan- 
sions, and with two unequal intromittent 
spicules. In the female the posterior end of the A 
body is nearly straight and conical, and the p-------7 
ovary is either simple or double, with the genital 
orifice situated at one side of the body. 

The S. strongylina has a smooth, tapering body, with a 
simple head and mouth. The male spicules are very long, 
relatively to the entire length of the body. The male grows 
to the length of half an inch or more. The female to more 
than three-fourths of an inch. It lives in the stomach of the 
hog, but ordinarily does not produce any serious disease. 


Figure 78.----Spiroptera strongylina ; a, male, natural size; 6, spicules and pos- 
terior end of the body, enlarged. From Guerin. 


PARASITES OF ANIMALS. 121 


Spiroptera megastoma Rudolphi, of the Horse. 


This is a small species, which has a more cylindrical body, 
tapering a little toward each end. The head is separated by 
a slight constriction and bears four lobes. The mouth is 
large. The male becomes rather more than a quarter of an 
inch long, and the female nearly half an inch. It lives in 
the stomach and cesophagus of the horse and produces 
tubercles, or hard tumors, of considerable size, most frequent- 
ly situated near the pylorus. These contain many cavities, 
connected together and filled with purulent matter, in which 
there are numerous specimens of the parasite. The tumors 
are sometimes one and a half inches in diameter, and there 
are at times several in the same stomach. 


Spiroptera sanguinolenta Rudolphi, of the Dog. 


This is a larger, reddish species, which produces similar 
tumors in the cesophagus and stomach of the dog. This 
species usually grows to the length of one and a half to three 
inches, but it has been found ten inches long, living in the 
cavities of the ventricles of the heart of dogs at Shanghai, 
China, where it appears to be very common. Its complete 
history is unknown, and therefore little can be said about the 
special means of prevention, or cure. It often produces death. 


Pin-worm of the Horse (Oxyuris curvula Rudolphi). 
Figure 79. 

This is a small, whitish worm, quite commonly found in 
the coecum and colon of the horse and ass. The female is 
about one inch and a half to two inches long, when mature. 
The male is far more rare and but one-third to two-thirds. of 
an inch long. The body is fusiform, tapering to a slender 
tail, thicker in front, with the anterior end more or less 
pointed. The mouth is situated at the end, and usually has 
the form of a small, round pore, but is provided with three or 
four small retractile papille, which can be protruded. The 
buceal cavity contains a peculiar apparatus of folds and tooth- 
like processes; the cesophagus is long and muscular, round 
externally, but with a three-cornered cavity; it-is separated 


from the round, gizzard-like stomach by a constriction, and 
16 


199, BOARD OF AGRICULTURE. 


then a second constriction separates the stomach or gizzard 
from another somewhat enlarged cavity, which tapers grad 
ually into the slender intestine. The anal orifice is near the 
posterior end of the body, and in the male also gives exit to 
the intromittent organ, which is a single, sharp, grooved 
spiculum, with a very small accessory one. The female 


Figure 79. 


orifice is situated near the anterior third of the body. This, 
like the other species of Ozyuris, produces eggs having firm 
shells. These probably hatch in water, and the embryos may 
thus be swallowed in drinking. The intestines of these para- 
sites are generally filled with vegetable matters derived from 
the food of the animals in which they live, and the structure 
of the digestive organ seems to be adapted to vegetable food. 
For this reason it is probable that they ordinarily cause little 
or no inconvenience to the horses that they inhabit. 


The Pin-worm of Man ( Oxyuris vermicularis Bremser ). 


This is a much smaller species than the preceding, but is 
similar inform. Itis very common, often in great numbers, in 
children, and occurs also in adults, especially in aged and 
debilitated persons, and inhabits chiefly the lower part of the 
rectum and the vicinity of the anus. 

The male is about one-eighth of an inch long, with the tail 
curved in a spiral form, terminating in a very short point. 
The female is about four-tenths of an inch long and one- 
fiftieth in diameter, with the posterior part of the body taper- 
ing to a very slender tail. 

The digestive system and structure of the mouth is similar 
to that of the preceding species. But the head sometimes 
shows inflated lateral lobes. 

Reproduction. 


This species is very prolific; each female produces thou- 


Figure 79.—--Oxyuris curvula, female, twice natural size. From Guerin. 


PARASITES OF ANIMALS. 128 


sands of eggs, in which the embryos are considerably de- 
veloped before they are laid. The embryos enclosed within 
the eges are shaped somewhat like tad-poles, the slender tail 
being bent up against the lower side of the body, which faces 
the flattened side of the egg. The body is broad and well 
fills the ege. The full history of the development of the eggs 
is not yet known. It is probable, however, that a portion of 
the eggs imbedded in the mucus membrane of the intestine 
hatch in that situation, remaining thus in the same person. 
But it is also probable that the eggs that are discharged will 
hatch in water, and that persons become infested by swallow- 
ing the embryos with their food and drink. 


Symptoms. 


The most marked symptom of these parasites is an intoler- 
able itching in and about the anal orifice, which is generally 
worst in the evening or during the night, when the worms are 
migrating or changing their localities. Thisis usually accom- 
panied by sensations of heat and inflammation. Not unfre- 
quently, by irritation of the adjacent nerves, they cause 
similar sensations in the genital and urinary organs, which 
sometimes become very distressing. They sometimes even 
migrate into the genital passages of female children, causing 
great irritation and very serious symptoms. By the irritation 
of the sexual organs, in both sexes, various unfortunate sec- 
ondary diseases and bad habits not unfrequently result, 
especially if they occur at the period of early puberty. Other 
symptoms caused by the irritation of the nervous system, are 
restlessness, general nervousness, involuntary twitchings, 
itching of the nose, chorea, convulsions, and sometimes 
epileptiform seizures. 


Remedies. 


The various medicines ordinarily used as anthelmintics, or 
vermifuges, will often bring away large numbers of these 
worms. Of these the etherial extract of male fern is probably 
the best, but santonine and panna have been used with good 
results. Ordinarily they can be treated more easily and 
effectively by means of injections of cold, or nearly cold, 


124 BOARD OF AGRICULTURE. 


water, to which may be added a small amount of salt, oil of 
anise-seed, or assafoetida. Sometimes decoctions of quassia, 
worm-wood, or southern-wood (Artemisia abrotanum) are 
used for this purpose, with good results. To these a portion 
of olive-oil may be added. But any remedy that may be em- 
ployed must be repeated as often as once every three or four 
days for at least three weeks, in order to destroy the young 
ones as fast as they develop. An application of mercurial 
ointment to the parts about the anus is recommended to pre- 
vent the migrations of the parasites and the uncomfortable 
itching sensations that they thus produce. 


The common Round-worm of Man (Ascaris lumbricoides 
Linn.). 

This species is well known as a parasite of the human in- 
testine, especially in children, though often found in persons 
of all ages. The round-worm of cattle is generally regarded 
as the same species. 

These worms are round and smooth, tapering to both ends, 
with a tough, elastic skin. The mouth is situated at the more 
pointed end, and is provided with three prominent papille, or 
fleshy lobes. The male grows to the length of six inches, 
and has the posterior end curved and provided with two 
slender spicules. The female is much larger, sometimes be- 
coming twelve or fourteen inches long and one-fourth of an 
inch in diameter; the female genital orifice is in advance of 
the middle of the body. 


Development. 


The females produce great numbers of minute eggs, which 
are provided with thick, rough shells. The eggs are dis- 
charged and pass from the human intestine before the 
development of the embryos commences. If kept 
in water the embryos go on developing slowly and 
gradually, the whole process requiring from six months 
to nearly a year. The fully developed embryos are 
round and slender, about +}, of an inch long, with 
an obtuse head and an acute tail. They have not been ob- 
served to quit the eggs of their own accord, but may live for 
at least a year within the ege-shell, after they attain their full 


PARASITES OF ANIMALS. 125 


size. It is probable that such eges, containing embryos, 
when swallowed in the water that we drink, will be hatched 
in our stomachs by the action of the gastric juice, and that 
the young worms thus reach their destined abode. It is 
possible, however, that under the proper circumstances the 
eggs will hatch in the water, and that the free swimming em- 
bryos may be swallowed in the same way. This part of their 
history still remains uncertain. 


Symptoms. 


The presence of one or two of these parasites in the human 
intestine does not ordinarily cause any marked effects or 
noticeable symptoms. But when they occur in persons of 
delicate health, and when in great numbers, as sometimes 
happens, they may cause great disturbance of the natural 
functions of the digestive system, and induce various serious 
consequences. Cases have occurred in which from 100 to 
500 of these worms have passed from one child. They live 
chiefly in the small intestine, but sometimes enter the stomach 
and may even be expelled by vomiting. In some instances 
they have been known to perforate the walls of the intestine 
and enter the abdominal cavity, and thus even to get into the 
other organs, including the lungs, pleura, gall-bladder, ete. 
In such cases death often results. 

Their presence in the stomach and intestine causes colic 
and shooting pains, often accompanied by nausea, vomiting, — 
dyspepsia, itching of the nose, and diarrhea. Owing to the 
irritation of the nervous system they may cause restlessness, 
convulsive twitchings, especially during sleep, and various 
mental disturbances. In some cases, serious convulsions, 
epilepsy, and insanity have been caused by them, and have 
been cured at once by expulsion of the worms. 


Remedies. 

The most reliable remedy appears to be santonine, but this 
is a powerful preparation, and must be used with caution. 
For children the dose is one to three grains, in the form of 
powder, which does best if taken in castor-oil or honey, 
though it may be sprinkled over a piece of bread and butter. 


126 BOARD OF AGRICULTURE. 


For an adult the dose is four or five grains, twice a day, on 
every second day, for a week, the quantity to be diminished if 
the medicine causes ill effects, such as spasms, tenesmus, etc. 
It often causes temporary perversion of vision, things appear- 
ing of unnatural colors, etc., but this effect soon passes away. 

The root of male fern (see page 191), given in powder, in 
connection with purgative medicines, is also recommended. 

As means of prevention, the use of impure water should be 
avoided.. And if water from streams and ponds must be 
used for drinking, as in most large cities, it should be 
thoroughly filtered through powdered charcoal. 


The Round-worm of the Horse (Ascaris megalocephala 
Cloquet). 


This species inhabits the intestine of the horse, ass, and 
mule, and is quite common. It closely resembles the preced- 
ing species in form and general appearance, but grows to a 
larger size, the male becoming ten inches long, and the female 
twelve inches or more. The mouth is surrounded by three 
large, rounded, very prominent lobes or papille. In the male 
the tail is provided with wing-like folds along the sides; in 
the female it is conical, terminating in a point, the female 
genital opening being situated in the anterior fourth of the 
body. 

This species likewise produces vast numbers of eggs, which 
develop embryos externally to the body, in water. Dr. Cob- 
bold states that he has reared free, active embryos from these 
egos by keeping them five months in water. The horses, 
most probably, swallow these embryos in the water that they 
drink. 

These parasites, when numerous, will no doubt produce 
effects analogous to those caused in the human body by the 
preceding species, and the remedies will be similar. 


The Round-worm of the Cat (Ascaris mystax Rudolphi). 


Although very common in the cat, this parasite is of inter- 
est chiefly on account of its occasional occurrence in the 
human intestine. 

It may be easily distinguished by the presence of peculiar 


PARASITES OF ANIMALS. I Ayl 


wing-like membranous expansions on each side of the head 
or anterior end of the body. ‘The male grows to the length 
of two and one-half inches; the female sometimes becomes 
four inches long and one-twelfth in diameter. 

This worm probably propagates its kind in a manner similar 
to that of the two preceding species, and no doubt gains ad- 
mittance to the human intestine, as well as to that of the cat, 
by the medium of impure water and unclean vegetable food. 

Its effects and remedies are the same as those of the com- 
mon round-worm. 


The Round-worm of the Hog (Ascaris suilla Dujardin). 


This very closely resembles the Ascaris lumbricoides of man, 
and probably has nearly the same habits. It differs chiefly in 
the structure of the reproductive organs. 'The male spicules 
are not so sharp, and the tubes of the uterus are much longer. 
The eggs are smaller. It appears to be less common than 
the Echinorhynchus gigas in the intestine of hogs, and prob- 
ably produces less injurious effects. 


STRONGYLUS. 


The genus Strongylus includes slender, filiform worms, 
mostly of small size, and often reddish in color. Several of 
them live in the windpipe and bronchial tubes*of various 
animals, including sheep, deer, cattle, pigs, etc., and when 
numerous may occasion the death of the animals that they 
infest, by suffocation. 

The body generally tapers toward the head, and sometimes 
in both directions. The mouth is small, situated at the end 
of the small head, which is either simple or with lateral ex- 
pansions. It is sometimes surrounded by small papille, but is 
often simple, and either round or triangular, but not enclosed 
by a hard or chitinous organ, as in Sclerostoma, etc. The 
cesophagus is enlarged, club-shaped, and muscular. 

The male has the posterior end of the body provided with 
an expanded, often lobed pouch, or bursa, for adhering to the 
female during copulation. The spiculeisslender and filiform, 
enclosed in a sheath. In the female the posterior end is 


128 BOARD OF AGRICULTURE. 


conical or pointed, and the genital orifice is placed in advance 
of the middle of the body, or more rarely toward the pos- 
terior end. 

The Strongylus of Sheep (Strongylus filaria Rud.). 

Figure 80. 

The present species is whitish, very long and slender. Th 
head is obtuse and without appendages, the mouth surrounded 
by three small papilla. The caudal pouch of — pioure 80. 
the male is entire, with ten rays (Figure 80). i 
The male is about two and a half inches long, 
and the female three and a half, though gener- 
ally not more than two or three inches long, the 
interior of the body of the female is mostly oc- 
cupied by two long convoluted uterine tubes, 
containing eggs in which the embryos are in all 
stages of development. These open at an 
orifice situated at about one-third of the length 
of the body from the head. 


Habits. 


This species lives in the lungs, air-passages, 
and bronchial tubes of sheep and other rumi- 
nants. They often occur, singly or several to- 
gether, in cavities in the substance of the lungs, 
producing great inflammation and destruction 
of the tissue, which often results in the death of 
ereat numbers of lambs, and greatly injures the 
health of old sheep, even if it does not actually 
kill them. In this way many thousands of 
lambs are annually lost in certain districts in 
England. In this country we have far less in- 
formation concerning the extent of its ravages, 
but have no reason to suppose that it is less 
common than in Europe, in localities that are favorable for its 
development. Sheep infested by this parasite continually 
cough up the eggs and embryos of the worms, and either dis- 
charge them directly from the nose or mouth, or swallow them 


Figure 80.—Strongylus filaria, male, enlarged. From Thudichum. 


PARASITES OF ANIMALS. 129 


and thus pass them with the feces. In either case they will 
often adhere to grass and other herbage, and may thus be 
swallowed by other sheep or lambs, fed in the same pastures, 
and pass directly into the windpipe, or else do so when. the 
cud is raised for mastication. Therefore lambs should never 
be put into fields or pastures where diseased animals have 
been kept, but such infected lands should be tilled, or at least 
left at rest for several months. As soon as an animal gives 
any indication of the presence of the parasites by the 
peculiar cough, it should be separated from the rest of the 
flock for treatment; or else immediately killed and the para- 
sites should be effectively destroyed, and not thrown on the 
ground as harmless, for all these worms are remarkably 
tenacious of life, and often may even be dried up completely 
for months, and then revive when moistened. 


Remedies. 


When these parasites are once lodged in numbers in the 
substance of the lungs, there is probably no reliable remedy 
whatever. When merely in the windpipe and bronchial tubes, 
expectorant medicines that will produce a copious secretion 
of mucus may be useful. It might be possible to remove 
them by a surgical operation, opening the windpipe from the 
exterior, but this would require surgical skill and would not 
pay, perhaps, except as a last resort for valuable animals. 


The Strongylus of Cattle and Horses (Strongylus micrurus 
| Mehlis). 


This species closely resembles the preceding. The male 
erows to the length of about one inch and a half; and the 
female to three inches or a little more. The body is very 
slender with a simple, blunt head. The bursa of the male 
has five rays. The female genital orifice is near the middle 
of the body. It is said to be viviparous. 

The habits of this species are nearly the same as those of 
the last, except that this inhabits the air-passages of cattle, 
horses, asses, and mules, instead cf sheep. It is much more 
liable, like the former, to infest young animals than adults. 
Calves less than a year old are particularly lable to be in- 

Asi, 


130 BOARD OF AGRICULTURE. 


vaded, and those that are once attacked seldom or never re- 
cover. The same remarks, concerning the means of preven- 
tion, made under the preceding species, will apply equally to 
this. If neglected, these parasites increase with great 
rapidity, and thus the disease that they cause appears like an 
epidemic, in certain localities destroying hundreds or thou- 
sands of animals, while adjacent farms may be entirely free 
from it. | 


The Strongylus of the Hog (Strongylus parodoxus Mehlis). 


This is a slender, whitish or brownish worm, with a small, 
simple head. The mouth has three small papille. The 
cesophagus is long and muscular. The anus is situated some- 
what in advance of the posterior end of the body at the sum- 
mit of a small papilla. The male becomes half an inch or 
more in length, and has the caudal bursa bilobed, each lobe 
with five rays, the lateral ones divided. The female grows to 
the length of about an inch and a half, but is usually about 
an inch long ; the-tail is terminated by a point, turned to one 
side; the genital opening is near the posterior end and a little 
prominent. This species is viviparous. It inhabits the wind- 
pipe, bronchial tubes, and lungs of swine. Its history and 
the effects it produces are nearly the same as those of the 
Strongylus filaria. 


The Strongylus of the Intestine of the Hog (Strongylus 
dentatus Rud.). 


This is a slender filiform species, about half an inch long, 
which lives in the small intestine, coecum, and colon of hogs. 
The head is obtuse and surrounded by six acute papille. The 
cesophagus is short and thick, muscular. In the male the 
tail is truncated and provided with an oblique bursa, formed 
of a single piece, strengthened by three subdivided rays ; 
there are two slender spicules. The tail of the female is 
elongated and slender, ending in a fine point; the genital 
opening is near the posterior end. 

The effects of this species and its history are little known. 


PARASITES OF ANIMALS. 131 


The Strongylus of the Intestine of Sheep ( Strongylus contortus 
Rud.). 


This is a filiform species, tapering to both ends, but more 
slender toward the head, which is provided with two semi- 
elliptical, wing-like appendages ; the mouth with three small 
papille. The male is about three-fourths of an inch long, 
with a bilobed bursa, each lobe with about eight rays; the 
sheath of the male spicule is very long. The female sometimes 
becomes four inches long. 

It is not uncommon in the small intestine of sheep, but its 
history is very imperfectly known. When abundant it may, 
without doubt, cause serious trouble. 


Strongylus filicollis Rudolphi. 


This species also inhabits the small intestine of sheep. The 
body is very slender and whitish or reddish. The head has 
two, very small, lateral, wing-like appendages. The male 
bursa is bilobed, each lobe with six rays. It is from a third 
to four-fifths of an inch long. — 


Strongylus radiatus Rudolphi. 


This worm lives in the small intestine and colon of cattle 
and several other ruminants. The head is simple; the mouth 
naked. The male is about half an inch long, with a bilobed 
caudal bursa, the lobes many rayed. The female is about 
three-quarters of an inch long; the genital opening is near 
the tail. 

Its complete history is unknown. 


The Kidney-worm (Eustrongylus gigas Diesing). Figure 81. 


This is the largest of all the Nematode worms, the females 
sometimes becoming three feet long and half an inch in 
diameter, though usually much less. The body is smooth, 
cylindrical, tapering somewhat to each end, and more or less 
deeply tinged with red. The head is simple, obtuse. The 
mouth is terminal and surrounded by six rounded, chitinous 
papille. The male becomes ten to twelve inches long and 
one-fourth of an inch in diameter; the caudal bursa is cup- 
shaped, circular and entire, without rays ; the male spicule or 


132 BOARD OF AGRICULTURE. 


penis is very slender. The female has a nearly straight, 
obtuse tail ; the anus is triangular, near the end; the genital 
orifice is anterior, near the mouth ; the ovaries and oviducts 
are simple, but long and convoluted. The intestine is large 
and blackish, with thin walls, and quite simple, running 
directly from one end of the body to the other, and is attached 
to the sides of the body, along its whole length, by fibres. 


Habits. 


This formidable parasite lives in the kidneys of man and 
various animals. It has been found in the dog, horse, cattle, 
hog, wolf, weasles, mink, otter, seal, elutton, raccoon, and coat. 
In this country it has been found quite frequently in the kid- 


Figure 81. 


neys of the mink. It has been found very rarely in the blad- 
der, in the abdominal cavity, and, it is said, in the heart. In 
man it is very rare. When lodged in the kidney it gradually, 
but completely, destroys the substance of the organ, which 
becomes filled with purulent and bloody matter, upon which 
the worm feeds, while the walls often become hardened with 
calcareous deposits. The effects and symptoms are the same 
as in other acute diseases or abscesses in one of the kidneys. 
The only positive evidence of the presence of the worm would 
be the discovery of the eggs in the urine. It is probable that 
no remedy can be applied when the parasite is once lodged in 
the kidney. 

The history of this worm is not fully known. According 
to Leuckart, a slender worm found coiled up in cysts in 
the muscles and peritoneum of fishes is the young or larva of 
some species of Hustrongylus. The larval form referred to 


Figure 81.—Zustrongylus gigas, male, less than natural size; a, spiculum and 
bursa; 0, anus of female, enlarged. From Guerin. 


PARASITES OF ANIMALS. 133 


is the Filaria cystica Rudolphi, criginally found in a Brazilian 
fish (Symbranchus laticaudus). It is, therefore, probable that 
the eggs or young embryos of E. gigas are swallowed by 
fishes, and in their bodies develop into the larval form and be- 
come encysted,.and if then swallowed by some mammal, 
migrate into its kidneys to become sexually mature. The 
frequency of these parasites in those animals that feed chiefly 
on fish, such as the otter, mink, and seal, renders this view 
very probable. 


The Gape-worm of Chickens, ete., (Syngamus trachealis 
Siebold). Figure 82. 

This parasite lives in the windpipe and bronchial tubes of 
chickens, turkeys, pheasants, partridges, crows, wood-peckers, 
and many other birds. In young chickens and turkeys it 

Figure 82. often proves very destructive, by filling up 
the air passages, and thus quickly killing 
whole flocks. In some parts of this 
country at least three-quarters of all the 
young chickens and turkeys are some- 
times destroyed by this parasite. The 
worms are reddish in color and have a 
smooth skin, but spiral depressions run 
around the body, giving it a twisted 
appearance. ‘The reproductive organs 
show through the skin, as slender, 
whitish, convoluted tubes. The males 
and females are almost invariably found united firmly to- 
gether, as shown in the figures, the integument of the male 
soon becoming organically united to that of the female, so 
that the copulation is permanent or for life. The females are 
very much larger than the males, becoming about three- 
quarters of an inch in length, and one-sixteenth of an inch 
in diameter. The anterior end, in both sexes, suddenly ex- 
pands into a trumpet-shaped, concave disk, in the middle of 
which the mouth is situated, surrounded by six small chitinous 
lobes ; the posterior portion of the body of the female is more 


_ Figure 82.—Syngamus trachealts Siebold ; a, male and female united, natural 
size; b, anterior part of female, enlarged; c, male, enlarged. From Cobbold. 


134 BOARD OF AGRICULTURE. 


or less bent and folded, and suddenly narrows at the end, 
terminating in a small point. The genital orifice is near the 
anterior fourth of the body, where the caudal bursa of the 
male is attached and concealsit. The male is only one-eighth 
or one-seventh of an inch long and very slender ; the caudal 


_ bursa is simple, sucker-like, with an entire margin, strength- 


ened by ahout ten rays ; the penis consists of two very small, 
cylindrical spicules, about 34; of an inch long. Theeggsare 
oval, about 335 of an inch long. The embryos develop while 
the eggs are still in the oviducts and uterine tubes, and the 
ego's or young probably escape by a rupture of the integument 
of the body of the female. 

The history of the young worms, after they are expelled 
from the windpipes of the birds, is not yet known, however. 
Possibly they may enter the bodies of insects to pass their 
larval state, but it is more probable that they bury themselves 
in the surface of the soil or other moist places, and are thus 
picked up directly by the birds and gain admittance to the 
windpipe by their own active motions. 


Symptoms. 

The disease commonly known as “the gapes” is caused 
solely by the presence of numbers of these worms in the wind- 
pipe, which thus becomes so filled up as to render respiration 
difficult, and if in considerable numbers, by their growth the 
obstruction becomes complete, and death results from suffoca- 
tion. Young chickens, thus attacked, seldom recover without 
special treatment for the removal of the worms. Chickens 
only three or four days old often show.symptoms of the dis- 
ease by opening wide their mouth and gasping for breath, and 
attempting to swallow. They also frequently sneeze. As the 
disease grows worse these symptoms become more marked; 
they continually gasp and struggle for breath, grow weak and 
dispirited, and finally droop and die. In fatal cases, one or 
two dozen of these worms are often found in the windpipe, 
completely filling it up. 


Remedies. 
The worms may be removed by a feather from which the 
web has been stripped, except a small portion near the tip. 


PARASITES OF ANIMALS. 135 


This may be moistened with oil, salt-water, or a weak solution 
of carbolic acid, and introduced into the windpipe, when if it 
be twisted round once or twice and removed, it will usually 
bring away several of the-worms. The operation should be 
repeated at intervals until all the worms are destroyed. All 
worms removed in this or any other way should be carefully 
destroyed, preferably by fire, for the embryos are extremely 
tenacious of life, and if left upon the ground are likely to 
spread the disease.. For the same reason, those birds that are 
infected should be separated from the healthy ones, and poultry 
should never be allowed to run in the same yards or grounds, 
or be kept in the same houses where infected ones have previ- 
ously been kept, unless the premises have first been thor- 
oughly sprinkled with a strong solution of carbolic acid or 
petroleum-water, to destroy those old worms or the eggs and 
embryos that may have been discharged from the sick ones. 
The vessels from which they feed sliould be frequently and 
thoroughly cleansed, and they should be supplied with pure 
water, frequently renewed. 

In extreme cases, the worms may be safely removed by a 
surgical operation ; but this requires some skill. This is done 
by first carefully securing the bird, or still better by adminis- 
tering a few drops of chloroform, placed upon cotton and 
held to the nostrils. The skin of the neck is then to be di- 
vided with a very sharp knife, and the windpipe opened by a 
longitudinal slit about a quarter of an inch long. The worms 
may then be removed by a pair of small forceps or other suit- 
able instrument. The incision in the skin may be closed by 
one or two stitches, and the wound will generally heal in a 
few days. By this operation an almost instantaneous cure 
may be effected, even when the disease has progressed nearly 
to the point of suffocation ; but in unskilful hands it is not 
likely to be so successful as the remedies already described. 
The Sclerostoma of the Horse (Sclerostoma equinum Dujardin, 

or S. armatum Davaine). Figure 83. 
This is a small, slender, cylindrical worm, reddish or brown- 


ish in color, which lives in the intestines, and in peculiar 
enlargements of the arteries of horses, asses, and mules. The 


136 BOARD OF AGRICULTURE. 


head is round, nearly globular, supported by a chitinous bulb 
or capsule, truncated at the end, where the large, round 
mouth is situated. The mouth is surrounded by one to sey- 
eral circles of fine denticles, or converging hooks. The cesc- 
phagus is muscular and thick, club-shaped, separated from 
the intestine by a strong constriction. 

The male is an inch or an inch and a quarter long, with a 
large, membranous, caudal bursa, divided into two lateral 
lobes, which are strengthened by numerous rays; there are 
two long and slender spicules. The female grows to the length 
of one and a half to two inches, with a long, tapering, caudal 
portion, the anus not terminal; the ovaries long and con- 
voluted around the intestines, and showing through the integu- 
ments; the uterine tubes are double and contain great num- 
bers of eggs, in which embryos are developed. 


Habits. 


This parasite is very common in the horse, generally living 
attached by the hooks of its head to the lining membrane of 
the intestine, particularly in the coecum and colon, but some- 
times in the small intestine and duodenum, and even in the 
pancreas. At the points where it adheresit Figure 83. 
causes small, dark-colored, raised spots. They 
sometimes occur in vast numbers in the large 
intestine, completely covering the surface ; 
the number sometimes amounting, it is said, 
‘to a million or more. Ordinarily, however, 
these parasites, when lodged in the intestines, 
do not appear to produce any marked dis- 
ease or notable symptoms, although when in 
ereat numbers, there can be no doubt but 
that they must cause some inflammation and 
pain. More serious results, sometimes prov- 
ing fatal, happen when the worms enter the 
blood-vessels. They produce large aneurisms or dilations of 
the arteries, chiefly in the anterior mesenteric artery, but 


Figure 83.—Sclerostoma equinum, female, natural size; and anterior portion en- 
larged; a,mouth; 0, circle of hooks; c, esophagus; d, intestine; e, reproductive 
organs. From Cuvier. : 


PARASITES OF ANIMALS. 137 


also in the arteries of the colon, coecum, small intestine, and 
liver, as well as in the posterior mesenteric and renal arteries, 
and others adjacent to the intestine. These tumors are gen- 
erally fusiform, and as large as a man’s finger; but they are 
sometimes globular, and may become as large as a man’s 
head. The middle membrane of the artery in these dilations 
becomes enormously thickened, sometimes being twelve times 
as thick as in the healthy artery. In old tumors various hard 
or calcareous deposits often take place in the thickened walls 
or in the inner membrane; and in such cases, the walls being 
weakened, are lable to be ruptured by some unusual exertion 
of the animal, when death results almost instantly. In *the 
interior of the aneurism there is generally a deposit of fibrin, 
firmly adherent to the inner surface. In this and in the dif 
ferent layers of the walls the worms are found, — sometimes 
only a few, but frequently large numbers. This disease is 
very prevalent among old horses. In France, as many as 
ninety-six out of one hundred have been found affected with 
the disease. 

I am not aware that any remedies have ever proved useful. 
Generally it would be impossible to detect the disease during 
life, unless the tumors became very large. 


Sclerostoma pinguicola Verrill. 

On two occasions I have received specimens of a rather 
large parasitic worm, which lives in the fat of hogs. In the 
first case, five specimens were obtained, at New Haven, by 
Dr. M. C. White, from the fatty portion of a spare-rib: in the 
second instance, at Middletown, Conn., Dr. N. Cressy found 
large numbers of the worms in the fat about the kidneys of a 
young Suffolk pig, brought from New Jersey. Un- 
fortunately, none of these specimens are in so good a state 
of preservation as to enable me to determine with certainty 
all the points of their structure. Those which I owe to the 
kindness of Dr. White, had been mounted in glycerine as 
microscopic objects and pressed out flat, before they came 
into my possession, and the tissues were thus injured and 
the organs deranged. Those from Dr. Cressy, were both 
pressed flat and dried. Yet by careful masceration, and 


with much labor, I believe that most of the important char- 
18 


138 BOARD OF AGRICULTURE. 


acters have been made out. The body is rather robust, es- 
pecially in the female, and tapers to both ends; the color is 
yellowish white, and the integument is seen to be finely 
striated transversely, when considerably magnified. The 
head is smaller than the body, truncated at Figure 83 a. 
the end; the mouth is terminal, roundish, or | 
somewhat angular, surrounded by the thick- 
ened rim of the chitinous capsule, or pharynx. 
This chitinous ring rises at intervals into four 
to six denticles, or very small teeth, which 
correspond to thickened longitudinal, chitin- 
ous bands, that strengthen the pharynx, and 
give a slightly angular form to the mouth. 
The pharynx itself is small, short, and rather 
squarish, when seen in profile, and has three 
or four small, conical teeth at the bottom. 
The cesophagus is thick, club-shaped, and very muscular. 

The male is 1.12 of an inch long, and about .05 of 
an inch in diameter; the tail ends in a small blunt lobe, 
united with two small, entire, membranous expansions, 
one on each side, forming a small bursa, which is. 
strengthened by several short rays, the exact number of 
which could not be determined in my specimens; there 
are two long, slender spicules. The females are 1.25 
to two inches in length, and, as flattened between giass, 
they are .10 to .15 of an inch in breadth. The posterior 
end suddenly and obliquely narrows to a small conical 
point, which is turned to one side. The anal opening is close 
to the end, and the genital orifice appears to be adjacent to 
it. The oviducts are long, voluminous, much convoluted, 
and unite in a large and capacious uterus, which fills most 
of the cavity of the body near the posterior end. The uterus 
and oviduets are both filled, in the larger specimens, with im- 
mense numbers of small oval eggs. 

It is probable that this parasite is by no means uncommon. 


Pentastoma tenioides Rudolphi. Figure 84. 


This parasite is not a true worm, but is now generally re- 


Figure 83 a.—Sclerostoma pinguicola ; a, male, natural size ; 6, posterior end, en- 
larged ; c, female, natural size; d, head, enlarged. Original. — 


PARASITES OF ANIMALS. 139 


garded as belonging to the Acarians, with the true mites. In 
the adult state it inhabits the nostrils and frontal sinuses of 
dogs and wolves, and more rarely, of horses and sheep. The 
larve, formerly described under the name of Pentastoma den- 
ticulatum, lives in, cysts on the outside, or in the outer por- 
tion, of the liver of sheep, deer, antelopes, peccary, porcu- 
pine, Guinea-pig, rabbit, hare, rat, and cat; and some- 
times invades the human body in the same way. It has also 
been found free in the visceral cavity of the body. 

In the mature state (Figure 84) the body is long, lance- 
shaped, tapering behind, flattened below, and divided into 
about ninety segments by transverse lines. The segments 
next to the head bear two pairs of small, but strong and 

Figure 84. sharp, retractile claws, which represent the true 

rote legs of ordinary mites. The mouth is broad- 
= oval, and provided with a hard chitinous lip. 
= ZA The segments behind the head are perforated 
—= = by small openings, regarded by many as 
= 3g spiracles, or breathing pores. The adult is 


smooth, but the larve are covered with many 


= rows of small, sharp spies. The male is 
= only .07 to .08 of an inch in length, but 
= the female becomes three or four inches long, 

= and half an inch wide. The female genital 

opening is in the tail, that of the male, in the 

= middle of the front part of the abdomen. They 


are oviparous, and the young undergo a com- 
plete and remarkable metamorphosis. 

The adults live in the nasal cavities of dogs, and 
produce an irritation of the delicate membranes, which 
causes a flow of mucus, often accompanied by sneez- 
ing. The eggs discharged with the mucus may ad- 
here to vegetables or fruit, or get into drinking- 
water, and in these ways gain admittance to the stomach of 
man, or other animals. In the stomach they hatch into mi- 
nute embryos, furnished with a boring apparatus and two pairs 
of double claws. They bore their way through the intestines 
and lodge in the liver or other parts, and soon become dor- 


140 BOARD OF AGRICULTURE. 


mant and enclosed in cysts, in which they pass a sort of 
pupa state. During this period of their life, the skin is cast 
several times, and the appearance changes at each moult, un- 
til they attain the next period of their life, when they 
again become active; this is the state described as Petastoma 
denticlatum. These larve are long-oval, broadest anterior- 
ly, and covered with numerous rows of transverse tooth-like 
spinules. They have two pairs of sharp, curved claws, which 
are situated near the mouth and placed obliquely, diverging 
from the median line of the body, and directed downward. 
Hach claw has a sort of hood or capsule, into which it can be 
retracted. If dogs feed on the liver or other viscera of animals 
containing these larve, they come in contact with, and man- 
age to enter the nose, working their way up by means of the 
motions of the body, aided by their spines and claws. In 
this situation they gradually become mature. 

In the human body the larval form is quite frequent, es- 
pecially in some parts of Europe; but there is little known 
concerning the effects that it produces. When in small num- 
bers, it probably causes very little disturbance, but if in large 
numbers, in the liver and lungs, it would no doubt produce 
serious disease, as does another species (P. constrictum), 
which is very common in Egypt, living inthe same way en- 
cysted in the liver and lungs. The latter, when in consider- 
able numbers, frequently proves fatal. 

As a means of prevention, dogs that show symptoms of 
the parasites in the nose, should be treated to a solution of 
carbolic acid, thrown up the nostrils by a small syringe. 
Feeding dogs with the offal of slaughter houses, or with un- 
cooked livers, etc., should be avoided, both on account of this 
and the other dangerous parasites that they getin this way, 
(see Tenia echinococcus, p. 202, T. marginata, p. 192, T. 
cenurus, p. 196, and Trichina spiralis, p. 222). Too much 
familiarity, especially of children, with dogs is always liable 
to result in the transfer of these and other parasites to the 
human body. 


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ERRATA. 


In making up the author’s copies, and repaging, several errors have been iutro- 
duced, which the reader should correct :— 
Page 3 third line of foot notes, for Corydalus cornutas, read Corydalis cornutus. 

“6, line 19, for orceps, read forceps. 

“ g “ 31, for pair, read pairs. 

“ 12, “ 13, for labium, read labrum. 

Solos figure 18 is inverted. 

“ 44, “ 14, for page 89, read page 16. 

“ 48, ‘¢ 10, for page 109, read page 38. 


“ 49, “ 31, for page 109, read page 38. 
“ 60, “ 10, for nemarum, read venarum. 
“ 61, ‘ 23, for page 101, read page 30. 
“ g5, “ 5, for page 191, read page 80. 


“100, “* 34. It should be stated that Dr. Cobbold, in 1860, fed dogs with a 
small cysticercus, from the liver of rabbits, but distinct from 
“ C, pisiformis,” and obtained specimens of Zwenia cucwmerina, 
which he thought were developed from them. 

“110, ‘ 30, for “such hogs are,” read such a hog is. 

“196, “ 6, for page 191, read page 80. 

(140, lines 32 and 33, for page 202, read 91; for 192, read 81; for 196, read 
85; for 222, read 111. 


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