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Pathology and Morbid Anatomy. 















Entered according to Act of Coni;rvn in the jttx 1895, by 


in the Office of the Libntriitn o( CougreiM, at WaHhington. All righta reaerred. 



The last edition of this text-book was so thoroughly revised by 
Mr. Stanley Boyd that my task in editing the present issue has been 
comparatively light. The rapid accumulation of facts, and the con- 
sequent changes in opinion which have distinguished many depart- 
ments of Pathology, have, however, rendered it necessary that 
several new sections should be added and several old ones rewritten 
or withdrawn. In making such changes as seemed advisable— and 
they occur on every page — I have adopted Dr. Green's concise and 
lucid sentences as my model, so that no disadvantages should accrue 
from the admixture of different styles of composition. 

In view of the existence of many larger and more elaborate 
treatises on pathology it has seemed unnecessary to burden these 
pages with precise references to original papers. I have, however, 
on several occasions referred the reader to articles likely to be 
within his immediate reach. 

Sixty new illustrations and a colored frontispiece have been 
added. To these the increase in size is mainly due. Nearly all of 
"them are from drawings or engravings by Mr. Ceilings, who has 
taken the utmost pains to ensure clearness and accuracy. Some of 
these replace less satisfactory illustrations in the last edition. In 
«very case where specimens have been lent I have acknowledged 
their source — in the case of those which have appeared in previous 
editions by adding the name of the donor, and in that of specimens 
which appear for the first time in this edition by a slightly longer 
and therefore distinguishing statement. 

I gladly avail myself of this opportunity of acknowledging the 
help I have received. To my friends and colleagues. Dr. Mott, Dr. 
Arkle, and Mr. Stanley Boyd, I am indebted both for suggestions 



and specimens. Dr. Mott has, in addition, contributed the chapter 
on Diseases of the Nervous System. I much regret that exigencies 
of space have prevented him from dealing more fully with the sub- 
ject. In like manner, Mr. Boyd has written the section on Tuber- 
cular Diseases of Bones and Joints. For various items of help — 
specimens, drawings, blocks, or criticism — I am also indebted to 
Dr. Macfayden, Dr. Manson, Dr. Kolleston, Dr. RufFer, Dr. Sher- 
rington, Dr. Woodhead, and the J. B. Lippincott Co. The Imlix 
has been prepared by my friend and demonstrator, Mr. Harold, 
who has also assisted me in the revision of the proof-sheets. 

I can only hope that neither lack of knowledge nor defect of 
judgment on my part will in any way mar the reputation of this 
text-book, or stultify the confidence which Dr. Green, my predeces- 
sor in the lectureship on Pathology at Charing Cross Hospital, ha« 
ventured to repose in me. 

March, 189B. 




The Normal Oell— Characters— Physiology — Development. Disease- 
Varieties — Etiology — Effects — Terminations 17-34 


Necrosis — Gangrene — CoagJilation-necrosis — Senile Gangrene —Fat-necrosis. 
Post-mortem Ohanges 3&-44 


Atrophy— of Bone. Pulmonai-y Emphysema 44-55 

Fatty Infiltration — of Muscle— of Liver. Patty Degeneration — of 
Rlood-veesela — of Muscle— of Heart — of Kidneys — Cerebral Softening . 56-79 

Cloudy Swellingr— of Special Parts 79-81 

Mucoid Deereneration. Colloid Degeneration— Zenker's Degenera- 
tion of Muscle. Hyaline Degeneration 81-85 

Ijardaoeous Degeneration — of Liver— of Kidneys -of Spleen — of 
Lymphatic Glands — of Alimentary Canal — Corpora Amylacea 86-99 


Oaloareoos Defeneration- of Arteries 99-103 


10 cosTEyrs. 



Pigmentary Degeneration— of Lungs 104-112 


Hyi)ertrophy— of Heart 112-118 

Regeneration — of Vesselu — of Connective Tissue— of Cartilage — of Rone — 
of Muscle— of Nerves— of Epithelium. Healing of Wounds — Trans- 
plantation of Tissues 1 16-131 


Tumors — Development— Growth — Ketn^reosive Changes — Clinical Conme— 
Causes of Malignancy — Etiology — Clawiticatiun 131-148 


Tumors of Higher Tissues — Mromuta — Neuromata — Angiomata— 
Lymphangiomata 149-163 

Ttimors of Oonneotlve Tissues— Fibromata — Myxomata — Liponiata— 
Chondmmuta — Osteomata — Lymphomata — Hotlgkin's Disease 163-168 

Tumors of Bmbryonio Tissue— Sarcomata— Cieneral Characters. 
Bound-oelled Sarcomata — CiUomatii— Lymph o-«arconiata — Alveolar 
.Sm-nniata. Spindle-celled Sarcomata — Melanotic Sarcomata — 
Osteoid Sarcomata — Myeloid Sarcomata — C'ylindromata — Blood-cysts . . 169-182 

Eipitbelial Tumors — Papillomata — Adenomata — Carcinomata, General 
CharacterH — .Acinous Cancer — Epitheliomata — Colloid Cancer 182-207 

Teratomata— Oysts a07-21» 


AnsBmia — Chlorosis — Pemiciou!> Ana-mia. IjeuobSBmia — Lencocy- 
tosis 21S-2S4 




liOoal AntBtnla — Hyperssmia — Arterial — Mechanical — Post-mortem 
Evidences — Mechanical Hypersemia of Liver — of Langs. Dropsy — 
Thrombosis— Characters of Clots and Thrombi — Later Changes in 
Thrombi. Bmbolism— Infarction— Results of Embolism — CapilUry Em- 
boli — ^Thrombosis and Embolism of Brain— Pulmonary Apoplexy . . . 225-270 


Temperature in Health — Symptoms of Fever — Post-mortem Rise of Tempera- 
ture — Pathology and Varieties of Fever 270-27S 



Histolocry — Changes in Blood-vessels, Circulation, and Tissues — Explanation 
of Changes. Olinioal Signs— Varieties — Serous — Fibrinous— Produc- 
tive — Interstitial — Parenchymatous — Suppurative — Ulcerative — Hemor- 
rhagic, etc Terminations — Btiologry— of Suppuration. Modes of 
Spread— Modes of Arrest— Phagocytosis 279-31ft 


Fermentation and Infective Disease — Theories of Fermentation — 

The Sohizomyoetes — Morphology and Life-history- Conditions of Life 
and Growth — Distribution and Habitat — Products — Fate in Living Tissues 
— Methods of Investigation — Classification — Etiology of Infective Diseases — 
Immunity. Pathogenic Baoteria-Sphaerobacteria— Fermentation 
of Urine — Suppuration — Erysipelas — (lonorrhoea — Pneumonia — Sarcinse. 
Microbacteria. Desmobaxjteria— Splenic Fever— Typhoid Fever- 
Bacillus Coli Communis — Diphtheria — Influenza — Plague— Septicsemia of 
Mice — Tetanus — Malignant (Edema. Spirobaoteria — Relapsing Fever — 

Tlio Blastomycetes— Oidium Albicans. 

The Hypbomycetes — Diseases Due to — Actinomyces and Madura 
Foot S16-403 


Tuberculosis — Morbid Anatomy and Histology — Etiology — Bacillus Tuber- 
culosis — Entry into the Body — Development in the Tissues — Tubercular 
Meningitis — Tuberculous Masses in Brain— Tuberculosis of Lymphatic 

12 coymxTs. 

OIjiikIb— of Mucoiis Meniliranps — of I^arrnx and Liiiiks— of Bones and 
Joints. Lupus Vulgaris— Scrofula— Leprosy— SyphiliB—Syplii- 
liiic Disi-axe of Liver- Glanders and Farcy- Bhinoscleroma— 
Actinomyoosis 4(i3-l(>l 


Septlceemia — Experimental Kescarclu-x — ObavrrationR on Man. Py- 
ffimia 461 -4«>8 


Appvamnces iieen on Kxaniination of Blo<xl— Etiology 4G8-47:{ 


Inflammation of Connective Tissue— of Cornea— of Cartilaere— 
of Bone-t'erioHtitiM— OBtitis— Necro6i.s. Mollities Ossium — Rick- 
ets 473-1S2 

Inflammation of Arteries — Acute Arterhifi — chronic Endarteritin — 
Efleett). Inflammation of Veins— Varicose Veins. Inflammation 
of Endocardium— Acute — ('hronic. Inflammation of Myocar- 
dium— Kil)roid Induration of Heart 4«2-49.5 

Inflammation of Lymphatic Structures- Acute— CIin)nic. Ty- 
phoid Fever 495-301 

Inflammation of Mucous Membranes— Catarrhal — Croupous ami 
l>iplitlieritic. Dysentery — Inflammation of Serous Mem- 
branes Wi-TAO 

Inflammation of Liver— Perihi'i);ititis—.\bs<'a« — Cirrhosis — Acute Yel- 
low Atrophy 510-516 

Inflammation of Kidney— Suppurative — Chronic Constructive — Paren- 
chymatous — Interstitial 516-528 




Infianunatioii of the Luncrs — Acute Pneumonia — Broncho-pneumonia — 
Hypostatic Pneumonia — Interstitial Pneumonia. Pulmonary Phthisis 
— Hi8tolog>— Pathology— Etiology 529-559 



General ConsidenitioDB. Inflammation of the Meningres— Pachymen- 
ingitis— Leptomeningitis. Inflammation of the Central Nervous 
System — Encephalitis — Cerebral Abscess — Myelitis — Poliomyelitis. 
Cerebral Hemorrhage— Secondary De^renerations — Primary 
Degenerations— of Efferent Tracts— Syringomyelia 559-587 


Baumoarten: Jahraibirieht. 

Lehriuch der pathologixhen Mykoloffie. 

Billroth, Theodor : Die ailgemeine chirwgitche Patkologie und TlurapU, 10th Ger- 
man edition. 

BiRCH-HiRSCHFKLD : Lehrbueh d. paihol. Analomie. 

BoYCB, RtlBBRT: Text-book of Moiiid Hidotoffy. 

Buhl, Lnowio, Limgenenitundung, TuberkuloK, und SchmndmehL 

Coats : Manual of Pathology. 

CoHNHElM : VorUgungen Sber allgaminen PatMogie, 1882. 

CoRXIL ET Ranvier : Manuel dC HiriologU pa,tiu)logique. 

DucLACZ : FermentJi et Maladies. 

Fluook: Mienhorganima. 

Forster, AuQi'ST : Handbueh der jxUhologitehen Anatamie. 

Hallopeau : Pathologie gtntrale. 

HAinLTON, D. J. : Tetl-book of Pathology. 

HoRSLEY : " Septic Bacteria and their PhTsiologicsI Relations," (in Rep. <if Med. 
Officer 0/ Local Govt. Board, 1881-82). 

HuTER, C. : Orundrim der Chirurgie. 

Journal q/' Pathology. 

Journal (f Phygiology. 

Klers: Handbueh der paihologisehen Anaiomie. 

Klein : The Anatomy of the Lymphatic System. 

Koch, Robert: Untersuehungen iiber die Aetiologie der Wundiiifeetiondkrankheiten, 
Leipzig, 1878 ; Traumatte Infective Diaeates, translation by W. W. Cheyne, 
New 8yd. 8oc. 

Kl'HNE, W. : Lehrbueh der physiologisehen Chemte. 

Lister, J. : " On the Early Stages of Inflammation," Philoiophieal Trans., 1859. 

LucKE : " Die Geschwiilste," Handbueh der allgm. u. spec. Oiirurgie, Von Pitha und 

MicrnparasHes in Disease, New 8yd. See — selected German Essays, edited by W. 
Watson Cheyne. 

Metchnikoff, Eli as: Lectures on the Comparative Pathology of Infiammation, trans- 
lated by F. A. Starling and E. H. Starling, M. D. 

Paget, Sir J. : Lectm-e* on Surgical Pathology, edited by Prof. Turner. 

Kecklinohausen: "Handb. d. allg. Path. d. Kreislaufs u. d. Erniihrung," in the 
Deutsche Chirurgie. 

RINDFLEISCH, E. : Lehrbueh der paihologixchen Oeuxbdehre. 

Btxeck : " Zur Kenntnisader Stase des Bhitesin den Gefassen entzundeter Theile," 
Bollet's Unlersueh. aus dem Institute fur Phys. u. Histol. in Oraz. 



Sandersox, J. BuRi><)N : Article on " Inflammation" in Holmetf SyOem (jf Sujyrry, 

vol. i. 
S<.'||AFER : Qnain's Anntmnt/. 

Scini'PKi, Oscar : " rntersiichungen liber Lymphdrusen-Tuberkulose." 
StersbKRii : Jloflerioliyy. 
Stkk'KKR, 8.: Various Faiiers by, in his Sludien aiig dem Ituliliile Jiir tiptrimentfUt 

I'uthoiogie in Witii, 1809. 
Manuai nf Human ami Oomparalke Uintology, vol. L, edited by Prof. Strieker, 

translated by Mr. Power. 
RfTTON, J. Ul,ASD: -III Intmdutiion to Ocneral Pathology. 
SrTTON, H. (iAWES : Leeluret on Pathology. 
Traimtclian* of the Pathological Society of iMiitton. 
UllLE USD Wagner: llandbueh der allgemeinen Pathologie. 
ViRCHOw, Rudolf : Pie Cellular Pathologic. 

Die hantha/ten GexhmiUie. 

Oetammelte Abhandlungen. 

Handbtieh der npftiellen Pathologie und Therapie, Band i. 

Waoner, E. : .Manmd of Oeneral Pathology. Translated by Drs. John Van Dtiyn 

and E. ('. Segiiin, 6th ed. 
Weber, O. : " Die (iewelwerkrankungen," HancUmeh der cdlgm. u. tpee, Chirurgie, Voo 

Pitha und Billroth. 
Weichselbai'M, Astos : Handbueh der pathotogixhen HiMologie, 1892. 
WlLKS AND MoXON : Leclwet on Pathologital Anatomy, 3d ed. 
WoODHEAD, O. Sims: Pradieal Pathology, 3d ed. 
ZiEOLER : Oeneral Palhologieai Analomy, translated by Donald MacAlistcr. 


Fio. 1.— Staphvixkxkxts PviKiKSEs AvREVs. riilliiii ill iiiiiiinil nmi <f ii. It 
will be noted that the orange color in limited to the mirface, the dee|Mr.fQr- 
tionx of the growth uecurring along the line of pnncture being whita- (ne 
p. Sli"). 'rV 

Vui. 2. — Bacilli's Anthracis. Culture in nutrient agar-agar. Th« gtvf^ 
ntveni the Murface, and extends alnng the line of puncture in tiw-.i 
of a thick white Hireak, with liner streaks spreading at right angJeB ' 
it, eKi>ccially in the upper part (see p. 377). 

Fi(i. 3. — TiiK IlAciLLf.<< OF Malihsaxt GCdema. Culture in nutrient 

a^r. The growth ixvurs in that part of the line of punctare whidi i« 
farthest from the air. ITere it liaH a somewhat irregular outline and jagged 
edge. When traced n])ward, it soon diminishes to a just peroeptibla tnCL 
There is a <-liaracteriHtic development of air-bubbles in the neighboriMod ef 
the growth isee p. ."Wll). 

Vui. 4. — I'ai' DiPiiTHKKi.F. Culture on I>efflcr's blood-Minim. This dos- 
ing is made from two separate cultures. The outlying gray spots, widi the 
i-entre rather more opaque than the |)eriphery (p. 384), is the form genenHy 
s<-en in primary cultures. The continuous line of growth represents a eoB- 
mon form itssumed in secondarh' and 8ul)se(juent cultures (see p. 383). 

Via. ■'>. — TnK SiMKiLLi'M OF CnoLKU.v. Culture in nutrient gelatin, atcodaf 
M-cond tiay. l.i(|uefaction has cH-curre<l at the up|ier end of the i"'"**"" ^ 
and a l>i.-ll-sha|ied cavity is pnKluced. The principal part of the coltore liei 
in the lower part of this depression and in the up|ier part of its ooifaow- 
like termination (see p. 3',H)}. 

Fl(i. (i. — HAfii.i.fs TtBEKCTU)sis. Culture on glyceriu-agar. The greater psil 
of the growth consists of opaiiue, gniyish or yellowish, heaped-up miaWi 
lint at the jK-riphery thin Hakes or scales, which are very characteristic^ oso 

Ih' s<H'n (see p. 4 !•">). 





Anatomy and histolooy investigate the naked-eye and niicro- 
*«copic structure of the bealtby body ; physiology examines the 
Cunctionfi of the parts revealed by them, and ^»tlIdies the chemical 
jirooesses which constitute healthy life. To obt.iin ii knowledge of 
«lisea«e ]>arallel courses must V)e adopted. At [lost-mortem exam- 
inations we note all the naked-eye departures from normal anatomy ; 
■vith the microscope we discover the finer changes to which these 
«lepartures are due; and by e-\pcrimcntal methods and bedside 
«:>lt8ervation8 we investigate the causes of the abnormal structure 
*»nd function, their mode of action, and the nature and sequence 
of the disturbances which they produce. In other words, just as 
"^e have anatomy, histology, and physiology, so also we have mor- 
\)\A unatomy, morbid histology, and pathology. 

Our guiding priiici[)le in modern pathology is that we have to deal 
«iot with new tissue-cells and functions, but simply with disturbances 
«3f ordinary elements and functions. It is obvious, therefore, that 
Tor the purpose of studying disease our aci|riiiintance with the body 
in health cannot be too intimate. New cells (bacteria), and even 
entire animals (parasitic worms), are frequently introduced into the 
tissues, but as niuiirD, not prmlurtti. of disease. 

The complex human organism can be reduced to very simple ele- 
ments — the relh ami the interi'iUuhir Hub»trtiice» to which they give 
origin. These two elements make up every tissue. Sometimes the 
cells are in excess, as in the epi<lermis. where they seem to be in 
abt>oliiie contact; and sometimes the intercellular substance, as in 
i 17 


thft rjiuwKlwH tiMUMi. It n now nnitersallT believed that the indi- 
vidual i^ell \n the M<rat of nutrition and function. Health and disease 
inuMt b(; coHMidcred ait terra.'t referring, not to the bodv as a whole, 
hut u> the actual cellti of which it consists. 

Ik-fore treating of disease allusion must be made to the constitu- 
tion of cells in health, as well as to their functions and to the con- 
ditions under which these are normally discharged. 

CONSTITUTION OP CELLS.— When Schwann established 
the analogy between the animal and vegetable cell, the former was 
held to be constructed, in all cases, upon the same 
principle as the latter, and to therefore, of a 
cell-wall enclosing a cavity in which were contained a 
nucleus and fluid contents (Fig. 1). But the fact 
that no-cell-wall could be demonstrate<l in embryonic 
cells, blood-corpuscles, and the cells of many rapidly- 
growing new formations led Lcydig and Max Schultze 
to believe that a little mass of matter, enclosing a 
nucleus, was all that was necessary to constitute a cell. 
Max Schultze established the identity of the cell-sub- 
.. „ ^ stance with animal sarcode — a contractile substance 

iniKvr ■iinwiiiic existing in the lower animals — and showed that it also 
I><'.I!i.*ni'.' nil' *'"•• capable of spontaneous movement. He called this 
«i«i, ■iwi mnio substance, of which all cell-bodies, animal or vegetable, 
■iivi.iinij '"■•'< »' ""♦' period ot their existence, composed, pro- 

toplasm, luid pointed out that a distinct cell-wall 
rwultod fmm ii retrograde process occurring in its outer layers. 

Tlio doftnilioii of a cell has been still further modified by the dis- 
covery thai a nuel«>us is not essential, for none exists in the crypto- 
gamia and in s«>me of the lowest animal forms. In these excep- 
tioiinl oa.'»es the cell iH>n8ists of a simple mass of protopla.«m, but in 
th(< higher animals the nucleus is an alnio.>it invariable constituent. 
The oell-Mnll is much K\os inmstant. and must be regarded, in ]K>int 
of vitality, a.o inferior to the rest of the cell. 

Protoplaani is a tt>mplex living IhmIv : of its molecular constitu- 
tion «o !»rx> ;«tiU ignorant. It contains a large <|uantity of water, 
and u> solid rrv^idue is largidy made up of proteid material : but 
»«tli this thort' an* always asmnMattnt. ap)tarently in an amalgam- 
like way. some earlndtydrate, fat. and inorganic ^^Its: for these 
are luxisiblv. and vet not in true combination. Some authorities 




■^Tcgiinl the protcid element as alone esaentiiil Id the manifestation of 
life. Protoplasm, as seen in the bodies of living cells, is generally 
structureless, soft and viseid, but varving much in fluidity. Gran- 
ules are freijiiently present in it. often in one jwirt and not in un- 
[>tber, and these are believed to differ chemically from true [ivnto- 
plasm. Small cavities, full of iiuid, iui)kin;j: like clciir sjiaces, are 
.often seen: one large one may occiij)y a considerable portion of the 
■cell, or many smaller ones may be distributeil through it. These 
ciivities are called vacuoles. They may apjiear, disappear, or change 
'their position. 

In highly specialized cells protti|da8m has acrjuired a distinct 

Kstrnctiire — e. </. the fibrillation of muscle and nerve-cells and the 

V«triatiou of nuiny ciliated cells and gliind-cells. In the simpler 

H cells, after hanleniug in chromic acid, a fine nctwurk of fibres is 

■ seen in the cell-substance — a fact which has led to the belief that the 

protoplasm of all cell-bodies is really iiiT!iiij:cd likv a spouj^e. the 

interstices being occupied by fluid containing granules which are 

moved about by contractions of the protoplasm. This view e.\[)lain8 

Ktnany ])henomena of cell-life, but np to the present time these 

^appearances have not been observed in living cells. 

Schiifcr has recently shown that protofdasiu is composed of two 

sul>stances : (1) sf>on</iophiiim, which forms a reticular framework, 

^ (2) hi/alopfnsm, which is structureless, seuiifluid. ami not neces- 

y confined within the limits of the rctictihir framework. The 

movements of the cell depend ujion those of the hyaloplasm. 

But«chli considers the structure of profoplasiu ;is analogous to that 

rof foara — "minute ilroptots of a watery iitjuid take the place of air 

n the buhblen of foam." He agrees with Schafer in considering it 

■fticular, but iliffers in his interpretation of what he sees, as well 

,«-H in his ob.scrvations on the arrangement and disposition of the 

framework ii.self. He thinks he can trace a reticular structure in 

he "processes," and that it fades gradually, in them as elsewhere, 

uto thf more lii|uid element. Schiifcr thinks the limit is sharply 

ofined and that the pseudopoilia arc houiogciicmis. 

Under certain circumstances protoplasm undergoes metamor- 

'|)hti«e>i into various other substances — .'. </. iiiuciii, globidiu, kera- 

n. pepsin and other ferments, glycogen, colloid matter, and fat. 

hese may form large portions of the bodies of cells. When gly- 

n;;en and fat arise from a proteid a nitrogenous molecule must also 





This protoplasm is the essential cou.stitueiit of the body of every 
cell. In comparison with tlie niicloiis the body varies much in aiae, 
being wimetimes lar^re Jind .S4)metimes (Hiite insignificaut. 

The cell-wall, v»lieu presteuf, is of much firmer consiistcncc than 
the rest of the body, and seeiii.s to t>e due to some uietnmorphoaiB of 
the protoplasm of the latter. 

The nucleus is more <-(int<tant thiiii the body, both iu sixe and 
form. It is usually spherical or oval, but may be quite rod-shaped; 
it is generally placed m.-ar the centre of the cell, and may \tv .■•injile 
or multiple. It resists destructive reagents more strongly than doc-s 
the body, and in disease often remains after this has been destroy i*«i ; 
it is stained more deeply by carmine and logwood. It.s presence may 
be concealed by fat. pigment, or other substances in the ceU-btHly. 
The nucleus of epidermic scales may finally be converte<J int«> 
keratin and disap])ear. 

The nucleus, which was formerly regarded as a spherical vesicle 
bounded by a definite memlmiue which separated the nuclitir fluid 
from the cell-substance, is now known to possess with greai c-firi- 
stancy the following much more intricate structure: (1|A mem- 
brane bounding it externally ; (-) u network of fibres, itrobahly 
contractile, and certainly capable of grout changes in closeness and 
general form; (3) one or more nucleoli, s^iid by some to be oiily 
Itodal point.H in the network ; (4) a clear, more or less fluid, siili- 
stnnee which fills the membrane and lies in the meshes of tlie tiet- 
Vfork. The more solid portions — membrane, network, and diicI(^>U 
— are spoki-n of as chromoplasm or nudfophism ; the les.'t fuilid, as 
nuclear matrix. The reuiarkalile changes which occur in nurlci 
previous to the division of cells will lie described subsetiuentljr 
(p. -27). 

PHYSIOLOGY OF CELLS.— In order to form an ade<|iiate 
conception of the changes which occur iti liisease it is essential to 
remember the normal functions of cells and the conditions under 
which they are discharged. 

A unicellular organism, like the anneba, taki-s in f<H)d, grows, 
excretes, reproduces its like, and performs certain functions, of 
which motion is the most obvious. The whole of this may bu 
regarded as work done, and implies the expenditure of force ; and 
we may be (piite sure, although we know nothing of the chemical 
processes going on in an amiebu, that its excreta are simpler coin- 



poiiuds than its ingesta, the difference in heat-value between these 
tw«» sets of coiu[ioiinils representing the force wliifli is iivailable to 
tiic organism. The ability to eflect these cheniiciil and iihy»ieal 
fifooesses, in which the " life " of the animal — as recognizable by 
08 — consists, is inlieritetl, ami is spoken of as '■'■ i>itiil aHiriti/ " or 
" vital encri/if." The possession of this is naturally the first essential 
to living. The other requirements of the cell are a sufficient supply 
of *iiittthlt- food and an iipi>roprliJte physicnl environment — such as a 
normal tem|)erature and suitable density of the surrounding fluid. 
To these must be added — in the case, at least, of nerves, muscle, 
and certain gland-cells in man — connection with a healthy nervvut 

In man, a multicellular being, the cells vary much in form and 
in the results of the chemical actions wliivli they effect. Although 
retaining more or less independence, vurying witii the kind of cell, 
they arc bound together for the coiaiuiiii good, and each has some 
special function to perform. Thus there are muscle-cells to pro- 
duce motion, gland-cells to secrete and e.xcrete. and nerve-cells to 
cv>ntrol the working of muscle, glands, anil perhaps other tissues; 
certain cells are set apart for reprfiducfion ; and. Kiutliy, there arc 
the connective tissues to unite and support the other structures, and 
epithelium to protect the surfaces. Thus each kiml of work done 
by the one cell of the auneba is in man ])erfViriued by a group of 
cells specializerl for the purpose. If then we recognize the inter- 
dependencies of the cells in the hiimuii organism upon each other, 
and the differences in their struetiirc aud in the economy, 
all that has been said of the amrcba will apply to each cell of the 
hotly : all the functions of the amtrba are j)robably present in each 
cell, but one — c. <j. contractility of a muscle-cell — is often so highly 
develojied as to be culled thr function of the cell. 

Vital Activities. — The vital i-neryy of each cell manifests itself 
iu three channels: hence Virchow speaks of the Nittritii'i-. Fmu;- 
tiiitial, an<l Jltpntiliirtirt' ArfiriticH. Between the two former there 
in no lint — the existence of one implies that of the other: both are 
clieiuical. and may be considered together. Fnml is taken into the 
body, digested, an<l absorbeil by lacteals and blood-ves.scis from the 
intestines ; the various excretory organs give off urea and, in small 
<|UHntity. other nitrogenous bodies, carbon dioxide, and water. Sup- 
posing the body to be in niitritivt: ecjuililn-iuw — neither gaining nor 
losing weight — the amounts excreted will account for the nitrogen, 



ciirhori. and hydrogen taken in as fooil. I'utting aside water, c«>r- 
tuin Kiilincs, and oxv^en. whicli are ofHcntiul to life, the fbud->>tuff8 
are proteids, carbohydrates, and fati) — the materials of which the 
body consists. It is evident that a large amount of heat tiiust Im; 
set free in tiie breaking down of these bodies into the simpler sub- 
stances above mentioned. Tiiis is the source of tlie force by which 
every act is performed. The blood carries the prepared food-stufls 
to the capillurio!*. whence they pass out with the lym|ih to come into 
actual contact with the cells — some in solution, others only in su»- 
|>ension. Certain, or all. of these bodies are now taken up (appa- 
rently actively, for allmmin will not ilift'use from a watery fluiil) and 
become part of the nufi»tiince of a cell, replacing some older material 
which has been broken down to supply force for assimilation and all 
other actions of the cell. This breaking down of cell-substnnco con- 
sists in the union of it with oxygen obtiiined from the blood and 
8tore*l by the tissues in some unknown way. All such oxidation 
processes are believed to take place «« thr celh, not in the blnoil : 
and this almost necessitates that all food shall become {lart of a cell 
before it is oxidized; it is not oxidized directly. Although the tis- 
sues of the body and the foo<l-stuifs have almost the same chemical 
composition, waste tissue is not repaired by a process of simple re- 
placement from the food, if we except fat : when a fat of the samt 
coni|K>sition as human fat is contained in the food, it may Ih> stored 
in the cells without undergoing previous change, but usually some 
slight addition or subtraction of hydrogen is necessary. It is prob- 
able that many changes, both analytical and synthetical, occur in 
the arrangement of the elements of food-stuffs before they form 
protoplasm, the real liriiuj ti.<sue. an<l force is thus alternately lib- 
erated and rendered p<itcntial ; but this does not affect the uiaia 
fact that the body is ultimately enabled to utilize the force equir- 
alent to the <lifference in heat-value between the ingesta and 

We have enumerated the compounds presented to cells in lymph, 
an<l also those which leave the body as the ultimate jiroducts of e<»U- 
ai-tion ; hut in no instance do we know the connecting links betweeo 
the end-|)roduct8. Whilst the ingesta of cells must be tolerably uni- 
form in character, their excreta are probably a« various as arc the 
uses of the cells in the body — witness the different compositions of 
the many secretions and the unei|uul distribution of the extractives, 
Ruch as kreatin and xanthin. On the one hand, the breaking down 





of tissue, or ufaste. which is going on constantly, and on the other, 
the building up. or repair, which in healtii keeps |»ace with it, con- 
stitute the nutritive i-xchnni/f of tiie cell or of the whok' body. This 
process is constantly being distiirbi'd from pathological causes; and, 
physiologically, formation exceeds waste during the period of growth, 
hut the opposite obtains in old age. when the vital efiergy of all cells 
is failing and their functions are imperfectly discharged. 

The excreta pass in two directions : into lymph and back into the 
bloofl. iir out to a mucous or cutaneous surface. ^vllcllCL' ]iart may be 
reabsorbed — »•. //. saliva, gastric juice, and |iart of ilio bile. 

Influence of the Nervous System on Nutrition. — Experimental 
physiology teaches us that the nervous system has an important in- 
floence over the nutrition and function of nerves, muscle, and such 
gl&nda aa act normally only in response to the stimulation of .special 
nerves. Thus when motor nerve-fibres are cut off from the gan- 
glion-eclls of the corresponding (interior eornu, they mpidly degen- 
erate and lose their power of transmitting electrical as well as 
voluntary impulses. The muscles they supply also undergo degen- 
eration (p. 78), and show changes in their electrical reactions. In 
the same way section of the chorda tym(>ani is followed by wasting 
of the submaxillary gland. 

It is at present uncertain whether the nervous system has any 
analogous intluenco over other tissues, such a.s connective tissues 
and epidermis, for, while lesions of these structures are fre(|uently 
foand associated with disease of the nervous system, it is in all diflicull to exclude other possible causes. Thus these lesions 
are accompanied by more or less aniesthesia, disturbance of the cir- 
culation, and fall in temperature; all of which may be actively con- 
cerned in the causation of the subsequent changes. For example, 
in inflammation of the peripheral nerves, such as occurs in chronic 
alcoholism, not only do the nerves and mu.scles undergo the changes 
just mentioned, but the skin supplied by the affected nerves fre- 
•jucntly becomes thin and shinv; moreover, bulhe not infre<(uently 

Occasionally in cases of hemiplegia and of sabre-wounds of the 
brain extremely acute bed-sores form on the huttoek opjmsitc the 
lesion, and similar lesions may appear over the sacrum in para- 
plegia from sudden and extensive lesions of the cord. They are 
distinguished from ordinary bed-.sores by the earliness (second or 
third dav) and acuteness of their onset, and by the usclessuess of 


precautionary ineaAures. It may be replied tbst these are but dif- 
fcrcni'i's of iK'grcf : that the bed-sores occur in the usual positions; 
«nd tiiiit appareutly siuiilar lesions show, in this respect, no propor- 
tionate constancy in their results. In this class of cases, t«M>. cys- 
titie iind pyelitis may a|>pear at about the same time as the bed- 
sores, and (.'lutreot thought that these inflammations were due to 
irritation of tr<iphic nerves: but as exceedingly foul urine, contain- 
ing organisms, is noted before, or with, the onset of the cystitis. 
others believe tliat these changes are due to the organisms — either 
introduced from without by u septic catheter or from witliin through 
the kidneys. The urine is thus rendered extremely irritant by putre- 
faction. Similar rcsidts occasionally follow the passage of a catheter 
in cascH of enlarged prostate. 

Trifireminal Keratitia. — Intra-crunial section of the fifth nerve 
causes cloudiness of the cornea in twenty-four hours, and often 
destructive panophthalmitis : at the same time ulcers apjtear on 
intmsitivi' parts of the mucous membranes of both mouth anil 
nose. The keratitis can be prevented by carefully cleansing and 
accurately closing the eyelids, thus protecting the parts from organ- 
isms an<l injuries. T\u'. ulcers in the mouth are probably due lo 
damage inflicted by the teeth, and the ulcers in the nose to the 
action of particles of dust nn<l organisms on the dried mucous meio- 
brane. In both cases the failure of the insensitive mucous meiu- 
brane to initiate any of the vasomotor and other protective reflex 
mechanisms renders the parts a suitable culture-grouml for pass- 
ing organisms, which arc thus enabled to thrive on the insensitive 
surfni'cs. Ulcers on the foot, often progressive, after section of the 
eciatii^ are similarly accounted for. 

Acute fati;y detr^neration of the heart may follow section of 
the vagi : the iiiiiiliin n/n-niitili is unknown. 

Erythema, Urticaria, Pemphigus, and especially Herpes, msjr 
ap](ear in the distribution of nt-rvcs which are the scats of somft 
irritant lesion. These changes have been obst-rveil at'lir fractured 
apine. in locomotor ataxy, in ayringomyelia, in compression i>f iho 
cord by an aneuryism or tumor, and in inflamiuation of the (Jas- 
serian or some posterior spinal ganglion. The nerves supjilving the 
area of the rash have been found in a state of neuritis. 

Qloesy Skin f Paget). — In some cases of irritative lesion of the 
sensory nrrves of limbs (»•. //. from gunshot) the skin becomea 
amooth, »hinv, hairless, sometimes hyperaimic, sometime* asdenu^ 



tocts. and often superficially intlameU or the seat of sores like chil- 
hlains; at the same time the jiart is oiVen the seat of intense neur- 
algia. All these chanj;os in the nutrition of the skin arc probahly 
•liie to vasomotor changes acting in conjunction witii externa! inflii- 
encos such as have been mentioned above. 

Pigmentation. — More or less symmetrical patches of lencotlerma 
and melatiiidermii may be distributed over tlie body, with more <ir 
less anscsthesia. Pallor with ansesthesia and localized grayness of 
hair mav occur in neuralgia of brauc-lios of llie fifth nei-ve. The 
c<dor of the hair may to some extent return between tiie attacks. 
CaKes have been rec()rde<l in which the hair has, within a short 
time of a fright, become gray. 

Serous Synovitis and Arthritis, with rapi<l. painless, and exten- 
sive criision of the articular ends of the bones, may occur in cases 
of hemiplegia and locomotor ataxy. These are supposed to be due 
Xn involvement of the cells of the cnrrcsponiling anterior cornu by 
progressive atrophy. The causal relationship between the nervous 
disease and the peripheral lesion cannot yet be said to be proven. 

Atrophy of Parts cut off from the Nervous System. — Mtis- 
bIp and certain glands have alreaily been referred to (p. 2-'l). In tlio 
of muscle it is to Ik- noted that if it is regularly exercised by 
t1»e galvanic current atrophy may be postponed. In a paralyzed 
limb all ti.ssues ultimately waste: so do those of the face when 
the facial nerve remains paraly/.ed. This is due to impaired blood- 
supply, for it occurs in limbs which simply kept at rest. Atro- 
phy of the cock's comb and the turkey's wattles residts from sec- 
tion of their nerv<;s, and is perhaps to be similarly ex])lained. In 
citses of progressive atrophy of half the face there may be nothing 
tn guide one to the nervous system as the cause; there uuiy be no 
'*»ijbje«'tive .symptoms, anil sensation ami motion may n-main nor- 
mal. If due to nervous influence, this atrophy wnuhl seem to favor 
tlie existence of trophic nerves. 

Hypertrophy of bone may follow section of the sciatic in young 
[nnimnls, anil is inflammatory: for it never occurs unless large ulcers 
[fV)rni, cxtemling to the bone and even causing necrosis. Hypcr- 
[tropiiy of the rabbit's ear after section of its nerves has been said 
Ito occur, but many observers have failed to produce the hypertrophy, 
>r have, at most, seen some thickening of epidermis and hair upon 
jthe surface of the ear. 

Pathology, then, affords nu reliable evidence of the existence of 


special trophic nerves, and no convincing prool ot the intorfe: 
of the ntTvous Hystom in the cheiuicul processes of colls whicl 
f«)riD 110 speiial function. That these inocesscs may go on umliv 
tiirbcd iu the absence of nervous influence is shown by »hc perfect 
ilcvelopmont of other parts which is foun<l in ancnrephah»iis autl 
umycious embryos ; by the growth of transphinteil epithelium ami 
connective tissues; and by the nnion of completely severed fwrts. 
At the same time, us we cannot offer a perfect c.xplniiufioM of 
many of the above-mentioned cases, we cannot say that the nervous 
system has no direct influence upon connective tissues ami epider- 
mic cells : it seems most probable that it has. It is impt^rtant tltat 
the facts shouM be remembered. The explanation of some of them 
is at present uncertain. 

The Jiefiroil active Activity remains for our consideration. In 
early life, at least, all cells possess the |>owfr of reiiroducing their 
like, and in the majority this |)ower is retained, althougli it mar 
iiot be exercised physiologically, up to advanced age. CeHSHtion of 
growth does not imply absence of ability to grow, for growth some- 
times seems to cease when the sup|)ly of nutritive material to a part 
is only just sufficient to maintain its statng ijuo. This is seen in • 
hair, which will not grow beyond a certain length : cut it short nnd 
growth at once begins again, the supply of food being greater than 
the now shortened hair re(|uires for simple nutrition. ']'o cause 
cells, which are capable of multiplying, to do so, the supply of food 
must be increa-sed. Thus exercise of a muscle causes iuereaseil 
blood-sup|>ly and conse<|uent growth ; but increased blood-supply 
to a working tissue, without exercise, will not have this efleot. It 
is different with non-working tissues. The hyperjemin round itn 
ulcer of the skin causes thickening of the epidermis and connective 
tissucM, and nothing is commoner than new formation of bone ronnd 
■ carious focus. To produce this effect the increased supply must 
be very fretjuent or long continued. (See •' Ostitis.") 

A non-working ti.-wue apparently tends to grow also when the re- 
siatauce offered to its growth by neighboring tissues is diminished : 
of this we shall find many examples in cirrhotic processes and in the 
etiology of malignancy ((Johnheim). 

The cells of the body inherit very different amounts of vit^tl energy. 
The c«'ll» of the thymus are soon exhausted, those of the epiphyseal 
curtilages later, and of the generative organs later still. Powers of 
maintenance, growth, and reproduction are by no means proportion- 




ate. Tbc power of reproduction poasessed by cells often seems in- 
versely pro|K>rtioiiate to tlie speeiiilizatioii of their functio!! (p. 118). 
In all ciises, probiibly, tbe rejirodtictivc activity is tlie first of the 
vital tnHnife.<itations to suffer; then the functional atul nutritive. 
Inability to perform Hiich elieiuical changes as ure necessary to 
remove cfl'ete material ami to repair waste is normal in old age; 
death, which may be termed natural, thou results from '' senile 

GENESIS OF CELLS. — Virchow's dictum — Omnis retlula e 
reUula — is now admitted by all but a few. Probably every nucleus, 
also, is derived fmm a jire-existitig nucleu.s. 

Jilultiplication of cells takes place by simple division. The cell 
divides generally into two, and the change is preceded by remark- 
able a]ipoarances in the nucleus. According to Flommitig, the 
jirocess of " karyokinesis " may he very briefly described a^s follows 
(Fig. 2): First, the niielenr iiicinbratu' disappears; then the regthuj 
nuclear network (a) becomes much finer ami closer, like a ravelled 
nkeiii : then again more open, and, if not already so. the cell be- 
comes round {f>). There seems to be now only one long fibre form- 
ing the nuclear network, which next assumes the form of a rosette 

Fio. 2. 

,.\ ' "'i^-j 


FafDU aiiKiiinv*! by a itiuU-un in <livii]liiK: u, rti^liiiK nunU'Uii ; t>, sICL-Ui-riirm, opi'ti xtagc; 
|^« wr«ath ftinii : if, lUttvr, t>r fliur-funn; r, vnuaiorinX atuKt* n( diviiiiun; /, Ki-|)urufiiiu more 
B<lraiicf<l : ;; uml ». HUir iinrt wrvmh fnriu* i)f <liiui;htvr-niH'lvl. (R«<luv«d from FIcmmlUK's 
I tirawiiiirt In the Afh. J. Mik. .ln<i/,J. 

«r wreath (<•) round a clear central space, whilst a clear zone inter- 
venes externally between the network and the cell-substance proper. 
[Jly division of the external bends of the fibre and approximation 
of the apices of the V's so as to obliterate the central space a star- 


f>?»_ *«(fv^ . /^ i« ;«r*iD<wi<L TL* fi!iip» at ili* <Ui£it <-fiea l«««:«ine 
iutT azri vf.'T* LTSKrc'^f bj V>!i£irs-iiikal ■i:Ti».>a ir'>3x: tbeir ft^ee 
«9ri« '/'-aari iLt- <i»;ire. Ist<«<»i <*f n>miit^g &>c-sl ike oeeTre. iher 
■»:■•»■ \'tc:yart ins i«rki3*l. aa^i tben <»>nTrt-ceBt v>var>i rw<« <-j-f«:t«iie 
c»>£Kti — iit- :»>j*s— >f til* •-rLgiiMii Bis^sru*. *•:• tiiii tL* fitne* now 
fr'TK r*":* mc» <-f V'i wiiii t£i«-ir utrle* ***J fi<i<m tL* «>i;|oator — 
«qpiasan*2 siaee -■< v A c-i'«ar «*|«ai<>ral hue a;>j<ar&. aiwl widens 
«^* » a» *<BFfr *irt '-'f V-4brc* rtxpt*:^ &>>9n ti* r^titT. Frc'Ca ir»«h group 
til*- iiioen* <■{ * -iaosiiicT-rt^S i5 f:*Tiii*«i hj jmssins tlir>>acL — in 
TtTtn^ "-r'ier— «Ii u«- <tau<e» al«>Te onHin^ked 4jr and « l until the 
rsRsziX •3ax<fr a^ re»titfL Meanwhile the f^^MOfulasB <«t* the eell- 
li^'iT <«>Z>en» iy»zsri c4ch n«e]ea»^ ana bj the tia»e theee have 
ajB^EOrtti the wRtt:h-(>ra iu 4iTi«>->n i« (io«i|Jete. The 'iaashter- 
<«&. a: xj¥t «a!aiL £iv.v. azr-i nar thenk^eires <^!>»n divide: thus 
Ki]t:}0>nz>c>n iiEav l«e- vetj ra;.>(L 

The ii*eie«$ zav divide <evenl t.mes «ith<kat anv division of the 
«ej}-lK<HiT itecvnins. hvt the laner iBcm^e^ <«>ntinvoas]v in size. 

This is said to be <>ne «av in which 
"giant" or -ayeJoid" cells — lai^, 
irregular. m«h:n«eleated masses of 
protoplaso;. fi>«nd in the marrow of 
gro^in-^ U.'ije. in cLivnic inflamma- 
ti<'>ns. and iii <«>zi:,e new jjrv'wths — 
maT W |.r\«iSa<*d ■ F^. o L 

PiDallr. it remaaks to W {••inteii 
OTjj that ceii> oririisat-ni: frv^m one 
t-nj^rv<•^l:^.■■ laver never give rise to 
ori]> "fa kind l-'raji-i &--rmalIy fn>m 
ai»:Ler layer. KpibUst forms ner- 
v.;.-as tjss-ae and the epithelium of 
<<•»*<-.« -rjaiis. vf ite ventricles of the 
Vr»:ii and iiti;:r»! cmidA of the t»nU 
.>f iLv skin. is.>-,ni.. and lower enti of 

Fk. :. 



1.--; •^-1 ?r ai "Qw r^Tac 

Hypoblast foriL: 

« ;V 

e e; .i:;v; 

••'' she urinary bladder, 
i*!-;-:r«*--rT itiki. and alitLeitary \-anai an i ••:" a^l glands connect e«i 
with h Tie Mesobl&st frais :Lr e; :;ht'.i.;2: .>f :i.v kidney, testi- 
cle, ai/^l .-.Tarr : •,h-r tr;i:Lv:: -k of vess*;* and s»-:vas membranes : all 
the <»'i:t.e'c^-'»'e liss^ses: l"-»-i; aad musciiar tissue. 

DISEASE. — Titr fitcii-'iis of an organ are rviallv the functions 



of the cells of wLicb it consists : if all these act nornially. we say that 
the orgau is sound, ainl vvlu'ii all tlu* fiinetidiis of every organ ami 
tissue in the body are nonually jierionned, we ilescribe the individ- 
ual as being in perfect health. A very little experience shows that 
physioloiiical functions vary within ctTtain, j>er!i;i|i!< rather wide, 
limits, the perfect well-being of the individual being maintained. 
Con»ei|rieutly, our standard of health is no rigid one; its inaxiniiim 
and minimum are widely separated, and the latter shades nil' iuijier- 
ceptibly into disease. may therefore be defined as the abnormal performance of 
funetion by one or umrr iiri/tam <>r tissues. This applies to " dis- 
ease " as a general term; but when we speak of an individual dis- 
ease, .OS rheumatism or .^yjihilis, the rtiu»r of suuh disease — that 
to which the peculiar disturbances of functiuti or structui'e whicli 
distinguish the disease in question from nil others iire due — is 
often implied in the word. The same or indistinguishable disturb- 
ances of function and structure may sometimes be j)roduced by several 
pauses ; it is the more or less constant groujiiug or seiiueuce of symp- 
toms or of lesions which in such cases establishes distinct diseases. 

It is worthy of note al.'so that the inniit/einnirf- »f <i physinlogical 
Moxivium or minimum must be regarded as pathological. For ex- 
ample, a man out of training will eliminate mufh more urea than 
normal on the first duy of a walking tour, but the average daily 
elimination for the whole tour will not vary IV<in) the uorniid. If, 
however, the man were to go on excreting the niaxiuiuiu iptantity 
of flif- first il;iv, his state would be one of disease. 

VAEIETIBS OF DISEASE.— The complete healthy life of a 
cell consists in the perfect performance of all its functions. For 
this three things are necessary : 1st. that which it inherits — its 
vital energy — must be normal : 2d, it must be supjdied with suffi- 
cient suitable food; 8d, its surrounding physical coiiditions must be 
uormal. Failure in any ont* <tf these will lead to disease, and two 
great classes of diseased conditions are at once evident : inherited, 
«lue to abnormality of the first : acquired, due to abnormality of 
the seconil and third. 

Inherited Disease. — The tendency to iuhurited ilisease either 
t'xists in the ovum at the ccnuuienceuiont of dcvflojunent or is 
aci|nired by the ovum in fertilization; tendencies furmed later than 
this are obviously acijuirud. As in normal development certain 



orgaiu inauifetit their iuberit^Hl t«ii<]enciej> many years after birth — 
i.g. the <levelo|inieiit of the female generative ssystem at pubertv 
au<l itK atrophy at the menoiiauire — hj iuherited tendencies to dis- 
«aH« way not show themM^lres until late in life. a]> xs the case in 
cancer of the brea«t or uterus. It ii^ fiosfsible that in many ca^es 
tlie Kame unrecognized conditions wliich induced in a parent the 
morbid tendency handed down continue to act on the offspring until 
— with or without some obvious exciting cause — the disease becomes 
evident. We cannot say when this tendency to begins : it 
may have been slowly gaining strength for generations. The fact 
that no progenitor had the disease in question, if he or she lived 
well past the age at which such disease usually manifests itself, 
shows simply that the causes had not acted long enough or with 
sufficient energy to produce it. It is important to recognize that 
even inherited disease has its starting-point in conditions external 
U> the cells of the body. 

With regard to the actual mode in which disease is inherited, it 
is in some cases probable that the {loison. the actual cause of the 
disease, is present in the ovum or spermatozoon, as has been shown 
to be the case in the silkworm disease (Pasteur). But how disease 
and tendencies to diseases which are not due to any specific })oi8on 
are hande<l down we know no more than we do how it is that chil- 
dren inherit the features of their parents. 

Often no actual tlisease is inherited, but the power of resistance 
of certain tissues against the causes of certain disea.<»es (e. tf. tubercle) 
is more or less ini[iaire<l. or the tissues degenerate early, esjtecially 
in the futty or ciilcareous manner, so that many members of a fam- 
ily may tlie at alM>iit the same age from fatty heart or a|)oplexy. 

Acquired Disease. — Starting with an organism or part possessed 
of normal vital energy, disease, if it occur, must necessarily be the 
result of external conditions : the supply of food is faulty either in 
((uantity or <{uality. or the physical conditions to which the part is 
or has l)e«-n exposed are unsuitable. It is difficult to separate the 
two. If the bhtod-supply to a part is abnormal in quantity, the 
temperature of the part will be changed; if a |>ortion of the body 
is mecliaiii<-ally injured, its bluod-supply becomes abnormal; if a 
|M>i.xon excites fever, the cells are exposed to a higher temperature 
than normal : a circuhiH vitiosux is established. Disease may be 
aci|iiired even during intra-uterinc lift — e. ij. one of the acute specific 
fevers or syphilis. 



General and Local Disease. — Atiy cliange in external conditions 
acting upon a unicellular organisiu would jirobably jiflcct every par- 
ticle of its substance and modify all its functions ; all its diseases 
would therefore be general. But multiplication nf cellx and spe- 
cialization of functions enable abnormal condition.^ to act upon cer- 
tain groups of cells and to disturb their functions without affecting 
— primarily, at least — those of other groups. We thus get local 
disease, ami the great majority of disea.'es belong to thi.* clu-s.s. 
Perhaps, indeeil. we may say that every disousc is primarily local- 
ized in a tissue or organ — the blood bciii^ counted as of the con- 
nei'tive-tissue type of which the iutcvcclluhir .substance is fluid. 

Structural, Organic, and Functional Disease. — A disease is 
localized in an organ or tissue during life by its symptoms and by 
its physical signs, and after death the localixation is justified by 
the discovery in the part of some constant structural change. This 
is Btnictural or organic disease. Diseases in which no such change 
has been found or is believed to exist are classed as functional, the 
belief being that in them the functions of certain cells arc abnor- 
mally performo<l without any structural cliauge. Modern icsearch 
has greatly diminished the number of functional diseases, but it 
is almost certain that a very largo nundier of the slighter ailments 
are due to transient errors in the metabolism of the cells. 

ETIOLOGY OP DISEASE. — The causes of disease are divided 
into two classes — Predisposing and Exciting. 

PuEDlspoi'lNfl Causks. — Any agency which tends to cause depart- 
ure from the physiological condition of a function must be regarded 
afl predisposing to disease — c. </. privation and tVetjuent irritation. 
Many such agencies, when acting more strongly, become excitants 
of disease — i. e. cause a departure beyond the physiological limit. 
Thus if t4» normally acting ciliated cells, detached from the body, 
a hot iron be approached, the first effect will be to increase or stim- 
ulate the movement of the cilia: but if the imn be kept near them 
long or be brought closer, the tnoveuictit becomes slower and soon 
ceases. If the iron be then removed, the cilia will after a period 
of quiescence begin to work again — at first one here and there, 
then all — and may after a time recover completely. This experi- 
ment of Lister's illustrates a point of fundamental iuijiortance in 
pathology — the infiereiit power of every cell to recover after injury. 
It shows for the elements what every one knows of the whole — 


namely, that, ecrterii parihus. a strong man will recover from a 
disease which would be fatal to a weakly one. It is certain, too, 
that the '' life " of cells resists the action of injurious agencies, and 
that this power of resistance varies l>oth in the case of different 
tixguen — e. g. the rabbit's ear resists the effects of ansemia much 
longer than a knuckle of its intestine — as well as in different indi- 
riJualf. Thus it is a common observation that certain ]>eople who 
have not suffered from the acute specifics may even nurse those ill 
of these diseases without themselves catching them, whilst others, 
again, fall victims to them, though not specially exposed. Such 
power of resisting certain causes of disease does not imply ability to 
resist others of a different nature, nor does it necessarily go with mus- 
cular strength. It varies at different times in the same individual. 

The following may act as predisposing causes : 

Aere. — Special treatises have been written on diseases of child- 
hood and on diseases of old age. showing that there are peculiarities 
with regard to disea.Hes at these periods of life. The special liabil- 
ities of childhood are to some extent explained by sup]»osing that 
the power of resisting injury, which all cells possess, is not fully 
developed until adult age ; those of old age. by the fact that the 
vital lowers are wearing out and degeneration occurring. 

Sex. — The organs special to the sexes render each liable to 
special di.seases. Women are the special victims of hysteria and 
chlorosis. We cannot explain the special liability of women to 
endemic and exophthalmic goitre and to myxoedema, nor their 
comparntivc immunity from Addisons di.sease, locomotor ataxy. 
and general paralysis. 

Heredity. — It has already been stated that feeble vital power, 
without actual disease, may be the heritage of the body or of one 
of its parts. It may further be noted that, like physiological and 
personal peculiarities, disease — e. //. gout — sometimes skips one or 
more generations (iitiirii»ti). In other cases, as in haemophilia and 
j»seu<h>-hypertrophic muscular paralysis, the disease ap])ears goner- 
ally in the males only, although the females may, without them- 
selves manifesting it, transmit it to their offspring. 

The diseases which most obviously " run in families " are — func- 
tional nervous disorders, such as hysteria, neuralgia, epilepsy, insan- 
ity, and these are more or less interchangeable : carcinoma, especially 
of the breast and uterus: some simple growths, especially if multiple 
(lipomata. osteomata. papilloraata) ; gout and tubercular disease. 



Exrmxo CAtrsES. — These may be nrrangofl under the heailings 
of Abnormal Bfooil-gupplt/ and Abnormal I'hysiral Conilitionn ; it 
mav be necessary to add, Atterai Nerve-iujluvnci; but we do not as 
yet know enough about it. 

Abnormal Blood-supply. — Defects in the b]of>(l-sii|i|ily may be 
due to errors in the circidation or in tlie eotn|io.sition of the ljh<od. 
It may result from Lypeneniiu or anteniia — from all abnormalitiea 
in blood-constitution, wliether due to faults in its fonuHtioii or jmrifi- 
cation or to the introduction of poi.sons or parasites from witliout. 

Abnormal Physical Conditions. — This group includes injuries 
from any one of the physical forces, applied either from without or, 
B«> to speak, frc)m within ; also the results of niecbauica) obstacles 
to discharge of function or of contents — e. g. stricture of a duct or 
orifice, strangulation of gut, pressure, and the mechanical effects of 


EFFECTS OF PREVIOUS DISEASE. — Some diseases, when 
they have occurred once, teml to recur again and again. In tlie 
case of others, to have suffered once is to have secured practical 
immunity against a second attack. (See " Immunity.") 

Certain other diseases, again, seem to modify very deeply the 
functions of the body. Many years after these diseases it is found 
that illnesses, which seem at first sight to have nothing to do with 
tiiem, yield only to the treatment proper for the original malady. 
Huch are malarial fever, syphilis, and gout. The poisons of the first 
two are probably still latent in the body ; as to gout, we know too 
little of its essential nature to speak definitely of the way in which 
itj influence is exercised. 

of an organ or ti.ssue is fre(iuently followed by secondary disease of 
other parts. This may happen in several ways : 

1. By direct spread of a morbid process, as when inflammation 
extends from .<kin to subcutaneous tissue or when cancer of the 
mamma invades the superjacent skin. 

2. By the Carriage of the Causes of Disease from a Primary 
Focua to Parts at a Distance. — Thus organisms may be carried by 
ihc li/mph(itici». and give to inflamed lymphatic glands ; pieces of 
clot may be conveyed by the blunil-i'ixHi'lK. and produce embolism ; and 
a renal calculus may be transferred through the ureter to the bladder. 



3. Mechanically, by so-called " baek-tflUng." Thus, stricture of 
the urethra causes hypertrophy of the bladder to overcome the 
obstacle to the outflow of urine, or dilatation of the bladder if its 
efforts are futile. In either case the diflSculty of entry of urine 
into the bladder is increased, and the ureters, pelves, and kidneys 
dilate. Interstitial nephritis results from the pressure, the renal 
functions are imperfectly performed, and this is detrimental to the 
organism at large. The succession of changes which result from 
mitral incompetence is another familiar example of this mode of 
extension of disease. (See " Mechanical Hypenemia.") 

4. Failure of any Part to do its Share of Work in the Ecod- 
omy. — The result of such failure will depend u|)on the readiness 
and completeness with which its defection can be compensated. 
If the work can be readily taken over by other parts, as can that 
of a sweat or sebaceous gland, nothing is noticed ; on the other 
hand, extirpation of a kidney which was doing work is followed 
by a time of danger from diminished excretion of urinary products, 
as the other kidney is at first unequal to the double duty. Absolute 
failure of the canliac or of the respiratory function will cause death, 
there being no power of compensation. 

TERMINATIONS OF DISEASE. — The possible terminatioiu 
of disease are rcrortry, or return of the part to the discharge of 
its normal functions ; /mrtial reorrry : and tleath, or complete 
cessation of function. Certain diseases can scarcely be said to have 
a termination : when once establisheil they remain stationary. 

It will Ik* useful here to give a list of the morbid processes to 
which all organs are more or less liable: 

The results of mechanical or Degeneration, 
physical injury. Necn»sis. 

Displacement. Regeneration. 

Heniorrh.ige. Hypertrophy. 

Developmental errors. 


« « • 

Ltnlgement of parasites. 

Ansemia. • * * 

Hvperwmia. Stricture and its consequence-'^ 

OMenia. may .nxnir in every duct orT" 

Inflammation. canal : and calculi may de-^ 

.\tn»phv. velop in any of them. 




The complete and permanent arrest of nutrition in a part con- 
stitutes necrosis, gangrene, or local death. 

ETIOLOGY. — Whatever interferes with the supply of nutritive 
material to a part or destroys the vital activity of its cellular 
elements may cause its death. 

A. Interference with the Supply of Nutritive Material. 
— Such interference may be the result of — 

1. Obstruction in the Arteries. — This is a common cause of 
necrosis. The obstruction may be caused by compression, by lig- 
ature, by rupture, by thrombosis, by embolism, or by disease pro- 
ducing thickening of the arterial coats. If the obstruction be 
complete and a collateral circulation cannot be established, death 
of the part quickly ensues. 

2. Obstruction in the Capillaries. — Obstruction is often the 
result of pressure upon, or stretching of, these vessels. This may 
take place from the accumulation of inflammatory products or of 
extravasated blood, or from the pressure exercised by new growths. 
The resulting obstruction to the capillary circulation causes the 
death of the immediately adjacent tissues. As examples of necrosis 
from this cause may be mentioned — necrosis of the superficial layers 
of the bone resulting from periostitis, and due to the compression 
of the capillaries between the bone and the periosteum ; the slough- 
ing of tendons in whitlows before the latter are opened ; and the 
formation of ordinary bed-sores. When inflammation causes gan- 
grene, it is by the production of stasis, leading to death of the 
tissues from malnutrition and coagulation of blood in their capil- 
laries. Whenever necrosis of a tissue occurs the blood coag- 
ulates in its capillaries, and thus hemorrhage from gangrenous 
parts is prevented. 

3. Obstruction in the Veins. — Obstruction to the return of 



Mood by the veins must be so complete in order to arreat DutritMiQ 
tbttt it is in itself rarely a cause of necrosis. It is when aMociMiii 
with cardiac weakness or obstruction in the arteries that it couyti* 
tntes an important agent in producing this result, for then the fom 
necessary to drive the blood on through the much-narrow cd venous 
channel is rjuite inadequate. Gangrene due to tiiese combinni 
causes occurs after ligature of a main artery and its vein, wai 
may follow accidental injury of the vein during the operation nf 
a ligature of a large artery, especially in the thigh. It tnty 
also result from constriction of a part by a bandage not tight 
enough to occlude the arteries as well. 

4. DiminiBhed Cardiac Power. — This is never by it-^elf a suf- 
ficient cause of necrosis. In, however, of excessive genrrtl 
debility or of disease of the cardiac substance, the wjnsefioent 
diminution in the contractile power of the heart materially «Jii> 
the foregoing causes in proiiuciiig a fatal blood-stasis. The nrrvM 
of the circulation in "senile gangrene," and in that form which •» 
often occurs in the tissues of the back in adynamic fever* and in 
chronic exhausting diseases, is in part the result of diminishci 
cardiac power. This arrest in the last-named conditions is osintlr 
dt'termined by some injurious irritation of the tissue; in otJier 
words, it is a part of an iutlammatory process. 

5. Inflammation. — As a cause of necrosis, inilamroation beloBf^ 
partly to the group we are now discussing and partly to that ou thf 
next page; for the effect of the inflammatory process is to impair 
or arrest the circulation, as well as to impair the vitality of tlic 
affeotcd part. The intensity of the process may be so great atO 
cause coagulation in the capillaries and death of the tissue. Il i* 
then cailetl nntyultilive or cntn/ufiitutn-nefroiiif (p. 3(*). When 
a strangulated or invaginated piece of gut is released and the ci^ 
culntion is re-established, severe inflammation, perhaps leadinji to 
gangrene, fre(|uently ensues. Cohnheim's experiment of tying »ff 
a rabbit's ear has, in effect, been repeated. (See " Embolism.'^ 
It is of practical importance to note that inflammation sets in onl? 
on rf-entahlinhmenf of the circulation — that is. when the gut ** 
returned to the peritoneal cavity: there is none whilst it is in t 
R«c. A much-contu.sed and lacerateil part may ultimately be kille-^ the pressure of the effusion from its injured vessels st 
further impedes tlie flow through them. Certain inflaniniatin! 
have a special tendency to terminate in necrosis, such as diphtheri 





cnrbiincle. noma, " hospitul gangrene," and spreading trauinntic 
gangrene. In these conditions the intensity of the injury to the 
tissues ii« jirobably duo to the action of minute nrgnnisins. In all 
cases the more impaired the nutrition of the part which becomes 
the seat of un inflammatory process the more likely is the influm- 
inatory jirocess to cause its death. 

B. DESTKiTrriox of the vital activity of the cellular elements 
mny be caused by — 

Physical and Chemical Agencies. — A part may be completely 
♦lisorganizcd and lose its vitality as the result of external violence, 
excessive heat, or extreme cold. Many corrosive chemicals, as acids 
nnd caustic alkalies, ilestroy the life of cells. Putrid urine or foul 
secretions from woumls will sometimes destroy the cells like a caus- 
tic. As implied in the last paragraph, other organisms as well as 
those of putrefaction may produce a similar result. These physical 
and chemical agencies frequently cause necrosis by exciting, in the 
first place, acute inflammation. 

These are the several causes of necrosis, but it must be borne in 
mind that the process is often complex, and due to the condiined 
intlucnce of two or more of them. The liability to necrosis will 
greatly depend also upon the potcer of the thsueii to resist iitjury. 
This varies, probably, in different individuals, and, certainly, in 
different ti.ssues in the same individual — intestine, for example, 
being much less resistant to injury than skin. Conditions which 
won]d lead to the death of a part in which the circulation was 
already impeded or in which the vitality of the cellular elements 
»as inipaircil would produce no such effect where such local weak- 
ness did not obtain. This is well exemplified by the necrosis of the 
tiiWueH of the back from pressure wliicfi so of"ten occurs in condi- 
tions of debility; by ihe foraiation of ulcers near varicose veins in 
the legs; by the gangrene of the extremities which sometimes re- 
sults from the long-continued ingestion of ergot; and especially by 
H.-iiil.' ■,;angreiie. 


lly resemble one of two tyj)es, known as dry and moist gan- 

ene respectively. There are three conditions whi<'h mainly 

etermine into which of these two varieties a given instance will 

These are — (1) the amount of fluid which the involved tis- 

aaturally contain ; (:i) the extent to which the vessels of the 



piirt affected are engorged with blood, uud the amount nf flnid 
which is therefore present at the time; and (3) the rapidity of thu 
evaporation from the surfiiue. 

Dry Qanerrene will therefore occur in those parts in which the 
tissues nutiirally contiiin but little Hiiid, such as bone, cartilage, and 
tendon. It will also be ft-enuently associated with such obfttructioiw 
of the arteries as may occur without any corresponding interference 
with the circulation in the veins and lymphatics. Dry gangrene, 
therefore, may result from enibolisni. from slowly progressing artif- 
rial thrombosis, and from the prolonged aduiini.'^tration of vtffyi. 
Again, free exposure to dry air, slow progress, and the dcj«tructwin 
of the epiflermis will all, by j>romoting or permitting evaporation, 
aid in producing dry gangrene. Tniler these circumstances the 
part, which is pale from the first, gradually dries up and b«c<inic« 
ctinverted into a dark, shrunken mass, undergoing but little fur- 
ther change. The conditions obtaining in dry gangrene are 
precisely those which render the growth of organisni-s alnxtst 

Moist Oangrrene. — I'nder opposite circumstances a part consist- 
ing largely of muscle and other soft structures may become rapidly 
gangrenous, either from an acute inflammation or from renuas ob- 
struction combine*] with a weak arterial supply. When this haj)- 
pen."* the tissues are accordingly gorged with an albuminous fluid 
full of breaking-down red blood-corpuscles. The haemoglobin of 
these fonns a reil solution which soaks into and stains all the tis- 
sues. The limb is much swollen, of purplish color, and often 
studded with bullie of blood-stained fluid. If such a part is 
exposed to warm, moist air, septic bacteria ipiickly enter through 
the skin, multiydy rapidly in the highly putrescible fluid, and gene- 
rate by their action gases — chiefly sulphuretted hydrogen, ammonia, 
nitrogen, ami carbon dioxide — which give rise to the emphjsema- 
tous crackling s^) often as.sociated with gangrene. The tissue* soften 
and liquefy, the whole part becomes exceedingly oflfensive. auii it* 
tissues change in color from reddish to brownish or greenish black. 
For putrefaction to occur it is absolutely essential that septic Imic- 
teria be admitted to the part; consequently, such cbnngfs are met 
with chiefly in external parts or in those intertuil parts to which 
organisms have free access. 

When the life of nn internal organ or part is destroyed and b«^ 
teria are now admitted to it, as in simple infarction, its tMsuek 




umlergo a series of degenerative fatty changes known as necro- 

Coagnilation-necroBiB is a term appliod to a peculiar form of 
sudden tissue-death. The cells in 'lying seem to give rise to some 
substance or substances which unite with the Ivniph and cause an 
apparent coagulation of the dying cells. Microscopically, the 
nucleus disappears, and the contents of the cell are replaced by a 
etructureless hyaline-looking material. Fatty degeneration subse- 
f|aently sets in. The process may be the result of bacterial action. 
It only occurs in parts freely supplied with lymph, and is never 
found iu the brain. 


COURSE. — Gangrene may be circumscribed or spreading. 
The courae varies chiefly with the eauge, but the remittance of the 
tissues, which depends ujion their vital energy and blood-supply, 
must always be taken into account, for causes which have little 
effect on healthy tissues may lead to sloughing in the aged, in the 
diabetic, in the albuuiiniiric, and in the intemperate. 

With regard to the first factor, circumscribed gangrene im])lie8 a 
circumscribed cause. This form is exemplified by the death of 
tissue resulting from mechanical violence, the actual cautery, or 
plete stoppage of the circulation. On the other hand, spreading 
grene necessitates a cause which spreads before it. Thus gan- 
grene from arterial thrombosis often spreads but slowly and with a 
well-defined margin. But the typical sfireading gangrenes are 
those due to intlammation, in which, probably, the actiiin of urgan- 
ijiins on the fluids of the part constantly provides fresh ijuantities 
of the irritant. 

When the process becomes circumscribed, the dead tissue — 
»pharelug or »luiigh — acts as an irritant to tlie adjacent living 
Mtructures, causing more or less inflammation of them. If the 
slongh is aseptic, the inflnnimation is slight, k-adirt;: merely to the 
fortnation of a layer of fibroid tissue round die dead mass by which 
it becomes encapsuled. This occurs especially in internal parts, 
and is bt>8t illustrated by the fate of simple infarcts. When thus 
encapsuled the dead part ceases to irritate ; it becomes decolorized, 
fattjr. infiltrated with small round cells which absorb the fatty 
•letritus, and is ultimately converted into a small fibrous scar, which 
mav calcify. 

When the slough is superficial it generally putrefies and becomes 


Etronglr irritant; but mummificatioD vill minimiie this. The 
inflammation of living tissue round the now limited slough is 
spoken of as the line of demazcation. Exudation and migration 
occur finely into a narrow sone of lirimp tisttu surrounding the 
edges and base of the slough : fibres and all firm connections 
between the liring and dead tissues are softened and eaten through; 
and. finallj. when this process is complete, the sloogh is cast off bj 
suppuration occurring along the line of demarcation. If the whole 
thickness of a limb die. the stump left by casting off the sphacelus 
will be conical, for the soft fiarts retract somewhat, and the bone 
separates lower down. The less vascular a tissue, the longer will 
be the time occupied in its erosion — f. </. fiiscia. tendon, bone. If 
the dead mass be deeplv seated and suppuration occur aboat it, 
fistulie will form, leading ftx>m it to the surface. Through one or 
more of these it mar nltiinatelv be cast off. as is seen in necrosis 
of bone. After removal of the slough an ulcerated surfiice is left. 

Sknius Oamobekb. 

This is a form of necrosis which affects especially the lower ex- 
tremities of old people, and is the result of several of those etiolog- 
ical conditions which have already been enumerated. 

The most important element in the production of senile gangrene 
is the presence of atheromat'iM* or mlearroH* cAan^n in the arierif$ 
of the limb, which greatly diminish their elasticity and calibre and 
profiortionatelv impair the circulation in and nutrition of the part. 
This is shown by the coldness of feet, cramps, and other abnonnil 
sen.«ations so often experienced by the patient for some time before 
the gangrene sets in. The slowing of the circulation is usually 
much increased by defective action of the heart, due to atrophy o^ 
degeneration of its muscular substance. Thus the contact of tia ^ 
blood with an abnormal vessel-wall is prolonged, and this is some!= 

times sufficient to cause the formation of a thrombus in the artert '• 

The clot thus former! slowly spreads until it may extend firom th" * 
foot t" the groin. Gangrene then supervenes. It begins in one or: ^ 
more toes simultaneously and extends slowly. It is often surpris-^ 
inply iimitetl. and even where the thrombus extends into the pop—* 
liteal artery part of the f<M»t may escape. In other cases emholi»m^ * 
with superaddetl tlin>mlx»sis, may be the starting-point, a chalkjr"^ 
jilate *>r a parietal thn>mbus being swept from a large into a smaller"^ 



Finally, the gangrene may be inflammatory, due to some trivial 
injury, such as a sliglit abrasiim of the fimt. the cutting of a corn, 
or some excess of heat or cold acting upon feebly-nourished tissues 
supplied by disejised vessels. 


Under the name oi faUneerosit a peculiar change occurring in 
fat has been described. It consists in the formation of opaque 
white areas half an inch or less iu diameter. are of firm 
consistence, and are scattered tiiroiigh otherwise normal fat. Tlicy 
stain with osmic acid and melt on the application of heat. Under 
the microscope the contents of the affected cells are either crystal- 
line or opa<jne and granular. 'J'he transition from diseased to 
' healthy cells is abrupt. The surrounding parts are occasionally 

Fio. 4. 

TM-necnwif, The «lirupt Irnii.-llinu ft-om Ilie htnllliy ctlbi nii the left to the nccroiied celto 

»i>n the right 1> well markuil. The content* of the affected celb an finely gnuiulju'. 
(From ■ tiwrimen hy Dr. Kollealuii.) 

infiltrated with small ronnd cells. Fat-necrosis is most frequently 
encountered in the subperitoneal fat, but is occasionally tuut with 

Pathology. — Four distinct e.xjtlanations of this change in the fat 
lavc been offered. According to Balser and Zenker, it is a primary 
[necrosis of fat, following its excessive growth, and occurring there- 
lore in fat people. Balser also noted its association with hcmor- 
Irhage in the neighborhood of the pancreas and surrounding parts. 


Langerhans attributes it to the destructive action of steap&in ab- 
Horbed from the intestine. Fitz, recognizing the frequency with 
wliich it is associatoil with pancreatitis, considers that it is due to 
the spread of inflammation from the pancreas itself. Rollesiton' 
raises objections to nil these views, and driiws attention to the 
occurrence of the change in conditions due to severe disturbance 
of the abdominal sympathetic. He points out that in acute lesions 
of the pancreas the solar plexus is likely to be involved, and sug- 
gests that '• fat-necrosis " should be regiirdeil as a disturbance due 
to some affection of the abdominal synipatlietic. In this way, it» 
ordinary Jigtriftutiong, its a-agociationg with inflammatory conditions 
near the head of the pancreas, and the »i/mpf.<>ms. resembling those 
of acute intestinal obstruction, wliicb freijuently accompany it, are 
all, to a certain extent, capable of explanation. 

Post-mortem Changes. 

The changes which always occur in tissues after death must now 
be confstdercd more particnlarly. First, with regard to the blood: 
this fluid undergoes the earliest and most rapid change. The hscmo- 
globin escapes from the red corpuscles, partly by oxidation and 
partly by the destruction of the corpuscles themselves, and, dis- 
solved in the liquor sanguinis, j)ermeates the surrounding tiasu 
The corpuscles are ultimately completely anniliilatetl, nothing 
niaining but a few minute granules. The staining of the tissues 
with hiemoglobin is conimonly known as post-mortem eteuninff, 
iiud the apfiearunces it presents are very characteristic. The lining 
mend)rane of the heart and blood-vessels, being in immediate con- 
tact with the blootl after death, are the parts princi])ally affected. 
The dissolved hiemoglobin also soaks through the walls of the veins, 
thus giving rise, on the surface of the skin, to red lines which mark 
the position of the vessels lying beneath. The staining is of a 
uniform pinkish-red color, thus differing from the punctiform 
and stratiform redness of byperjemia, from which it must be care- 
fully distinguished. The amount of staining is in proportion to the 
rapidity with which decomposition lia.s taken place and to the amount 
of blood contained in the part at the time of death. Marked stain- 
ing of the endocardium and great vessels occurs very rapidly after 
<lcath from septicaemia. 

Post-mortem discoloration must be distinguished from jxtst- 
■ Trant. Path. Soe. of lA>nd„ 1893. 


mortem staining. It is a purplish color seen in dependent parts 
which are not pressed upon, and is due to the gravitation of fluid 
blood into the vessels of these parts. It disappears if the body be 
turned over. 

In muscle the arrest of nutrition is accompanied by a state of 
rigidity known as Bigror Mortis. This is a peculiar condition of 
the muscles observed in almost all bodies after death, in which they 
become firm and somewhat shortened, a^ though in a state of per- 
manent contraction. It comes on as soon as the muscles have lost 
their irrit*bility — i. e. their capability of responding to artificial 
stimulation ; in other words, as soon as the nutritive processes have 
completely ceased. The time of its appearance will therefore de- 
pend upon the state of nutrition of the muscles at the time of 
death ; the more healthy and vigorous this is, the longer it is before 
the nutritive processes completely cease, and consequently the long- 
er it is before the rigor mortis supervenes. The length of its dura- 
tion and its intensity are in direct proportion to the lateness of its 
appearance. In people, for example, who are in perfect health and 
die suddenly, as from accident, the rigor mortis does not usually 
come on until from ten to twenty-four hours after death ; it is very 
marked, and often lasts two or three days. In those, on the other 
hand, who die from some exhausting disease, as from chronic phthi- 
sis or the adynamic fevers, in which the nutrition of the muscles 
becomes much impaired, the rigor mortis appears very soon, some- 
times as early as ten minutes after death ; it is very slight, and may 
pass off in less than an hour. It has been said that in cases of 
death from lightning and from some of the severer forms of the 
adynamic fevers the rigor mortis is entirely absent. It is doubtful, 
however, if this is the case, as the rigor mortis has probably escaped 
observation, owing to its early supervention and rapid disappear- 
ance. As soon as the rigor mortis has passed ofi* decomposition of 
the muscular tissue commences. 

With regard to the nature of the change, Kiihne and others have 
shown that it is really owing to the coagulation of the albuminous 
substance of the muscle — myosin. The myosin, fluid during life, 
coagulates when nutrition has ceased, the coagulation being at- 
tended by the liberation of a free acid. Thus are produced the 
firmness, hardness, and opacity of the muscle together character- 
istic of rigor mortis. These disappear as soon as decomposition 
commences. The transverse striation of the fibres then becomes 



indistinct, and gives place to irregulnr rows of granules and fat- 
nioieciiles. In the mean time, the muscle jioftcns, its sarcoleroma 
ili^appears, and ultimately nothing remains but a aoft Ktructur«l(«s 
debris. This change is not confined to muscle: in the cells of 
other tissues a similar coagulation of the protoplasm takes place on 
the cessation of the nutritive processes. 

Respecting the pn»t-mortcm changes in other tissues, pn>toplasm 
geneniliy not only coagulates, but tends to become finely grnnulM*, 
after death. Ft sometimes increases in bulk, so that the c«'lls look 
swollen ; and in nucleateil cells tlie nucleus often shrinks or eiitirelv 
disappears. The cells ultimately break up into molecules of vnrions 
sizes. In adipose tissue the cells diminish in size, owing to the 
escape of the fluid fat, which diffuses itself throughout the sur- 
rounding structures. The fibres of connective tissue swell a|t, 
become opa<(ue, and ultimately li(|uefy. In nerve-fibres the white 
substance of Schwann coagulates and collects into small ilrons 
within the neurilemma. Cartilage, bone, and hair resist the putre- 
factive process longer than any of the other tissues, and arc the 
least altered by it. 



It has been shown in the preceding chapter that the complete mnA 
permanent arrest of nutrition in a part causes death — that is, ce«- 
satiiin of function. We have now to consider those morbid pro- 
cesses in which nutrition is more or less impairvd, and in which, 
therefore, proportionate diminution of functional activity will be 
the characteristic consc()Ufnce. Nutrition may be impaired in two 
ways: in f/umititif, so that waste comes to be in excess of Hssiniila- 
tiou, or in qunlitt/, either the food or the metabolism of the cell 
being abnormal. Excess of -waste over assimilation leads simply 
to atrophy, or sim)dc diminrition in the sixe of a part r>r of the 
whole body, whence results impairment of its functional powers. 
On the other hand, alteration in the chemistry of the cell or in 
the (jualitv of the food supplied to it mnii lead to degeneratioQ of 
the cell-contents: some abnormal substance appears in the tissues. 




iothim! by metamorpliosis of the ceIl-f>rnt(>|ila.siD, or deposited in 
the cells by the blood and uot consiuned. This, nguiti^ causes more 
or less impairment of the functions of the degenerate tissue-elements. 
Both atrophy and degeneration must therefore be regarded us stages 
toward death ; and in both cases the impairment of nutrition not 
uncommonly becomes so extreme that it amounts at certain spots 
tu absolute arrest. Death of the most affected cells consei|uently 

Several abnormal substances may appear in the tissues as results 
of their degeneration, and, according as these substances arc believed 
to be derived from the t-ell-protoplasin itself or to be merely deposits 
from the blood, the degenerative processes are divided into two 
groups: the metamorphoses or degenerations prof>er sind the 
infiltrations. They differ essentially. In the metamorphoses 
the cell-protoplasm is gradually transformed into a new material. 
This process is often continued until complete destruction of the 
histological elements has taken place and all trace of the original 
structure is lost. In the earlier stages of tlie process function is 
impaired: in the latter it may be completely arrested. In the 
Infiltrations the new material is not derived from the cell-proto- 
plasm, but is deposited from the blood : there is an infiltration <if 
a new substance. This is rarely followed by destruction of any of 
the histological elements ; hence the structure of the tissue is much 
less altered than in the metamorphoses, and function is usually 
much less interfered with. 

The metamorphoses are — fatty, mucoid, colloid, and probably 
albuminoid. The infiltrations are — fatty, calcareous, and i)ig- 


Atrophy must be carefully distinguished from arrested develop- 
ment. It is a decreuiti' in the amount of a tissue, owing to diminu- 
tion either in tlzv (simple atrophy) or number (numerical atro- 
phy) of the histological elements of which it is coni[>osed. It is 
attended by loss of weight and iuipairnient of function. The two 
varieties, simple and numerical, are often associatLil, the latter 
being an advanced stage of the former. 

Atrophy may be general, affecting to a greater or less e.xtent all 
the organs and tissues of the body, or it may be local, and therefore 
limited to particular parts. In general wasting the stress falls at 



first iifinn the aiibcuttineoiis adijiose tissue, tlion u[ion fiit in other 
situations, as anmud visciTa und in the oiucutiiin. then ujion the 
mugclesand glandular organs, and lastly mid least upon the osseous 
and nervous structures. 

AiIlpcMC tlKBiie : n, ncinnal ; b, mnipliic, (W>m a caxe uf |ilithiiU : a, ■ 6lnslv £>t-ceU, wllh 
ceU'WaU, nuvleuii, and drop of fat. :< ai»). (Vlrthow.) 

Musfulur tissue also may atrophy by simple diminution in the sixe 
oT its jiriniitive fascieuli : and here, a,s in adipose tissue, atrophic 
prolifcratifin of the muscle-nuclei seems to be common. 

I'nless their vital nrtli'itj/ is exhausted the shrunken cells arc 
capable of recovery ; all that is necessary for their restitution is 
diminution of waste or increase of assimilation, according as one or 
other is faulty. 

MICROSCOPIC APPEARANCES.— Diminution in size is the 
most common condition met with in atrophy, and may affect all 
tissues, as is well shown in ordinary emaciation. Thus adi{H)se 
tissue is merely common connective tissue, many cells of which are 
distended with fat. When a person emaciates the fat is gradually j 
removeil from the cells, which diminish in size, and the fat which 
once filled them completely may be reduccil to a few isolated drops; 
it is usually partially replaced by serous fluid. The cell-wall ami 
nucleus often become distinctly visible (Fi<r. ■'>). and multiplication 
of the nucleus is not infreijuently observed (atrop/iic />roUt'f!rittion). 
This example, though usually given, is not a good one, inasmuch 
as the diminutiiin in size of the cells is due to the absorjition of s 
substance with which they have been hijjlirntvil. and which is not 
essential to their well-being, whilst the protoplasm, at first at nil 
events, is not affected. The cells of all glands may undergo true 
atrophy; they become smaller, being often finely granular from the 
presence of molecular fat. Shrinking of the whole organ results. 

FiQ. 6. 

ATROPHY. ^^^^^^ 

Numerical atrophy is often an advanced sta^e of »imple atrophy. 
The elonienis not onlv tliiniuislt in si/.o, but some actually i»erisli, 
as is well seen in advanocil mrujiliies of niiiscle ; then restitution is 
possible only by the production of new elements, whereas in simple 
atrophy repair can be eflected withont new Foniiiition. In certain 
tissues — as the spleen, lymphatic glands, and skin — in whicli growth 
occurs by addition of new elements, and not by enlargement of 
j)re-existing cells, atrophy is probably always due mainly to nu- 
merical loss. 

Although atrophy in its strict significution consists simply in a 
diminution in size or in number of the component elements of a 
tissue, it is rarely ii perfectly simple process, but is iisually asso- 
ciated with more or less fatty degeneration. This itidicsites fuiilt in 
the chemical processes of the cells. Probably, when the nutrition 
of a part is sn much interfered with as to cause it to atro|)hy. those 
portions of its celts which sh(uild be combined with o.xygen and 
rendereij soluble remain : fatty degeneration is the natural fate 
of protoplasm under such conditions. It is jiossible, too, that an 
atrophying tissue would not store sufficient oxygen for its use. It 
will be seen subsequently that fatty degeneration arises from causes 
similar to those which produce atrophy itself. 

PHYSICAL CHARACTERS.— The naked-eye recognition of 
at^Tophy is often difficult. Atrophied organs are usually diminished 
in weight and size. They also contain less blood, iind are ilrier, 

pa-ler, firmer, and more fibrous-looking than in health. The great 

B *^*'" tf "on IS diminution in weight and size of an organ; but these 

^'•■•^■y considerably in health, especialh' with the weight and size of 

^_^"*^whule body; moreover, they may be small from incomplete <le- 

^^^lopment. Again, accumulation of blood and other fluids in an 

o»-|^Q may bring its weight and size up to or above the average, 

*it.Lnugh its essential tissue is considerablv diminished in amount. 

«c8anie fallacy mav arise from overgrowth of the fibrous stroma 

*" an organ. 

-'^11 the tissues of which an organ consists may waste simidta- 

'^^Kju.sly, but the term " alro[ihy " implies, primarily an<l chiefly, 

'^«»ting of its characteristic cells, as opposed to the stroma. The 

^^Kels and nerves of course share in the wasting process. The 

blirous constituents are the last to atrophy ; and this fact, together 

*itb the diminished blood-sup])ly, accounts for the pallor, dryness. 


toughness, and fibrous appearance above mentioned as nsnal in atro- 
phied organs. Not uncommonly, as the higher cells shrink and 
disappear the connective tissue of the organ incre<ue9 — as in the 
secondary " scleroses " of the spinal cord — and it may become the 
seat of fat-infiltration, as in pseudo-hypertrophic muscular paralysis. 
This tendency to take advantage of the obvious weakness of a con- 
tiguous tissue is perhajvs to be explained by Cohnheim's theory of 
the " physiological resistance " offered by one tissue against invasion 
of its territory by another. (See " Tumors."') More probably, how- 
ever, the overgrowth of connective tissue in such cases is due to a 
general attempt at repair which only results in the increased growth 
of the least specializeil and most easily regenerated tissue. 

BTIOLOOT. — The occurrence of atrophy is sure evidence that 
the nutritive exchange in the atrophied part is disturbed, so that 
tc<ui< tjccfed* attimilatioH. This is the imnuduite caune of aB 
atrtiphie*. A*gimiltttum may be deficient because of insuffieienl 
tuppljf of food, or because of inabiliti/ on the part of the tissues 
to u*f the food supplied. The circumstances which excite excessive 
waste in individual cells are but little understood. It is convenient 
to speak of </«*h<t«j/ atrophy as distinct from locaL 

Qeneral atrophy may be causeil by : 

1. Deficient Supply of Nutritive Material. — Whatever inter- 
feres with the supply of nutritive material to the tissues will be fol" 
lowetl by their atrophy. Thus the following conditions may all l>® 
causes of general atrophy : Deficient supply of food: obstructio**^ 
to the passage of food into the stomach or intestines, as in strictu *"* 
of the ivs4>pbagus or pylorus ; the mala^imilation which resul *^ 
from the various conditions giving rise to dyspepsia ; interference' 
«ith the abs*>rption of the chyle fn>m obstruction of the thorac^- 
duct or fn>m disease of the mesenteric glands, constituting the sC^ 
calKn) "tabes mosontorioa." 

•2. Bxceasive Waste. — .\ll C(>nditions attended by the loss o^ 
larc»» «|uanti«ios of nutritive uiatori.ii may also be causes of general 
atr»>phy. Among these ar\» — ivntinuous hemorrhages : profuse and 
kntK-cootiaucHl suppuration fnnn chronic bi>ne disease or empyema; 
^iMfkna; and the excretion of large quantities of albumin in 
^|kl** diMMiie or of sugar in dialvtt^ mellitus. The waste from 
Mtd timue-changr^ acr>mi|Kinying acute febrile disease must also 
MnA under this hv«d. 





^^. Impaired Vital Activity. — This constitutes nn important ele- 
n]^r:it in tiio piotliiction iff the atrophy of old age — eenile atrophy, 
life ailvnuces the ability of the elements to perforin those cliem- 
processes which are necessary fur the preparation and aosiniiia- 
of the tissue-food dimiuinhes more rapidly than the ability to 
iFortu those which arc uoticerned with the prodnetiuii of the waste 
«lucts. Hence, these elements gradually atroidiy, and ultimately 
all :xrDaoifestation3 of their vitality may cease. 

Although general atrophy may occasionally be referretl to one of 
.he? foregoing causes, it is usually due to the combined influen<u' of 
tw«:» or more of them. The atrophj* associated with pulmonary 
ph'tVjisis, for example, re^sults partly from /o«« nf nvtritiw material 
in j»r()fuse expectoration and dian-luea, jiartly from deficient siippltf 
cor* eic(jaent upon imperfect oxidation of the blood and upon inter- 
fere?' nee with assimilation, which is so often caused by structural 
ch(m.dges in the stomach and intestines, and partly from the inrrca»cd 
ti$tm^M^e-wngte of fever. In senile atrophy, again, in addition to the 
ge»»«jral diminution of nutritive activity, there is freipiently some 
oot»«3itiou of the digestive organs which interferes with a^^similation : 
tbi^ materially aids in producing the ultimate result. Increased 
tisEK^je-waste, loss of appetite, and interference with assimilation all 
''**1> to produce the atrophy which accompanies fever. 

^t^OCAL ATROPHY. — In local atrophy it is often very difficult 
'** *iiscover which factor in the nutritive exchange is at fault. 

1 - Deficient Supply of Nutritive Material. — The effect of di- 

""^^ishing the blood-supply to a part will vary, according to the 

''*S*'ee of the diminution, from slight atrophy to absolute necrosis. 

t^iminished supply of arterial blood is a common cause of atrophy 

i/**-»««Vf), and may he brought about in various ways : (1) By oh- 

"^^tt-ction of the itupplyinff vesaeh hefore thetf enter a part. Thus 

P''<^«4sure of an abdominal aneurysm on the 8j)ermatic artery may 

^Uso atrophy of the testis, and fracture of a long bone above the 

P***»»t where its nutrient artery enters may result in wasting of the 

Pl>«r fragment. (2) Bif uniform and eontinnoux prexxure which 

**'^»* not compress the veins disproportionately. Thus atrophy, 

' ^^»i of hones, results from pressure of aneurysms and tumors; 

^^f r fissures are formed in solid organs fi-om pressure of band-like 

** «-» ^jsions ; atrophy of the kidneys will follow obstruction in the 

***ary passages; and, rarely, wasting of a testis may be due to 



pressure of oM hivinntoeeles nr liyilroceles. Pressure msv nl^o arise 
within the enpsiile oi' an orj^uu by the appeuruuce of some now 
growth or infl a minatory eft'usion, especially that leading to the 
forniiilion of young, ftrongly-coutnictile eientriciul tissue. Tlic 
eflcet of this is seen in cirrhosis of the liver, and, according to some 
piithohjgists, in grannlar-contrnctcd kidney. In all "pressure 
iilrophies" the coustaiit pressure also acts directly on the cells of 
the jiart and tlius impiiirs their powers. (3) Mfchanical ronffettinn 
in the same way sometiuies leads to atrophy. The circulation is 
iiu|teded, and the blrMid is not returned normally by the veins. 
Hence there is deficient iirterial su]»]ily, and atrophy results. Thi.i 
is seen, for example, in the niechanieally congested liver of heart 

2. Diminiahed Functional Activity. — Atrophy always caiiw* 
diminished funetionid activity, but sometimes dimitiished fiiurlwwil 
aetiviti/ seems to be itself the cause of atrophy. In these cases the 
immediate cause is either deficient supply uf food or impairrd rittil 

Dimini.sbed functional activity of a part imjdies that the chemical 
proces-ses in its cells are less active than irormal ; such celU n-ipiirc 
less fiHid. How tiie needs of each tis.siie are made known to the 
bloiid-lorming organs is not utnlcrstood. but the su])ply is, as a rule, 
speedily adapted to any variation in the demand. Couse((Ucntly, 
tissues will, .soon after they have ceased to perform their funcliorn*. 
receive only sufficient material for tho.^e chemicid processes wlii«3" 
still go on in them. This is insufficient to maintain the mass *>' 
proto]ilasra retpiired to do the full work of the tissue, so some of '' 

After birth, those parts which nre no longer required in t»" 
altered circulation gradually atrophy. The umbilical arteries »'• 
vein become thrombosed up to (heir first branches, and shrink to * 
fibrous cord as the clots organize — ^_just like any other vessel Ci* 
across or tied. Hut this does not explain the closure of the ductii'^ 
venosus or iluctiis arteriosus, in which the conditions are not faviir-^ 
able to thrombosis. lUililenitiori of these vessels caji at present liff 
sjKiken of simply as a developmental fact, comparable to closure 
of the foramen ovale. The Wolffian body disappears as the kitlnevg 
develop, and the thymus wa.stes in the second year. These, ]h'T- 
haps, are examples of atrojdiy of organs following the development 
of others better fitted to do the work — illustrating, as it were, the 


converse of the law that when an organ atrophies or is removed, 
correlated organs hypertrophy and take on its function. (See 
" Hypertrophy.") 

Muscles atrophy when they are rendered inactive by chronic 

<lisease of joints, by splints, or by paralyaia from disease or injury 

of the nervous system above the anterior cornual cells with which 

they are connected — i. e. by an " upper-segment " lesion. When 

the muscles of a part waste, all its other tissues — nerves, vessels, 

bones, etc. — suffer ultimately from impaired blood-supply. Thus, 

in part at least, we may explain wasting of the bone in a stump or 

limb long kept at rest ; the absence of that intermittent pressure 

which it is the function of bones to bear is probably a secondary 

■cause : at all events, increased strain causes hypertrophy of a bone. 

After removal of the distal part of a limb the main artery and 

branches supplying it become smaller and thinner. The rectum 

dwindles after colotomy to a scarcely pervious cord : in this case 

the passage of faeces over the mucous membrane no doubt acts as a 

stimulant to its vessels, as well as an excitant of muscular action, 

and, as after colotomy the rectum is never distended, its tissues 

adapt themselves to the empty condition. Atrophy of the stump 

of the optic nerve follows removal of the corresponding eyeball. 

The female generative organs atrophy at from forty-five to fifty 

years of age, the male somewhat later; the spleen and whole 

lymphatic system waste after middle life: probably in these cases 

the vital energy of the cells of the parts concerned is exhausted 

*l>out the times mentioned, and diminished function is the result, 

•»ot the cause. Thus these are really examples of "senile 


Ttephoneurosee. — When a muscle is cut off from its connection 

^*ththe cells in the anterior comu, or when these cells are destroyed 

*■■ seriously injured, fatty degeneration of the muscle, a more rapid 

V'ocegs than simple atrophy, sets in. In the case of atrophy those 

^^a-nges which nervous stimuli alone can excite (p. 23) probably go 

***> but in the former they are completely arrested. Examples of 

'Uis atrophy are afforded by the acute bulbar and spinal paralyses 

™ adults, infantile paralysis, some cases of progressive muscular 

•ttophy, neuritis from any cause, and rupture, contusion, or section 

^' a nerve. Salivary glands waste on section of their nerves. 

Serves cut off from their ganglion-cells (of which they are long 

Processes) also degenerate rapidly and waste. In all these cases the 


yuTiiiTioy mpAinKD. 

intorstitini connective tissue increases, and often becomes loaded 
witli fat as tbf higlicr tissue lii^appears. 

'i. Excessive Functional Activity. — This mav. (|uite cxcojitioii- 
ally, be a cause of atn»|iiiy — e. g. of the testis, and possibly of the 
kiilmy. Tliis will be further discussed in the section on "Chronic 
luttTstilial ^'ejiLritis." 

Atbopht of Bone. 

As in other tissues, iitrojihy of bone is usually accompanied by 
more or less fatty degi'neratiou. Old aye, dinunf. and coristant 
prenKure art* its most freijuent causes. 

When due to old <r<if tliere is ditiiiuHtinn in wcirrbt, Imt no change 
in size. The loss of weight is the result of the gnidinil ennversion 
of the cdtiipact tissue into one closely resembling the canctdlous. 
The spaees become larger ami their bony walls thinner; the con- 
sfijuent britlleness (if the bone is therefore a nnirked feature. This 
form, known as eccentric atrophy, occurs with other senile changes, 
and generally affects all bones, but is specially marked in the neck 
of the femur, rendering it liable to frnrture from trivial injuries. 

Atrophy from dinu^i' or from rtiuHfaiit /irrmurf is acconipanietl bv 
diniinutiiin in size as well ns in weight. The bone beneath the 
periosteum is gradually absorbed, and the medullary eanal shrinks 
pro|Mirtionately. '['his variety is known as concentric atrophy, 
but the ehatiges charact-eristic of the eerentrir form are often pres- 
ent as well. It is a local alteration, and is met with, especially in 
the Inng bones, in cases of long-standing ankylosis, dislocAtion. or 
paralysis. The effect of constant pressure in the production of 
atrophy is well shown in the enlargement of clefts ami perforations 
of the hard palate which often residts from the in.sertion of jdiigs. 
These interfere with ihe blood-supply, and thus cause atrophy. 

Atrofdiy of bone must not be confounded with arregted dnrlop- 
mmt. The latter is eomtuiuily met with in the later stages of 
infantile paralysis. A very similar result may be proiluce<l by any- 
thing which causes premature ossification of an epiphysis, such as 
rickets, inflammation, or injury. These are the common catises of 
stunteil lindis ; and microcephaly may be tine to premature ossifica- 
tion of the cartilage between the basi-sphenoid and the basi-occipital. 


This appears to be a proper place to describe the changes in the 



Inngs in emphyBema, as the chief of them is atrophy of the inter- 
alvcolar 8e])ta. 

Emphysema consists essentially in a permanent enlari^ement of 
the infunilibula and air-cells due Uy atrophy of the intervening 
septa; it should l»e distinfriiishtvl from the acute over-disteation 
often seen, especially in children, uftur death from bronchitis or 
whooping cougti. The condition of the lungs met with in these 
diseases is sometimes called "acute emphysema." 

VARIETIES. — Two varieties are described : (1) Ilypertrophous 
or " large-lunged "' emphysema — by far the most important, and 
always indicated when the term "emphysema" alone is used; (2) 
Atrophous, small-liingeil or senile emphysema. 

1. In Hypertrophous Emphysema the lungs are enlarged, some- 
times so much that tliey lu-tually in the raid-line in front, 
obliterate the superficial cardiac dulness, project markedly into the 

Fifi. « 

Rmphynema nf thr long I from a case of clironlr hriini'liUU): A pniiinn of th« rounded 
anterior edio! of the lung The vnrli'd size of ih<? lavltles furmtxi hy lUtteiitlon oftbc alveoU 
«n<l atrophy of the ]Mrtitiuns in wi-11 shown. (From n «|H:c'lm«ii liy Dr. Arkle.) 

neck, and push down the diaphragm. Owing to the of their 
elasticity the lungs collapse but slightly when the chest is opened. 


and their usually sharp edges (in front and round the base) are pale, 
thick, round, or more or less irregular from the protrusion of soft, 
pale, rounded swellings : similar swellings frequently project toward 
the diaphragm ; the tongue-like piece of the left lung below the 
notch is often extremely swollen, and the lungs may bear distinct 
grooves corresponding to the ribs. Everywhere, in advanced cases, 
the air-cells are seen through the visceral pleura with abnormal dis- 
tinctness, but the apices and sharp edges are first and chiefly 
affected, and spaces of considerable size are here met with. Ab- 
normal pigmentation is usual. The lungs feel much like a down 
pillow; they "pit" easily, and crepitate but little. On section the 
emphysematous parts are pale, dry, and bloodless ; and when large 
spaces are present in the part cut, the collapse of the affected areas 
is very marked. 

Microscopic investigation shows that the dilatation commences in 
the infundibula, and extends thence into the alveoli opening into 
it ; that the inter-alveolar septa atrophy and ultimately become per- 
forated, their elastic fibres yielding and then disappearing; that 
the stretched capillaries become thrombosed, and then likewise 
vanish. The apertures in the inter-alveolar septa enlarge; and 
later others form between the infundibula, and thus are developed 
irregular cavities which are sometimes as large as a filbert. The 
largest are situate in the pale, rounded, bleb-like swellings. Fattv 
degeneration of the alveolar epithelium is commonly present, and 
is probably secondary to vascular disturbance. 

The communications between the pulmonary and bronchial 
vessels become dilated. The connective tissue round the smaller 
bronchi may be increased as the result of bronchitis. 

Hypertrophy or dilatation of the right ventricle (p. 117) fre- 
quently results from the obstruction to the pulmonary circulation, 
any marked dilatation being accompanied by the venous congestion 
of cardiac failure. The thorax becomes barrel-shaped — almost 
fixed in a position of full inspiration. 

2. Atrophous Emphysema occurs usually in thin old people 
who seem to be undergoing general atrophy. The lungs during 
life may leave the heart unduly exposed ; when the thorax is opened 
they collapse excessively, falling together "like an inflated bag of 
wet paper " (.Jenner). They are excessively pigmented, and their 
apices and borders, even after collapse has occurred, usually show 
appearances like those in the large-lunged variety, and are due to 


similar naked-eye and microscopic changes. In this form, appar- 
ently, the elastic tissue is not so generally affected as in the largc- 
lunged variety. 

liTIOLOQY. — All conditions which increaae, either absolutely 
or relatively, the pressure on the inside of the air-vesicles, or which 
w^eaken their walls, may act as causes of emphysema. 

(1) Intra-alveolar Pretture Increased Absolutely. — Increased 
pressure in the air-cells may be due to violent expiratory efforts 
with closed glottis, as in coughing; to violent muscular efforts 
while the glottis is closed and the thorax distended ; and to the 
blowing of wind instruments. Those parts of the lungs which are 
least supported — the apices and edges — will be most affected. This 
is the expiratory theory of Jenner. Emphysema due to causes such 
as these is often called primary. 

(2) Intra-alveolar Pressure Increased Relatively. — When, by 
reason of collapse, compression, or consolidation, the entrance of 
air into, and the consequent expansion of, any part of a lung are 
interfered with, inspiration will tend to produce a vacuum in the 
immediate neighborhood of this portion with greater force than in 
other parts, and the air-cells in this particular neighborhood will 
tljerefore tend to become more distended than those in other parts. 

Similarly, when from the same cause a whole lung fails to expand, 

ita fellow stretches over toward it, and even the mediastinal con- 

tCEkXi may be displaced in the same direction. This form of em- 

pii^sema is termed vicarious, compensatory, or secondary, and this 

®*r»lanation of its causation is known as the inspiratory theory. 

(3) Weakening of the Alveolar Walls. — This weakening may be 

**'^*^ to (a) the atrophy and loss of elasticity which accompany old 

^S^, the most important element in the causation of atrophous 

^***r>ly8ema; (6) atrophy following the stretching, narrowing, and 

** "I * deration of the blood-vessels, which in its turn is a result of 

**^^*"-distention of the air-cells from any of the causes before 

***^*itioned ; and (c) inherited weakness (emphysema may run in 

*^^**ilie8) or weakness due to some interference with their nutrition 

Worn the mode of living or other causes. 





The term Patty Degreneration is here used to include all 
of abnorninl acciinitilatioii of fttt in tlie tissues: but it is fre)|urnll 
cniploved \i» synonynious with "'fatty metamorphosis" nnd 
opposed to "fatty infiltration." 

The abuorraal nccuuiulntion of fat in the tissues may ri'siilt fi 
either iitfiltratiou or metamorphosis (p. 4.3) — two essentially iliffer 
ent processes as regards causes, nature, and effects. E.xample* ol 
both occur in health (pp. t)l, (34). 

According to Cohnheim, all fat found in the body has the win 
chemical composition, being a mixture of tripalmitiu, triolein, ah ^M. 
tristearin. It has since been shown ' that if dogs are fed on colics 
oil. linseed oil. or mutton fat, tiie melting-point of the deposite<l fm.« 
will vary with that of the form in which it was given, and thmin 
the case of the colza-oil diet the tissues will contain eracic »cici« 
which under ordinary conditions is absent. 

In fatty infiltration fat bron;rlit by the blood is taken up 
deposited in the substance of ci-rtain cells — viz. those of the c-onM*"*' 
tivg tinntf of certain parts (especially subcutaneous and subserous) 
those of the mnhilln of limb-bones; and to a less extent those ** 
the lirtT, which thus serve, physiologically, as reservoirs of fal. ' 
is impossible to draw any line between normal and pathulogi^^' 
fatty infiltration so long as the process is confined to those e 
grou|>8 which are j)hy8iologically liable to this infiltration. TL»- 
the subcutaneous fat and the fat normally present along the coi 
nary vessels in mi<ldle-aged a<Iults varies much in amount consL 
ently with pt-rfect health. But when the fat spreads wiiU-ly ov- 
the surfa^-c of the heart, it is clearly abnormal, and the evident 
of disease is still stronger when the fat appears between the m 
cular fibres in cells which noriually contain none. The tondcn 
to morbid fatty infiltration may be general {o/n-iiifi/) or local. 

CAUSES. — It may be stated generally that, whenever oxidizalil 
material is present in the blood in excess of the amount rciiuire^ ' 
' Lebeiletl and Muiik, i|Uoted by Uungo. 



r tho supply of force ami maiutenance of heat of the body, there 

a tendency to the deposit (storuge) of fat, first in regions in 
hich it \a normally firescnt. and later in parts which usually con- 
lin none. For this, fat itself need not be jiresent in excess in the 
)od; the presence of carbohydrates in quantity sufficient to satisfy 
ihe Wants of the organism will protect fat from oxidation. But it 

ould seem that there are factors in the process of fattening other 
ian the relation of food-supply to oxidation, for nothing is more 
»rtfflin than that a tendency to obesity or to leanness runs in 
tmilies, and it is notorious that some very stout people are small 
Iters and active, whilst many thin subjects are just the reverse, 
'ohnheira has, it is true, advanced the hypothesis that in the 
Wmer oxidation is naturally slow and imperfect, but we know of 
experimental facts in support of the view. 

With regard to the sources of fat deposited in the body — the 
•l-stufTs whence it is derived — many views are still lield. 

(1) It appears possible, from the facts stated on the preceding 
ige, that Bome fat may be absorbed and deposited without change 

the tissues, even when the food contains fat dissimilar in com- 
ition to that generally met with in the human body. On other 
•casions if any fat of the food is store*! in the body it must some- 

*•!"« undergo the change (usually the loss of some hydrogen) 

•ossary to assimilate it to human fat. it is generally held that 

Fig. 7, 



which implies passiveness on the part of the cell, is therefore prob- 
ably incorrect in these instances. 

(2) It is t;eueniny believed that ftit is not formed directly frmn 
carbohydrates, but that these take the place of the material from 
which fat can be formed ; there are, however, many facta in favor 
of the opposite view. Thus bees while livin;;; on carbohydrates 
continue to produce wa.x. In the case of pigs it has al.»o Wn 
shown ' that under certain conditions the deposit of fat is Aw to 
the carbohydrates in the food. Nothing is known concerning the 
nature of the change. 

(3) It is thought that the chief source of fat deposited in the 
tissues is the proteids of the food. These are said to be absorbe^i 
and sydit into a nitrogenous and a non-nitrogenous molecule, from 
the latter of which fat is formed, and stored if not re<|uired. 

It would appear, therefore, that excess of the diet over th^ 
wants of the body, particuhiriy if the excess be in hydrocarbons •»"■ 
carbohydrates, is one great of fattening. 

With regard to the second great canse — diminished oxidatioo— — 
this may result from sedentary and luxurious habits, ease of miO" 
and body, high external temperature, destruction of much lu»|Z- 
tissuc by chronic disease, or reduction of the oxygen-carryio ^ 
power of the l)lood owing to diiuiiiiition of red corpuscles or c» 
their hienioglobin. The fat contuiued in a normal diet may, umi*^*" 
such circumstances, be incompletely oxidized. Locally, oxidatio** 
may be tliniinished by slow circulation or by the circulation o* 
deoxidized blood through a part — conditions which normally obtai ^ 
in the liver and in parts thrown out of work, as in a muscle kept »•* 
rest. Excesses of fat may sometimes be present in the fluids around 
certain cells — «•. g. the liver-cells after a meal containing much fat» 
and the connective-tissue cells and wandering cells near a focus of* 
fatty degeneration. 

Thus to prevent fatty infiltiMtion the diet should be moderate, 
carboliydrates and alcohol being as far as possible excluded. 
Appropriate exercise and the drinking of large quantities of water 
will favor oxidation and ensure the prompt removal of waste 

-1. Microscopic. — Cells undergoing fatty 
c«»titjiln dropKts of oil — very small at first, 
insk; aud nthere, qiioird \\j Buogv. 



II distinct droplets. These run together, jtush the cell- 
Ptts asiilr, and distend the cell until its original contents seem 
bave become u mere capsule to the fat (Fig. H). As the fat is 
ie«l to the previous cell-contents, the cell is enlarged in propor- 
>& to the amount of fat it contains. 


UviT-ci'llc In vnriniui 
KtOKOi of Catty liilUlm- 
tliin. X aoo. (Riiid- 

'2. Naked Bye. — A fnttily infiltrated organ is consetiuently 
|wr« or Ie«8 swollen. Any sharp edges it may 
K^ssfes)! teml to become thick and rounded. It 
tnoro or less pale and yellovvi.>*h on account 
f anicmia (from increased intra-capsulur pres- 
re) and the presence of fat ; it is doughy and 
•t'lastic, and both receives and retains an iui- 
fP-'wion from the pressure of a finger; and it is 
'ftt*r than natural. But, except mechanically, 
fat does not hinder the protoplasm of the 
11 from discharging its functions. I'lti- 
oly, however, pressure npon the cells proper 
J" become so severe that they iiiuy fjiil to get 
cieut nourishment ; they will tlieu undergo fatty metnmorphnsig 
atrophy. The knife used to cut a fatty organ becomes greasy, 
»Btty show distinct oil-drops on the blade. 

lEJATS. — The cells commonly affected to a morbid e.xtent 
tliose physiologically liable to the process — viz. connective-tissue 
and liver-cells: with regard to the former, it is to he noted 
normally the cells of the interstitial connective tissue of woik- 
organs (muscles, nerves, and glands) are not infiltrated, but 
Itecome so. especially if the activity of the organ and the con- 
lUent afflux of arterial blood are in any way arresti-d. In obesity 
le commonest result of morbid fatty infiltration — the subcuta- 
*»>s and subperitoneal connective tissue suffers earliest and most, 
iiiBltration spreading later to the interstitial connective tissue 
l-org»n» in which oxidation is still active. The process in con- 
st! vi- tissue needs no description beyond that just given and illus- 
te*! by Figs. 7 an.l 0. 

Fatty Infiltbation op Muscle. 

niuscle fatty infiltration is common as a morbid process. The 
»i tA/! connective titumt which surrounds the fasciculi of the 




muscle becomi- filknl with fat, and tbis development of fat fHrtwfiHt 
muscular fasciculi (Fi<;. !•) must not be confounded with degcnei* 
tion of the fibres tliemselvcs. Tlie interstitial fat varies iu amount 
In some rases single rows of fat-cells alternate with rows uf niw- 
cular fasciculi ; at other times the accumulation is less refiular. morr 
existing between some fibres than between others: in all bnt tht 
most advanced cases, however, the mnscular elements luay. under 
the microscope, be discovered lying amongst the fat, even thongfa to 
the naked eye the muscle appears to be entirely converted into fat 
Ultimately the muscular fibres may undergo true fatty nict«mor|iho- 
eis an<l atrophy until they completely disappear. 

This condition is fi-eijuent in animals which have been fattenctl, 
the fat not only increu-^iing in the usual situations, but also accumu- 
lating between the fasciculi of the muscles. It mav also occur in 
muscles which from any cause have been incapacitated for lutmt 
time, and in which, conseiitiently, circulation and oxidation arc 
reduce<l to a minimum. Thus it is found in Ioug-st4tnding paralyse 
from lesions of the brain or cord. an<l in muscles which have been 
rendered u.^eless by ankylosis of a joint. In progressive muscular 
atrophy anil in chronic lead-[)oisoning the affected muscles exhibit 
this change, together with true metamorphosis. 

Fatty Inflltration of the Heart. — This is not infre(|Uftii in gen- 
eral obesity an<l after pericanlitis followed by adhesion of the two 
contiguous surfaces. It must be carefully distinguished from th« 
much graver condition of fatty degeneration. In health thero w a 
varying amount of fat beneath the visceral pericardium. alMavs 
most abundant around the vessels in the grooves between the auri' 
cli'8 and ventricles. This may so as to cover the right 
ventricle, but the left is rarely, if ever, completely en velopcnl; at 
the same time, the fat may push in along the vessels between the 
muscular fibres, so that on the rigiit side, to the naked eye. all 
appearance of muscular structure may be lost, the walla looking liktf 
a layer of fat. |>erhaps half an inch thick. In hearts leas aflected 
■triffi of fat will be seen lying amongst the muscle (Fig. 9). Tho 
lilt is always most abundant near the surface, the muscular struc* 
tun- b«'couung more evident toward the endocardium: at the base 
of the ventricles thick villous processes may form. 

The interstitial fat displaces and compresses the muscular tibrea 
between which it lies, and diminishes the blood-supply and conirac- 
tile |)Ower of the muscle [lerhaps ultimately causing tnii; laRj 



metamorphosis of the muscle ([>. 73). These two processes not 
uncuinmnnly go hand in hand, hut it is difficult to s[)e!ik dogmati- 
cally as to which in vnxy given case is primary: fatty intiltration is 

K:r;. 'I 



F»tty InflUrnticin of heurt : n nwtlon from the outer part of the left ventricle, ahnwlng 
ICTowth of fkt I/) drfiMrn the muscular fibres. In some pliiei's (Utty metnniorphimis Is eora- 
meDelng(d). x 'J»a. 

probably possible only as the functional activity of the heart (or 
any other) muKcle sinks, and the continued action of the causos 
leading to this depression woidd idtiniately cause degeneratiim of 
the fibres; the presence of interstitial fat must, however, tend in 
the same direction. Fatty dcfrfneriition and atrophy of muscular 
fibres on the other hand, is very likely to be fidlowed by inter- 
stitial infiltration. 

Fatty Infiltration of the Liveh. 
CAUSES. — In the liver fatty infiltration is exceedingly frequent, 
constituting what is commnidy known as the " fatty liver." This 
is owing — first, to the excess of non-nitro;;ennii3 oxidizalde matter 
in the portal blood : secondly, to the deoxidized condition of the 
jMirtal blood; and thirdly, t" the low pressure and slowness of cir- 
culation in the portal vessels — conditions least favorable to oxida- 
tion and most favorable to deposition of particles. An accumula- 



tion of fat in the liver thus occurs uixler two opposite con«Iitions — 
one in which there is general obcgiti/. and the fat nccmiiuhtt*.-;) in t 
liver in coiuiuon with other futrts; the other, in wliich there 
r/ffit'nil emnrintion, an<l a consequent iiupninncnt of the nxyjr" 
Hating power of the blood. The liver in ])hthisis is an example 
the Bccond of these conditions, though in this cnse the dcfcrt in tb 
O.X vpenating power of the blood is increased bv the dcstnietion 
the lung tissue. 

Pbyaiolosrical Infiltration. — The liver-cells always contain 
small i|uuntity of fat, which is tcinfMtrarilj increased a(\er tla 
ingestion of fatty sub.stances. Ingot<tion of food rich in fat 
followed by a temporary excess of fat in the portal blood, and ha 
the conse<|iu'nt deposition and temporary accumulation of part( 
this in the livcr-cell.x. Thi.s fat is first de|K>sited in the rin-umfi 
ential r.tlh of the lobules : that is, in those which are in immediifl 
contact with the capillaries nf the portal vein, From these it p 
ually passes to the central cells, whence it is ultimately conveyi 
again into the circulation. This process goes on until the exoeai 
of fat is removed from the blood and the cells regain their form* 
character. There is thus a transitory accuiuulatiou of fat with* 
the liver-cells, but the vitality of the cells is not iui]iaired therebV 

APPEARANCES.—!. Microscopic— The morbidly fatty Ii%'' 
isonewliicli constantly contains an abnoruial ({uuntit}- of fat, s* 
here also, as the fat is usually dejwsited from the blood in the por^ 
capillaries, the is first observable in the external /one * 
the hepatic loliules (F'ig. 10). It accumulates here within the ec J 
ns minute globules which increase, coalesce, and form large dro] 
of fat- The.Hc ultimately distend the cells, which become larger ari 
more globular (Fig. >^). As the process advances the iufiltrati<ii 
spreads from the periphery toward the centre of the lobule, unf- 
its whole mass may be involrol and all its cells di.stended with fal 
The vitality of the cells is not materially impaired by the infiltra 
lion, as is shown by the presence of bile in the stools and in th 
gall-bladfler. lu some exceptional cases the accumulation of fal i 
most nuirkfil iiroiirnl the intni-lobular veins. In these Virchm 
suggests that the fat is becoming excreted, anil that onh' the Im 
cells retain a little of it. In extreme cases, such as sometiiac 
occur in persons dying uf cancer or phthisis, a section of the liv« 




may look exactly like ordinary adipose tissue, being distinguishafde 
from it only by a faiut afipearance ut' a radiating structure here and 

Fio. 10. 

,^--* 1^.>_'^^'X"-,9 

'***7 Uvor. showing ■ccumulalion of f»l, miiri- usiii'ilally In thr cells of the cxJcmal «one 
!*"***« lobule. TliC'iv is al»u some Incrcasu lu the iuter-lobulur uonnectlve Itnue (cirrbimti)): 
• "CfMiUc vein; *, Intcr-lobuUr connective tliwue. x 50. 

*^»*« or an occasional section through the portal canal and its con- 
[taitted vessels. 

2. Naked Eye. — The fatty liver is increased in size, in advanced 
stages to perhaps twice the uormal. The surface is smooth, the 
*''6es are thickened and ruuiulfd, nnd tlie si)ecific gravity is 
***Ujinigliyj^ 80 tliat detiiclied portions may float in water, aitiiough 
^"* absolute weight uf the whole organ may be increased. If the 
•ufiltrntion be slight, involving merely the portal zone of the 
'""ules, the cut surface will present a mottled appearance, the 
txtepnal fatty zone being opa(jiie, whilst the cen- 
tre ig unaltered or is hyperiemic and appears as a red spot {fattif 
mitjiug liver). The more extensive the infihrution, the larger is 
tbt pall- zone, and ultimately, when the whole lolmie is involved, 
tbfre is left in the centre only a reddish-brown point marking the 
posiliou of the intra-Iobuhir vein ; in many cases even this point is 
loul Then the organ is of an almost unifurra opaijiie yellowish- 
tiliite color, and the boundary between the individual lobules may 



be coiDfiletely obscured. In excciitiMiuil cases the »ccumiilnti<in of 
fat is uiucb more fibimdaut in some ji'irtions of the liver than in 
others, so that on section yellowish points and streaks are seen scat- 
tered over its siirfiice. The cousistence of the organ is luiicb dimin- 
ished, it feels doughy, and pits on pressure with the finger, and the 
knife used to cut it becomes coated with oil. The pressure exercised 
by the infiltrated fat j>roducos eonsidenible anaemia of the organ, but 
the interference with the circulation is mi'tr miffirient to cause atcitfi, 
hemorrhage, ur other evidenreH of jjurtnl coniffstion. 


This differs from fatty infiltration, inasmuch as the fat is formed 
not from the fatty, saccharine, or nitrogenous principles of the food, 
but by metamorphosis of the protoplasm of the cells tliemselvcii. 
There is reason to believe that cell-pmtojihisiu. as it becomes efFetc. 
takes up oxygen and sjilits into a nitrogenous roolecnie, which is 
tlie first stage in the foritiatiuii of urea and a n<>n-nitrogeniiu« 
nudecide which forms fat. To repair its loss, the living protoplnsiu 
at the same time assimilates material if lias ])repared from the pro- 
teiils of the fund. In the process of hcaltliy nutrition ilestructioo 
of small ijuantities of protoplasm and corresponding reptur are cod- 
stautly going on, and the products of the decompositinn of effete 
albumin are still furtlicr oxidized, rendered soluble, and then At 
once removed. Cijnse(|uentlY, we do not find in healthy cells fat- 
granules bearing witness to the occurrence of the above-described 
decomposition. When, however, a whole cell or many cells die and 
are protected from ferments, evidence of fatty luetamorphosia of 
protoplasm is soon forthcoming. This we can watch in various 
])hysio!ogical processes — e. g. the formation of colostrum, sebum. 
and cerumen. In all of these the fatty degeneration, death, cast- 
ing off, and disintegration of superficial cells, and the constant pro- 
duction of new ones in the deeper layers, play a chief part. Evi- 
dence of the same process is seen in the fatty degeneration nf the 
musctdar fibres of the uterus undergoing involution. It was for- 
merly suppose<l that the transformation of entire bodies which have 
lain for many weeks or months in water or ilamp soil into adipoctrt 
(an ammonia or a lime soap) wa.s an illustration of the same proccco, 
but the change is now known to be due to organisms. 

It is now universally recognized that the fat seen in the musciilM* 
fibres in fatty metamor]iho8i3 is the result of a change in the fibres 


lemselves, and ia not derived from without. The experiments of 
Bauer prove this, Those experiments were made to de- 
lermiiK' the source of the fjil in the aeute fiitty degeneration pro- 
duced by poisoning with phosphorus. Dogs were starved for twelve 
days, so that all availahle fat, whetlier in the tissues or in the food, 
"li^lit be exhausted. At this period the daily excretion of nitrogen 
(uron) »veraged eight grammes. Small doses of phosphorus were 
thetx given. The average daily excretion of nitrogen at once rose 
to t'wenty-four grammes, while the amount of oxygen taken up ami 
"f carbon dioxide given off was greatly diminished. The animals 
were then killed, and large quantities of fat were found throughout 
tlie l(ody. The increase in the excretion of urea showed that the 
|de!*t mction of proteids was also increa.sed ; and the presence of the 
|1'U'J5« i}uantities of fat found itftiT dvnth made it highly probable 
rtbai^ it had been formed as part of the general pmteid destruction. 
In other words, the phosphorus produced very extensive ami gen- 
era. 1 fatty degeneration, and the fat must, have arisen from the pro- 
tf{*f<j»tn of th<' cell*. Voit concluded from these investigations — 1st. 
Tha*.t the transformation of cell-albumin is independent of the 
*up»j3ly of oxygen, but that if oxygen be deficient the fet and 
otl»cir products of the transformation, being incompletely oxidize<l. 
*ct5»-»mulate in the cell. 2d. That the presence of fat in the cells 
™*^^^ thus be due to increased tran.sformation of the albumin or to 
<lii«a inished oxidation of the products of its decomposition. 3d. 
T»»«.t the fatty degeneration in poi.sivning by phosphorus is due 
''"*l» to an increased transformation of the albumin of the cells 
"•^i to diminished oxidation of the fat and other products of the 
L Stolnikow and Gaide have recently published experiments which 
to show, as Cohnheim suggested, that fat can be produced by 
"^ ilecomposition of lecithin, the phosphuretted fat of the nervous 
'.^**tvm and a constituent of many other ti.ssues. According to 
">ose observers, glycero-phospLoric acid, stearic acid, and cholin 
"•s formed in the process. 

OaUSES. — A study of various examples of fatty metamorphosis 

i'«*»iOer8 it clear that the occurrence of this change indicates the 

|^*^*^-ay of the protoplasm concerned ; that the larger the proportion 

^ the cell-albumin replaced by fat the nearer is the whole cell to 

^^^h ; and that the nearer the cell is to death the more impaired 




will be its power of taking up oxygen and coubiniDg it witli cBfi 
materials. Con8ei|iiontl_v, we may give tbe riinse of fattv mctai 
tuorphosis as grave depresiiioii nf thr rilal actiritif of a cell — loadin 
to (1) too rapid destruction of protoplasm, (2) lesaeninl sbilitv ra 
repair louses, and (3) im[>aired oxidizing p«.)wcr. Tbi.>« depre«M>4 
vitality is always the prorimati' rainif, an<l is iisiinllv indacetl b 
(a) alteration in the iiuantity and (|uiiiity of tbe food brought t 
tbe cell: or (/») by change in tbe physical contlition of tbe cell 
((•) by the gradual but natural death of tbe cell, for there u 
natural limit to the life of a single cell, as there is to tbe life 
the whole organism. 

a. The effect of diminisbing the blood-supply (•'. e. food la 
oxygen) to a part is seen in the fatty degeneration of the hearCQ 
walls whicb follows atheromatous changes in the coronarr arterice 
t» well as in organs in which the lumen of tbe vessels is diminishc« 
by lardaceous or sy]>bilitic changes. Working organs and titisoa 
which have been long disused, and to whicb, consequently, tk' 
blnoil-supply is diminished, undergo fatty changes anil atniphj 
until they become so small that the blood-supply is sufficieut t- 
maintain the nutritive ei]uilibrium. Impaired circulation in a pir~l 
— e. g, mechanical congestion — has a similar effect. Fatty dcjci»H 
eration of the cells of cancers and other rapidly-growing tu; 
and of inflammatory exudations is oft<>n due to insufficient b1 
aapply : but the cells may be naturally sbort-liveil, and in inflm 
mation the cause of the process must have an injurious action 
the leucocytes as well as upon the fixed cells. These variatioi 
the (fuantity of the blood-supply act locally (p. 77). Alteratioi 
the ijuiillty of the blood-supply act gciirrally, and all colls are 
liable to be affected. Thus, fatty metamorphosis of the iu<»*' 
important organs may result from various forms of anaemia, fro* 
scurvy, and from the addition to the blo<id of a protoplasmic p**' 
son, like phosphorus, arsenic, or antimony. Poisoning by cu{r*^ 
monoxide has a similar effect, due to the power this g«ii poiuMja^' 
of combining with oxygen and thus preventing the oxygen firt^ 
nijcbing tbe ti.ssues. It is sometimes maintained that the presett ^ 
nf an excess of carbon dioxide is a more important fact4)r in t^^ 
prudnction of fatty changes than any deficiency in the supply (^ 

h. The action of fever as a cause of fatty metamorphosis depeotd 
pftrtly on the action of a high temperature on protoplasm; but tltf 



iuses of the specific fevers and other circumstances probably give 

rise t<i blouil-i-han^es which act in the same direction. A high 

External temperature tends to diminish oxidation. (See "Fever.") 

e. When the limit of life of a cell is approached, it undergoes 

ttty degeneration; thus wo account for xemfe fatty nietamorpbosis 
)f tht* cells of cartilage, cornea, bone, and other parts. Under this 
[leading may be included the fatty degeneration of nerves which 
Kdlows interruption of their connection with their corresponding 

fWs. Such degeneration seeni.s to be the direct result of the loss 
l>f the normal physiological stimulus (Fig. 41, p. 12.")). 

A PPEARANCES. — 1. Microscopic. — The process consists in 

the tran^ifiirmation of the proto|)la.sni of ceils into molt'cubir fat, 

rbich appears as minute granules, first of all in the protoplasm, 

»nd later on in the nucleus. The granules — characterized by their 

tmall size, sharp contour, strong refractive power, staining reaction 

(black with osmic acid), insolubility in acetic acid, and solubility in 

etlicT — gradually increase in number till the whole of the proto- 

iplaiSTn may be transformed; some of theiu may coalesce and form 

•'"'■tinct drops of fat. As the process advances the cells umlergo 

*" increase in size and become more globular in shape, the nucleus 

''•'*^«^»Dn« involved, the cell-wall, when this exists, is destroyed, and 

''*^ cell may thus be converted into a mass of fat-granules, known 

" «» granule-cell (Fig. 11). 

^^ranule-cellB may be of two kinds: (1) dend or dying cells con- 

^]|^''*"t.i'il into ma.xst's of c<dieriiig fat-granules, or (2) living leucocytes 

f*~f*nule-rinrif!rg) which have taken up fat-granules from a focus of 

'J^t'tierafion, probably to convey 

-141 into the lymphatics and thus 

'"Bet ab.sorption. Connective-tis- 

*«<i and neuroglia-cells near foci 

*' degeneration similarly become 

Nutirjrwl with fat-granules, (iran- 

]lle-<!tl|8 are often called " influni- 

a»aiory" eorpiisi-le.'H or " corpuscles 

[**• Ciluge." .\mong typical gran- 

I I ^ I" %, t Cr t'lllIlK- I'll-' llllltTMlI}' 

I'ule-celU. formed by metamorphosis nU'-ccUs," «mi »t«ii iii.> mannur in which 
" ®liilhelial cells or leucocytes, are 
"^ "c<ilosirum"-cor|)uscle8 of the first milk secreted, but later on 


Fio. M. 


FMtty im'l»mon>hoiil« of i'i>ll»: o, from ■ 
caiiirr : b. fniiii the liraiii hi rhroiilc ioft- 
eniiii; The liitUTKhow the larcc "Bmii- 


•* process becomes one of true secretion, and the resemblance ceases. 



I'ltiiniitcly fatty degeneration may affect connective-tissue fibres. 

In old foci of fatty degeneration slieaf-like bundles of acicular 
crystals of margaric acid and rbuuibic crystals of choiestcrin are 

It is said tliat in fatty metainorjiliosis tbc percentage of fat in tlic 
tissue is but little incfcased, tliuugh this is disputed by Krehl:' 
apparently many of tbc granules are formed by the invisible f«t 
wliicli is noiunilly bniiiid up with protoplasm, as it were in «n 
"aniiilgam" (p. 1.^) (Birch-Hirscbfeld). 

2. Naked Bye. — In advanced stages fatty metamorphosis pnv 
duces defiuitu naked-eye ajipenrances. Those are — (1) slight or 
modcriite swelling, which, however, is often replace<l liy mort' or 
less shrinking of the organ when absorption of the fat is going 
on, as in advanced acute atrophy of the liver; (2) admixture of »d 
opatiue yellow color with the normal tint of the ti.ssue, often in the 
form of patches, spots, or streaks, as extreme degrees of the change 
are usually reached only in limited area.'^ : and (3) loss of elasticitr 
with diminisheil consistence, the organ being flabby and friable ami 
its capsule wrinkling easily. Fat may be foinid upon the kiiifis 
and the nortnal ilistinctness of structure (upon section) is obscurM. 

The mieroscojie is necessary in the diagnosiB of the earlier st.n2«** 
of this metamorphosis. It reveals the gninular and somewhat- 
swollen state of the cells. The larger size, higher refractive powf. 
insolubility in acetic acid, solubility in ether, and blackening ^X 
osniic acid distinguish the fatty gniniiles from the albuminous gr»** 
ules of "cloudy swelling" soon to be described. When possil*!^* 
the distinction from fatty infiltration must also be made. Difficalty 
in this arises with regard to coimeetive-tissue cells, liver-cells, bTi*' 
intestinal ejiitlielium, in whicli both intiltratiou and me(aiiiorpb«»*** 
may occur; perhaps also the usual epithelium may contain infil- 
triited fat when this is being eliuiinated after severe contusions. 
The cliief point of difference between the two processes is the siie 
of the droplets, which are small in the metamorphosis, but tub 
readily together in the infiltnition. This holds good as a rule, hit 
infiltrated fat e.vists in small droplets at first, and becomes fint'/y 
divided before absorption, should this occur; on the other haini. 
<brm in fatty metamorphosis. an<l are characforisdi- 
rule atrophv ancl ])hosphoriis-poi.«ioning, anil in 
len the metamorphosis is at all advauced. I'i»g- 
whl, DniUth. Areklv /. Uin. Med., Bd. It 



lis may. therefore, occasionally be impossible. Evidence of de- 
ruction of cells is conclusive in favor of metamorphosis. 

IITERMINATIONS. — 1. Absorption. — The fatty particles into 
licb the cells have been transfoniu'<l arc, under favorable circum- 
inccs. readily absorbed. The ik'generative process may 
itl the fat be removed before the part has been dangerously 
Irolved. Such recovery probably often occurs, for example, in 
e kidneys and heart. Also when elements are completely degen- 
kted the fatty dt'bris is usually removed by absorptitni. This is 
»n in the fatty degeneration and absorption of inflammatory prod- 
Is, such as occur in t;rou|H)us pneunioniii: iu the degeneration 
d absorption of the cells of new growths, leading to central 
Juppiug"" or •' unibiliciition" of nodules or to shrinking of the 
lole nmsi* (atro[)hic scirrhiis); mid in tlie degeneration of small 

Rsuch as results from embolism, thrombosis, or hemorrhage 
brain or other organ. As the restilt of such absorption we 
.. jave loft a mesh work of vessels and connective tissue whence 
' os^ential cells have disappeared, as in the later (red) stage of 
*t« yellow atrophy, or we may have an ordinary scar from the 
^'•loproent of fibrous tissue ; or, lastly, a cyst of dear fluid may 
^ain. For absorption to occur the tissues roiinil the degenerated 
■ « mu.«t be freely su|)plied with blood. 

8, Caseation. — In this mode of termination the fatty products 
not absorbed, but are gradually converted into a yellowish 
ble material which has been compared to soft cheese. It is 
k.erally said to result from disproportion between the degenerated 
38 ami the vessels by which absorption might be effected — a <lis- 
portion which is, in the first instance, the principal cause of the 
;eueratton. It is most fre(|uent, therefore, in parts which con- 
3 but few vessels or in which the vessels become obliterated by 
^««iire from without or by thickening of their walls by endar- 
tis. Caseation is. conse(|uently. most often met with in tuber- 
ir and gummatous masses and in rapidly-growing cancers and 

t-'lieesy niassea are constantly met with in the lymphatic glands, 
k brain, the bones, and especially in the lungs. Considerable con- 
>5on has arisen as to their nature and origin. Formerly all cheesy 
*»e9 were regarded as essentially tubercular, and it is true that 
>ercular lesions have a greater tendency than any others to case- 


ate fully nn<l to form tyjncal cheesy collections. (See " Tubcrculi> 
sis.") Bat, ns just stated, other formations may under^jo a change 
which is practically imlistin^uishable: so caseation cannot be re- 
garded as proving more than the occurrence of fatty degeneration- 
A caseous mass is tubercular only when it is due to the presence of 
the bacillus tuberculosis. Still, it is doubtful if fatty defeneration 
of a gumma or of a rapidly-growing tumor ever give* rise to ^ 
typical " caseous " mass, such as we often fin<l a.1 the result of tuber — 
cular inflammation, and it has yet to be shown that caseation caim 
occur apart from the action of some niicro-orgnnism. 

The process consists in a grailual drying up of the degrncmtecS^ 
I elements ; the fluids are absorbed, the cells — which are many oP 
'them incompletely degetieriited — shrivel and atropliy. the fiit utidiT — 
goes partial saftouification, cholesterin forms, and the tissue ihu^ 
becomes converted into a soft, yellowish-white cheesy suhstaure.. 
compose<l of atrophied cells, fntty d«?bris, and cholesterin cryst«l*- 
The cheeey material may gradually dry up more and more. txoM. 
ultimately become encapsuled by a layer of fibrous tissue, ntufl 
even calcified. In other cases it may undergo a process of sof^eniu^ 
and lii|uefaction. 

8. Calcification. — This is an advanced stage of the preceding 
process. It most frei|uently occurs when the caseous mass is com- 
pletely shut off from the external air. as in lym|>hatic glands tnd 
bone, or when encapsuled in the lungs. The mass becomes infil^ 
trateil with ealcnreotis particles, and is thus converted into a calct- 
reotis concretion. Single cells in a fatty focus may undergo tlii* 
infiltration — p. g. ganglion-cells in an area of cerebral .Hufteninfr. 

4. Softening. — An inHammiitory cell-exudatioti. usually nf tuber- 
cular origin, may undergo fatty metamorphosis, and, as it* ci-lU 
break up into granules, sufficient food is often effused to form a 
thin purifonn liquid, usually containing curd-like cheesy mB*se«; 
this looks like pus. but really consists of granules. fat-<ir(>ps, and 
perhaps cholesterin crystals suspended in fluiil (" pathological milk "\. 
This is the pathology of chronic abscess of tubercular origin. If 
nut diicbnrge<l. the fluid may be absorbed, leaving a caseous mu^ 
which may calcify. 

Sometimes, after long (juiescence, caseous and even calcified 
masses iifi|><-itr to excite sufficient nutrition to result in the forraa- 
tion of an abscess and in the discharge of the ui!i.s.s. Tin- nat 
of the fresh irritant is unknown. 





The effect of fatty mctainor|ihosis is to iinjiair or arrest function. 
Recovery is only possible in the earlier stages. 

Pattt Degeneration of Blood-vessels. 

f rimary fatty degeneration of blood-vessels is in most cases a 
serxilc change; it is an expression of that general iin|iairuient of 
vits«.lity which exists in advanceil life, and is usually asssociated 
witFi similar changes in other parts. There is, however, a variety 
liin i ted to the lining meinbraue of the largest arteries : this is often 
me-'t with in early life and in persons who are otherwise perfectly 
hi's«. 1 thy. 

Jt'-fttty Degreneration of Arteries. — This may hv primary, or 
8e<2<Dndary to atlieronia or r)tlier intlauiuiatory condition of the ves- 
wle*^ the fatty change being preceded by cell-infiltration of the sub- 
end othelial connective tissue. (See " Athcnmia.") 

- fc- *ri mary fatty degeneration is not preceded by any disease of the 
par-** affected by it. It may affect any or all of the coats of the 
•n^sry, but is most commonly met with in the intima. The change 
"'ViaJilly commences in the endothelium and the subendothelial eon- 
"ccr-tive-tissue cells, small groups of cells becoming affected in va- 
"OVJ8 parts of the vessel: and it may gradually extend from within 
OD'txrard, the intercellular substance softening, until, in exceptional 
<^»«3s, the whole thickness of the intima is destroyed (Fig. 12). 

L n the earlier stages this condition is recognized by the existence 
of ^mall. irregidar. opaipie. yellow bite patches projecting very 
sli^litly above the surface of the iutima. These, which are so con- 
*'««'»»tly met with on the lining 
'»«-* 1 nhraue of the aorta, may at 
first be mistaken for atheroma. 
Ttx^yare in most cases, however, 
Tf««.*lily distinguishable by their 
«««T*^crficiality, ami by the facility 
*'»tli which they can be stripped <s 
on from the subjacent lavers, 

» . , ' ■ Fattv (Icgi'neriit ion "f llu' iiilirniil inni nf 

■*o>cti present a natural aj)fiear- the aoru: Kmiiu yi'iiowish-whUo« 

»ttCC. In atheroma, on tiie other v^-»catlvrvd ..vir Ilu- UninK mornhmni- ..r 

thp vennel. A »'ery Ihiti Inycr wiw iweleil nIT. 

bWil — which affects the deeper Tho (m>iii»i or ratmniiTiiiM »ti<i tin- iiinirihu- 
^tractiirt"*— if the superficial «'">'•' i"! m the i.uinm «r.. ,ho«n. x m 

hyer be removed, the opacity anil thickening are seen to exist 
tienfiith it. In many cases the change is limited entirely to the 

Fio. 12. 



innermost layers of the vessel. Tlie more the subjacent tissues i»r« 
involved, the greater is t-lie irreijithiritv in the shape of the putchct, 
anil the less readily can they be separated ■with the forceps. 

The opai|ne patches occasionally break down. For this to happen, 
the cells must beconie destroyed by the fatty change, and the inter- 
cellular substance softened. The f2;ranidar dc'bris thus formed in 
carried away by the circulation, leaving small, irregular. 8uperfici«l 
erosions upon the lining nienibrane of the vessel. These erosions 
are not iilri-r» in the true sense of that term, not being the result 
of an inflammatory process. They resemble the superficial ero- 
sions so common upon the mucous membrane of the stomach. 

Simple fatty degeneration may occur in any artery, but in the 
smaller ones it is especially liable to affect the e.Kternal coat (Fig. 
18), and in this situation its injurious inHuence is most marked. 
Here, by diminishing the elasticity and contractility of the vessels, 
it causes degi'tuTative changes in tlie parts whicii they supply, and 
often leads ti> rupture. This is exemplified by many cases of 
chronic cerebral softening and cerebral hciuorrhage. although in 
such instances atliei'oniatous are generally associateil with the 
simple fatty changes. In the larger arteries, as the aorta — where 

it is exceedingly common — it is of 
less importance; the more e.xtCD- 
sive jirocess, atheroma, has a far 
more ileleterious effect. 

Fatty Degeneration of Capil- 
larieB. — Fiitty changes arc also 
fouml in the capillaries, especially 
in tlie nervous centres and the 
kidneys, in Bright's disease (Fig. 
13, b). The process commences 

F«tty defioncmtlon of •mull vi-wrln uf . i i i- i ii i 

pin m«ier (from a r«i* ..r chronir nriKhtfi "" the endotliehal cells, and may 
.ii»(»«-) : «, iininii .rtfo'. "'f onMia ..f involve considerable areas of the 

which ore nonu'Whnl Ihlrlieiicil; h, h 

implUnry. In whleh an siin h fiw r>d Capillary Wall, 80 that ruptUre IS 

WoodHarpuwie.. y «oo. ^^f^^j^ ^^^ ultimate result. Thi.* is 

common in the smallest cerebral blood-vessels, where it is 8ome> 
times a cause of cerebral (ca[)ilhiry) hemnrrhage. 

Fatty Deobnbbation of Muscuj. 

Both striated and non-striated muscle may be the sent of fntty 
degeneration. In both the iiiusculur fibre-cells are the seat of the 

Fio. 13. 


change; they become filled with fat-granules, and are ultimately 
destroyed : the process thus differs essentially from fatty mflltra- 
tion (p. 59). 

Non-striated Muscle. — Fatty metamorphosis is frequently met 
with in the middle coat of arteries undergoing fatty degeneration 
and in the muscular fibres of a uterus in process of involution. 

Striated Muscle. — Both the voluntary muscles and the walls of 
the heart show identical changes. The earliest stage of the affec- 
tion is characterized by an indistinctness in the transverse mark- 
ings of the fibres, which in many parts become studded with minute 
particles of fat (Fig. 14). These gradually increase in number and 
size, but almost always remain small, and are usually distributed 
somewhat irregularly within the sarcolemma. In some parts single 
or parallel rows of granules are found running along the length of 
the fibre ; in others they are grouped around the nuclei, which they 
seem to lengthen, or arranged in transverse lines 
corresponding with the strise of the muscle. The 
fibres become extremely friable, and are readily 
broken up into short fragments. As the process 
advances the transverse markings entirely dis- 
appear, and nothing but molecular fat and oil- "' 
globules are seen within the sarcolemma. It has tinn of muscular 
recently been affirmed that in some cases the stria- carter"' sto^ 1', 
tion is merely obscured by the fat-droplefes, and more advanced, x 
that these are in the early stages confined to the 
interfibrillary sarcoplasm. The sarcolemma itself may ultimately 
be destroyed, and nothing remain of the original fibre but the fatty 
debris into which its albuminous constituents have been converted. 
This is true " fatty degeneration " of muscle. 

Fatty Dbgbnbbation op the Heart. 

It is in the heart that fatty degeneration of muscle is most fre- 
quently met with, and here it assumes a most important aspect from 
the deleterious influence which it exercises upon the motor power 
of the organ. The degeneration may be diffuse or eimimgcribed, 
acute or chronic. The wider the extent of tissue that is affected, 
the less advanced, as a rule is the degree of the degeneration. It is 
in those cases in which small tracts of tissue only are involved that 
the process is met with in its most advanced stage. 

When the change is slight, as in the difhise form, the muscle is 


somewhat softer and more flabby than naturnl ; it in more friable, 
and i»fti'ti breaks witli a *ift griimilar frsictiiro ; and its color is rather 
[mler and more (i])ai|iK' tbaii that oi" healthy eardiac tissue. The 
microscope shows the muscular fibres to have lost to some extent 
their striation and to coiiKiin {jranules of fat (Fig. 15, /»). 

Tlie diffuse form of degeneration is caused by defects in the "/W- 
ity or in the amount of the blood which is supplied to the heart- 
walls. Thus it may be due to — 1. Diseases in which the oriJatinn 
prorenKes are reduced to a miuimuui. This will be the case in dis- 
eases which are attended by nnirked anivmia, whether gradually or 
rapidly induced: such are uniemiafrnni repeate<l or excessive bleed- 
ing, pernicious anaemia, advanced leuchieniia, malignant and other 
caclu'xi:e. The aeenuipanying drawing (Fig. 10) was taken frona 
the case of a weakly young girl who was under my care suffering- 
from slight valvular disea-so. She cjuickly succumbed with acat® 

Fig. 16. 

Acute fatty difivncrntloD of hcnrt iind of other muacles: <i. heurt: fc, rertii* *Moml^=^ 
Tlu' wlinli- <if till" lu■urt•ll^sul• «u* uflectuil, uiiO Bind tlif miiDdeti In other pnrt» of the 

fatty degeneration of the heart and other muscles, induced by pi 
fuse loss <d' blood thiring a menstrual period and by inability tc 
retain food,' (See '• Pernicious Anicmia.") 2. Certain poiton*^ 
especially phosphorus and arsenic, have a similar effect. In ihifi^ 
' Tfati*. Clin. Soe. Land., vol. riii., 1875. 


group must be included poisons developed in the body in the course 
of acute infective diseases, especially diphtheria, in which a some- 
what high degree of degeneration may be attained and be the cause 
of sudden death. 3. Interference toith the circulation in the coro- 
nary arteries is also a frequent cause of a more or less general 
degeneration of the muscular tissue. This occurs especially in 
connection with aortic incompetence, and explains the early failure 
of cardiac power in this form of valvular disease. Atheromatous 
changes at the orifices of these arteries lead in the same way to 
diffuse fatty degeneration. Adhesive pericarditis and myocarditis 
act similarly ; they hamper the heart mechanically, and the cause 
of the inflammation acts injuriously on the muscle-cells. 

There is no clear line dividing the circumscribed from the dif- 
fuse form. Sometimes the degeneration, although perhaps more 
or less general, is much more advanced in some parts than in others. 
In such cases the heart presents a mottled appearance ; opaque, pale 
yellowish, or brownish patches are seen irregularly distributed 
throughout its substance. These patches, which vary considerably 
in size and form, are met with especially in the papillary muscles, 
the columnse carnese, and in the layers of fibres immeiliately beneath 
the endocardium. They may also occur beneath the pericardium 
*nd in the deeper portions of the organ. They correspond with 
the most degenerated portions of the tissue. They are soft and 
flabby, and have a rotten consistence, tearing readily under the 
"^ger. Under the microscope the fibres are seen to be in an 
advanced stage of fatty degeneration, the sarcolemmata containing 
"***lecules of fat and oil-globules, which in many parts have escaped 
.^*i lie free amongst the surrounding but less degenerated tissues 
' *g. 14, b). These more localized degenerations are most common 
*^ld people, and usually result from considerable disease of many 
t:he small branches of the coronary blood-vessels, and not from 
'. **<litionsof general anaemia. The peripheral layers of muscular 
^^We also frequently undergo extensive fatty degeneration as the 
J ^^alt of pericarditis. The connection between these localized 
^fenerations and the occurrence of rupture or of aneurysm of the 
^^Tt is well known. 

^rown Atrophy of the Heart. — Somewhat allied to, and occa- 

*^*»ally associated with, fatty degeneration of the heart is the con- 

^^ion known as brown atrophy. This consists in a gradual atrophy 

''^ the muscular fibres, together with the formation of granules of 



brownish-yellow or hlurkish pigment. These granules of pigment, 
which arc pruhahlv the L-ohiring matter of the muscle, are either 
groujied in eliisters arouiul the nuclei or more generally ilistributcJ 
witLii) the fihie. The fibres are Jre([uently, at the same time, the 
Beat of more or less fatty degeneration (Fig. ItJ). This change 
usually occurs as a senile one or as a part of general 
marasmus from other causes. It is also met M'ith io 
Some eases of canliae hy|iertro]ihy. Its recognition 
is in most cases impossible without the aid of the 

Fio. 16. 

Fatty Degeneration of the Kidneys. 

Fatty degeneration of the kidneys fretjuentlj 
occurs as a result of inflummation of these organs. 
This secondary degeneration will he alluded to 
when treating of rcitul inihimitiations. Primary 
fatty degeneration is much less freijuent. It murt 
iiiiv.' In wmie 1,^. borne ill mind that the renal epithelium verv com- 

piirln uiiili'ntniiv 
flight r« 1 1 y 

Brown Mrophy 
of the hcjirl, 
showliiK t h V 
gTNIillli.'S or (iIk- 
tniMit and thv 
ainipb)- nr the 
tlhrt's. Thi' lallvr 

monly coutuin.'* more or less fat. hut it is onlv when 

mctamorphosiii. jjjjg jj, excessive that it can he rejiarded as a diseMcJ 
condition. This e.xeessive formation of fat in the 
kidney is less common than is generally supposed. It is, however, 
occasionally met with in chronic diseases, especially in pulmonury 
phthisis. It is also a result of ]n>is(Uiing by phosphorus. 

In sinifde fatty degeneration the cliangc is usually confined t" 
the epithelium of the cortex. The cortex presents on section » 
somewhat yellowish-white surface, often slightly mottled, and th»*i 
in most cases, is marked near the bases of the pyrauii'*** 
There is no adhesion of the ea|isiile or granulation of the siirfa*?* 
Microscopically, only the nuclei of the vessels and of the connect* ^ 
ti.sauc stain «vell. This ehniige apjjears t<v interfere but little, if 
bU, with the ftinctinns of the organs, and in this respect it rese; 
bles the analogous chatige in the liver. It is not usually accoc 
paniod by albuminuria. 

Cerebral Soptenino. 

This is, perhaps, the most suitable place to speak of cerehra 
eofteuing. iiia.-^much as fatty ilegeneration of the brain-tissue usuallj 
constitutes a prominent feature in tlie histological changes. Soften' 
Jng of the cerebral substance is essentially a necrotic process, ant 



ly result from any cnndition interfering with blond-supply — viz. 

lammation, embolism, thrombosis of arteries or. mueb more rarely, 

of veins. Portions of tlie brain wliieli are the seat of this change 

Kmay be merely rather softer than the surrounding healthy tissue, 

^HHaking down more rcailiiy under a stream of water which is 

^Hnbwed to fall upon tliem, or they may be comjdctely diffluent. 

They arc never distinctly circumscribed, but pass by insensible 

gradations into the neighhoriti;; tissue. 

Il'nder the microscope the chaiij^e is seen to consist in a disinte- 
gration of the nerve-tissue. The fibres suffer earliest; their white 
substance first coagulates, and then breaks up into masses of various 
sizes, giving the reactions of fat: these give place to masses of fine 
fat-granules. These granules are for the most jiart the proilucts of 
the degeneration of the myelin, and are due to the decomposition 
of lecithin, which is its |n'iticipal constitiieiit. 

Next, when the gray matter is implicatLMl, the large nerve-cells 

H are involved in the necrotic stage, but. though full of granules, 

their outline may lon^ remain visible. Tiastly, the neurogliii-cells 

I and those of the small blood-vessels degenerate similarly, and the 
tissue is thus converted into broken-down fibres, granular matter, 
and molecular fat. among.«t which are many granule-cells (p. 67). 
These corpuscles are more common in cerebral softening (Fig. 17) 
than in any other condition, and form very characteristic objects: 
■ they vary from j-J^f to j^'f^r inch in diameter, and the granules they 
contain are possibly myelin, but usually fat. Many are formed by 
degeneration of gangiion-eclls and neiiroglia-cells, but many, per- 
iaps most, are leucocytes which have taken up granules. Ulti- 
roately all trace of structure is lost. 

The color of the softened portion varies considerably, chieHy 
with the amount of blood in the vessels or extravasated into the 
tissues. It may resemble that of the surrounding healthy tissue or 
o^ of a yellowish or red<lish tint. Aecoriling to these variations in 
*^*>l<)r cerebral softenings have been classified into white, yellow, 
*1«5 red. As, however, a yellow softening m!\y be but a later 
®*-^ce of red. and as white may be succeeded by red due to hemor- 
*''*«ge into the area, and again, as softenings of iuflamtiiatory and 
**• simple degenerative origin may be to the naked eye indistinguish- 
f*>l«». this classification ha.s little practical or scientific value. 

"White Softening is sometimes acute, iiml is then diu- to embo- 
WsjD of one of the larger arteries, and which usually soon causes 



riironlr whltPBnftcnliiiir 
of the brain : ncriiniilur 

death. Far more commonly it is chronic, occurring especially in 
tin' agcil. It is then fltic to gradual narrowing of the artcrif* liy 
chronic endarteritis (atheroma), often couibincd with senile impair- 
ment of the heart force as a subsidiary cause of the imperfect 
blood-siipiilv. Narrowing of the arteries from 
syjihilitic vtnlarteritis will act siuiilarly iu ear- 
lier life. The process is really one of ttiniplf 
necrosis, sudden or gradual : when it is grsiinal 
there is no reason for hemorrhage, and even 
when it is sudden hemorrhage is often absent, 
for infarction is rare after embolism of tlie 
brain. When the blood-supply is suddenly 
cut off. it might be expected that coagulative 
necrosis (p. 39) would occur, but it never doesi- 
oirpimuUi", brnketnii.wn The urea is softeiH'cl nitd untinged hv hlo<»«l. 

iKTVc'-Hhnii. iiuii fiit-itraii- ■ i i • • ■ i- * i-.. 

uiw. of whuii the »oftoii- involved, and presents either a dirty *hit^ 
«ui*tanciii. composed, ^olor or looks exactiv like the brain sronnd 

ii> one orlwo nucleatert . ,ni • n- i ' _a 

coll* are prob»biy ncne- It. i hts affected area may be merely soltenecf 
cciu, or quite dilHuent ; it may result in a cyst "f 

clear flui<l irithout any hlooti-pifimmt in it» wall, or in a scar — tli« 
latter appearing at first as a meshwork the spaces of which ar« 
full of milky fluid. Before the circulation ha.s ceased and tUe 
death of all the element.s in an area of white softening i» coi**" 
plcte a fatty degenerated vessel may burst into the area aud 
transform it into one of red softening. 

Red Softeniner is commonly depenilent upon vascular obstruction*' 
either from embolism or thrombosis. There is collateral hyperjem***^ 
rupture of capillaries, and extravasation of blood : the softened •^''^i 
sue usually exhibits reel jioints and patches mingled with white a'* 
yellow; the patch is swollen in proportion to the hemorrhage a** 
ledenia, and is rarely <liffliietit. Red softening is most common • 
the viusenlar gray matter of the cortex and of the basal gaiigli 
Red softening is also sometimes associated with the chronic whi^ 
variety. It may be inflammatory. 

Yellow Softeningr is a later stage of red softening, and. lilt 
it, is usually situat« in the gray matter — chiefly of the con vol i^ ' 
titms. The color is due to the presence of altered blood-pigment 
the result ftf the previous extra va.sat ion. The pigment mav be seel 

lules and hivmatoidin crystals scattered through th<^' 
roglia and the nerve-cells of the gray matter : i^ 


first sight the granules look like fatty particles, but are distin- 
guished by their deep black color. White and yellow softening 
may remain unchanged for long periods. 



Cloudy swelling is a frequent change, being found in all dis- 
eai3«8 attended by considerable pyrexia. Wickham Legg and 
li ^ hermeister, having produced it by subjecting animals to a high 
ext;«rnal temperature, regarded the change as due simply to the 
fev-^r, which, in their opinion, caused increased destruction of 
alt> mjmin. Increased destruction of tissue may, however, itself pro- 
da «:s« the elevation of temperature; moreover, the change is not 
roc^sn marked in long-continued secondary fevers, but in the rel- 
ati -v- «ly short primary fevers of the acute specific diseases. Further, 
th^ degeneration is specially pronounced in bad cases of diphtheria, 
ii* '^rhich disease the temperature is often low. All this leads to 
th^ belief that mere fever is an insufiicient cause. A more prob- 
"■"l^ explanation is that the infective material in the blood — the 
<!avise of the fever — has a more or less deleterious action on the 
tissues. This is supported by the observation that cloudy swelling 
"* tie first change noticeable in poisoning by phosphorus, arsenic, 
**»<! the mineral acids, all of which lead ultimately to fatty degen- 
®'"*^tion of protoplasm. Again, cloudy swelling is found in inflamed 
P&rts, and we shall see, when considering inflammation, that it is 
*Iwny8 due to the action of an irritant, which, if it were of suf- 
"*^»ent intensity, would produce death of the tissue. It would 
*Ppear, therefore, that cloudy swelling is due to the action upon 
^« tissues of some poison which tends to cause their death ; eleva- 
*»on of tijg temperature of protoplasm above the normal would 
'^^doubtedly assist its action. 

Iq considering the histology of this change we shall find that 
*'**anced cloudy swelling passes insensibly into fatty metamor- 
phosis: it is therefore to be regarded as the fir »t step toward fatty 




SEATS. — Tlte lurjro mjissies of jtrotoplasni sliow the change most 
plainly — the liver, kidneys, heart, anil voluntary muscles: but 
probably all protoplasm suffers. The change may be much more 
advanced in some organs than in others, owing perha](S to differ- 
ences iu the local circulation. 

APPEARANCES. — 1. Microscopic. — The cells are swollen and 
their protoplasm is finely granular, the nucleus and any cell-stmc- 
ture being obscure or even intlistingiiisbable ; the granules refruri 
light but feebly; they are unstained by osmic acid; they dissolve 
in dilute acetic acid, but not in other, and are therefore albuininnu?. 
In advanceil cases larger, strongly-refracting granules, blnckeiiiug 
with osmic acid and soluble in ether, but not in acetic acid — there- 
fore fatty — are found associated with tlie albuminous pranale« 
which first appear like a precipitate in the cells. 

2. Naked Eye. — When the change is well marked the affecl£s-'<l 
organs are somewhat swollen, and may be either an:cmic or sligbt^^y 
hyperremic ; the surface of a .«eetion bulges up a little ; the ti!«i 
is soft-er and more opaque than natural. 

EFFECTS. — This change must impair, in proportion to 
degree, the vital activity of the cell ; on the other hand, *- 

Fio. 18. 

Fio. 19. 

I.lvcT from ■ case of acute rheumBtinn 
with hlijh tcmpiTaturt?: tlit UvLTcells 
•wiiUeii anil irronulNr. the nuflc-tia In many 
twluK iiIino8t iDdlttlDguldhatilc. X 2D0. 

Mii.fciitar tlMutr of tliu hcnri i 
ft faee of aevore typhoid fever t : 
fibres arc granular. Ihr ourlrl 
scared, and the strlatlon lust, x 

affected parts completely recover in those cases in which the primal 
disease does not prove fatal. (.If course its most serious action 
upon the heart. 


The Liver. — Here the change is usually most marked, and is 
absolutely characteristic (Fig. 18). 

The Kidneys. — The cortex is principally affected. The Mal- 
pighian bodies and the pyramids are usually hypersemic, and con- 
trast with the general pallor of the cortex. The tubal epithelium 
presents the appearances above described; they are veil seen in 
tiie early stages of scarlatinal nephritis. 

The Heart and Muscles. — The heart becomes slightly opaque, 
pale, and soft. The muscular fibres are finely granular, and have 
lost their distinct striation (Fig. 19). Such a condition must 
materially interfere with the contractile power of the organ. A 
similar change is met with less frequently in other muscles. 

The Lungs. — The change cannot be recognized by the naked 
cje. The epithelial cells, according to Buhl, are swollen and 
granular from the presence of albuminous and fatty particles, and 
M'e easily detached from the alveolar walls. 



Mucoid Dbobnebation. 

MtJcoiD DE6BNEBATI0N consists in the transformation of the 
proteid constituents of the tissues into mucin. 

C^bemically, mucin is closely allied to albumin, more so than to 
*ither gelatin or chondrin. Like albumin, it is met with only in 

_**line fluids, being held in solution by the free alkali ; it is pre- 
f P*tated by dilute acetic acid and alcohol. It differs from albumin 

" Dot containing sulphur, it being insoluble in an excess of the 
*'^*'l, and also in not being precipitated by boiling, by tannin, or 

y perchloride of mercury. These two reagents will distinguish it 
*'8o from gelatin and chondrin, which are both precipitated by them. 

CAUSE. — This is unknown. It appears to be a reversion to an 
*»rlier state, for in the foetus the connective tissues consist almost 


entirely of soft mucin-yieUling substauce: the umbilical cord ami 
vitreous humor rt-tdiii this pwnliarity. Throii^ihout life a mucoid 
cluinge occurs libysiolugicaily in the secrctiou of mucus ; a clear 
drop of mucus apiiears in the protoplasm and increases till the cell 
bursts and the mucus is evacuated, the cell, ns a rule, not being 

Myxoedema, a disease due to atrophy of the thyroid body, was 
80 named because it was supposed that the swollen connective fis«iie 
contained a large quantity of mucin. Recent observations, how- 
ever, have shown thtit ut ihe time of death the proportion of roiirin 
in the skin is only slightly, if at all. in excess of the normal amount. 

SEATS. — Pnthohgicnlhf, mucoid degeneration may affect both 
cells and intercellular substance. It is met with in catarrh of 
mucous menibrsines. the transformation occurring niueh more rap- 
idly than under normal conditions, and the cells iieiiig often MSt 
off; also in connective tissue, in cartilage (especially the inter- 
vertebral and costal cartilages of old people), in bone, and in 
many new growths, not only in those of the connective-tiMU« 
type, but in both cells and matrix of cancers. 

APPEAEANCES. — I'luler the mu-rnKcopr these are the 8aJ»* 
as in the [diysiological process, but the cells are much more fr*^ 
quently destrojed. T<t the naked eye the affected parts are tr****^ 
formed into a homogeneous, colorless material of a soft, mucil»^'' 
nous, jelly-like consistence. When the change is limited to i**^^ 
lated portions of the tissue the softened parts, surrounded by th«^^ 
which are unaltered, often present the appearance of cysts. Th*""' 
cyst-like formations containing mucoid substance are not unct>* 
monly met with in the costal cartilages and in new growths. 

EFFECTS. — Complete mucoid degeneration implies aboliti ^^ 
of function. 

OoLLom Deoenehation. 

Colloid degeneration consists in the metamorphosis of cell-prot^^ 
plasm into a substance known as " colloid." 

Chemically, colloid differs from mucin in containing sulphur an*' 
in not being precipitated by acetic acid or alcohol. It swells whet* 
treated with acetic acid. 


ilu the adult many vesicles of the thyroid Dormally contain 
Uoiil; it is only when the formation of this mate- 
becomes general and excessive, producing one Fw. 20. 
of goitre, that the process is to be regarded as 

JAUSE. — This is quite unknown. 

IBATS. — Colloid degeneration occurs most often 

tlic thyroid; then in certain new growths, both 

Kxnata and cancers : the secondary growths in 

a*\* and elsewhere unilergo the same change. It 

It bo remembered that the term " colloid tumor " 

ilic!< nothing as regarcls the nature of the growth. 

triau tumors often contain "colloid," but sometimes the contents 

'<? nearly correspond to mucin. Other seats are rare. 

lI'PEABANCBS.— 1. Microscopic (Figs. 20 and 21).— One 
r%%-o(.niall masses of colloid appear in the cell, increase, and )iush 
^ the nucleus until they have replaced all protoplasm and the 
is considerably swollen. The nucleus usiiuUy atrophies and 

CoUold tx\\» (ftvm 
K t'oUiiliI ntucur). 


'""^(wccr, tbuwing the Urtcv alvcoU wlthlu which 1* coutalned tbti gulitUnuiu coUuld 
iniitrrliil. X «M. (RlndfleUch.) 

li«ijjpe»n». but may become colloid. Neighboring cells coalesce 
ini'i small masses, and these again into larger, which not uncom- 
iiiaiilv, under the microscope, look as if they were concentrically 




laminated (Fig. 21), Thus cavities full of colloii] are formed. 
TLo intercolluiar substance atro|iliies rather than <lept'i' 
whilst iu mucoid degeneration it is frei|ueully aflected by the i...:; 

2. Naked Eye. — Colloid is colorless or pale yellow, glistenili|;<- 
and has tlie consistence i>f rather soft gelatin, which, indeed. Ttj 
much resembles. Quite small points of colloid catch the eye: ibejf 
do not stain characteristically with iodine or the aniline dt 
The physical characters of colloid tissues are thus very diffefel 
from those of mucoid tissues. In advanced stages, however, wlloi 
may soften, and masses of softened colloid separated by scpu 
comparatively undegenerated tissue give the appearance of eyrt* 
a tumor. 

EFFECTS. — Abolition of function is proportionate to the ei 
of the metamorphu.'iis. 

but its nature is doubtful. 
Fio. 22. 

Zenkbr-8 Deoenebation of Muscle. 

This change has been regarded as allied to colloid dcgenerml 

It was first described by Zenker 
occurrinp in the muscles in typlw 
an<l chietiy in the recti abdominis, 
ductors of the thigh, the riiaph 
and tongue-muscles. It is now k 
to occur, though less often, in oti 
infective febrile diseases, such as small- 
pox and cerebro-spinal uiciiingitis: in 
trichinosis; also in the neighborhood 
of burns, bruises — either before »r aft«T 
systemic death — abscesses and tumon 
of muscle. Probably, as Cohnheim 
suggeste<l, the unusual appeannee «f 
muscle thus affected is due to a disturfc- 

A portion of the miIimu iiium'U* . .■ <■ 

,fr..m........rty,.i...MfLvon fr.|v "n<'t' '" "'i' ordinary post-m.)rtem e«j«s- 

■mtion xvuMv^ »ft.r with ulation of mvosin : in other »nril», 

Uailrr't fluid. X '»>, i*«Jutf.l J. r. 1 . 1 ■ .... , 

" /ienker s degeiienition is an example 
of coagulative necrosis. The appearances may certainly b* pi»- 
duced after systemic death, and may almost certainly occur doriag 
life iu individual fibres dying from any cause. 


APPEARANCES. — The altered fibres are much swollen and 
the transverse striation is lost. The sarcolemmata are occupied by 
* homogeneous, structureless material, which is exceedingly brittle, 
SQd usually presents a wrinkled appearance or is broken up trans- 
versely into several irregular fragments (Fig. 22). 

The portions of muscle aifected are, to the naked eye, semi- 
opaque, pale, slightly lustrous, of a reddish-gray or brownish-yellow 
color, and abnormally friable. They appear somewhat like the 
Qiuscles of frogs or of fish. The fibres are never universally af- 
fectiei ; many normal are found associated with the altered elements. 

3FPBCTS. — This change necessarily impairs the contractile 
po ^?«-er of the muscle, and it is believed often to lead to rupture of 
wnc*. e of the fasciculi and to hemorrhage. The dead fibres appear 
"be readily absorbed and quickly regenerated. 

Hyaline Dbqensbation. 

'-■-''his name was given by Recklinghausen to a morbid change 

:haa.:»acterized by the presence in cells of drops of a substance 

n^'^^'ing an appearance like that seen in albuminoid degeneration, 

^"^"•i not giving the color-reactions of the latter. It is stained pale 

yellow by iodine, and in other respects seems allied to "colloid." 

"is said by v. Recklinghausen to be a normal constituent of cell- 

pi'^^toplasm, and to be set free when the cell dies. Very little is 

kaown about the substance, however, and there is a tendency on 

^"^ part of some writers to include under this heading all morbid 

^ii^-Bges resulting in a hyaline appearance, and especially those due 

*« coagulative necrosis. 

The chief seats of this change appear to be the arteries of the 
'"■*in and of lymphatic glands ; in arterioles the adventitia is con- 
v^i^ed into a shining thickened layer. In larger arteries becoming 
•ttenrysmal Meyer has described the yielding as being due to 
V aline degeneration starting Internally and passing outward. The 
*"x»e degeneration is said to be frequent in inflamed parts, the con- 
nective tissue being affected. Gull and Sutton have described a 
"yalin-fibroid change in the arteries in chronic Bright's disease. 




(Syn. Waxy, Albuminoid, ob Amyloid Degeneration.) 

This, which \s one of the most imiwrtant degenerative procesMi 
is characteriKofl by tlie ajtpciirancc in the tissues of a colorl 
translucent, firm, Innhiceous Bnhstunce, giving them somewhat thi 
appearance of boiled bacon or of white wax. This substance offiT 
an exceedingly imdonged re.sistiince to gastric digestion, am 
exhibits some remarkiibly cbnractcristie staining reactions. Th« 
reaction with iodine led Virchow, its discoverer, to regard the sub 
stance as allied to starch and to jiropoae for it the name *'amyloi« 

Chemical Nature of the New Material. — By submittiuj 
affected organs to gastric digestion the substance may be obtained 
practically pure, ami, thus ol>tained, it has been shown by Kiiba 
to be nitrogenous, closely allied to albumin, and not starchy. It ■ 
distinguished from albumin chiefly by its resistance to the action* 
(1) dilute acids and iilkiilies, (-) the gastric juice at the body-teia — 
perature, and (;^) jiiilrefacfion ; also by certain eolor-reacti"n»- 
Marcet has shown that the organs containing it are notably defi- 
cient in potnssium and phosphoric acid, but they contsin excess of 
Bodium and chlorine. 

With regard to its color-reactiona, the best and longest kno*l> 
is that with iodine. To obtiiiii this, wash a thin slice of an affected 
organ thorouglily to free it from blooil, and then pour over it » 
watery solution of iodine, made by diluting one drachm of li(|Uor 
iodi with seven of water. In this way the lardaceous portions are 
(juickly stained dark mahogany brown, the healthy tissues assum- 
ing a bright yellow color. 

If this stained surface be treated with a 10 per cent, solution "f 
sulphuric acid, de^'ciicriited (iiirts assume, cither at onee or after 
some time, a dark greenish, blui.^li, or blackish hue, whilst healthv 
parts become grayish. Unfortunately, this second reaction is very 
variable and of little value. 

For microsctjjiic purposes the iodine and sulphuric-acid reaction 
may be obtained by staining the sections with iodine, mounting 
them in glycerin, and placing at the edge of the cover-glass a Tcry 



sail (juantity of strong sulphuric acid ; in about twenty -four hours 
"the ianlaceous tissue will be found staint-d blue. But a more 
valuable though still somewhat variable process is that of staining 
tbe sections with methyl aniline or gentian violet (1 per cent. 
«atery solutionj ; after some hours the degenerated parts are 
I'taine^l bright magenta, but the healthy, blue. This staining is 
more penuanent than that by iodine, and is valuable as a c-onfirnia- 
torj test; for the iodine reaction may be obtained with glycogen 
»nil some forms of altered albumin, and cannot therefore be re- 
garded as absolutely characteristic of lardaceous degeneration. 

ETIOLOGY. — Lardaceous degeneration is said to be much 

<-"<>inmi>ncr in males than in females, and the ages of tbe great 

"•ttjority of patients fall between ten and thirty, especially between 

''^"oiity and thirty. It is almost always fteeondary to prolonged and 

pre^fuge suppuration, due usually to tubercular disease of lung, 

•*c»uc, joint, or kidney, but sometimes to traumatic (septic com- 

Jound fractures) or other causes (dysentery, actinomycosis). Much 

'•^ss commonly it is found in the cachexia of tertiary syphilis, 

*"*t>«cially when there is chronic bone disease. Rarely it appears 

** the cachexice of severe malaria, of leuchtemia, and of cancer, and 

■■y rarely, especially in children, the degeneration may seem to be 

~«Hwry. Most of these diseases belong to the class of infective dis- 

, and Birch-Hirschfeld suggests that the degeneration may bo 

^ to an infective cause, but he adduces no evidence in favor of this. 

The degeneration may be very rapid (two to three months, Cohn- 

i m) in ap[iearing, or, under apparently similar circumstances, its 

'^'^Siet may be long delayed; this is more likely to be the ease in 

Ck»-»ng children than in adults. Like hectic fever, thi.s degeneration 

c^u^s much more readily from suppuration of foul, ill-drained cav- 

»«^ than from a much more free discharge from a cutaneous ulcer, 

l>*jn which the pus cannot accumulate under [iressure. 


©EATS. — The change is almost always widely distributed : only 
^*"cly is it limited to a single part. It may be found in almost any 
'''•'gan ; those most fre(juently affected are the spleen, liver, kid- 
**ey8. intestines, and lymphatic glands. Less fref{uently, anil 
specially when the change in the organs just mentioned is ad- 
*iiQced, minor degrees of it may be found in the stomach, supra- 
renal capsules, pharynx, oesophagus, bladder, prostate, generative 



organs, serous membranes, tlie nieiiilinmes of the brain and cori 
anil muscle. There is uo rule as tu tlie order in which the organj 
are uffected, nor as to which will be uffected in any given case. Aj 
a local change, ajijiarently t|uite distinct from the condition imli- 
cated by " lardiU'eous defeneration," it occasionally affect.s jinthn- 
loi/iral pro<liict¥. us old thrombi, iiiflumed glands, scars (esj>eciallj' 
syphilitic), and tumors. 

APPEARANCES. — 1. Microscopic. — The morbid subsfnnce 
usually appears first in the subendotliefial connective tissue of tbe 
arterioles and capillaries, and in the media of the former: the 
endothelium is unuffeeted and the adventitia usually escapes. Tbe 
change greatly diminishes the lumen of the vessel; it does no* 
affect the latter uniformly, but freijuently causes spindle-shapt'tri 
cnhirgements ; and not only do the vessels of many jiarts escap 
eutirely. but the distribution of the change in an affected orgai 
may be quite irregular. 

With regard tn the further spread of the change, all authoriti* 
of recent date apjioar agreed tlisit the couuectifr ti$tuv in ever 
affected organ Buff"ers most, and swells into homogeneous, w»x, 
looking masses, fre((uciitly CKulescing, between which the essenti 
cells of tlie organ atrophy even to disappearance. With osmic ad 
and ordinary staining reagents Ziegler says that there is no difficult; 
in {Icuionstnitiug the fatty liver-cells between the homogeneou 
block.i into wliicli the connective tissue has swollen (Fig. 23, fmi 
Rindfieiscli, and saiil by hiui to represent degenerate liver-ccIL*^ — 
Many writers, in opposition to the old view, now deny that epitbcs— ■ 
lia! cells can undergo this <'liange, though others, like Ziegler. cor» — 
tent theuiselves with saying that they may be (]uite nnafiected »'* 
advanced stages of the disease. Opinions differ as to wheih«?r 
muscle-cells and tlmse of lymphatic glands become lardaceons. 

'1. Naked Eye. — (•rgaiis in which this cliniige is at all a^lvaiiccii 
present features so characteristic that its nature can be reailily r«c- 
ogni/ed by the jmktMl eye. They are considerably increased in sw, 
but their geneml form is preserved, any edges becoming more or less 
rounded. Their absolute weight is increased, and also their specific 
gravity ; their surface is smooth and the capsule tense and strctcl/ctil 
their consistence is firm and somewhat elastic. On section tiiov 
[exhibit a peculi-i" '•" 'is, glistening, translucent appearand"' 

t»omew • wax. Owing to the vVv^Ww^*^ 





Fio. 23. 

calibre of their bloo<l-vc8scls and to the pressure exercised by the 
ae»v material, they contain btit little blood, and hence are always 
|)alt' in color. In slighter degrees 

of tLe change spots and patches of 

the morbid material may be scat- 
tered, like grains of boiled sago, 

through the tissue. Although the 

above chiirnctcrs are sufficient in 

advanced stages, the color-reactions 

alrea<ly mentioned should always be i-ardnccoiis iivcr-ccii* (accordinjt lo 

u?e<l. for they will reveal altered whi. i. imv.Moftio.c.i. • :«>. iTobHhiy 
patches — r. q. in intestine — not ob- th<.'ttiK)vfmiii>»c»ari' fhl(fmt■(lUofcu^^l- 
_- • 1 ' 1 T-> 1 laric» or of conncrtlve ttwue. 
»»<»us Without them, rnr the recog- 
nition of the degeneration in its earliest stage the microscope is 
necessary. The pregencc of hirdm-foug degeneration it often marked 
hf *i>mif iithf.r ehnnije, egpenally fnttij. 

"Tile primary change may occur in the connective tissue of an 
' '""■5*"> *nd not in the vessels. 

Effects. — The result of diminishing the blood-supply to the 
^^•^fntial elements of a part by narrowing the nrtcrioles and by 
* ■"t'c.t pressure on the elements is naturally to cause atrophy, fre- 
H'*-*«ntly accompanied by fatty degeneration (p. 4'J). and propovtion- 
'^-*-s diminution of function follows. The change in the veB.sel-wall3 
*-»1<'r!« the <|nantity and ((Uiility of the transudation, as is shown by 
*"*«j changes in the urine when tiie kidmys iiie iiilected. 

It acems probable that removal of ihe cause — c. </. chronic sup- 
Plration — of lanlaceous degeiuTiitioii may lead to arrest of the 
'*p(Kisit and to its removal from the di.Heased organs, even in marked 
cases; but in the great majority of instances the change is steadily 
priigressive, and proves fatal by exhaustion, fireceded by anreraia, 
lirdrwmia. albuminuria, and diarrbcpa, — all of which are easily 
accounted for by the morbid anatomy. But the other effects of the 
immary disease must also be remembered. 

infiltration or a metamorphosis? It is generally regarded as an 
infiltration : and it is believed that a soluble lardaceous substance 
i» iloposited friiiu the blood in tissues predisposed by some morbid 
change to receive it, and to combine with it to form the very insol- 



uble " lardacein " or " Iardace<:)U8 substance " found in the organs. 
The latter change accounts for the irregular distribution of the 
degeneration. A parallel was di'awn by Virchow between this 
degeneration and calcareous inliltnitiun. in which the deposit of 
salts occurs only in dead tissues. The nature of the process is, 
however, by no means certain, some facts supjiorting the view that 
it is a metamorphosis — e. if. the occurrence of the lardaceous sub- 
stance in thrombi, and perhaps in casts (page 93). Dickinson 
maintains that the substance deposited from the blood is dealkalized 
fibrin, rendered insoluble by loss of alkali carried away in the pus. 
But this explanation fails to cover many cases, and Budd considers 
that such a substance should digest easily. 

Seegen thought he found in normal blood a substance named 
"dystropodextrin," which has the peculiarities of the lardacein: 
he believes that this substance loses its solubility and is then 

According to Kekule and others, lardacein is a possible inter- 
meiliate product between albumin on the one side and fat and 
cholesteriii on the other. 

Lardaceous Degeneration op the Liver. 

APPBAEANCES. — 1. Microscopic. — The change usually be- 
gins in the walls of the capillaries and arterioles of the hepatic 
artery; rarely, it is said, in the capillaries of the portal vein. 
Thence the deposit spreads to the intra-aciuous connective tissue 
nmnd the affected vessels, ultimately reaching and affecting the 
tissue between the lobules and leailing to confusion of their out- 
lines. The connective tissue swells into homogeneous columns 
wliich split readily into flakes, like hepatic cells, and which, in 
section, look like masses of degenerated cells or even whole lobules. 
<^nreful examination (p. 8fi) will, however, reveal between the Inr- 
<iaceous masses the liver-cells more or less atrophied and pigmented, 
the peripheral cells, especially, being infiltrated with fat. These 
changes are beautifully shown if a very thin section be dehydrated 
in alisolutc alcohol, stained in an alcoholic solution of alkanet, 
ilecolorized in alcohol acidulateil with hydrochloric acid, washed in 
water tinted with acid hsematoxylin, again washed in water colorwl 
with solution of iodine and iodide of potassium, once more rinsed 
in water, and then mounted in glycerin: the fat is bright red, the 
lardaceous substance brownish-red, the liver-cells yellow, and the 



nuclei dark grayish-blue. The fatty liver-cells show up clearly be- 
tween the lar<laccous lusisses, esjieciaHy if a condenser is used (< )rth). 
2. Naked Eye. — The lardaceous* liver i.s increased in size, and 
may be so large as almost to fill the abdominal cavity. Its weight 

Fig. 24. 


Fio. 26. 

sEiSwMmu liver, iwrt of II luliiiU', showliiK mnsscs of Inrclm'Cims Fuhftanoi". ri'M-mlillnK 
In ncflliin <1eecncriiU' ami ftisol hi-ijntlc i.'clls. nivl vTi'iiliT liii|illi-nlliin of the iiitermecIltiK' 
>une. Ex1«rnAlly «iv »>xt\ scvornl fntty cvlU, ii i-crtaiii aim^iiiit of (Btly iDHltratiua bving 
ciutcd with the Inrdaceous change, v, hc-pmle vein. ,-. Iim. 

is increased, and also its specific tjr*^'i'^y- Tlie enlargement being 
uniform, the natural xbape of the organ is Imt little altered ; the 
free edge is rounded, the surface smooth, and the capsule tense and 
stretched. The consistence is firm and elastic. The cut surface is 
dry, bloodless, smooth, translucent, 
and waxy-looking, and of a pale 
reddish-gray or dirty-yellow color. 
If the change is very far ad- 

• vanced, the tissue may be perfectly 
homogeneous, all distinction lie- 
tween the individual lobules being 
^. lost. In other the lobules are 
^ distinctly mapped out; they are 
enlarged, and the external zone 
niay be of an opaijue yellowish- 

wLrte color, owing to the presence Ijmlaceoun Uver, stained with IwUne. 
mi-' • • p \ p Thedorkpat portlnnn rrprenonttlicoffcet- 

Of fat. IhiB aasociationof the fatty ert intonncllut.! »mw. Natuml slzu. 

and lardaceous changes ia exceed- 
ingly common. Lardaceous degeneration does not obstruct tlie 
portal circulation, and hence does not cause ascites. (See " Cirrho- 




sis of Liver.") It causes fatty degeneration and atrophy of the 
hepatic coll.s, antl thus interferes with the functions of the organ. 
If thin washed sections of a liver in an early stage of the affec- 
tion be staineil with iodine, the mahogany color will be found limited 
to the so-called '" intermeiliate Kone" of the lobules, the area of dis- 
tribution of tlie hepatic artery. The apjtourauce thus produced is 
that of a number of partially compressed rings with pale centres and 
still paler iuterveiiiug sjiaces (Fig, 2.')). The earliest seat of larda- 
ceous degeneratiiin thus differ.s from that <vf fatty infiltration, in 
which the fat first accumulates in the cells of the outer or portal 
zone (Fig. '24), and from that of pigmentation of the hepatic cells 
from mechanical congestion, which begins in the central zone around 
the hepatic vein. All these changes not uncommonly occur together. 
As tlie lurdaceoMS change advances the whole lobule and the inter- 
lobular connective tissue may become involvetl. 

Lardaobous Deqenehation of the Kidneys. 

The ki<lney8 suffer frecjuently fnutt tlris ehiiiige, though the .spleen 
and liver are. as a rule, mure uiarkedly all'ected. Sometimes the 

degeneration apjiears to commence in the 
kidneys. Albuminuria being one of the 
most constant sign.s of this cliange, it is 
often classed as one of the varieties of 
" Bright 's disease." 

The combination of lanhiceous aud fatty 
changes is exceedingly common in the kid- 
ney, the latter being to some exteut sec- 
ondary to the former, but the two bear no 
constant or proportionate relation. Lurda- 
ceouschangeisalsofrcijiiently combined with 
the signs of intlamniation, both interstitial 
and pareuehyuiatous : the nature of the 
relation is sometimes obscure. It has been 
hebl that the nephritis causes the Iard»- 
UrdiccoiH kidney, stoinert ceous change, that the lardaceous cdianj^ 

with iiuliiif. Tlie lUrk piirta , , . . , , , , 

rcpr, «-„i tiu' M«iMKi.i..n i-kUi-k causes the nephritis, anil that both arc 
iin.i Hrtiriei! wi.itii ii«v..' unrt.-r- coDcomitant results of the same cause. 

IfoiK* the lanUoetiUft change. 
(From a rhlld.l Niitunil size. 

APPEARANCES. — 1. Microscopic. — 
The degeneration usually begins in the Malpighian bodies. At first 

Fio. 20. 


i'Vwi •' 






only a few of the capillary loops in each tuft are affected, but all the 
loops griidiijilly become involved. The whole coil tlu-u presents iin 
ill-defined outline and glistening surface. The change in the mean 
time extends to the afferent arteries, to the capillary network around 
the tubules, to the arteriolie rectic of ttie medulla, and in advanced 
cases to the intertubular tissue, and even to the tunica propria of 
the tubules. It is doubtfid if the epithelium vvvr undergoes larda- 
ceous change. The distribution of the change may for long be very 

The minute changes are first observed in the subendothelial con- 
nective tissue, the endothelium remaining sound: the uiedia of the 
arterioles is next involved, the luuscular fibres either ;itni|ihying or 
degenerating; in this way a homogeneous glistening iuyer of vary- 
ing thickness (Fig. 27) is formed. The lumen of the vessels is 
finally obliterated, and the enlargi'd Miil[iiirhiiiii ttift becomes a solid 
ball, bearing on its surface the unaffected epithelial cells of its caj)- 
Bule: these can be demonstrated by ordinary staining reagents. 
From the Malpighian tufts and afferent vessels the degeneration 
spreads as above described, giving rise to the dots, streaks, and 
finnllT coalescent patches presently to be described. 

At first the tubes and their epithelium appear normal. Many 

Fio. 27. 

UinUccou* de«rneratl<in of* MRlplKhlnn tuft «n<l imall artvr; of the kidney. «how I ng 
t»ie tbU-ki-uttiK i>f Um wnUs <if the veiwi'l. the vnlonremciU nf the Cflls of thf circular nnii^ 
cular rout, mid the homiiKciieuui Inyer funned liy the intima iind liniKitiidinal inutiiilnr 
m.r.^ . aw. rednced \. 

c«Mitain the pale hyaline casts wliicli appear in the urine. These 
■re probably simple exudaticin-prodiicts. but tlit-v orcjisionallv stain 
de«p brown with iodine, and thus have been supposed to consist of 


lanlnccoiis substance formed by metamorphosis of the exndati'>w 
iiiaterini ; ueeonlinii to Ziegler, however, these casts Jo uot exLdul 
the otiier reactions of h»nlaceous substance. As the change advaucc* 
and the new material increases in amount, the blood-siipidy become* 
less and less, while the tubes themselves are subjected to actual on 
jiression, which, if it is uniform, lends to their atrophy, and perha 
even to their disajipea ranee, anil, if it is irregular, to their dilatation 
into small cysts, The epithelium undergoes atrophy ami fattjr 
metamorphosis, producing the opaque yellowish streaks and pati:li€?» 
above mentioned, but this change varies much in it.s amount and 
distribution. Not uncommonly a parenchymatous nepliritis L< pre^ 
ent, the tubes being distended with cloudy or fatty cells and ti«^ 
intertubular tissue being more or less infiltrated with leucocyte^ 
{large white tardaccouB kuinri/). In the later stages of the proni»*i 
there is almost always increase of the intertubular tissue, whifh^ • 
together with the disappearance of tubes, leads to shrinking nn^ fi 
toughening of tlie organ, to adhesion of the capsule, and tu irrcgtv^ ' 
larity of the surface. 

2, Naked Eye. — These will vary with the extent of the degr-n 
eration. and may be modified by the presence of associated ehangi 
such as fatty degeneration of renal epithelium, and of those due 
intluniuiatory processes. 

At first the changes are microscopic only : at this stage the stain- 
ing of thin sections with iodine will show here and there a Mal- 
pighinn body as a brown dot, and the straight arteries of the pyr- 
aniid.x as brown lines. The unstained kidney is either still normal 
to the naked eye or perhaps pale, yellowish, and slightly softened. 
As the disease advances the organ enlarges, especially the cortex. 
The surface is to the naked eye smooth, and the capsule separates 
reailily. The enlarged cortex is remarkably pale and aniemic, and 
ha* a jM'culiar translucent, homogeneous, wax-like appearance, 
lis <'orisisicnce is hanl and finn. A few scattered vessels may 
be !si-en on the surface, and the bases of the pyramids sometimes 
exhiltit iniTcn.xed vascularity. If iodine be ajiplied to the cut sur- 
face (p. H<!), the Malpighian bodies and the arteries of the cortex 
become mapped out as clearly as in an artificial injection (Fig. 26). 
The enlarged Malpighian bodies may indeed be seen as glistening 
pointK before the iodine is afiplied. Frequently the homogenc«tt« 
aj)peMrance of the cortex is interrupted by minute, opaque, yellow- 
ish-white lines and markings : these are produced by the fatty 



,a»nges in the eitithelium of the tubes, already descrihed. I'lti- 
frtely, thir caj)siile becomes more or less adherent, and slight irreg- 
I g L depressions make their appearance upon the surfaee of the 
Hpk; the latter are due to atrophic changes in some of the tubes. 
'as is usually the case, the process is associated ■with an increase 
^«lie iutertubular connective tissue, the atrophy may render the 
^4iD even smaller than normal. 

Sometimes the enlargement of the organs is very great. In 
the increase in size is mainly due to inflamiuatory 
inch as have been referred to. The freiiuency with 
iich Buch combinations occur render it advisable to examine all 

SLpalc kidneys for lardaceous changes, 
PFECTS. — The first effect of this change is to obstruct the 
Fculation in the cortex ; hence the incresi.Hing pallor of this part. 
|e arterial walls are so altered that iiuida and albumin readily 
•*ineate them, and thus is produced the large quantity of urine, 
fctled with albumin, which characterizes the earlier stages of this 
!«-"clion : the polyuria i.«, however, not so great as in the granular 
htraeted kidney, in which the arterial tension is much higher. 
is unusual to find the heart hyjiertrophied in cases of lardaceous 
kiase. As the arteries and the tubes become more obstructed the 
»Bc diminishes in quantity. The excretion of urea is less inter- 
ted with than in other forms of Bright's disease, and hence symj)- 
hx due to its retention seldom occur. Tube-casts are rarely 
fcuerous; they are for the most part hyaline or finely granular, 
► «gh sometimes they are covered with fatty epithelium. 
In advanced cases there is marked dropsy. 

^B Lardackous Degeneration of the Spleen. 

VARIETIES. — The spleen is very liable to this change, and is 
Jiidlv one of the first orjjans to be affected bv it. Two forms are 
bcrally described: (1) the sag^o spleen, in which the disease is 
fcited to the Malpighian corpuscles; and (2) the diffuse form, in 
[ich the whole splenic pulp is implicated, but in which the Mal- 
duan corpuscles generally csca[)e. Kyber speaks of the latter 
renchymatous degeneration." and makes a thiril form, indis- 
ISBwhabb* from it by the naked eye, in v.hich the disease begins 
fhultaneously in the Malpighian corpuscles and the pulfi. He 
strongly that these forms do not pass into each other, and 

Larclacpniis dviieiK'rntliin of thv spk<«n i"siik<> «plci;u' > ; part "fiin nltcrvd Mal(>iKhi«n ' 
piuolv, <i, witli the aiUacent noruml aplviilc Uasue.t). Tbe Muali in u «re ileKi.'nvratr<l t< 
svIb. ■ 2(1(1. 

[lurticiilarly that tbe parench}'niatou» form is not uu advauceil sU^^* 
of the sago spleen. 

APPEAEANCES. — 1. Microscopic. — In tlie sago spleen ifc»« 
change commences in the capillaries und urteriolcs of the Malpighi*-** 

corpuscles, next involves the filiri 1» 
of the network of which the corpus*" 
cle liirjjely consists, and then extcDi-4* 
to the small vessels in the neighl)»«"~ 
hood. At first the central artct"^ 
of the corpuscle usually escap*^^- 
When it becomes affected the changT* 
is first observed in its middle co**'- 
In tbe difPuse or parenchymatoix^ 
form the degeneration begins in tU^ 
neighborhood of the capillary vciii^ 
of tbe pulp, and spreads thence t«^ 
tbe trabcculiTS, arterial capillaries, and pos.siblv — though this is very 
doubtful — to the cells. The Malpighiun bodies often escape, bui^ 
tiieir central iirterics are generally involved. Kyber's general 
lardaceouB degeneration shows the lesions of both the other furiu* 
progressing simultaneously. 

2. Naked Eye. — Tbe sago spleen is more or less enlarged ; its 
weight and density are al.-^o increased. The cut surface is smo(ith, 
dry, and studded all over with small glistening sago-like bodic*. 
varying in size from a millet to a hemp-seed. These are stained 
reddish-brown by the iodine solution, but, as the central artt-rv 
generally escapes, the mahogany-colored nodules have pale centres. 
These nodules may enlarge until they occupy a considerable portion 

TjirdAopniu sagn iip)o<>ti, ititlnpil with 
ln<lliu'. Mal|>i|{hiaii hi»lk-s Hre darkly 
staliic-il. nnil u ■ niK- haw untiliilni'd 
cvntni. (From a child.) Natural hIju.'. 


of tlie organ, although in earlier stages of the affectiou they are so 
minute that they can be seen only in thin sections of the tissue. 
In tixe later stages, therefore, there is a considerable resemblance 
bet^-een iodine-stained sections of liver and spleen respectively, aa 
maj- be seen by comparing Figs. 25 and 29. 

In the parenchymatous and general forms the organ often 
attains a much larger size than is met with in the sago spleen. It 
is remarkably hard and firm, and the capsule is tense and trans- 
Parent. On section it presents a dry, homogeneous, translucent, 
bloodless surface of a uniform dark reddish-brown color. Thin 
sections can be readily made with a knife, the organ cutting like 
soft ^ax. The corpuscles, if affected, are not visible, as in the 
K>*"Hier variety, being probably obscured by the surrounding pulp. 

_ ^iPPEOTS. — Anaemia and emaciation follow the interference 
***li the blood-forming function of the spleen. 

Labdacbous Dboensbation of Lymphatic Glands. 

-iTn the lymphatic glands the process much resembles that in the 
'Pl^n. The small arteries in connection with the follicles of the 
S'^k-%d are the earliest seats of the change, and from these it extends 
'** "khe trabeculae and possibly to the lymphoid cells. The follicle 
'■'^^^a becomes ultimately converted into a small homogeneous mass. 

"^he glands themselves are enlarged, and on section the minute 
'^>t-like bodies can often be seen scattered through the cortex. 
•'^^^ cut surface is smooth, pale, and translucent. 

Ihe effects are the same as in implication of the spleen. 


T?he whole alimentary tract may be affected, but probably never 

P'^ixnarily or alone. The change frequently coexists with tuber- 

**l«r ulceration. The disease in this situation is very apt to escape 

observation, as it usually produces but little alteration in the ap- 

P^a.Tance of the parts. The mucous membrane may look somewhat 

P^l«, smooth, translucent, and oedematous ; in very advanced cases 

there may be some rigidity and thickening of the bowel-wall, and 

even nlcers, due, it is supposed, to the tearing off, by the passing 

ox food, of rigid villi. But the effect of the application of iodine 

to the washed mucous surface is very characteristic. In the small 

intestine— perhaps the part most commonly affected — a number of 



Bmall n-fltlish-brown points u[)|)eiir over the whole surface of the 
lueinbraiie ; tlit'sc rorresponi] to the intestinal villi, the arteries, nml 
Ciijiilliiries of wliieli have undergone the liirdaeeous chiingt?. In the 
stomach and (esophagus the vessels are similarly uia|)peil out br 
iodine (j). S(>j. 

The change in the intestine gives rise to serous diarrhoea. prol>- 
ably due to increased perueability of the degenerated vessel-walls. 
Both !ilisor|ition and secretion are much impaired, so that im|ili(-a- 
tioit of the alimentary tract has a grave general effect. 

The Corpora Amylacea. 

Corpora ainylaeea, or "iitnyloid hodies." were formerly looked 
upon as consisting of lardaceons substance : there appears, how- 
ever, with the exception of a certain similarity in their behavior 
with iodine and sid])hiiric acid, to he no connection between them. 
They are round <ir nval boilies formed of a succession «»f concen- 
tric layers, anil arc often changed to a deeji-blue color by iodine, 
thus bearing, both in structure and elieuiical jiroperties. a strong 
resemhlaiiec to granules of vegetable starch (Fig. •■5"): but some- 
times the blue is exhibited only after the subse(|uent addition of 
sulphuric acid, and thus a rescuibbince is shown to the lardace«>UB 
substance. Many of these bodies, however, are colored green. « 
even brown, by these reagents. The green is due to their admix- 
ture with nitrogenous matters, which give a yellow color with 
iodine, and lienee the nnuiliination yields a green. The greater the 
amount of tiitrogeiuuis iiiatter the more lirown does tlie color 
become. They vary in size from microscopic granules to bodies 
which are distinctly visible to (he naked eye, sometimes being as 
much as one or two lines in diameter. The larger are usually 

fiu'uied hy tlie conglomeration of smaller 
granules, which are often enclosed by a 
common envelope. 

They especially occur in conditions of 
atrophy or softening of the nervous sys- 
tem. The ependyma of the ventricles, the 
white substance of the brain, the choroid 
plexus, the optic nerve and retina, and tlie 
linal cord ar- •'•••^•r favorite seat.s. The larger fonns are met witli 
ost f«"' e prostate. The prostate of nearly every ailult 

.♦e bodies, and thev mav accumulate in th«t 

Fio. 30. 

Corporn iin>yl«««« ttova W\v 
]>rn«titt«. iV' 


organ to such an extent as to form large concretions. They are 
ocea!<ionally met with in the lungs and in mucous and serous mem- 

From their laminated structure these bodies would appear to be 
formed by the precipitation, layer by layer, of some material upon 
the surface of pre-existing particles. The material, however, does 
not appear to be that met with in lardaceous degeneration. The 
two processes are so different, both in the circumstances under 
which they occur and in the characters and seat of the morbid 
products, that tliey cannot be looked upon as analogous. Larda- 
ceous degeneration is a general change, whereas the formation of 
the corpora amylacea is evidently of a local nature. The latter is 
often preceded by those local atrophic changes associated with 
advancer! life, and appears to consist in the deposition of some 
material, probably liberated in the tissues themselves, upon any 
free body which may exist in its vicinity. 

The corpora amylacea, especially those occurring in the choroid 
plexus and in the lateral ventricles, are very liable to become calci- 
fip'l, and they then constitute one form of " brain-sand," which is 
** often met with in these situations. 



^^EPINITION. — Calcareous Degeneration or Calcification consists 

the infiltration of tissues with calcareous particles. It is a purely 

^**-e«V<' process, the cells taking no part in it ; the tissue is grad- 

"^*ly petrified by the deposit of earthy salts from the blood, for 

*^ir quantity greatly exceeds that present in healthy tissues. It 

'* *lifficult to find a physiological type, but perhaps the deposit of 

^'*^*"thy salts in the walls of the primary areolse (see " Rickets") in 

* Sirowing long bone may be regarded as such. Onitification is (juite 

*>»tinct from calcification, for in it everytliing points to life and 

P')wth ; the cells are undergoing active changes, and are obviously 

•^•^ncemed in receiving the salts from the lymph and in combining 

them most intimately with the organic matrix. 



ETIOLOGY. — Earthy salts in solution, chiefly the pfitigphatu* 
ami furhMiiitfH nf ntlriuvi and nuif/ni'xiiim. are brought to the part 
by bliuiit and lymph, cjirbon dioxido being probably the !*olvent. 
We have to determine why these salts should be peruiauenlly 
deposited in certain tissues, and we are at once struck by the fact 
that in the imnieit.'<e majority of" eases the tissues aft'ected are de»il 
or dying. It is probable, therefore, that feeble nutritive activity 
and a retiird('<i hlood-stream are together respon.^ible for its occur- 
rence. Rindlleisi-h taught tijat carbon dioxide escapeil from the 
stagnating lymph-stream, and that the earthy salts were conse- 
((uently jirecipitated ; more recently others have held that calcifica- 
tion is due to a combination of these salts with certain albuminoid 
bodies and with fatty acids. 

Much more rarely calcareous infiltration appears to be due to u 
absolute increase of calcareous salts in the blood, such as may be 
supposed to occur in extensive caries and in osteomalacia. A |K>r- 
tion of the c-^cceas is then deposited more or less widely in the 
tissues — first in the lymphatic glands and kidneys, more rarely in 
the lungs, stonmch, intestines, dura mater, and liver. The deposit 
takes place chiefly in the connective and least active tissue of the 
organ, which, moreover, ininuMliately surrounds the vessels — e. g, 
in the interlobular tissue of the lungs and in the stroma betwccii 
the glands of the stomach ; but in the kidney the epiiheliuin is 
infiltrated as well as the intertubular tissue. Analogous to this 
form of calcification is the deposition of the excess of bi-nratc of 
sodium which takes place in gout. It is probable that in this ease 
also the deposit occurs first in ti.ssues in which the nutritive activity 
is most feeble. A certain -iniount of chalky — like fatty — infiltra- 
tion may perha])s occur without marked impairment of function; 
but, as completely calcified parts are certainly dead, either the 
infiltration has the power to kill or it affects dying parts. 

SEATS. — Diminution or extinction of vital activity being MB 
important element in its causation, we are not surprised to find 
that calcification is very common as a senile change, affecting mast 
frci|iu'iitly the arteries an<l hyaline cartilages, excepting articular 
cartilages. It occurs similarly in pathological tissues of which the 
life is feeble — e. (/. in uterine myomatu after the climacteric and 
in old scars. Lastly, dead ti.ssues locked n|i in the body are very 
likely to become calcified — e. </. thrombi (jMfholithf), parasites 

Fio. 31. 


(Fig. 31). atheromatous patches in arteries, and caseous masses — 
(lie results of arrested tubercular inflammation so common in lungs 
and Irmpbatic glands. The best ex- 
ample is the complete calcification of 
a dead fcetus. which sometimes occurs 
when this is retained in the abdomen 
in the case of an extra-uterine fcetar- 
tion {jUthnptrdion). 

AJ>PEARANCES. — 1. Micro- 
scopic. — The calcareous particles 
make their appearance both within 
the ct'lis and in the intercellular siib- 

('Alclfted trichina' In mnsde. In two 

of till' (uiriulti'ii thi' raiwiili; anil con- 

tcntK arc so fur cttU'iflcil llial hiinlly 

BtaUCc; they are much more fre- any imei- or tbi- rolU-d pmbryu remttlUB. 

, -11 In the other the Irfrhlna Is dead, ehrtv- 

•jueut, liowever. in the latter situa- i.ii,,,i.a„,nw«:oiuinginniit«i«d. 


tion . They are seen at first as very 

fine dust scattered irregularly through the intercellular substance 

(fiff, :J2), They are characterized, when viewed bv transmitted 

light, by their opacity, black color, irregular outline, and solubility 

1 «lilute mineral acids, usually with evolution of bubbles of carbon 

•wxide. They gradually increase in number until ultimately large 

jtracts of tissue may be convertetl into an opaijue calcareous, in 

^*J>icL the cells are enclosed and can no longer be recognized. These 

c masses have a sharp black, irregular outline, and as the 

cification becomes complete acquire a homogeneous, glisten- 

'"g, serai-transparent appearance. The cells themselves are much 

Fio. 32. 

A nlrlflnl sarccima. Minut<- ralcarvoiu [lartiL'U-^ are Hcativred tJirough the intercelluUr 
lObftanrv. on the left ko thickly an U* aUnoHt voneeal the eelUt. ■. 'JUU. 

Javi fre<jnently infiltrated, being merely enclosed and obscured by 
tie calcified intercellular substance. Calcareous particles may, 
however, make their ajipetirnmc in the protoj)lasm, and, gradually 


increasing, convert the cell into a homogeneous calcareous botlv- 
C'ak-ificntion of gnnglion-cells nlone is tmt niicoiiinion in degenera- 
tive jirocessei* in the Itrain. 

If the Baliue mutters itre dissolved out with a little dilute miueRil 
acid, the structure of the part may be again recognized, unless^ 
iiitlet'd, as is tn} often the cafe, it has been destroved by soiiio- 
antecedent change. 

2. Naked Eye. — Ajiart from the microscope, calcification can li^ 
recognizetl more readily by touch than by sight. If the calcareous 
particles cohere in minute groups, such as is common when tli^s- •succeed.'* that of ca.seation. a white niortar-like sub.«tanc^»- 
i,s produced. When the cohesion is more marked the de|)osit leK' 
coinimrable to fine sand, and all stages between this and nolici. 
stony masses may not iufrcipiently be met with. The latter bre«hc: 
with an irregular surface and j)resent a yellowish or grayish aspe<'t:_ 

EFFECTS. — .\ calcified part is dead ami inert : it therefo 
uiidcrgncs no ftirther dumge. In this respect calcareous diffen 
from fatty degeneration, in which subsctpicnt changes invariahlj 
tiike place — either softening, caseation, or calcification. It diffc 
also in its effect upoti the tis.suf, for. unlike fatty metamorphosis'. 
it does not annihilation of the tissue-element.s. The tissiie- 
is simply impregnated with calcareous matters, which have no oth*?*" 
effect u[ion it than to render it inert; its vitality is destroyed, b«** 
its structure, in so far as the calcification is concerned, renini"® 

Calcification must thus be looked upon in many cases as a s»l**" 
tiiry lesion, the impregnation witli calcareous matters preventi**^ 
suh.seijuent changes in the part. This is especially the case whci* * 
occurs in caseous tithernilur t'uri, as it imprisons the cause of *•* 
disease. It is doubtful whether calcification of a fiinmr is of a f^- 
benefit to the patient, for the infiltration is probably limited to t ** ' 
•lead or dying parts of the growth and does not hinder its spreJ»* 
< )n the other hand, when it affects the arterial system calcificati* * 
may be attentled with the most deleterious consci|uence8. as will K^^ 
seen in the foUowins seetimi. 

Calcification of Arteries. 

Calcification of arteries, like fatty degeneration, may be primary 
or sifcondan/. As a secondary change it occurs in atheroma an*' 


forms one of its final changes. In this form it is constantly met 
w-it:h in the aorta and its branches and in many other situations. 
JPrimary caloifloatioii is essentially a senile change, a result of 
tb^t impairment of nutrition which appears and increases as life 
advances, but which appears earlier and increases more rapidly in 
some than in others. The change is more or less general. It is 
associated with atrophy of the arterial tissues, and in some cases 
witL fatty degeneration. It usually occurs in vessels of medium 
size, the arteries of the upper and lower extremities and of the 
brain being those most commonly affected. Its most common seat 
is the middle coat, where it commences in the muscular fibre-cells. 
The calcareous particles, deposited from the vasa vasorum, make 
their appearance at first around and within the nucleus, and grad- 
ually increase until they fill the cell, which becomes converted into 
a small calcareous flake. The process may go on until the muscu- 
lar coat is completely calcified, or it may be limited to isolated por- 
tions of the coat, giving rise to numerous irregularly-distributed 
<»Ic«reous rings and plates. These are best seen in vessels clarified 
•n spirit and turpentine. From the muscular it may extend to the 
external and internal coats, until ultimately the vessel becomes 
<»lcified throughout. 

The vessel thus calcified loses its elasticity and contractility ; its 
lumen is diminished, and it is transformed into a hard, rigid, brittle 
tube, or " pipe-stem artery." Such an artery is strengthened 
*S*in8t dilatation, but is predisposed to rupture: in amputations 
great diflSculty may be found in securing such vessels, as ligatures 
cut throngh them at once. The nutrition of parts supplied by 
"»ena ig more or less impaired, and tubular calcification of the 
'^teries of the lower limb therefore predisposes to "senile gan- 
6*"ene " (p. 40), inasmuch as it renders the vessels less able to 
*<iapt themselvea to the varying requirements of the circulation. 




PiOMENTARY Deoenkration, Or Pigmentation, consists in ^b-^** 
abnormal formation of pigment in the tissues. 

Normally, many pigments occur in the body, and probably ^ ^ ' 
are the results of cell-action upon hiemoglobin. Some of them pa «===-* 
out in the fieces and urine ; others are deposited as normal co^c^ - 
stituents in cells, the best examples being the cells of the rete M». ^ - 
pighii (especially in the negro) and those of the pigment-layer cm^ "^ 
the retina. But pigment is not limited to epithelial cells ; it exi» "^c a 
in the cells of the choroid and iris, of the sclerotic (lamina fusca ^ i 
and of the pia mater. Muscle also is pigmented, and yellow i j^ '* 
brown granules may sometimes be seen in the heart. - 

Pathological pigmentations may be arranged under four heacr~*.- 
ings, according as the pigment is derived (1) directly from hcemm'—^- 
globin ; (2) from the blood by ceU-action ; (3) from bile ; (4) fn>^"«ci 
extraneous subgtanres introduced into the body. 

1. Heematio Piennents, or those derived directly from haemogltzz*— 
bin. are the commonest. Red corpuscles break up and the^i x- 
hsemoglobin becomes dissolved. This may occur either within tb». ^ 
vessels (malaria, septiciemia), which is uncommon, or after esca|~»«? 
of the corpuscles into the tissues. The latter is due either *: o 
wounds or rupture of the vessels, or to congestion or inflammation* 
without any breach in the vessel-wall. Such causes of pigmentation 
are common ; witness the frequency of bruises and apoplexies. <'• 
congestion from varicose veins, portal obstruction, and cardi**" 
incompetence, and of stains after various inflammatory lesions- 
All are familiar with the changes in color which occur after * 
bruise — first purple, then green, and finally yellow. col<'^" 
changes are due to corresponding tissue-changes which follow t»* 
infiltration of the skin by the extravasated blood. Briefly, *b*^ 
ehanjres are as follows: 1. Some of the fluid and cells are absorb*^ 
at once by the lynipliiitios. 2. The hivmoglobin is dissolved out " 
many red cells, and tlie stromata disappear — no doubt after faf*^ 
degeneration. \ red fluid is thus formed which infiltrates tl'^ 
tissues and stains them yellow or Itrownish red: the cells are cO*' 
ore<l more tlecply than the iiitereellular sub.stanee or than the meflO' 



W branotia or fibrous structures. The color-changes on the surface 
I »rv owing to changes in this ilisw)lvt'cl ha-niniilohin. which is srjon 
I ilrcoiujiosed into hieuiatin unil an iilbiiiuinciid boil y : [tart of the 
I lia'Diatin is reabsorbed, and appears in the urine as nrobili]i : the 
I rest II niierjroe!« a change, and is deposited as granular or crvftiiliiue 
I iiioitiutiiidin. 3. Many corjmscles simply shrivel into brownish 
I grstiiikr nuisses of pigment, said to occur chiefly in " h:eiuatomata," 
I or ttimor-like collections of blood. 4, Many — according to some, 

f nifMt red corpusclea, or the ])igiueiit-ra:isses rcsiihiiig from them, 

, •I'l' tnken up by leucocytes, which wamlcr in large numbers into 
I •^•e extrava8,ation and are converteil in them into hjematoidin. 
"ue f liguient thus formed mfiy be deposited on the death of the 
^clll <ir it may be carried by the cell into the lymphatics, when it 
'''" probably be arrested in the nearest lymphatic glatuls. the 
yniF*li-piiths of which will be found beautifidly iiuirki'd out by [lig- 
nent - or it may pass through into the circulation and give rise to 
pign^nt-emboli of various organs. 

"^^^nntftuUn appears to be closely allied t(» — according to some, 

^luvnt^ical with — the coloring nuitter of the bile, bilirubin, which is 

*'*•' a derivative of h.Tinoglobin. It exhibits similar reactions 

«n«H treated with concentrated mineral acids, displaying the same 

varvjitjons of green, blue, rose, and yellow colors. It is insoluble in 

**'«?r, alcohol, ether, acetic acid, and in dilute mincriil aciils and 

•'Kllies ; it Is soluble in concentrated acids iiiul in the caustic 

■'kiilies, giving in the latter case a red color. It docs not con- 

*"» iron. Mixed with hsematoidin. and very closely resembling 

I ' '8 a pigment containing iron. This has been named " hjemo- 


*hese final stages of extravasated blood occur in two forms — 
j'^nular and crystalline. IJoth are of a very permanent nature, 
may remain uiniltered for years. 

ie granules of ha^matoidin vary in size from the snuillest par- 

'^'es to masses as large as a red blood-corpuscle. The larger are 

^'^••iijonly irregtilar in shape, sharply defined, and nmrc or less glis- 

"'>»g. Their color varies from yellowish red to brown or black ; 

'nt' older they are the darker they become. The smaller granules 

*** usually dull and opa(|ue. 

I Tlie crystals of Inematoidin are opa(|iie rhombic prisms, usiuiUy 

L ''f a beautiful yellowish-red or ruby-red color, sometimes approach- 

I ^ to brown or black. They may also occur as little plates and 



Pio. 33. 


Uu'ioatuldin cryiUU. 

fine needles, bat these are les8 coninion forms (Fig. 33). Theruc 
in most cases so small that considerable care is reijiiired to recogniu 
their crvstalliMc nature under the microscope, and they may ewilv 
be overlooked as merely irregular granular masses. In some cm««, 
however, they attain a larger sixc. Ther ut 
more or less transparent, and present a shiih 
ing, strongly refractive surface. 

Intensely black pigment, granular or en* 

#VV tallinc, has been called viflonhi. This term, 

as at present cniployod. includes several dif- 
ferent pigments, some containiDg iron ud 
some free from it. 

Whether hiemoglobin is conxerted into 
granular or crystalline hacmatoidin appears partly to defiend n|Mti 
the tissue in which it is situated, crystals being exceedingly com 
mon in some situations — c. (f. the brain and ovaries — vt hcresj* ii 
others, f.. g. mucous membranes— only granules are met with. 

Acconling to Kunkel, some of the pigment left by hnMnoglobin i 
pure hydrated peroxide of iron. ^^ 

As to the idtiniate fate of extravasations — ^B 

1. Absorption may be, and in vascular parts often is. to the nakc 
eye, complete, but crystals or granules of htematnidiii may n* 
infrequently be found by the microscope. '1. A yellowish, browl 
ish, or blackish scar, from gramdar or crystalline pigment, m* 
mark the site of the destruction of ti.ssue by hemorrhage. 8. ■• 
collection of prune-juice or chocolate-colored fluid may long rrmM 
surrounded by a capsule of inflammatory tissue, often lined b 
layers of clot, more or less decolorized and organized (hjematonia"! 
the fluid contains pigment and fat-granules anil cholesterin-cryst»Ii 
4, The fliiiil may be absorbed and the clot become completely dei-o 
orijse*! and organized — a good example of «hich is seen in tb 
so-called "•membranous pachymeningitis." The process can fr« 
• (uently be watched in aseptic wounds. ;"i. A cyst, with more o 
les« pigmented walls, containing clear fluid, may be left, especially 
in the brain. 

Pigmentation is a very common form of degeneration, but, f«M 
nately, one of little importance. The presence of pigment i^m 
between the cells of a tissue can have little effect on the clemenf><» 
their functions; any di.'sturbance of these must be attributtMl rathe 
to the conditions upon which the formation of the |iigment depenib 



Fio. 34. 

As evidence of antecedent conditions (hemorrhage, congestion, or 
iiiliainmation) the presence of hicraiitoiilin iimy sometimes stand 
ilone; c, ,'/. after cerebral hemorrhage from capillaries ery.stals of 
bffinatoiilin may alone remain ; agiiin. slate-gray discoloration of 
the intentinal mucosa points either to chronic catarrh or portal con- 
RWtion, and that nf the vesical mucosa to chronic catarrh. Slate- 
gray discoloration, seen po8t-mortetu on solid abdoiuiiiiil viscera, 
«nd de|ieDding on the action of sulphuretted hydrogen (from decoiu- 
|"wition) upon the iron in hiemoghthiii. must not he mistaken for 
true pignientatiiiti. 

2. Pigment derived trova the Blood by Cell-action. — The 
chief examples of this change are mehuiotic warts, nsevi, sarcomata, 
«nd careinomata. The pigment lies in the 
ceil« more often than between them, is gran- 
ular, and varies from yellow to black in color ; 
'' probalily contains iron. It differs s])ectro- 
"Wliicajiy from all known blood-pigments, and 
•* often inc]iide<l among the melauins. 

The bronzing of the skin in Addison's dis- 
i.s not sati.sfactorily explained. Irritation 

"'" the abdominal sympathetic is believed to """^"■'« "' "•« liver). 

f>« • 1 . ■ • • *^- 

"■Use mcreascd pigmentation. 

Variations in the normal pigmentalion of the skin occur rluring 

I'fegnancy and with various uterine troubles, in leucoderina iiml 

•"Pliiniiderma ; but no certain explanation of these, or of blanching 

" the hair from neuralgia or fright, can be offered. 

8. Pigmentation from Bile. — The only well-established cause 

" this variety is obstruction of the hepatic or of the common bile- 

''»ct. This is most fretjuently due to swelling of the walls from 

ti^tarrhal intlamiiiation, to Idockinj' of the luuien by j;ull-stones, or 

^ the pressure of a growth outside the duct. The bile secreted 

wbiiid the obstruction is ubsnrbcd by tlie veins and lyniphiitics, 

w»d distributed throughout the budy. It a])peurs first in tlic urine, 

KMTi afVer in the conjunctivrc and .skin, and may ultimately .stnin 

»11 the tissues yellow or greenish yellow. The stniniiig of the skin 

is kiKiwti as jnundiiH' or icUtrun, and persists some time after the 

oil* hw ceased to circulate in the blood. When the seat of obstruc- 

"*u is in the small bile-iluct.s, as in cirrhosis, the change may be 

hraitcd to small areas of the liver. 

The pigmentation is due to diffuse staining, but granules and even 

r«ll« rontainiiiK I'iff- 
mi'iil (fnuii a iiK-liiiinUc 


NUTRrrrox rat paired. 

crvstttls of bilirubin are occasionally found, especiallv in ickmi 

With regard to the slight jaundice that occurs in septicaemia. tlM 
malignant forms of acute infective fevers, and some other disetioi 
no inarkod obstruction can be demoni*tratt'il in tlii- ductit. anil tko 
exact cau8c ii!> doubtful. It is probable that both iurreased coniuC 
ence of the bile and diminished pressure in the bbwd- vessel* m^ 
each cause the teiis'iiin in the ducts to exceed that in the blo^fd-iM 
aels, or, at any rate, in the lymphuti(■^<. and thus induce a slight »b 
sorption of bile into the vessels, sinil a conseiiuent niiM ilegreeW 
jaundice. This is the most probable ex|)lanation of many of tb 
<loubtful cases. 

4. Pigmentation by Extraneous SubBtances. — Exaniplw < 
this form of pigmentation occur in the lungs, the skin, the \xt 
phatic glands, and the mucous membranes. The substances accri 
ited with its production are carbon, silver, lead, arsenic, and hi 
pigments as may be used artificially : to these may be added, in r* 
instances, mercury and picric acid. ^| 

The inhalation of fine particles of carbon and other substiBi 
produces pigmentation of the lungs and bronchial glands. This* 
of considerable im|>ortance, and will be described in the next secti«3 

The prolonged administration of salts of silver leads to the der 
opuient in the skin and adjacent mucous membranes of a |>eculi 
brownish-gray color. That portion of the metal which finds itavi 
to these parts is, owing most probably to the action of the ligl 
de|)OHited as an oxide. This comlition is known as urtfy riit$i*. 
is permanent. 

The presence of lead in the tissues is often demon?trate<l f»y tJ 
occurrence of a narrow, well-defined black line in the gums whei 
they are in contact with the teeth. It is due to the action of ll 
•ulphuretted hydrogen given off by the decom|»osing matter whic 
collects between the mucous membrane and the teeth ujxm the lei 
in the adjacent tissue. The •• lead-line " is, therefore, usually brukei 
and in those whose teeth are kept thoroughly clean often absea 
even though other symptoms of lead-poisoning may be prii««>ii 
I'igmeiitutinn <jf the mucous membrane of the large intestine hi 
been found associated with the presence of considerable i|uaDtiti> 
of lead and of mercury reA]>ectively in that |iart of tbe alimentat 

In tattooing artificial pigments are placed in the dee[>er I«y«n I 



the stkiti. Most of the pigment remains in its original position. Of 
tbv reiuainder, some is devoured by wandering leucocytes, and some 
w »ra.shed on into the lymphatic and filtered out by the glands, where 
it h x~«Uined. 

I>^^Mi tistui's in process of separation are frequently discolored — 
bfnvk , greenish black, or slute gray — by the action ivf !<u)|ihuretted 
hydirogi-n. and atrophied nr(fan«. in which the pigment is, as it were, 
concentrated, often appear darker than normal. Neither of these, 
how^ %rer, is an instance of true pigmentation. 

Pigmentation of the Lungs. 

I lr» no organs is pigment met with so frequently and in such large 
I (fuaritity as in the lungs, and mucli discussion has arisen as in its 
I nati»T»> mid origin. Its iiuioiint gnidually increases witli ;nlvanciiig 

I »gc the lungs of infants being free from it, whereas those of adidts 

I invuriiiMy contain considerable quantities. 

I 'it\» pigmentation of the lung.'* is due principally to the presence 
I ui Carbon, an<l not of hiematoidin. The carbon — derived from 
I "H'ltupiete combustion of wood, coal, and other substances, and 
I ''^ajTS present in varying quantities in the atuiosjihere — is inhaled, 
I ""d the minute particles pass into the finest hroticbi. Many are 
I •*««!» np by mucus-corpuscles, juui may be seen as small black 
I ^fannies in the cells of the grayish-black sputum fre((ucntly e.xpec- 
[ ''^>"atcd in the early morning. Much of the ciirbon is thus elimi- 
■***ecl by expectoration, but many particles pass into the air-vesicles, 
F ■li«l here, their removal by this menus being less reaiiily effeeted. 
I *"«y gradually penetrate into the alvenlur walls atnl interlnbuhir 
I ''ss«n?. Most of the pulmonary pigment is found in these situations, 
I *'thfr within the connective-tissue cells or free among the fibres 

(Pig. .35). 
I According to Tyndall, exhaled complemental air is free from 
I V*rticles. The carbon particles can be carried by the air only .so 
I w as it is tidal or complemental. Any cilia would work against the 
I "<i.Hcent of the particle and its carrier cell. The difficulty with whieh 
I »«ptic organisms gain access to the minute ramifications of the air- 
I V*»8nges is shown by the rarity with which empyemata from per- 
I fi'Tntion of the lung putrefy, and by the reatly ilisappearauce of 
I putrefaction in offensive sputum when intra-laryngeal injections arc 
I employed. 
^^ The means by which the particles of carbon can penetrate the 



walls of tlic air-vesicles and make their way into the inter-alvcdlir 
tissue has been explainod by Klein. The branched couuectiu'-ii- 

Fia. 35. 


Pltnneiitntloii nf the lung ift-om » woman, wt. dxty-flve, wllh hUkIiI rniphywinnl. «how 
till- fItiiiiUon iif the plipiit'nl in thi- thirki-ni'cl alveolar w«ll» nml uroiinrt the blno<l»»«r S 
The wullii of the Utter nre aUn thickened and its tnmcn diminished, y 78. 

sue cells of the iilvrohir walls send a process or a greater or I<? 
iiortioii of their bddv between the eiiitttelial cells of the alveo! ^* i 
into the itlveolar cavity. As tliese coiini'etive-ti.'»8iie cells lie in tt • 
seroHS canals which constitute the coninieueement of the |>eriv»-^^ 
cular lymphatics, it is easy to understand how tliese openings in tl^ 
alveolar walls (pseiido-stomata) may become .sufficiently di.stenJcJ t: 
allow cells and ottier substances to pass through from the alveola- 
cavity into the inter-alveolar tissue. When once the carbi>n b» 
made it,< way into the interhditdar tissue, some of it is taken a 
by tlie fixed cells in this situation, whilst that which is not thii 
fletained [msses on to the lymphatics, ami is deposited in the bron- 
chial lyiiiphatie glands, where the black |mrticles are also visible. 
The wandering leucocytes ])robably convey particles from the luiiicn 
int« the mucous membrane of the bronchi. 

Closely allied to the physiological pigmentation of the lung fn>!n 
the inhalation of carbon are those morbid con<litions which restdl 
from the inhalation of particles of coal, stone, iron, and other sub- 
st4inces, of which the lungs of miners, stone-masons, and grinders 
afford fre()uent examples. Here also minute particles enter the 
bronchi, penetrate the walls of the alveoli, and are de]iosited prin- 
cipally in the interstitial tissue. In the case of miners — in which 
this is most ecuumon — the parlicles of coal enter the lungs in sncll 





Urge quantities as to give to tlicni an nltncst uniform deep black color 
(tttillinwimirL). In stiiin'iiiiisoiis, j^i'inik'fs, ami others the lungs al«o 
bcoioie deeply pigmented (iniUcijsig), although to a less extent than 
those of miners. 

The Itliiek eolor of the lungs in these cases, however, is not 
entirely due to the (iresence of the inhaled substances, but partly 
to that of hivuiatoidiu. The inhaled and irritating particles set up 
intlauimatory changes in the bronchi and pulmonary tissue, causing 
chronic bronchitis, chronic catarrhal jinenmonin, and a large increase 
in the fibrous tissue of the lungs, which thus become consolidated, 
tough, and fibrous, in the most severe forms ulceration, starting 
from the bronchi. pro<lnces cavities {'• rolliers' " and ''knife- 
grinders" phthisis"). Owing to these structural changes, there 
is a considerable e.scapc of red corpuscles fnuii rupture of capil- 
laries or inHaiuinatory exudation, and hence a large formation of 
l>igment. to which much of tlie dark color of these lungs must 
undoubtedly be a.scribed. The lungs of stonenia,sons and grinders 
"re, like those of miners, deeply pigmented, though to a less degree; 
l>«t the black color in the former eases 
r»nnot be entirely accounted for on tiie 
""Pposition that it is due to the presence 
"'" iiihaled particles. Carbon particles 
•"* V>lack, angular, and very variable in 
"*e and shape. They are unaffected by 
*troDg acids and alkalies. I'igiiieiit ile- 
•"iVfJ from tlie blorid is generally brown- 
ii»L and ffrnnular relU from the nputum ..r nciitc 

«no granular. hromliltl*. «h»winij ilir mUmte 

•*igmentation of the lungs from the (tranuiM or [.iimuni within the 
I'res^nce of hjvmatoidin occurs as the tain,, f.w f.uty xwo. 
"^ult of many other morbiil conditions. 

"laiiy diseases of these organs being attended by the formation of 
l**gim»nt, In chronic phthisis pigmentation occurs, partly as the 
f^ult of ijje inflammatory process and partly fnou the obstruction 
*** the vessels caused by the new ti-^sue; lines of pigmetit are con- 
**tjtly seen surrounding the nodules of consolidation. In acute 
*^OU|>ous pneumonia the blood which is extrava.sated into the air- 
dcd, and which in the early stages gives to the expectoration a 
y or jinine-juice color, «ubsei|Uently becomes converted into 
pigment, and the sputum becomes of a grayish-black, the pigment- 
P»ii«lc» being visible in the newly-formed cells. The cells met 



with in tlie sputum of ln'niichitis also contain griinules of pijrtiicut 
(Fijj;. -itJ), and pigmentation ])lays an important part in tlii' comliiinn 
of tlie lungs known as brown induration. 

I'l^rniunt in the lung usually occurs as black irregular grauuh-r; 
it is rarely met with in a crystalline form. In all cases in which it 
is fiMUHl in any ipiantity in the lung it in found in the bronchiiil 
ghiuils also. It i« taken up by the lymphatics, and. like tbe 
iuhaletl carbon, becomes arrested in its passage through these 
glands, where it remains perniauentlj. 





The morbid processes ih\\» far described have been attentB- * 
either by arrest or by impairment of nutrition : there remain 
be ciiusidered those in which the nutrition is so changed tl^^ 
ftirniation exceeds waste, and growth resull.s. They include hypt*-^ 
trophy, regeneration, and tumor-formation. 

Normal growth depends u])on — (1) the itiheriled tendency of t^K^ 
cells to grow ; ('2) the siipjd_v "f food; and {'i) the amount of wast -^ 
In all abnormal overgrowth one or more of these factors arc ^^ 
fault. There is, however, a marked ilistinction between hype^^ 
trophy and regeneration on the one hand and tumor-formation <> -^ 
the other. In the fonner the new tissue is an exact reproductiu:^* 
of the original, and has the same function ; in the latter the 8tru(^^ . 
ture of the new tissue is not an vrai-t reproduction of the old. aiii- 
the arrangement of its elements is still more distinctive, while DC 
tumor possesses any known function. 


Hypertrophy may be defined as an " increase in the siy.e, weight, 
and functional activity of a part beyond the limit of health, due lo 
an orderly enlargement or midtiplication of all its normal constitu- 
ents." From this definition it will be seen that the wrt^wrr of the 
process is strictly physiological ; in extent only it is pathological- 



^H^ ETternnl form and luiuiite structure alike exhibit a single change — 
^H tJiHt of size. The weight of an liyiiertropliifil organ, however, 
^H gives the most reliable indication of the extent of the change. 
^H Strictlv proportional to the increase in size and weight is that in 
^H functional activity. 

^H The termH "• false hypertroj)h_y " and " pscu<Io-hyper{rophy " are 
^H owd to indicate tiiat the increase in size, wliile presenting a siiper- 
^H fii'iiil resemblance to hypertrophy, is <liie eitlier to the unequal 
^H overgrow til of the tissue-elements or to liiv giontli of only one of 
^H tlicm, often at the expense of the rest, ami that lliere is no increase 
^B iu functional activity. Thus pseudohypertrophic nuiscular paraU 
^H 5*'8 is characterized by a marked enlargement of certain muscles. 
^H <liie to an increase in their connective-tissue eleiiienls, and accoin- 
^H panied by atrophy of the muscular tissue and diminished functional 
H activity. 

^H Hypertrophy is said to be '"simple" when it is due to an in- 
^H freast.' in the size of the elements of the affected part; "numeri- 
^H *l."' when to increase in their number. The latter is also called 
^B •'yporplasia. These terms are of little practical value, for hyper- 
^1 trophy is in nearly all cases bclicvcil to be numcricitl, and in most 
^H <**e8 it is simple as well. In the great example of physiological 
^m "yiHTtrophy — tiie gravid uterus — some of the muscular fibres may 
H "'- tea times their normal size. 

^ Etiology. — in many cases we cannot say how far a given 
'Ostaiicc of hypertrophy is due to excessive vital energy of the cells 
**f the part, to the setting aside for its embryonic rudiment of too 

|'*''}fe a number of cells, to iliniiuutioii of the resistance to growth, 
'** «n ampler food-supply, or to diminished waste. 
Iti a large number of cases hypertro])liy seemi to occur as a 
ttpponse to a tlemand which has arisen for increased work. Thus 
P^ifficulty arises in the circulation. It may be due to a narrowing 
'" the arterioles, or to obstruction at one of the orifices of the 
"Wirt, or to some interference with die movements of the heart- 
1^ *all» themselves, such as may be caiised by the jiermiiucnt aclliesioii 
^f **' thf visceral and parietal surfaces of the pericurdium. Under 
"I' altered conditions the normal blood-flow can only be maintained 
"y 'nrreased functional activity on the part of tlie heart. Now, it 
PQemliy happens that in jiroportion as the dilFiculty gradually 
""kWe* itself felt, so the part or parts of the heart upon which the 



extra work re(iuirc<l fulls gruduuUy hypfrtrophy : thus tbe t 
creased (leniuncl is pertiuuiently provideil for. At the snmc tii 
the supply of blooil tiirnrif;li the coronaries is a!s(» increased 
would seem, indeed, that this is the conuectiug link hctween \MitM 
increased functional iictivity and the production of the hypei 
trophy; for if, through disease of tlic coronurics or other cause, m: 
increase in the hlood-su])jily to the heart niuuot be effected, tH 
rciptisite liy|icrtro|>hy din's not occur. Whi'n hypertropliy arises i 
tlii.s way it is termed " ciunpcnsatory." 

'I"he power of an organ thus to hypertrophy is by no inoaKkS 
iinliniitcd. One Sfuirce id' liinitntion is very clear: this is in tl»e» 
l>loo(i-sui>ply. If in any way the i|nality of the blood dcterionite* 
or the coronary vessels become rigid or partly obstructed, not onl^ 
is increased growth an impossibility, but, as has already been said. 
fatty degeneration will inevitably ensue (p. HO). The other chic*f 
source of limitation lies in the "growing capacity" of the ceil»- 
When the original disease is of a progressive character or when 
its ravages are increased by the help of allied discuses, it is cle»»r 
that there must ctinic a time when, even though the coronary circu- 
lation be apparently adetfuaie. tlic inherited capabilities of the coll* 
will fail and gimvtli ('i)iisei|Ueiitly cease. We know very little con- 
cerning this inherited gruning capacity, but it is a very iiuportnli* 
item. Trobably no increase of the blood-supply could save • 
thymus gland from atrophy or increase the number of ndal* 

When muscle contracts freipiently against an increased load, i* 
hypertrophies — as is seen in tj-aining — unless the load is too heavy- 
when atrophy may result. Frequent contraction alone is insufficient .» 
for the uin.>*cles of hands used actively but not forcibly do no* 
enlarge, imr is rrequent micturition in pyelitis followed by thick' 
ening of the niusctihir walls of the bbnblor. But insert an obstrac- 
tion in the urinary jmssages which the iiladder can, by more power 
I'ul contraction, overcome, and hypertrophy begins. Other e.xam- 
|>lcs of these rnni/ifiiniitiin/ hypertrophies may be seen in the wall* 
of (he intestine ju.<t above a peruianent stricture or in those of 
a vein in aneurysmal vari.x, or of any vessel through which an 
abnormal ijuantity of blood is forced. 

\\ lieu an organ is removed or prevented from fulfilling its ordi 
nary function, other organs which take on its work hypertrophy, 
receiving the blood which should have sup]died the diseased organ 



itir own. Tliis ia best »wn in the kidney, raivly in 
twti^ anil lung. Removal of one snbniaxillsiry gland '\n not 
eceMarily followed by hypertrojihy ni" ntlier salivary glands; this 
ould occur only from more frequent stimulation of their seeretory 
trvcs, which probably producer the large submaxillary glands 
len in epithelinma of the tongue. But the kidneys are under 
irve-coutrol in a diflerent way : they seem to be exvited to secrete 
] the presence in the blood of material suitable for their secretion, 
lilhyiiprtrophy naturally results from continued greatly increased 
ipply of Idood containing excess of urea and other products of 
teue-inctabolism. Enlargement of lymphatic glands ha.s been 
He<l lifter removal of the .ij)leen. Increased weight thrown on 
Iwne causes thickening of it — e. </. of the fibula in ununited 
Itcture of the tibia. 

Repeated hyperaetnia from hard use and slight injuries is fol- 
ded by thiekeuiiig of the epithelium, as in a laborer's hand. 
B'ler (limilar comlitions a corn may arise. Increa.seil blood- 
f»ply fo a limb may cause lengthening of a bone if the epiphysis 
iiDunited. as has been seen in large ulcers, caries, necrosis, and 
Ict conditions. The soft parts iiK-rease secondarily. 
IV hypertrophied spleen of intermittent fever and the thyroid 
enilemic goitre (Klcbs) are due to active hy|«eneniia, perhaps 
btod by the presence of organisms. Exophthalmic goitre ha.s 
^Btributed to vasomotor paralysiR from disease of the sympa- 
Bc ganglia, but it is very doubtful if it could result from such 

Diminished waste is, apparently, not a couiumn cause of hyper- 
|)hy. An example often ijuoted is the subinvohited uteruH, the 
!lt of which is made up of hyjiertrophied muscle and connective 
►lie with thick-walled vessels, but it is doubtful whether chronic 
lammation is not largely res|ionsible in these cases. Uncut hair 
I nails anil, in the of many animals, unojipo.svd teeth grow 
^Wir ves.sels su)iply only nutriment ciiough to uuiintain tlu-ni in 
^Hially-attained condition. Tlie sclerosis of bone produced 
^mall doses of phosphorus, the increase in size and strength 
[tals treated with small doses of arsenic, and the invigorating 
this drug upon Styrian mountaineers may perhaps be 
iined by "liminished waste. 
removal of resistance to grrowth is difficult to ascertain. 
' a factor in the production of such deformities as 


"knoek-knee" {genu valyum): here excessive pressure is thrown 

ou till- outtT articular siirfacos of the femur ami tibia, whilst the 
weight Ijorin' liy tlu' imii-r surfaces is less than iKiriual. anJ thev 
conseiiuentiy grow excessively. Many ideroses or hypertmphie* 
of connective tissue fitllow ujion ittrojiliv of the essential elements 
of the organ : the natural resistance between the two tissues hn* 
been removed (see p. 140). 

There reniiiiii certain cases in which the etiology is even more 
doubtful than in the above. First, cases of true " ifiaiit-tfrotrth" — 
increase in length, rather than in breadth, being implied; hyper- 
trophy of the whole body (giants) : of half the body; of whole limbs 
or of parts of them, as fingers and toes. Such yiarts are. on dissec- 
tion, normal except in size. Secondly, cases of /'h/mc (/iV/H^w/row/A, 
in which tlie connective tissue alone is increased, the part being; 
often iiiisshapen ; lyiupliatics are often ililiited mid the Idood-vessels 
may he usevoid. Examples are met ujih especially in the lip (mnkro- 
cheilia), tongue (makrojfhiisia), and lower extremity. Hypertrophy 
of connective tissues ami surface epithelium uuiy result from an 
exces.sive though slow and impure supply of blood. In some of the 
above, which are congenital or appear soon after birth, there may 
be excessive vital energy or too large a number of the cells 
forming the rudiment of the part or tissue. 

Nothing is known of the causation of senile hyj>ertropby of the 
prostate, uor of the enormous but rare enlargement of the female 
breast which may occur at puberty. 

Hypertrophy of the Heart. 

Hypertrophy of the heart has been already referred to, bat is of 
sufficient importiince tn merit a more detailed account. 

The whide heart may be uniformly affected, or the enlargement 
may he mainly contiired tt) one of the two ventricles. 

Uniform hypertrophy of the whole organ is a common result of 
adherent pericardium. By this change the sliding action of the 
heart is interf<"rci! with, and the work thrown u|Kin its muscular 
walls proportionately increased. A heart thus enlarged may weigh 
from twelve to thirty ounces, even after the parietal layer of the 
pericardium has been dissected off". The normal shape of the heart 
is preserved, hut its general dimensions — both external and internal 
— and the thickness of its walls are alike incrciised. 

Hypertrophy of the left ventricle follows any changes that give 



rise to obstruction at the aortic orifice or permit regurgitation from 
tie aorta. It also follows obstruction in the arterioles, such as 
occurs in some forms of chronic Bright's disease. The weight of 
tie organ frequently exceeds twenty ounces. In shape it is elongat- 
ed; the septum — and therefore the left coronary artery — is displaced 
to the right of its usual position on the anterior surface. On ex- 
ininiiig a vertical section the apex is seen to be formed entirely out 


Hyi>^itrophy of left ventricle (flront view). Heart Is elongated. Septum occupies middle 
of ■n«4e Yita aurfitce. (From a case of granular kidney from a specimen In Charing Cross Hos- 
t*«^ ^Mtxueum.) 

of tlx« wall of the left ventricle, and the walls of this cavity are 
theaaselves thickened (Fig. 39). 

Fio. 38. 


Hjrpertropby of right ventricle (ftx>nt view). Heart is quadrilateral and septum is displaced 
tolbeleft. Right auricle is dilated. (From a case of chronic bronchitis and emphysema 
tarn a specimen in Charing Cross Hospital Museum.) 

Hypertrophy of the rigrht ventricle follows corresponding 
changes in the mitral orifice and regurgitation from the left ven- 


tricle. It may also be due to obstruction to the flo' 
through the lungs, as in eiuphysnnn (p. ."►4). In this chh 
is (juadrilattTiii. ami its anterior surfarp consists, almost « 
the wall of the right ventricle. On section both ventricle 
to take about an equal share in the formation of the s 

Fiu. 3». Fi«. -10 






AnUTliir half »t hrait iFIg 3D, «e«n 
ftwm bchlnil U-ft vciiirlcU- rormn the 
whole of itixx. Wall of /.)': wall of 
MV:: 10: 'J i niirinitl |ini|Nirt Ion .^ : 2). 

Antpiior ImUiif liran (Ply. 

brhlnil Klutil v. i ' ' 

)m*M(r<riili«r\< In ftwi 
vonirlilf lUic*. Ml. 
i*iu*il, hut ni»l DO thick iw tlia 
i-iiji|»Ul iirltli'c «nil RA Arv til 

organ, while the usual difference between the thicknei** ol 
i» much diminished. Except in cases of congenital d 
thickness of the ri<rht ventricle never reaches that of the h 
distinctions are well shown iu the accoiu{>an\'iug illnstmti 



DB»TRrCTION of tissue-elements has freqnently been 
in earlier chapters as the result of injurit^ and various 
tive and inflammatory processes, We must now briefly 
such losses are repaireil. It has already been saitl (p. 2) 
oells of one embryonic layer always produce tissues orij 





reloped from the same layer; and it is upparcntly true also that 
true regenerntion of u tissue occurs only (Voin cells of that tissue — 
muscle from muscle, epithelium from epithelium. Any form of con- 
nective tissue may, however, give rise to any other form — areolar 
tissue, bone, cartilage, etc. With regurti to the origin of these 
liMue* from leucocytes — if this ever happen — the latter must, when 
wc consider their sources, be considered as connective-tissue cor- 

The regenerative processes which may go on in inlult niesohlastic 
ligsu«s« are still imperfectly known. Their reproductive energy hiis 
I been supposed to be limited to molecular repair. Nevertheless, it 
is certain that the cells of most iidiilt tissues retain the power nf 
multiplication, 'i'hiit this is not tniuiifest under normal conilitions 
is possibly the blood-supply the ti.ssues receive is sufficient 
^Vly to maintain the status i/ii.'>. while the re.sistanres opposing 
roh"'^tli. such as pressure within the tissue, arc erjual to the force 
•"th which they tend to multiply. But if the intercellular pres- 
sor© be loosened by wound or by destruction, absorption of the 
uuuage«i elements and multiplication of cells round about will 
wgin. Such injuries usually increase the blood-supply. 

'-*' fi»r as investigation ha.s yet gone, the nuclear figures described 
it p. 27 hove been found in each tissue to form the first stage of 
division of cells. 

•^ no extensive regeneration occurs without the formation of 
"P* vt'ssels. we shall first state what is known concerning their 
[.rod motion. 
1 Vessels. 

'Qe formation of new vessels has been studied chiefly in the tad- 

W^ * tail, in sections of healing wouiids, and in teased ))reparation.s 

"' Krj»m,|„tion tissue. At the eml of the second day after the inflic- 

liou of fi wound, anil later, solid jiointeil processes are seen project- 

'"g from cells forming the walls of capillaries ; they increase in 

^''Rth iitid join similar processes from other eapiUaries, or, occa- 

'■lottally, processes of brajichcd conneitive-tissue corpuscles. At 

hM Very fine, the proce.sses gradiiully widen and become hollow. 

*"'» thus an unnstomosing set of vessels (/«</7/-cellular rliaimels) is 

F'Mluced. At this time a few nuclei are seen in their walls, the 

"suit of division of the original cell-nuclei, but nitrate of silver 

'"*'** Hot show the lines of union of individual endothelial cells. 

""•"•• develop subsequently. The process eorrespomls with that 



observed in the embryo (with the exception that no red oorpuscl« 
form in the cells), and is the same in the healing of wounds, in nrw 
growths, and in reproduction of lost parts. 

Two much certain modes of origin of vessels are dejtcribtil; 
(1) In frraimlatinn ti.'ssire Thiersch states that lymph-streams is-tiiing 
from the vefsel*^ Form ehiiiiuels between the looselv-eonnected cell*, 
which uhiuiatelv eoiiinituiicate with vessels and fill with corpufdi-*- 
Observations of Bireh-Ilirschfeld siipfwrt this view. (2) Spindle- 
cells in granulation tissue are saiil so to arrange themselves n* t"* 
form canals which eomimniicate with vessels. It is probable tb***- 
they are really collected round a hud from a vessel (Zieglcr). 

.'\s ill the embryo, the new ves.xels may increase in size withti*" 
demands made upon them, muscular and iihrous coats being form «^~^ j 
by cells which apply themselves around the original tube. 

Adult vessels may increase greatly in si/.e and thickness, as is sC'^ee^"^ 
in the gravid uterus and collateral vessels of a limb in which t 
main trunk has been tied ; such vessels generally become tortuous 
well as wider. Increased How through the vasa vasorum is alw« _ ^ ^ 

Common Connective Tissue. 
This is the most freipient seat of new fornuition of all kinds 
hypcrtr<i|i|iy, tumor-formation, and regeiierntiou. With regard 
the latter, it seems most probable that loj^s of substance is made u 
by iiiultiplicatiou of the surviving eounective-ti.ssue cells. For 
time it was thought that adult connective-tissue corpuscles wer 
incapable of growth, and that almost all new fibrous tissue i»« 
formed from wandering leucocytes. The difficulty in estimating 
the [lart jdayed by each of these elements is extreme. Senftlehcn' 
experinu^nts on the cornea prove the regenerative power of con 
nective-tissue cells. Sherrington and Ballance deny leucocytes aiiy 
fibrnus tissue-forming power. Metchiiikoff" believes that only tlif 
large moiionuclear leucocytes are capable ftf such development. 
The subject is discussed more fully in the chapter on " Inflamma- 
tion. "' 

Adipose Tissue. 

This is merely connective tissue, of wliich the cells are infiltrated 
with fat. Newly-forme<l eonneetivc-tissne cells may certainly thus 
become infiltrated — e. y. in pseudo-hyfiertrophic and, to u loss 



extent, iu infuntile paralysis — but inflnimnatory tissue as a rule 
reiuaiiis free from fat. 

I A ■Mound t>r lireach in curtihigu is iroutTiilly r(.']iuire(i in tbt' fir.^t 
I instance by .si/ur-tissue. Tliis may l>e rejibiuetl hitcr hy byaiine 
I cartilngt' funned from the pericbondriuni and by prolifcratiou of 
I neigh bririufr curtibige-i'ell.s. Tlie uiutri.x i.s formed, iiccordinii; to 
I StnuwiT. from tbe protoplasm of the ct'lls. Often tliis replacement 
I by cartilage docs not occur, in cases of fractured rib-ciirtilage the 
I fibmiis tissue may os.sify into a clasp of bone round tiie )>roken 
I eiuU. 

I The regenerative power of bone is couj^idernble. It depends 

I chiefly UfKjn tbe periosteum, find to a less* extent iifiori tlie niiirrow. 

I Tb*; prooeM.x '\n be?t illii.-strateii by tbe rejiair of a simple fracture. 
Repair of a Simple Fracture. — During the first twenty-four 
'"•urs an examinatiiin shows tbe broken ends of tbe bone lying in a 
collection of blood coagulated where it is in contact witli tbe tissues, 

I "Ot fluid round tbe fracture. The ends of the bone are sliarp and 
j*|rge<l, tlie periosteum is more or less torn and stripped off. and the 
•"eJiilla deeply eccbymosed. The injury to the ves,sels of the part 
excites exudation of fluid and of colls: the torn ti.xsues are infil- 
'•"ate<l bv these cells, .so that in ttiree or four days they are found to 
navo lost their earlier appearance, and to have beeonie soft, jiink, 
autj gelatinous, as is best seen in tbe medulla. In fact, they arc 

I ■ grnnulating," and the granulation tissue in amount 

|*'Htil the blood arounrl the frnetiire lias altogether disap])eared. and 

|ttie emh of the bones are imbedded in a mass of soft tissue. This 
**sue i* formed from tbe periosteum, medulla, and any other soft 

l^l'^i-ts that are injured. From the thini or fourth day certain largo 
'*•}? iilar cells are seen close to tbe bone : these play the part of 
Osteoblasts. Here, as elsewhere, the source of the cells of the 

lK*^nnlation tissue, after tbe effect of the primary injury has sub- 

'••l«ttl. is disputed, some referring their origin to leucocytes, but the 

'•yority to the cells of the medulla ami periosteum. Possibly both 

**»tTibHle: the effect of irritation (nmbility of fragments) in caus- 

• tijj fjgj. f„,.njj,tion of new tissue is urged in favor of a largely 

I •'••oocylic origin. This soft tissue is found in plenty about the 
'^•*tli day, when it is difficult to recognize tbe periosteum, which is 




nHollen and in6]trate4i with cells like other parts. Next, tl»*i 
^riiiiitliitioii tissue bc><.'orac8 firmiT, and at nbtmt thr foiirtcfntli tl«y 
tlic i><.Tio8feiim can again be seen covering a spirnUc-^'hBpcil »wclliB|B< 
wlrich extends beneath it for sotne distance up and down the bone- 
A» Billroth says, the ends nf the bone are stuck into this jpimilr- 
sliaped mass a« if it were soft sealing-wax ; there is » ring out»itl« 
and a plug in the medulla. This uniting tissue is called the prt^- 
visional callus. In animals it is generally convcrto«l into orti- 
lage, but in uinn direct ossification usually begins in the tbtrrf 
week. In man. however, when tolerable rest cannot be nmintaintxL. 
M in fractured ribs and many fractures in children, cartilage iwy 
be develojied. It is always in greater ipiantity where the bunr i«i 
thickly covered by soft parts, and rarely forms a complete rlDjf in 
man. It is strongly developed in any angle or gap. Where lk« 
most perfect rest is obtnincd, us in fissures of the skull, little dtB 
liroviwional (or permanent) callus is formed. " 

Ossification of the provisional callus begins in the angle bctwwo 
the periosteum and the bone. an<l extends thence beneath the fieri' 
ostouui and along the surface of the bone. The plug in the niedulVf 
ossifies a little later. At first the bone is soft and open in str«»< 
ture, and easily picked ofl' the shaft. Its canals are more or le* 
vertical to the surface of the shaft, and continuous with abnonn»^' 
witle Haversian spaces in the latter. Ossification begins round t> 
vessels passing from the callus to the bone: the cells farthevt fr^ 
the veswels assume the shape of osteoblasts, and become surroun<i' 
by or converteil into bone. Osteoblasts inside each ring next l^ 
down laminnr of bone until Haversian systems are forme<i. T* 
callus is now intimately unito<l with the original bone and hold* t J 
ends firmly together, The medullary canal is blocked by bone all 
osseous buttresses fill up any angle. This complete oseificatioD.tfl 
the provisional r-allus is finished in man between the four 
eighth weeks, according to the size of the bone. 

So far. the bony tissue has not been mentione<l. The nexf4 
is to unite the two ends directly by what is termnl permanent C 
definitive callus. This begins to form when tin- provisional callu 
has fixed the ends of the bones, but preparation for this iinioi 
begins much earlier. The enils of the bones are to be softened iirt 
a tissue which can bridge over the gup, blend the two fi . '' 
into one. and finally ossify. A rarefying ostitis begins in 
ability immediately after the iiyury, and results in a rounil-wllc 



gron-th, which slowly eats away the walls of the Haversian canals, 
viiicli thns become enlarged. Naturally, this is a much slower 
process than similar infiltration of the soft parts. So long as the 
bones are moving on each other the granulations would have little 
chance of blending across the gap, but so soon as the fragments are 
fixed this union occurs, and ossification, running on to sclerosis, 
foIlo-^8. It is probably not complete before the fourth month. 

Tlie final process in the union of a simple fracture is the rounding 
off of all prominences and the absorption of all unnecessary provis- 
ional callus. The completion of this may occupy years ; but, ulti- 
mately, in an accurately set fracture, the medullary canal may be 
I opened up and most of the thickening around the shaft removed. 
Generally the seat of fracture remains evident, but Billrotli says 
that in some cases it cannot be recognized. The analogy between 
the repair of bone and the repair of ordinary connective tissue, as 
ilescribed under Healing of Wounds, scarcely needs pointing out ; 
ossification of the scar-tissue is the main difference. 

Repair of compound ft-actures is effected by the ossification of 
gnnulation tissue, either directly or after its conversion into fibrous 
tissue. But suppuration, implying more or less destruction of the 
"**" tissue, and oflen necrosis of soft and hard tissues, greatly 
(lelayg the process. (See "Necrosis of Bone.") Even where com- 
pound fractures become simple from the first by union of the wound 
"•^y are often much longer in healing : the reason is not evident. 


■A. wound in muscle, as a rule, gapes widely and heals by granu- 

***on. In some parts, as the tongue, retraction is prevented, and 

***on by first intention occurs readily. The protoplasm escapes 

^''Ougli the opened sarcolemma, and leucocytes penetrate for some 

'stance between the fibres. Ordinary scar-tissue develops from 

** granulation tissue and unites the ends of the muscle. Now 

®*Is are now produced by the muscle-cells on each side of the scar, 

^** they invade, and may eventually replace, the cicatricial tissue. 

^^■^flke says that new muscle-cells are produced only by multi- 

P'lcation of the nuclei of the old. Each nucleus becomes sur- 

^ttuded by a spindle-shaped mass of protoplasm and divides to 

'**'0» muscle-fibres. In some cases no regeneration is evident. 

Hegeneration occurs more frequently to repair losses from degen- 
*^tion, snch as that which occurs in acute febrile diseases, espe- 


cially typboitl. Tte new cells are believeil to spring from 
elements Ij'ing between the original muscle-fibres or by «plittia 
the oM eells from end to end. 

Involuntary innscle-cclU multiply also by division. Tluir 
Aome doubt us to whether those may not arise from euuucctivc-i 


Nebvb-oells and Nerves. 

Nothing is known of a regenerative process among ganglion-* 
and many think that none oecurs in adult life. An ordinary «cv ii 
all that is known to replace destroyed ganglionic tissue. J 

When a nerve is cut across, union takes place readily by mR 
tissue if the ends are brought together: and. as a rule, function il 
restored in the course of time, even when a considerable piece (i* 
some cases nearly two inches) has been excised. 

Afti-r division, myelin escapes up to the nearest nodes of Ranrier 
and blood is extravasated between the fibres and in the sfactiK 
Then leucocytes infiltrate the en<is for a short distance, rcndcrinj 
them bulbous; the soft parts are similarly infiltrated, and a uiaA> '>( 
granulation tissue soon unites the ends. Later this develops inii 
ordinary scar-tissue. 

Boyontl the degeneration of a lew fibrils no immediate chsOi 
occurs in the central eml. In the peripheral end, however, chaog* 
occur rapiilly, antl lead to destruction of the nerve. In ¥farni-bloo3< 
animals, according to Runiver. after twenty-four hours the nud 
in the primitive sheaths are found enlarged mid the sheath is eve*" 
where visible; then accumulates round the nuclei, at*-' 
nodes and other points, replacing the medullary substance. On*-' 
third or fourth day these protopliismic m;i!<sf.H are so large as 
completely break up the slieatli of Schwann at many points. -> 
the same time the nuclei are seen to have multiplied once or t»ic! 
\ little later almost all the degenerated myelin has disappeartr 
and the axis-cylinders are broken into short segmentit which mx) 
finally sufTer the same fate, nothing remaining of the peripheral cri 
of the nerve but the primitive sheaths, distended :it intervals b 
nuclei which are abnormally freijuent. Sometimes dro[>8 of fat pel 
aist. A few fibres do not umlergo degeneration. They are thoDgl! 
to have sprung from other undivided nerves lower down, and to b 
taking a recurrent course in the divided trunk. These fibres deger 
rrate in the central end. These changes are said to begin in tla 



Kio. 41. 

miiscle-platps in motor nerves, but they occur practic;illy at the name 
time throughout the iicrifiheral ends. They are generally complete 
in fourteen ilays. The nerve i.s now gray ami shrunken: its fibrouc 
tissue overgrows, and further wasting and induration follow. 

No regenerative changes occur for 

four or five weeks. Then it is found 

H thrtt the axis-cylinders uf the central 

eufl are dividing into two Imndles 

»(whi«j-lj again divide several times) or 
into several, and that these small new 
axi»-c\linders are finding their way 
through the sc^ar-tissue into and be- 
^ptweon the old primitive sheaths. 
(iro\vth of the axis-cylinders always 

Ihegi r»3 from a node next above or 
close to the section, where tlie sheath 
<>' Schwann is bulbous. A cross-section 
"f tijc perijihoral end at about the 
figlitli week shows small riiedtillated 
»'>'• non-medullatcd nerves, among the 
"111 primitive sheaths, full of proto- 
pljksm_ The course of these new fibres 
H '* "^©'y irregular, especially through 
the scar, where they may even loop 

■ hac-lt At first non-niedullated, they 
'";*^\»jire. later, sheatlis of Schwann, 
'*-*3 nodes of Ranvier, which are at 
'^*'t placed at short intervals, as in 
'. '-^ng nerves. In the sear even primi- 
^ gheaths are at first wanting, but 
'^ ultimately form from the sur- 
^* Jiding connective tissue. 

Fibres fnmi llif iHTljiliiTal cnrt "f 

H nervo ten tluysuaerftecllou, ittained 

~j^, "-' with rjsmic acid. One rlhre HliKWBthe 

-*^Iany months, or even a vear, may mHsse* <.r <iei{ener«tiri mjeiin ; the 
t« before function is restore.l, a ^'.^Tr ' m^h r*; siT'"' " "^''■'"''" 
Tier time being required in sensory 

•n in motor nerves, and it is supjiosed that during this time the 

*»-cylinders are slowly finding their way nlong the nerve. The 

^^le varies with the length of nerve beyond the division und with 

' ^ distance between the ends. The number of axis-cylinders pro- 

Atj^jej in this process is much greater than that of the nerves 



deNtro_ve»l. It pccms |tnibnhle. tluTofore. that manv atro|ihv;bat 
their further history is not known. 

CaseH occur iu which restoration of Heusation takes place witlim 
a few (lavs of the division of a nerve. The probable explanition 
is that coniniiinicutiug nerves take on the function of ihr iliriilc<l 
line; but Hoss and others think that, if the ends are kept in md- 
tact " iunnciiiate " union of the axis-cylinders may occur. 

When union does not occur, and after removal of the pcri]ilifrsl 
part, the jiro-vima! end becomes bulbous (p. 160). 


Epithelium is always derived from pre-e.xi8ting epitheliuni bj 
simple division of the cells. This is shown by the f»ct that i> 
always spreads in from the edge of an ulcer, unless islets of thr 
retc have been left undestroyed iu the midst of the graniilatiofl 

The epithelium of the skin and mucous membranes and of luno^ 
{;lan<ls is beinj; destroycil and replaced throughout lift" — si>metin»** 
very rapidly, as in catarrhs of mucous membranes ami of the kidu^? 
(acute nephritis). 

Rut if all ihe cells of an u<'inus or tubule of a gland be destroy*^ 
llii-re is prol)ably no repniductioii of epithelium. A woiintl of ' 
gland, with or without loss of substance, heals by scar-tiMK-**' 
which is permanent. According to von Meister. regeneratiiui ^*" 
liver-cells can take jdace in the dog, cat, and rabbit. The mnlt 
however, needs further investigation. The more highly specialii 
tiie function, the less likely is the tissue performing it to be cspal 
of regeneration. 

llegeneratioQ of nails and hair is frequent. 

Heaunq of Wounds. 

The union of most wounds and the repair of losses of substalu^* 
are effected primarily by the formation of more or lews scar-tissni- — - 
/. f. by the development of new vessels and new connective tissue. 
Subsei|uently more or less regeneration of the injureil tissui-s may 
take place in the modes above described. Several modes of healini; 
are desi-ribeil, but they are fundamentally the same. They ar^^ 
(I) Immediate union: (-) I'nion by first intention; (8) Healing by 
second intention or by granulation; (4) Healing under a scab; (5) 
I'nion of two granulating surfaces. 



Fio. 42. 

late Union. — Described b_v Macartney in 1H8H, the occiir- 
llio process has been confirmed by Paget and Thiersch, 
states that it occurred in wounds inflictetl on the t<jngiie8 
The union is said to be effected by a blending of the 
unchanged surfaces of the wound, no lymph intervening 
It is com|)b,'te in twenty-four Imtir*. and no scar results. 
lologists deny that such a process ever occurs. Tliey 
at lynijih, jiossibly only in niicroscopic i|Uiintity, invnria- 
the first bond of union. Willi tiieui uninn by jirM iiiten- 
speedJe.xt mode of healing possible. 
iy First Intention. — This generally occurs in well-treateil 
uiids. It is prevented if the surfaces are not accurately 
tgether, but left gaping sii- 
or separated in their deeper 
reign bodies, blood, or fluid 
in any tjuantity. It is also 
by movement of the surfaces 
ither. by sloughing of the 
r by irritation of any kind 
ites inflammation going be- 
brinous stage. When these 
»re avoiiled by carefid arrest 
^age, cleansing, drainage, 
provision for rest, and pre- 
septie and infective inflam- 
he following changes take 
capillaries become tlirom- 
to the neare.«t collnferal 
any arteries or veins have 
or torsioned, the changes 
in Chapter XVIII. set in. 
inflicted by a knife is se- 
\j localized, and of short 
It excites free exudation 
id corpuscles. At first there 

ed corpuscles in the e.xudation, hut they rapidly dimin- 

! fluid becomes clear and deep yellow. If this exudation 

rpjantity. it can escaj>e between the edges of the wound, 

'. channels should be purjiosely jirovideil. The fibrin <'ipii- 

tbe exudation coagulates on the op]iosed surfaces, bind- 


Union by flrat tntcuiion. (Sec text.) 


yummoy ixcheased. 

Fio. 43. 

in;^ them togetliiT; it foiitaiii.s ii viiriaUle jiroportion of leucocvlwL 
It is tliis "lyiiipli" wliii'li Ibrmsi the "jiiti/.o" on wounds left oprn. 
The exudation <liuiini»lie8 greatly as the cfTeet of the injury |«i»« 
off. Mit-ntsfoftii- exinuiiintii(n iiftrr fwi-nty-foiir to thirty-six b'iHr« 
MJiows the i'(jj;i's of the woimd aefiuraled by ti narrow band of siiial! 
roiind-cetlEi : the tissues close to the incision are swollen and h»iT. 
and more or Iosh infiltrated with leucocytes. New vessels develop 
after the second day and shoot acros.s from side to side, converting 
the lymjdi into jiranidatiim tissue. This then goes on to the ilrvcl- 
optiient of scar-tissue. The mnnber of leucocytes about the wound 

varies with the amount and diimtinn 
of tlie irritation; in some casts it 
is ijuite diflieuit to make out what 
tiolds the edges to;.;ether. Thii.i in 
a herniotomy wound examine*! on 
the fourth day (Fig. 42) the line of 
incision was recognized iilmost soiclr 
hy the fact that the fat on one si«it 
was adherent t« tlie deeper Ujff 
of the cutis on the other ; the t«o 
seemeil to he in actunl contact, «»" 
there was hardly any round-ci'lh''* 
infiltration. The taken bj t*** 
tissue-elements in sear-formatioD '•H 
discussed in Chapter X\. T**' 
older a scar is, the more cloS**- 
does it resemble the normal tisi***' 
Union by Granulation. — Wb** 
a wound cannot be brought ** 
getlier. or wlien union by first •* 
tentioa is [irevented, this form * 
.. . , occur. I'ntil union takes place 

I'nlon of iwii KniiiuIMlnK niirmiT!! . . . ^ 

Trom a breant wcumi. Tti.- iiiiiiiiiK raw surface 18 necessarily exjiop*' 
nmteri..! I. m mm-1. «n.»ur amount to some irritation. This, s-me thin I 

Ihmi III Fig. 42. X V>. 

keeps u|» a constant e.Kudation <' 
fluid and leucocytes from the new vessels, just aa the original injnf 
excited such exudation from the vessels of the normal tissue. ar» 
fill- liMicoeytes imbedded in a little intercellular substance becoD>' 
^ into granulation tissue. The majority of patholog 
ilieve that after the primary severe irritation has 




yjflefl gniniilation tissue is protluced by nuiltiplicnfinn of the npijt;li- 
biring comiectlve-t issue corjiuscles. However fornieJ, the tissue 
incroaMS in amount until the wound is filled up to the level of the 
sniTac-e, when the granulations skin over, as described in Ohajiter 
XX. A granulating wound under the old-fashioned dressings sup- 
pumted more or less freely; but one treated antiseptically, and 
therefore protected from irritation by the iuitisejitic euqdoyed, dis- 
cliitrpcs a serous fluid. A seetinu through graiiiilatioii tissue shows 
on tLe surface a layer of small rmind-eeils with bi- or tri-partite 
i hnclei, imbe<lded in a substance which is actually fluid superRcially : 
this biyi-r is breaking down into pus. Deeper down are found 

IfibroMasts, and ilecper still scar-tissue in all stages of formation. 
The thickness of the surface layer and the amount of jms formed 
Vary with the irritation to which the tissue is subjected. In some 
tases destruction ei|uals or exceeds growth of granulations. Here, 
•g*in, therefore, treatment should be directed to the avoidance of 
»II unnecessary irritation, 
^ealinff under a Scab. — In this form the exudation is small in 

k amount and ilries into a scab. It is not common in man except in 
•'i[>^Tficial abrasions. Formation of gi-anulation- and scar-tissue 
"^-'CtiTs beneath it, as also does the inward growth of epithelium. 
Wti^ii "skinning over" is complete the scab drops ofl'. The dry 
•<*V> is but slightly irritant in itself, and it does not putrefy. 
"Qen ulceration spreads beneath a scab some infective agency is 
. |ir(>"lj,jl,]y (jjg cause. The process of scab-formation is sometimes 
H imitated by closing wounds, often leading to cavities, with coUo- 
H 4i<>u, „r by allowing blood or tincture of benzoin on lint to dry 
H »n«J occlude the opening. Such treatment is, however, dangerous, 
H lor if septic or infective organisms have entered and excite inflam- 
r mation, the absence of drainage will be most prejudicial. 

XJnion of Two Granulating Surfaces. — When two surfaces 
h&Vc granulated as above described, they may be brought together; 
iin»\ frequently the two surfaces Avill blend, thus saving the time 
*bich would be required for filling up from below. Free suppu- 
r»tion and im]»erfect drainage will prevent such union. This is 
tlie way in which abscesses should heal when their walls are allowed 
(0 full together by evacuation of the pus (Fig. 43). 


yvTiiiTioy rycREASED. 

Transplantation of Tissues. 

Even before Joliri Hunter's success in tran8]>lanting a cock's i 
into it» comb it waa believed that pieces of the body, like tbc 
of the nose or finger, might remiito if fixe<l in position soon afl 
complete separation from the bodv. But accurate knowledge 
this subject has been nciiuired only since Reverdin's di«coverr) 

The tissues, as is well known, may survive systemic de«»b (i»r 
a short time. Portions of almost all tissues may be removed froia 
one part or animal and successfully transplanted to another (« 
or nniinal if the conditions are suitable. These are: Transferrn 
v»f the portion of tissue with suflicient gentleness and t|uit-kiie-<»( 
ensure that it is alive when transferred: close contact with the raw 
surface [trepared for if: maintenance of its temj)erature : nml 
avoidance of all irritation. e.><peciully septic. The piece of tiw 
will, under these circumstances, become united by first inlcnti 
to its bed. and will be nourished by lymph transuding fn>m 
surface until vessels shoot across into it. Naturally, thmc liiwd 
which are least highly organi/.e<l and which re<{uire the Ifi 
ntifrim<'nt bear transphintatinn best. 

Epithelium is the tissue which bettt-r than any other benr» tni 
planting. Use is made of this in the operation of grnt\iiig. 
which small bits of the tujtfrfiriul jinrt of the rete are placed np 
a healthily-granulating surface. At first, nourished by the cxiiJ 
tion, these fragments grow, adhere, and form centres wht-nce 
thelium spreads over the surface. The cells of the root-itheath I 
plucked-oiit hairs answer the purpose well, (jrranulatioii li.« 
mav be skinned over in this way, but unless scar-conlracti( 
accompanies the skinning over, the cicatrix is liable to br 

\ piece of akin an inch sfpiarc. freed from all fat. may be tri 
planted, and thus fi'tro/non ami similar deformities may be reme 

Similarly, a bit of murouu mrmhraiD-, usually obtained frooi < 
rabbit's conjunctiva, is transplanted in ca.xes of rtitropi'im. 

t'ltrtiltu/f and /irriimtfuw, especially when young, bear transpl) 
tation well. (Sec also pp. 157 an<l 143.) So also ilo bits of 
Macewcn of Gbisgow built uji part of an ulna with bits rero<i 
from ilcformcd tibiae, ami introduced the practice of ri-plncini 
of the bone removed in the opening made by a trephine. 

TUMORS. 131 

Pieces of muBcU have been successfully transplanted, and part 
of the sciatic nerve of a bird has been substituted for a correspond- 
ing piece excised from another bird : the transplantation of nerve 
lias been successful in man, so far as the mere healing-in of a por- 
ion of rabbit's nerve placed between the ends of a divided median, 
'ut time had not been allowed for restoration of function when 
lie notice was published. 


Th E first notion which the name " tumor " conveys is that of 
?lling; but swelling may result from very different pathological 
•cesses, while the term " tumor " has a much narrower connota- 
"• It is impossible to give an accurate definition of its meaning, 
»Use its real nature is not understood. It is generally described 
* formation of new tissue which is abnormal to the part ; which 
itarbs its form, and differs from it more or less markedly in gross 
'I in minute structure; which performs no physiological function; 
lich tends to continuous growth, and is more or less independent 

the general nutrition of the body ; and which has not arisen 
oitt the causes or in the course of inflammation. 

Ihat tumors are formations of new tissue necessitates the rejec- 
wn of all swellings due solely to retention of secretions (retention- 
iysts) or to extravasation of blood (hsematomata). True hypertro- 
phies must be rejected because — though they involve an increase in 
i«e— the shape, structure, and function are preserved. Finally, all 
wflammatory swellings, tumor-like products of infective inflamma- 
*'0D»— such as gnmmata, tubercles, farcy-buds, and condylomata — 
•Ddall localized oedemas and effusions — such as hydrocele — must 
^ eliminated. 

The definition of a tumor as an atypical new-formation would 
leparate the class from retention- and extravasation-cysts and from 
roe hypertrophies; but many an inflammatory new-formation, 
rch as callus or a condyloma, is atypical enough both in form and 
•uctnre. Moreover, there is a whole group of tumors (sarcomata) 
licb it is impossible to distinguish anatomically from the results 



of inflammation. It is therefore neccBsary to include in a definition 
of tumors soinetbing wliitL sball draw the lino between thcra ami 
inflammatory products : such a ilistinetion may be found in their 
causes, modes of origin, and progress. We may say, then, tbit 
{I tumor in tui aU/pifol new-format ion not the remilt of an infinnmn- 
tion. False hypertrophies, especially such as affect limited »nxi 
{e.ff. accumulation of fat on the buttocks of Hottentots), are chisflf 
allied to simple tumors and especially difficult to separate fn>m 

DEVELOPMENT.— The nutrition of tumors is not rcgulmed 
like that of iioruiai tissues. When the body gets thin and tlie'^^^ 
••utanvfius fat disiippears, & fatty tumor wastes but little or not »t sll 
and malignant growths often grow luxuriantly while their victim 
are rapidly emaciating. With this fact it may be noted tumor* 
have no uerve.s, though the relation of nerves to nutrition is wrrt 
little understood. 

A tumor consists of cells, formed by multiplication of pren'xistiug 
cells, nnd here, as elsewhere in nature, the characters of the psrrnl 
arc handed down to the off'spring. In other words, a tumor nnilth« 
cells from which it springs always belong histologically to the -tuo* 
class of tissues (see p. 28). 

In development and structure the tumors resemble the norH**^ 
tissues — every pathological growth bus its physiological prototyP^" 
The resemblance, Jmwever, is by no means coraj)lete, for. as \o" 
cated in the detinitiun, they are always more or less atypical • 
their structure. As a rule, the diff'erence between the normal »** 
abnormal tissue is such that with the nakeil eye one can tell roug»**. 
where the one begins and the other ends. 

The histological processes which give rise to the formation »• 
tumor are doubtful in the extreme. It is uncertain whether 
tumor grows from a portion of the mature tissues or from a ki'* 
of "resting spore " of embryonic tissue, as suggested by Cohnbr** 
(p. 143). Evidence of the multiplication of normal tissue-elemef 
round about a growing tumor is often ulitainiible. hut it is very J* 
ficult ti) tell what becomes tif them, and Ziegler was incline<l * 
think that most disappeared. A cancer-embolus in a gland almt"*^ 
certainly grows without any additions from the surrounding eel ■■ 
and there does not seem to be any a priori reason why a fibroma 
a sarcoma should receive any either. 


The elements from wliieli tniuors most freipiently originate are 
those belonjiin;: to tlie common connective tissue and U< the 
blood-vessels iirnl IvmpLiitic system with whicii it in so iiitiiiiatelv 
liated. By eoinmon connective tissue is meant that tissue 
wTiich ui all piirts surroumls the l)lootl-vesseis uiul is so iiniversaliv 
•listributed throiigbout the entire orguuism. This must be ciirefully 
tiirtingiiished from the special varieties of connective tissue — tendon, 
artilage. bone, etc. In this eouimon eotinective tissue we distiii- 
guish two kinds of cells — the stable or connective-tissue corpuscles, 
•111 tlic mobile or "wander-cells." Both are in intimute relation 
*itli till' endothelium of the lymphatics, which commence as spaces 
distrilmtod throughout the tissue. Further, the etidothelinm of both 
lymplintics and blood-vessels closely resemldes in its pliysiological 
functions the fixed cells of the connective tissue. 

Coniiei'tive tissue is .said to give rise to tumors by multiplication 
wits cells, the part played by the two kinds being donbtfiil, Em- 
■"Tonic tissne consists of small round-cells with no limiting mem- 
'"'«»n> and a large nucleus, lying in a .scanty, semi-tlnid, and faintly 
['■»n«ilar intercellular material. This tissue is ofteti called " indif- 
f'Pnt." aa it is impossible to determine in this early stage of the 
'''»**'th what it will ultiinati'ly bfconie — whether u libronia, a ,sar- 
<"•»»., or an enchondroma, etc. 

» his " indift'ereiit " tissue now develops into that of the perma- 

"»t growth, much in the same way as the immature connective tis- 

•^ of the embryo develops into variou.s conTrective-tissue substances 

iicous tissue, fibrous tis.sue. cartilage, nr bune. The embryonic 

iwue may undergo no higher development, the cells remaining 

"Uiid or oval an<l the ground-substance homogeneous; or the nuclei 

'' several cells may multiply without any corresponding division of 

we cells themselves, thus forming giant-cells ; or most of the cells 

"•ay lengthen out into spindles. an<l perliajis here and there fibrilla- 

li"U, with disappearance of some Cflls. may occur. We thus get the 

wund. oval, myeloid, or spindle-celled sarcoma; also the fibro- 

Mrwjma. General fibrillation with di.<appearance of most of the 

cfUi, and raucous degeneration, choiidrification, or ossification of 

fie ttroma. may occur, thus forming fibrnma, my.\oma. clmiidroma, 

r osteoma ; or fat may form in the cells — lipoma. A combination 

f two or more kinds of structure may be met with in the same 

mor — as a combination of sarcoma ami lipoma, of enchondroma 

it myxoma, and so on. We are i|uite ignorant of the causes. 



upart from heredity, which determine the ultimate character of tht M 
tissue. m 

Next to connective tissue, epithelium — surface and glandular — i« M 
the tissue fmm which tumors most frequently originate; ami m H 
from connective tissue are produceil growths of the cnnnectivr-tii«uc H 
type, so growths originating from the ej)ithelia preserve the ejiitJn'- I 
lial type. A priori, it would be entirely contrary to evolution fnr W 
them to do otherwise; ami the great majority of observers ststru ■ 
the result of their investigations that epithelium never arise* but I 
from epithelium. It is nevertheless believed by some that an rpi- I 
thelial eel! may by mere contact so influence a eonnective-tis'i** 1 
cell that it becomes epithelial, or viff vfrnii. This influence of une I 
cell up3n another is called *' spermatic " (Creighton). The point I 
lias Iku'Ii carefully investigated by Zieglcr with a negative resnlt. I 

Fnuu the remaining tissues. muBcle and nerve, the devel<>|»- I 
ment of tumors is comparatively rare, and from the highest aiinlt I 
nerve-tissue it is doubtful if tumors ever arise. I 

According to the similnrity or diflference which subsists lift«c^'*» I 
the new growth and the tissue from which it grows, luiuors »** I 
divisible into two classe.x — bomologrous and heterolog'ous. Wb*-"" | 
the tumor resembles in its structure and development I In- tifs**'^ | 
from which it originatt'*. it is sai<l to be hoimdogous; *lieii it diflT*^*^ i 
from it. the tumor is said to be heterologous. A eartilagin***** I 
tumor, for example, growing from cartilage, is homologous, t**^ 
growing from any other tissue, as from the parotiil gland, it ^ 
heterologous. This distinction is probably artificial, not real. I» 
be correct that tissue-typt^s "breed true," the only even opparr""**j 
heterology which we know to occur is the development of the diflT**^ 
ent connective tissues from the same embryonic tissue. In C-** , 
example given cartilage does not arise from the essential epithel » 
cells of the |iaroti<l. but from the 8upjs>rting i-onnectivc tissue ^^^ 
from an aberrant bit of cartilage from the rudiment of the ja "^^ 
Heterology, however, is not limited to the production of a ti«s^* 
which is dissimilar from that fmiii which it originates: a tumor 
also said to be heterologous (or beteorotopic) when it difiers fn*' ^^ 
the tissue in which it is ritwited : and this may occur without 9 "^^ 
being the direct product of the latti-r. It is heterology in tl» * 
sense that is so characteristic of malignant growths. Cahceri. f5»— -^ 
example, become heterologous, owing to the gr<>wth and extensi*^ 
of the efiithelium beyond its normal limite (see " Epithelioma " ~^ * 



M)d tLe same form of heterology obtains in the case of all growths 
'>ngiiinfing frmu ok'Uients which have iiiii;viito(l or boen carried 

ffom their original habitat, ami have t.leveh'[it'<i into a tissue difter- 

ing from that in which they are found. 


TISSUES. — The relation of the tumor to the surrounding striic- 
liires varies. In one case the tumor is circumnrrifu'ii, m<'rely dis- 
placing the surrounding parts and stretching and irritating their 
conne<-tive tissue, .'<i> tliut this coines to form a fibrous capsule 
•roHiid the tumor, by which it is completely isolated. The lipo- 
iiiata, fibromata, and encbondromata arc usually thus ciicapsuled. 
fn other ca.ncs tlie growtii inviuiri) the a<tjaccnt structures. There 
i«th«'n no line of demarcation between the tumor und the surround- 
ing part*, and, although to the nakoil eye there may seem to be 
lino, tlic microscope will siiow that tlie apparently healthy tissues 
»"* infiltrated with a small round-celled growth (Fig. 44), into 
*l»icli the specific tumor-cells are advancing. The former is proba- 
*■'>' tlio result of tissue-irritation set up by the latter. 

Retrogressive changes. — a tumor very rarely disap- 
I'cai-D. and it thus diflcrs from iiu intlammatory growth — <». </. a 

Fi... 44. 

.^ 'frhtu »f the niBnuna. SpreadiiiK mnrtrln: •mull oellrd Innitrntlon nf the raiMcuUr 
I ^*'*^ Mill KilijMi»« tliisui: ill ihe iieij(lil)4»rluHMl of IJie kIhikI. • 'jno. 

^**ii!nft. It may either remain stationary, or grow — slowly or 

*iUly. Sooner or later it usually becomes the seat of retro- 

sive changes. The time at wliicli these conimence varies. As 

I ''•lie. the permanence ami durability of a tumor bear an inverse 

I ^'•'ttion to the rapidity of its growth and to the inferiority of its 

'^'Kanizafion. The more rapid the growth and the more lowly 

•"ganiieil the ti.ssue formed, the less its durability and the sooner 

retrogressive changes occur. The carcinomata and sarcomata 


yurntTwy iscreased. 

develoi) nt|ii<Ily and degenerate ([uickly. They consist for llii' 
most part of (.-ells ; their eit-nu'iits art- unstahle and soon jtcrisii. 
Omscous tumors, on the other hand, develop more tslowly, and are 
but little liable to retrogressive metamorphosis. They consist of « 
u more hijfhJv orjiunized tissue and have niiicli trreater stabilitv, 

'I'lie retrogressive changes are similar to those mot with in theimr- 
mal tissues. Deficient aujiply of blood is followed hy fattj/ daienrrn- 
tion and its various terminations — softening and caseation. /'';/- 
mvntary. calcareoux. i-dlloiil, and mucoid dejjrneriitiftn may «1» 
occur. Tumors may become the seats also of inflaiiniuitioH, u/crii- 
tioit, 7U'cro»i», and hemnrrlitHfv. 

OLINICALi COURSE. — Tumors are divided clinically into two 
great groups, the simple and maligrnant. A simple tumor is one 
which, as a rule, grows slowly and steadily, or. having attaim'<i * 
certain size, remains stationary. It consists of tissue apjiroximatii'B 
closely in structure to srnue normal adult tissue, and is general*}" 
surrounded by a distinct capsule, ont of which it can be complete*? 
shelled, for there is no infiltration of stirrounding parts. Aft*^ 
such removal it does not recur locally, and secondary growths ** 
glands or more distant parts ilo not result from it. Its interferef*-'^ 
with health is only mechanical, unless sumo accident — as inflamU*^ 
tion — occur in it. Tumors of the fully-developed conueetive-tise"*-* 
type generally pursue this course and may grow to a huge size. 

A maligrnant growth, on the other haBitl. generally grows rapiil *_^| 
and tends to enlarge continuously. It consists of tissne which * 
markedly "atypical," and is, as a rule, surrounded by no capsuJ' 
but progressively infiltrates the surrounding tissues. Af^er app 
rentiy complete removal it recurs locally, and, whether removed ^^ 
not, tends to give rise to secondary growths in the nearest \jX0^ 
phatic glands or in distant parts, or in both. Though the palicT^ 
is itfteu in excellent health when (he tunuir first appears, he soont^ 
or later wastes, loses strengtli rapidly, and becomes very anieinic 
cachexia is produced. This is due t(i many causev« — e. g. to removal'-' 
from nornml tissues of imtriuient reijuived for the active growth or 
the tumor-cells: perhaps to the metabolism of the latter, ponrin^^ 
abnormal excreta into the blood; to pain ami an.xiety; often ti^ 
jirofuse discharge ami .septic absorption conseijuent upon nlccra- 
tion: and occasionally to actiml interference with the ingestion and 
absorption of food. The more rapidly and the more completely 


8 tumor produces thene results, tlie greater is its malignancy. 
E^erl frrowths of the same class vary iinich in these respects, and 
ililfert'Ut classes vary still more. Though in a high degree charac- 
It-rintic of cancers, the purely clinical term " malignnnt " must he 
diiitinguished from the pathological term ^' f<mcerim«." which im- 
plies a specific structure in tiie growth to which it refers. Sarco- 
mata lire often rjiiite as malignant as cancers. 


cur /i«v7//y after removal, and either after nr liefore removal growths 
wmilar to the primary tumor may form in the nearest lymphatic 
gkndxw in more ili»tnnt timt-wn <>r ort/ini». In the highest degrees 
of luiilitinancy all occur. Each must he considered sejiarately. 
Reproduction of the Tumor in Adjacent Structures. — This 
riTurri-nce in furo after removal is usually the earliest and the 
'•'ast imfiortant evidence of malignancy. It is due to some of the 
tnmor-colls having been left behind, and is, therefore, much more 
''*ely to occur in those growths which infiltrate tlie surrounding 
tissnea, and ri'aHit extend beyond their iip/iitreiif limits, than in 
'Oose which are enc*psuled. The cells left behind contiiuie to 
If^yr and recurrence occurs. Cells may be carried to some little 
•''"tjince from the primary growth by Ivnifih- or blnod-ciirrents, and 
•'o becoming impacted form the nucleus of secondary nodules vdiich 
•••y spring up around the original tumor. In some tumors local 
'^urrence occurs many times, and often kills the [latieiit without 
*'«.v infection of glands or distant tissues. 

Reproduction of the Tumor in the Nearest Lymphatic 

^^■lands, — This is owing to the entry into, and transmission by, 

^''e lymph-stream of cells from the maligiwiit growth, which 

••ocome arrested in the nearest lymphatic j^lands an<l there develop 

•li«to secondary tumors. These are in all cases of the same nature 

■'** the primary tumor. Wheti the lymphatic glands have theuiselves 

•Jev«-lopefl into secondary growths, they in their turn constitute new 

**tttre5 of infection, and may thus infect the more distant glands 

tlie immediately adjacent tissues. When the lymph-sinuses of a 

iftd are so blocked by new growth that lymph cannot pa.«s, a 

•^^Riirgitant flow is the natural result, and the lymph, bearing 

tutuor-cells, has to pass through abnormal vessels and glands. In 

'hi& way we can account for infection, say. of the abdouiinnl glands 

"T a tumor of the lunj;;- and for the numerous nodules in the skin 




which sometimes occur widely all roiiud an ntrophied scirrhtu ftf 
the mauiiun. A ilisturit l_vnij)liatie glainl iiiiiv bo infected by cmlio- 
lism of its urtt'i y. The tendency of uialigunnt growths to bccoOMl 
reproduced iu the lymphatic glands varies very mach. It is Tcrjl 
mnrked in the carcinonutta. while in the sarcomata it \h compm< 
tively slight. The reason fur these dilferences will be seen io i 
({Uent chapters. 

Reproduction of the Tumor in Distant Tissuee. — Thi» i) 
usually the final stage in the history of malignant growtiis, and H 
known as their "gencraliv.atiou." The reprotliu'tion <>f the niilig 
nant growth in distant tissues is. in the grest majority of n*M 
owing to the entry i)f some of its elements into the blnod-xtrram 
The secondary tumors are therefore the result of etnbidism 'iftiiimir 
cells, and the {mints at which the cell-masses may be »rrr«te<l in 
stated in the chapter on Embolism. As in the lynifdmtic glsiul* 
they are in all cases of the same nature as the primary one, altlntu^l 
they may be larger, and are often softer, more vascular, and in»n 
active in growth. They may themselves become secondary ccntret 
of infection, and in the same way cause tertiary growths in pirtl 

Although the general dissemination of a malignant growth is ibiH 
iu most due to the transmission of its element,-' by the hicio«l' 
stream, this is not the only way in which it may be brought alioat 
Exceptional cases have been described in which the elements <^ < 
tumor have been distributed, and have caused secondary growih ^ 
other ways, as by passing ilown the trachea, between the layer* ^ 
the |K>ritoneum. or from the kidneys down the ureters to the bl«d«l* 

Lastly, it must be borne in mind that growths may be s<Tonfl*' 
to each other oidy iu tinii' ; that is. they may be entirely inilcufl 
ent of each other, originating from different primary foci. ^| 

We have sjKiken of generalisation and lymphatic infection 
being due to the transference of tumor-cells from the primary gr 
That the primary growth i« the real source of the secondary 
is shown by their similarity in structure, by their time-relationsb^ 
by their deiiioiistrable i-onnection by means of blood- or lymph-ch* 
nels, and by the fact thai tin- set-ondary growths often occur i^j 
Mues iu which primary tumors of the structure in question i^m 
S?ome Buthorilies tliiiik that it is the juice, anil t»oi thei^H 



of the primary tumor wliieii is 

8c>conilary no<liilc8. But against this view may be urged the loc^ 

conveyed to the future site nf tJ 

TUMORS. 139 

ized action ; the distribution of secondary growths in the next capil- 
lary area, and the possibility of explaining exceptions to this rule ; 
(ie occasional discovery of tumor-cells in the blood, most often im- 
pacted in the vessels as emboli ; the frequent existence of tumors 
growing into veins and lymphatics, so that cells may easily be swept 
off bj, or migrate into, the stream ; and, lastly, the fact that second- 
ary growths have never been found in cartilage or cornea, which are 
both permeable to fluids. 

Two views are held concerning the way in which migrated cells 
produce secondary growths : 

1. It is said that the cells impacted at a certain spot so influence 
the vessel-wall and surrounding tissues that their cells multiply and 
produce a structure like that of the infecting particle. The objec- 
tion has already been stated to this theory of " spermatic influence," 
which would require us to believe that liver-cells, for example, may 
by their multiplication produce not only epithelial cells like those of 
scirrhusor epithelioma, but even connective-tissue cells of all kinds. 
2. The cells of the secondary nodule are believed to be the prod- 
nets of multiplication of the cells of the tumor-embolus. The 
'inestion thus arises. Can a bit of tumor thus cut off from its base 
grow ? Artificial embolism has been produced with pieces of fresh 
P«no8teum, with the result that they grew, and produced first carti- 
"ge and then bone, but after the fifth week all trace of them had 
•iisappeared. In effect, they went through the same course as do 
pieces of normal tissue or of tumor which are placed in the subcu- 
'»»eoa8 tissue. We see, therefore, that they can grow, but some- 
thing in the healthy tissues prevents their attaining any size. On 
we other hand, a piece of bone or other tissue placed where similar 
''*ue usually exists does not thus disappear, as transplantation 
operations show. 

THE CAUSES OP MALIGNANCY.— Why do some tumors 
'"Tade adjacent tissues and distant organs, whilst others do not, even 
'wugh the latter grow as rapidly as the former ? Hitherto differ- 
*"<!« in structure has been held to explain the matter. The more 
pOTely cellulur the tumor, the more numerous its blood-vessels, and 
™e less developed their coats, the more rapid is its spread and the 
••rlierand more certain is its generalization. 

Bat occasionally we find that a tumor which has run a simple 
worse, and which does not recur after removal, has a structure 


uccct«8itating its being placed among the sarcomata. Epulides. ceo- 1 
tral sarconiiita of bones, and some sarcomata of tlie ovarie.i mid I 
fascisv may grow to a large size witiiout itiva<ling other ti»sul•^<lr I 
generalizing. On the other hand, examples of the gcneraliulion 1 
of many simple tumors have been frei|(iently reeorde<l — «'. g. I'lion- 1 
ilroniata, myxolipomata, and even tibromutu ; also adenomata uf tlic 
ovary and thyroid. It is true that eonuective-tissne growths ilo 
generally contain a prejionderance of round-cells liefore they general— | 
ize: but in .some cases the structure of the secondary growth is tfanK. 
of the primary, and is such as is usually seen in specimens wbicfc*. 
show no mnlignaney. Cohnheim thought, therefore, that th^^ 
essentia! faetor in " malignancy " was not a certain sfriictiire nwr^ 
the part of the tumor, but rather some change in the siirroiiuilin^^ 
ti.ssues which rendered tlieui iniafde to resist invasion. For. froi^cB 
the way in which physiological tissues lie side by side, never iuvsii— 
ing each other's precincts, though one or both jnay he growiu.^^ 
actively, it is evident that each tissue possesses a {wwer wbic^ 
opjioscs infiltration iiy any other tissue; this jwwer Cohnbri^s 
called " physiologrical resistance." Its existence is further shn« m» 
by the results following the artificial production of embolism »itb 
pieces of periosteum (p. 139): these results prove that bits of ti««<' i 
transplanted into the tissues of a normal animal may become vii»- I 
cularized and grow ; linf also that they will sliortly after disa[>|K'»r, I 
the healthy tissues seeming to regain the upper li.iiid. To pcrniil J 
the infiltriition of one tissue by the eleiiients of another the pliV'"" I 
ologieal resistiiiiee -^f tlie former must be rediiceil. This ma> I" I 
effected by {!) Irgury, and therefore in iiijlammation, as in chronic I 
inflammation of epithelium-covered membranes (lupus, chnm"' 1 
glossitis, eirrh()si.s of liver, interstitial |>ncnmonia, etc.), wbtrc I 
raa.sses of epithelium are found in the infiltrated connective tisno*' I 
(2) Age: connective tissues grow most vigorously in early life. an'' I 
.sarcomata, which are of the connective-tissue type, are comiuom*' I 
during this period. But the [preponderating activity of one form I 
of tissue at one special time is best illustrated by Thiersch, wb" | 
showed that after midlife connective tissues atrophy from dimin- i 
ished vital activity: diminished physiological resistance probable 
accompanies this, aod thus the more active surface epithelium it 
enabled to invade tha sub-lying cutis. This he regarded as esseif 
tial to the growth of an epithelioina. It is certain that normally I 
epithelial tisfluea grow most actively in later life, and that the least 




(Specialized forms show the tendency Inst — a fact which may explain 

»liv cancer of some organs occurs at an oarlifr ajr<' titan that of 

otJjcr organs.' (3) Heredity: hereditary weakness on the part of 

tic ttaaue surrounding a "' tumor-germ " mnst he assumed in young 

/"♦^tple. in whom neithiT injury nor ago can be regarded a.s a cause 

of diminished physiological resistance. But even if the power of a 

liitnor to infiltrate is dependent on the presence of this diminished 

physiological resistance in tin.' adjacent tissue, the structure of the 

gro««'th probably has also a marked influence upon its malignancy. 

fmnors which have great power of growth, whose cells are lield 

loosely together, perhaps actually lying in lymph-spaces, and which 

possess numerous and thin-wjilletl blood-vessels, must generiili/.e 

inor«' readily, when this is possible, than tumors in which the oiijto- 

«t« conditions obtain. 

ETIOLOGY. — Little is really known on this point. We have 

'o account for the presence, in the affected tissue, of cells which 

biive capabilities of growth greater tlian those po.ssessed by the 

"'H'tnal cells of the tissue. lncreu,»ed /(iini-ituii/ift/ will of course he 

t'«ltjired, but this is of secondary importance; so also are the sur- 

I founding physical conditions, which may be favorable or unfavorable. 

-/Vt first, all tumors appear to be local, and local causes have 

itoxiseipiently been sought. A causal relation seems in .some cases 

I to «5xist between iixjury or irritation and the formation of a tumor. 

B»»t we know that the effects of these iiifliifnces on normal tissues 

i«rtf inflammation and hy])erplasia, and thai they produce these 

■ eir<&«t8 even in those who are the subjects of tumors. Further, no 

u'story of injury can be obtained in 1.') jier cent, of the cases, and 

*■*«? injuries followed by tumors must constitute a very small )>rii- 

l**i~tion of the total number of injuries. Still, it is probable that 

"*Jtiry, by producing hyjierivmia and inflammation, may bring 

*tt.ra food to cells ready to grow, and may diminish the j)hysio- 

''*t5ical resistance of the tissues round them. Irritation certainly 

''**e« seem to have a powerful effect in the production nf certain 

*t*itbeliomata : of these, rcHletit ulcers and epitheliumata occurring 

'^*- «ild scars or in the scrotum of s\vcep.s are good examples. For 

**>o vast majority of cases no local cause can be found. 

The cachexia produced by malignant growths, together with 
*«*eir very fre<|ucnt recurrence, their multiplicity, and their heredi- 
■ Woodbead : Morton Lecture, Brit. Med. Journ., vol. i., 1892. 



tariness — all pointing, it was >iiiiil. to a deep affection of thi* wbftle 
iii'gnni.xiu — gftvi.' rise to the belief' tluit niiiliguunt growtU8«en4 
constitutional origin. This is a bail term, for it may mean "yrt- 
eral" nnil refer to the constitution of the whole organism, iir it 
may refer to the constitution of certain cells and have » Itn-al m^- 
nificance. We shall therefore use the word tjenenil. Now. we L»ff 
already explained that cachexia, local recurrence, and multiplicitT 
may be the results of the growth of a tumor which wn.* pniilurfil 
by multiplication of a few ubnornial cells — /. r. that may be duel" 
a Itxral abnormality. There is therefore no need on these gmuniis 
to consiiler that the physiologii-al processes of all the cells of thf 
organism are abnormal and tend tu produce cancer : or that renioa^ 
of the primary growth would be useless, because continuance of ^t^M 
general abnormality would reproduce the disease elsewhere. Sw 
does heredity lead to this conclusion, for the whole of normil 
development is nothing but the transmission of local peculiaritiw: 
and, moreover, heredity is at least a« marked in multiple oimple 
gro«th.« — fibromata, warts, lipomata. osteomata — as it is in cano 
It is pi-olialtle tliiit III! tumors are at first Inail, and that ccri 
of them become malignant, as above explained; als4> that 
inherited peculiarity which results in ubnoriual growth at a cert»i 
time affects only a few cells, or it may be many foci of cells, in "M 
tissue, and not the organism at large. It is obvious, howcTCTf 
that neither the constitutional nor the local view luakes any 
tence at explaining how the abnormal ability to grow is acqui 
by the cells that give origin tu the tumor. Cohuheim adNaoi 
an hy|K)thesis which, if true, would offer a partial solution of 

Theory of Embryonic Remains. — (»n thinking over the bypw 
trophies, the excessive formations (supernumerary digits Knd umrt 
marked examples of "monster by excess"), the teratomata. 
other congenital tumors, all of which are admitted to be due tn 
embryonic cause, many of which are hereditary, and some of *hicli 
do not appear until years after birth, it occurred to Cobnheim lli»t 
all tumors might be iluc to developmental faults, lie supgenteJ 
that more colls than are needed for a part are produces!, and ihii 
the sur))lus remain in nn embryonic state, either in one spot or 
acattered over a whtde tissue. The of this error, and tb* 
reason why the cells do not develop like their rotifrrrfM and simply 
enlarge the |wrt, arc unknown. We know little of suck collections 

TUMORS. 143 

"resting" embryonic cells, perhaps because of their small size 
I resemblance to leucocytes. Small nsevoid spots may enlarge 
«tly after birth ; congenital moles which have the structure of 
eoiar sarcomata may later on become malignant ; and islets of 
■tilage from which tumors may start have been shown by Virchow 
occur in the shafts of long bones. Perhaps all these may be 
;arded as embryonic remains. 

Affiuming that such embryonic foci may remain among adult 
jues, Cohnheim found that his view accorded with observed facts, 
ere would be no difficulty about the reversion of adult cells to 
! embryonic type ; the cells in question would start with their 
1 developmental force. The rea-sons for believing in the unde- 
loped nature of the rudiment are — (1) that ])Ower of growth is at 
greatest in the cells of the embryo, as is shown by the fact that 
ibrjonic cartilage transplanted to the anterior chamber of the 
e grows into a regular chondroma, whilst adult cartilage is 
sorbed; (2) that many tumors are obviously distinct from the 
rt in which they lie — e. g. adenoma of the mamma is encapsuled, 
d ite ducts do not open into those of the normal gland ; and (3) 
it tumors are not subject to that regulating mechanism which 
iders the metabolism of each tissue subservient to the good of 
! tissues generally. 

Moreover, many tumors occur at points where the developmental 
Jcesses are complicated, and where, therefore, errors are most 
ely to occur. This is shown by the frequency with which car- 
loma affects (1) the openings on the surface of the body ; (2) the 
ophagus, where it is crossed by the left bronchus (the food- and 
-passages were originally one here) ; (3) the cardia, pylorus, and 
nmencement of the pyloric portion of the stomach, where the 
»nge of epithelium occurs ; (4) the rectum, at the line of union 
»een the invaginated epiblast and the hind-gut; and (5) the 
ernal os uteri, where MuUer's ducts opened into the uro-genital 
us. Adeno-myomata of the prostate occur at the same spot in 
male. Smooth myomata occur almost exclusively in the uterus. 
! whole uterus is made up of foci of cells awaiting the stimulus 
mpregnation to great development. Atypical development of 
focus may occur without the usual stimulus, and perhaps we 
lid rather expect this when pregnancy has been absent or infre- 
it ; so we find that myomata are commonest in elderly sterile 
len. Adenomata of the mammae may be similarly explained. 



Heterologous tumors are always so placed that it is posstblr 
see how, by dovelopineiital error, some cells which would nator»Ilj 
give rise to tiic heterologous tissue might have been included m tb4 
tumor-germ. Thus, dermoids occur in the neighborhood of norm 
invaginations of the epiblast. Muscle may easily get luto tl 
Wolffian bodies from neighboring muscle-plates, and cartilagv GrxMl 
the rudiments of vertebrte. 

Finally, from so atypical a rudiment an atypical result mi^U 
reasonably be exj)ected. 

.Vguinst Cohnheim's view it may be said that nothing i* reallj 
known of such embryonic remains; that many of the [loiiiO 
com[dicated development which he mentions are aUo jMiint.* iif 
tatiou — c. //. the narrowing* of the alimentary conal : and that mas; 
tumors of the gullet and rectum, for example, though nrar tb 
[wints mentioned, are not at them. Cohnheim himself was olili, 
to exclude from this class of tumors such cases ius epitiieliiuua m 
Bears, of the scrotum in sweeps, and of the arm in paraffin- w(.irker«i 
in all iif which irritation plays s«» obvious a part. 

The concurrence of increased blood-supply is evident in man; 
cases — f. (/. enlargement <if ovarian dermoids at puberty, of tiiB' 
of the breast, ovaries, and uterus in pregttancy. Ttiis may oi 
the multiplication of cells capable of growth, and may explain 
apparent causation of tumors by injuries. 

Parasitic Theory. — Malignant growths — carcinoma and 
— in their obscure origin, their tendency to spread lucallr, 
their ilissemination by lymph- and blond-paths, present so obv 
resemblance to certain infective disea.«e8. such as tuberculosis, th^^ 
the parasitic nature of these infective diseases having been ili 
strated, the malignant growths are naturally suspected of hiv 
the same etiology. Some pathologists lean strongly to the ««? 
that these growths begin by the inoculation at some »p<it of n'l 
parasite which excites the cells to rapid multiplication, and lieli*** 
that infection takes place from this focus by the c<)ii\eyance of tB*" 
parasite along the lymph- and bl(X)d-path8. In the somewhat uO' 
usual cases of a general outbreak of malignant growths it is a«»tiiB«« 
that the primary focus, in which the poison wa^ re<'eived •»<' 
multiplied, was not recognized : a parallel can be established be- 
tween them and cases of general tuberculosis in which no |Miu>an 
focus is found. 

The "constitutional theory" is also resuscitated, but it is D0« 



ic to correspond to the " tubercular diathesis," or iiredisposition 
of cert II in tissues to |ieriiiit the jjrowth uf the bacilhis tubercuh)sis. 
It IS nu lunger supposed that all the tissues of a cancerous patient 
ire tending to grow cancerously or throwing something into the 
blood which "will out" soujcwhere. but merely that certain tissues 
will permit the growth of the hypothetical parasite, should it ever 
reach them. This '• malignant predisjiosition " may be inherited or 
leqnired; it may be so strong that nothing is reijuire<l for the pro- 
duction of a malignant growth but the arrival of the genu at u pre- 
ili«|K»ed sf»ot. In other cases the f)hysiological resistance of the 
timues may reijuire still furtiier dejn-ession by injury or ))rivation 
before thev will jiermit the niiilti[)lic:ition of the gerui in their 
midfli, the effect of irritation and injury in cases of tuhi^'cular 
diaeane following bronchitis or strain of a joint, and those of cancer 
MIowmg irritation by soot, t-ar. or a blow. Irritation is upon this 
>iew, in the case of cancer, held to depress the vitality of the 
epithelium, and to cause it to admit to its own sub.stance a germ 
previously resisted ; and the frequent origin of cancer of the breast 
»t the menopause, when the breast-epithelium is degenerating, is 
'|«ote<l in support of it. The analogy betwwii cancer and tubercle 
may he traced into even finer details : thus both, when they affect 
the face (rodent ulcer und lupus), take an unusual course — slow 
olcerHtion without any affection of glands or of di.stunt parts and 
*itliont any accompanying " cachexia." 

It is further suggested in favor of the parasite theory tliat the 
»bi<.>rption of the products of bacterial decomposition would help to 
MpI«iD the cachexia, and might account for the fever which accom- 
C'liies the growth of some tumors, especially lyiiiphomata; and that 
wih the alleged incompatibility, so to speak, of active tubercular 
*"« eaucerous disease in the same subject, and the rare disapjiear- 
^uce of a malignant growth after a fever, especially erysipelas, may 
wdue to the triumph of one organism over the other in the strug- 
gle for existence. 
The presence of sjiecific parasites in emboli derived from tumors 

Hoiild, it is said, explain the growth of secouilarv tumors without 

the aid of any special diminution of the physiological resistance of 

the tissues in which the embolus lodges. 
Ltstly. there is a small number of cases recorded in which can- 
of one labium has caused cancer of the ofiposing surface, and 

;ripps mentions a case of cancer of the arm resulting from contact 



with an ulcerating scirrhiis : tbe-se are regnnled as provnog inon- 

This concliideAi the a-priori case which has hccu made out for tli» 
parai«itic origin of tumors. There is but little positive evidence la 
its favor. Gussenbancr alleged that he had discovered the caiuera 
certain minute highlv refracting particles in and between the an- 
cer-cells. Observers have uniformly failed to fiml any [Mmwilebt 
means of the ordinarif staining methods or by me«iui of cultiTV 
tionH. Shattock an<l Balhiiice publisheil the results of eultivati»B> 
from a large number of tMni<.)rs, malignant and simple, in whirl) 
no antiseptic (that might kill any germ) was used; but their evitt- 
vations reuiained sterile. They concluded that if the parasite i»» 
pnitophyte, it must be of a very special kind, aud inclined t" lt<» 
view that it is probably a protoitoon, which either exerci»e» • 
"spermatic influence," or lives as a true parasite in the epitbflial 
cell, or, by conjugating with an eiiithelial cell, t'onfers u|Min it fiwh 
life and power of multiplication. 

During the last few years many observers have found in the 
epithelial cells of cancers what they believe to be parasitic jtfw- 
tozoa. These "cancer-bodies " will be describol and figured in tb* 
chapter on Carcinoma. Their features have many points in ocw 
mon with the coccidia known to produce marked epithelial prnlif*- 
ration in the rabbits liver: the absence of 8|)ore8, however, conrti- 
tutes a notable difference. TneiTectual efforts hare been laaii* t* 
supplement the purely anatomical evidence. The capsule of ««»" 
cystf'd protoioa is believed to consist of chitin or of celluloM. W* 
careful analysi.s of cancerous growths fails to establish the preMoe* 
of either of these. No one has yet succeeded iu se(iaratiD(; c'' 
cultivating these supjMJsed parasites. 

Inoculations of cancer-juice u)>on luan aud animals fail not ddIv 
to produce the disease, but even any inflammatory reactioiu though. 
i»n the other hand, it is argued, with fairness, that to produce t''*" 
ili.^ease predisposition may be recjuired. 

In spite of the resemblance between the modes of spreaditig W' 
the conse<|Ucnt morbid anatomy of the itiulignant growthii iO<' 
tubercle — which really goes for very littU- — and of the plauKiH' 
nature of the other arguments adduced in favor of the parvit"' 
origin of malignant growths, the probability seems to us to be ■* 
much agaiii^^t as in favor of it, at least as regards the true cano*'*' 
In the infective grauulomala bacilli carried by the lymph- or bloo''' 

TUMORS. 147 

earn lodge and excite an inflammation similar to that which they 
ised at the primary focus : the cells of the granuloma are chiefly 
icocytes — not the progeny of cells from the primary focus — and 
; tendency of the cells of granulomata, even when supplied with 
lod, is never to multiply indefinitely. It has hitherto been 
ieved that secondary sarcomatous growths were truly the prog- 
f of the primary growth, formed by multiplication of cells car- 
d from the primary focus ; and the melanotic nature of the 
«ndary growths in melano-sarcoma has generally been regarded 
proof of it, there being no positive evidence of "spermatic 
luence" (p. 134). But, as sarcoma tissue is indistinguishable 
m inflammatory tissue, and as our beliefs as to the origin of sar- 
n»-cells are based on inferences, and not upon direct observation, 
3 possible that we are mistaken as to the nature of some morbid 
coma-like processes, and that we shall find them to be inflamma- 
T and to depend upon an infective cause, like rhinoscleroma. 
ith regard to the epithelial multiplication which characterizes true 
icer, however, there can be no such mistake : the immediate cause 
cancer must induce this. The question then arises. Is it conceiv- 
e, in the face of the necessarily deleterious action upon their host 
all parasites, that this cause can be a parasite ? 
Reviewing the whole question, it is obvious that we have only 
re or less probable surmises before us. With regard to simple 
Hon Cohnheim's theory of "embryonic remains," which brings 
m into relation with " monsters by excess." seems to be the most 
ely. As to true cancers, the view that the physiological resist- 
ueof the connective tissue is reduced until epithelium, having, 
fhapg, only its normal tendency to grow, can invade it, appears 
accord best with known facts: unusually rapid multiplication 
epithelium would then naturally result from increased food- 
?ply. As to the etiology of the sarcomata, there is even less 
>Qnd for surmise. 

CIjASSIPIOATION. — Tumors having the most obviously simi- 
' structure vary much in their clinical history, whilst others of 
lically different structure have very similar physical signs and 
"rses. In our present state of ignorance no satisfactory classi- 
Mion of tumors is possible. The one we shall adopt is based upon 
sir histological characters. Tumors arising from mesoblastic tis- 
*8 will be arranged in three groups; the/r8< resembling the most 


highly differentiated tissues; the second, the ordinary connec 
tissues; and the third, the embryonic tissue. In dealing v 
tumors from epiblastic and hypohlattic tissues the same order \ 
be followed. 

For convenience' sake all cysts will be grouped together, a 
remarks on them made at the end of Tumors, though the gn 
majority of cysts are not tumors. 

Classification of Tumors. 

I. — Type of Higher Ti»itue». 

Type of moBcIe Myoma. 

" nerve Keuroma (aee note on p. 150 

" blood- vessels Angioma. 

" lymphatic vessels .... Lymphangioma. 




II. — I^pe of Fully-developed Connective Ti»»ut$. 

Type of fibrous tissue Fibronu. 

" mucous Myxoma. 

" adi|KMe Lipoma. 

" cartilage Chondroma. 

" bone Osteoma. 

" lymphoid tissue Lymphoma. 

III. — Type of Embryonic Connective Tittue. 
The varieties of Sarcoma. 

IV.—Type of Epithelial Titnut. 
Epiblast f Papills of skin of mucous membrane PapiUoma* 



hypoblast ((Jlands f Adenoma, 

V. — Teratomata, or Congenital Mixed Tumor$. 






TuE Myomata are tumors consisting of muscular tissue. There 
rp two varietirs — tlie .stritatetl and non-striateil. 
, I. The Striated Myomata con.sist of striated muscle. They are 
Iceedingly rare, only two or tiivee examples having been recorded, 
«1 these were congenital. Striated muscle-cells, generally mixed 
til a few mm-striated. occur in the sarootiiata of the kidney and 
tis found in young chiltlren. Striated muscle-cells, in congenital 
>wth8 of organs developed from the Wolffian body, are probably 
fc to inclusion in this body of cells from the ai^aceut muscle- 

p. The Non-striated Myomata are most frei|uent in the uterus; 
y occur al.**o in the prostate, the oesophagus, the stonuu-h. and the 
featines. They frequently become pedunculated and ftunu [lolypi. 
py are much commoner tiian the striated growth.^, and pmbaldy 
Fays originate from muscle. They may form distinctly circum- 
ited tumors surrounded by a fibrous capsule, or ill-defined 
Ocular ma!<8e» in tlie mid.>Jt of the muscular tissue in which thev 

I^hey consist, like the )>hysiological tissue, of elongated spindlc- 
wjth rod-shaped nuclei, more or less isolated or grouped into 
li of various sizes, with a varying quantity of connective tis- 
P The muscular elements either present a more or regidar 
ement or pass in all directions through the tumor. The 
reaoels, which usually are not numerous, are distributed in 
connective tissue. 
■Tie mnsi frequent secondary change which myomata undergo 

Bciflcation. Hemorrhage, mucoid softeniner, and the foruia- 
^ cysts are occasionally met with : also inflammation, ulcera- 
and necrosis. 

Kically, the myomata are perfectly innocent. 
. >ma of Uterus. — The uterus is by far the most frequent seat 


uta, and here thev constitute the so-called 


In most of these muscular tumors of the uterus there is a 


large proportion of connective tissue ; hence the terms " fibroid " 
and "fibromyoma." This is the case especially in older growths. 
Those newly developed, however, consist almost entirely of true 
muscular tissue. They either form firm, hard masses imbedded 
in the uterine walls, or project into the uterine or abdominal cavi- 
ties. When projecting into the uterus they constitute a comnioD 
form of uterine polypus. They do not form till after puberty, and 
are commonest in elderly sterile females. Their growth is usuallv 
slow. Pregnancy causes them to enlarge rapidly, and they undergo 
some involution after delivery. They generally atrophy at the 
menopause. These tumors are often multiple. The older ones are 
liable to become calcified. They also sometimes undergo mucoid 
softening, which gives rise to the formation of cysts in their 


The Neuromata are tumors consisting almost entirely of nerve- 
tissue, and are among the rarest of new growths. 

The term " false neuroma " has been applied to many growths 
found in connection with nerves. Fibrous, myxomatous, and 
gummy tumors growing within the nerve-sheath have been includ<?" 
under this head. Small multiple fibromata of superficial nerves a^e 
sometimes hereditary. The bulbous ends of nerves in stumps are t»y 
some called amputation-neuromata. They often consist only ^* 
fibrous tissue, but may contain rolled-up nerve-fibres — attempts' ** 
regeneration rather than a tumor. They are usually intimate'* 
connected with the cicatricial tissue of the stump. 

The structure of true neuromata is most commonly that of a m*^ 
of ordinary mcdullated nerve-fibres; they therefore resemble * 
structure the cercbro-spinal nerves, from which they most frequent'^ 
grow. The nerve-fibres are associated with more or less connecti"* 
tissue. A'irchow has also described as exceedingly rare formatio** 
tumors composed of non-medulhited fibres and of ganglionic ner*'*^ 

Neuromata rarely attain a large size, but usually exist as sraa^ *' 
hard, sin;;lc nodules. 

True neuromata always originate from pre-existing nerve-ti9.«* 
— eitluT from the cranial or from the spinal nerves. This fa<^ 
deti-rniinos tlieir site. 

' If, :is seems prob-ilile, nerves an- oiitgrowtlis from the cerebro-spinal centre, tr«* 
neuromata should be <-lassed as epibla»tic growths. 



Clinically, the neuromata arc perfectly innocent tumors. They 
often cause considerable pain. Their growth is slow. 


The Angiomata, or vasciiliir tumors, consist of blooil-vesseis 
licid together by a smuli amount of connective tissue. 

This group includes the various fiirtns of ntevi and aneurysm by 
anastomosis. They may be divided into two rarieties — the simple 

Fid. 45. 




^^pllUry narviis tmm aiiljciiutiiM'iiui (Imiic of h child: tap, vemels of new growth ; a, nor- 
I"*! "iltry ; /, fal-velln : c, rupaulv. .. aou, reduced I. (Boyd.) 

oi" oapillary angiomatii, in which the new vessels resemble chiefly 
oornial capilhirics ; and the cavernous or venous an<;iomat!i, in 
*hich the blood circulates in a cavernous structure similar to that 
'" tilt, corpus cavernosuui of the penis. The characters of both 
*'"*' Well shown in tiie accompanying Figs, 4.') and 4*3. 

1. Simple Angiomata. — These consist of tortuous and dilated 
'■»pillary vessels held togetlier by a small ipiantity of connective 
"'"' adipose tissue (Fig. 45). It is doubtful wiiat ]iroportion of 
*"* Vwisels is due to tiilatation of the original capillaries: Ziegler 
thinks that many are formed this way. Some are of new forma- 
''on. V'ery irregular dilatations are common. The capillary walls 
"••y be thin or thick, consisting of a double tier of cells. One or 
**o supplying arteries can be seen in most sections. These growths 
^^fterally occupy the superficial layers of the cutis, and form the 
P'^rt-wine stains and niotber's marks: they are sliuhtlv or not at 
*" elevated. Others lie in the subcutaneous or submucous tissue. 

r^vi'miiiu nitvus- uf liver (fnim a Huniuii utti'rl ;i!)(: «, Intxc •p«o«» Imuuilcd by ""*"!' 
w»llfi, aome coiitalnliiK lil(>o<l-<l<>brts : c, livi'rrvlU IUhi Ihixv), tnwanl wliiij) tb« Kto^** 
lioundi'd liy thick lllirmiit walls. X *'. rwlin'od I. (B<iyil.) 

genital, thoiigli they nuiy not be noticed for a few weeks »t^'''^ 

Simple angioma is often combined witli lipoma, glioma, or s*""' 
coma. Somotinu's cyst? contniiring ihirk fluid form in them. 

2. Cavernous Aneriomata. — Tliese are the venous tumors, 
growth is made up of irregular fibrous alveoli, which conimunic»** 
freely with one another ami are lined with an endothelium simil*' 
tu that of the veins (Fig. 4ii). These spaces are distende<l wit"* 
blood, which is supjdied to them hy numerous tortuous vcsaela ai*" 
circiihitcs wit!) varying (h'grees of rapidity. The arteries opt*** 
directly into the spaces. Tliese growths are commonly of a blui?'* 
color. They may be diffuse or form distinctly circumscribed tumors 
They sometimes exhibit distinct pulsation. Their favorite seat i* 
the skin anil subcutaneous tissue. They may occur also in the orbit* 
muscle, liver, spleen, and kidneys. They may develop by dilatation 
of the vessels of a .simple angioma. They may be eougenital, bnt 



^* the liver Ziegler thinks they may develop after middle age, when 
*^e cells begin to atrophy. 

Aneurysm by Anastomosis. — The arteries of an area, especially 
"o the head, become dilated, greatly elongated, and tortuous ; per- 
''*p8 new vessels form. Some are congenital, others follow injuries. 

Ziymphangiomata. — See p. 168. 




The Fibromata consist of some form of fibrous tissue. 
Tue fibres, which constitute the chief part of the growth, are 
'^"«r loosely or densely packed according to the variety, and are 
rrangej either without definite plan, or in intercrossing bundles of 
*"^>ous sizes, or in whorls around the blood-vessels (Fig. 47). Yel- 
'"■ elastic fibres are very rarely met with. The cells, like those of 
•"Qiai fibrous tissue, are generally few in number, and are usually 
^*t abundant around the vessels. They are minute, spindle-shaped, 
^•form, or stellate bodies, the latter having processes of varying 
^gth. which communicate with similar processes from neighboring 
'**». In the fresh specimen the cells are often so small and indis- 
'<^ as to become visible only after the addition of dilute acetic 
<1. These cells var}' in size and number with the rapidity and 
^ of growth — the slower and older the growth, the denser the 
*Ue and the flatter and less numerous the cells. 
rhe fibromata usually contain but few blood-vessels. In the 
*er growths, however, these are often more numerous. Dilated 
*»8 sometimes form a cavernous network, the walls of which are 
*»ly united to the tissue of the tumor, so that if divided or rup- 
■e<i they are unable to retract or collapse, and profuse hemorrhage 
•y thus ensue. 

Partial mucoid softeningr and calcification are the most common 
^ondary chancres ; ossification occurs in fibromata springing from 
**e. Ulceration also sometimes occurs in those growths which are 
'^ated in the skin and submucous tissues. 


Fibrous tuuiors present two varieties, the soft and be 
Bponding to, and usually originuting from, the loose 
varieties oi' ordinary connective tissue respectively. 

Kio. 47. 




Klhniiia tiimnn tram the lUn. N'i<ar the cut bloml-veiMU, V, mre M«n 
niirra I'lil Iritnarpreelx- ■ WO, »u<l reduced i. 

1. Soft Fibromata. — These consist of the looser and 1 
form of fibrous tissue. They are met with an diffused gr< 
the sabcutanoous and submucous tissues. In the former 
they often form large pe<luneulato<l and non-encapsule<l 
which are commonly known as wens. These arc sometimes 
A similar growth of subcutaneous tissue is met with in tnc 
flbrosum. In this disease the large masses which hang do 
tiu- tlii;;Ls, butineks. and other situations consist entirely 
fibrous tissue. They often contain many large blood-vessela 
their removal may lead to severe hemorrhage. 

In addition to these difruse<l growths, more circumscrJ 
encapeuled fibrous tumors of the soft variety are occasioi 
with growing from the scalp, scrotum, labium, intermu!«cull 
or other situations. 

2. Hard Fibromata. — These are composeil of dense fill 
sue, like that in tendons. They are firm, hard, encapsuled 
presenting on section a grayish-white, gli.stening. fibrous 
anee. These tumors often occur in connection with bone — et 
the upper and lower jaws — originating either in the eentfi 
bone or in the periosteum. (Growing from the perio.*ti-i; 
alveolus they constitute .simple fibrous epulis. They are 
with in the nose, where they form one variety of naaal P0I7 
in the nasopharyn.x. springing fmui the fnuit of the »pin» 
the base of the skull. In these liriii fibrou.s jrrowth.-^ thr v 
form cavernous spaces. 


Another variety of hard fibrous tumor grows in connection with 
i^trves, and is often described as a neuroma. True neuromata, 
Wever, are, as has been said, among the rarest (p. 150) of new 
growths. These false neuromata most frequently occur in connec- 
tion with the superficial nerves. They grow from the neurilemma, 
sodas they increase in size the nerve-fibres become expanded over 
'icm. They are very firm rounded tumors, and are frequently mul- 
tfpie and hereditary. 
Some old tumors of the uterus are almost or quite pure fibromata ; 
lot the so-called uterine " fibroids " are in most cases local over- 

povrths of the involuntary muscular tissue of the organ (p. 150). 
The fibromata orififinate from connective tissue ; from the cutis 

or anlcutaneous tissue, from submucous or subserous tissue, from 

fascia, firom periosteum, from neurilemma, or from the connective 

tissue of organs. 
Clinically, the fibromata are perfectly innocent ; they grow slowly, 

«nd <Jo not recur after removal. 


file most characteristic feature of this rare growth is that it con- 
sists largely of calcareous particles. These are contained in the 
coftcentric bodies already described as the corpora amylacea, where 
^^y give rise to the so-called "brain-sand " — hence the name of 
the growth. The calcified corpora amylacea are held together by a 
''wying quantity of loose fibrous, highly cellular, or mucous tissue 
fotttaining vessels. 

I*8ammomata grow from the pineal gland, the membranes of the 
■•rain, or the choroid plexus. In the latter situation a psammoma 
often contains numerous cysts. It is of no pathological importance, 
eicept when of sufficiently large size to produce symptoms from 


The Myxotnata consist of mucous tissue — i. e. a fragile connec- 
*"e tissue of which the intercellular substance is translucent, homo- 
l?*Oe<»08, and jelly-like, containing much fluid and yielding mucin, 
"hysiologically, this tissue is met with in the ritreotis hodtf of the 
^yC" in which the cells are roundish and isolated ; and in the */;«- 
tiitcai cOT"d, in which the cells are fusiform or stellate and give off 


Flo. 48. 

MyxnniK (fhnii thmrinl.ihowlnKthe 
fharertiTlntU l>ruiirhp<l knutoniiinliiK 
i-rlU. a f<-w li<u<'<x'yl>-«, mid one <ir two 
•(•lixllrcrlU. X JW. 


fine ansstoinosing prolongations. All enibrrnnic counrctive i 
(p. 82) pow^e.sses nn intercellular Biibstaneo oontuining much uiuda. 

eMpt;cially that mIucIi snh)M<<|iifiitlr 
bfcouiei* adi|K>s«. New formatioiii 
may iinilfr;;<i miicoitl ilfgi'nrratinn. 
and thii-H fhiscly rOiH-inhU' in tJirir 
phyeic-al and cht'tniral charkctvn ti* 
niyxoniuta: but n myxoma cnn>iit> 
of miii.'oui'i tiiufuc from the first. Tiif 
niyxouiata arc thus very clo«cljil- 
lied to the sarcomata, auii by miat 
arc included in the .«anie clawnf Df« 
formatiiinH. An (t-deuiatou» fibrmuA 
or lipoma closely resemble* a ditk* 
oma or niyxo-li|Kima: Ki>»t«t br- 
lieves that they are iiieutical. 
Structure. — The majoritr of tS»« 
cell.'* are angular and stollntc. with long anastomoHiiig prolon^ff*" 
tioni*: others are isolated, and fusiform, oval, or spherical in >btf»* 
(Fig. 48). Their contour is rery indistinct, owing to the refnic^ 
ing nature of the intercellular substance. The latter i« wry 
abundant, jierfectly h<imogene<iu.s, soft, gelatiniforni, viscifl, »!»•• 
yiehls large ([uantities id" mucin; in it are a varying number c»" 
anneboid cells. Blood-vessels are not uumerons, ami are reaihl ^ 
visible and easily i.solatetl. A few elastic fibres are soni<'timc* w" ■• 
between tin- cells. 

Among the secondary chancree the most common is rupture'** 
the capillaries, bemorrhaGTe, and the forinatinn of blood-cystic 
this, however, is It-ss frc(|iieiit than in the sarcoinata. The cti • 
theraa«dves may umlergn mucoid or fatty defeneration, anil th««* 
l>e destroyed : this is usually ac('om|)lished by liipiefaction of the inle^" 
cellular siibsiaiice. The growth may inflame, ulcerate, and necn*^- 
The varieties of myxoma depend principally upon its combu*^^ 
tion with other growths; a pure myxoma is very iiniisuKl. I* '' 
moxt common combination is a myxo-lipoma. Combinations*'^ ' 
sarcoma, fibronia. cboiirlronia. and a'lenouui are also met with. 

To the naked eye the my.xomata are of a [K>culiar aofl griat ' 
ifonn consistence and of a pale grayish or reddish-white c««l"' 
Their cut surface vieldi a tenacious mucila;'inouh liiiuiil. in wb»*" 
may be seen the cellular elements of the growth They arc xan»' ' 



separated from the surrouiKliiig structures by a very thin fibrous 

capsule. Fine prolotij^ations extend from this into the growth, 

ilividing it into h)bules of various sizes. In exceptional cases a 

myxoma may increase by the continuous invasion of the surround- 

it\^ tisxuen. 

Myxoniiita grow trova connective tissue, und arc most common 
in subcutaneous and sul)serous fut and in submucous und inter- 
BiHscnlar tissue. They also grow from tiie periosteum and medulla 
nfboric. from the connective tissue of organs (esjK'cially the breast), 
»Dil from the piTineuriitiii of nerves, forminfi one variety of "'false 
neuroma." They may grow from the jplarcnta, constituting the 
»i>-CBllcd "uterine hydati<ls." 

When situate in superficial parts thoy may become i)cdiiiic(ilatod: 
ia the submucous ti.ssue of the they constitute one form of 
na^al polypus. In the skin they are often papillary. 

Clinically, myxouiata occur chiefly after mid-life, and are, for 
•he most part, benign. Their growth is usually slow, but they 
may attain an enormou.s size. If completely removed they rarely 
fpcur. Sometimes, however, they recur locally after removal, but 
oy probably never reproduce themselves in internal organs. In 
•peaking of their malignancy their occasional association with sar- 
coma must be borne in mind. 


Fiu. 40. 


.A Lipoma, or fatty tumor, is a localized and circumscribed 
formation of fat. 

The li]K)mata resemble in their Btructure adipose tissue (Pig. 
^). They consist of cells containing fat 
*1 a variable i|uantity of comiuon con- 
"ftctive tisAue. The cells are like those 
"'" adipose tissue, though usually some- 
what larger. The nucleus and proto- 
[ilasui are so compressed against the 
•^ll-WttU by the fluid contents that they 
■""^ readily visible only when the cell is 
*tpopbied and contains less fat (Fig. ;>, 
48). Connective tissue varies much 
atnrtiinf, unites the cells in nuisses or 
lo^Jiiles which are larger than normal, and 
'omg in niost cases around the tumor a thin capsule more firmly 

Upomk. Somi- of tin- celU con- 
tiiln cryetslUiseil fiilly nrlilii. x 



ailhercnt to surroiiinlin;; parts than to the tiiinor ; so the latter, in 
most cases, "shells out" easily. Bh)od-vessoIs are ilistrihiiiisj m 
the fibrous septa. Mucous tissue is often associittod with the fattj 

Secondary changres in tlie lipomata aro not cnnitnon; 
fibrous septa may. however, become calcified, or oven 
Softening may occur also from a mucoid change. InflainmAti( 
is rare, but when large and situated in the 8ubcutani-<)ua tiwuetli* 
skin over them may become adherent, and ulceration and necrow 
of the tumor occur. 

The chief varieties are the flbro-Iipoma, in whieli the filrM'- 
tissue is excessive, and tiie myxo-lipoma, or combination of lum i i- 
with fatty tissue. (For lipo-sarcoma, see p, 171). 

To the naked eye the li[Kiniuta are more or less lobulateil. «ini 
usually snrroundeil by a fibrous capsule. When subcutaneous th'J 
move freely over the <leep fa.scia, but often the attempt to rniw th« 
skin from them causes it to dimple. On section they present \kt 
ordinary a[)|iearnnce of adipose ti.ssuo. with more or less d«W« 
fibrous sejifa between the lobules. Their consistence and theit 
adhesion to the capsule vary with the amount of fibrous tinu* 
which they contain. In their growth they occasionally beMB>* 

Lif)omata firrow firom connective tissue, and their iiossible iii^>' 
tribiition is almost coextensive with that of ailipose and connecii*"* 
tissue. They (x'cur most fr<M|uently in the subcutaneous tissueo** 
the trunk, especially of the l)ack ami abdominal wall; .somflimw i^ 
intermuscidar 8e|ita, subsynovial and subserous tissui«, and ooe^*' 
sionally also in the submucous tissue of the stomach and inte*line^*> 
and even in internal organs where there is normally no fat. 

Olinically, i!ie lipomata are ijuite innocent : they grow slowly, bt»* 
may attain a huge size; thev are usually single, but are not iiifr^^ 
ijuently midtiple and hereditary. Sometimes they change tli<?»'' 
]H>»ition considerably, presumably from the influence of grmritV* 


A Chondroma is a tuinor composed of cartilage. 

In minute structure these tumors consist of cells and of 
intercellular substance, Itoth of which present all the vari«ti«»' 
observed in normal cartilage. The intercellular substance in< 
be hyaline, fibrous, or mucoid. When fibrous the fibres m*y 



Fio. 50. 


Fibruiis chondroma. 
X 200. 

Qged like thofie of fibro-cartilage. or more or le.sp conceiitrii-ally 
ntl the cells. aj» in the reticular cartiliiges of the ear ami laryii.x 
:■ 50). The fibres may be distinct or hardly peree[)tible. 
m hyaline or mucoid it i» sotnetinies quite soft in consistence. 

cells may be numerous or few in |)ro|Mirtion to the matri.v. 
he fibrous foruis they are oiYen suiiiii. and 
I oomewhat spindle-shaped, more resem- 
g those of connoctivc tissue; in the iiyiiline 
Mthey are usually large, and eitiier round or 
[(Fig. SI); and in the rarer mucoid forms 
rare more commonly ."tellate and brani'lied, 

the transitional cell.s at the edge of artic- 

cariilages where the synovial membrane 
i. They are either single or arranged in groups, and are 
Jly surrounded by a capsule, as in normal ciirtiluge. although 

is often very indistinct. Tliey enclose one or tiiorc nuclei and 
btly granular contents ; sometimes a cell-wall cannot be dis- 
alciflcation is the most common secondary Chang's. It affect.s 

peculiar frequency the largest group of chondrnmata. those of 
metacarpals and phalanges of the hands. It spreads from 
V centres, commencing in tite capsules and then involving the 
cellular substance. Ossification is especially frequent in the 
dronuita which grow near the junctions of the e])iphyses and 
H of long bones. These ossify as they grow, and form the 
nculatcd e.xostoses. So also does the couimnn subungual 
.0818 of the great toe, which is generally an ossifying fibroma, 
ilroma. or fibro-chi>ndr(imii. Fatty degeneration and mucoid 
ning are common changes, and may 
to the formation of large softened 

•which present the appearance of 
In rare cases the skin covering 
imor ulcerates and a fungatiug mass 

le varieties of chondroma ilepend 
the nature of the intercelluliu' sidt- 

e, and are therefore fibrous, hyaline, 

. , , ,, 1 • . ■ HyuUne rhondromA. X ann. 

nucoid ; these areottcii combined in 

»me tumor. As a rule, those originating from the medulla of 

f the hyaline and min'oid class, whilst those originating 

Ki.,. .51. 




from connective tissue in otlier situations are moro 
fibrous. The ra|iidI_v-growing fibrous ibrnis a|i|iroacL verjJ 
to the sarcomata (chondro-sarcoma), the mucoid forms to \hm 
mata(myxo-chondroma); and these two kinds of growth iin 
a.ssociated in the same tumor. Chondromata are rarolv boo 
in the strict sense (p. 134). 

A variety of chondroma has been described under the itai 
OBteo-chondroma, which in structure more closely rescmbiM 
than cartilui'e. It consists of a tissue similar to thai miH 
between the periosteum and bone in ricketa, which, from it.* r 
blance to osseous, has been called osteoid tissue. This 
re(|uircs calcifying to become true bone. Like bone, it is ma 
of trabecultp and mcdulliiry spaces; but the trabeculn!, inste 
being formed nf boric-corpuscies and lamcllie. consist of 
angular cells without a capsule situated in an obscurely fibri 
matrix, which in part is calcified. The medullary s|)ace« oc 
a fibrous stroma and many blooiUvessels. The osteo-chondro 
although consisting mainly of this osteoid tissue. Cf>ntain 
a small projiortion of cartilage. They originate beneath the 
osteum, their common seat being the ends of tiie long boneei.H 
grtiwth is very rapid, and they often attain an enormow 
They are much more freely supplied with blood-veS!»els thai 
ordinary chondromata, and hence they are much less frequentl 
■eats of retrogressive clmnges. They arc especially proi 
become ossifieil. and to be thus converted into true bone. 

To the naked eye the morr tloH'h/-</rowing chondrouat 
hard or slightly elastic tumors, smooth or lobiilated. and a| 
exceeding the size of an orange. They are enca|isuled, and « 
either of a single tumor or of several smaller masses held tog 
by fibrous tissue, in which the few blood-vessels run. On « 
they present the appearance and consistence of hyaline or 
cartilage, frequently inotlified by one or other of the »eoal 
changes above mentioned. The appearances may be tha 
fibroma, the cartilage-cells being unrecognizable without 
of the microscope. 

The more rapuili/-<jrotcin(/ forms, such as often start from tha| 
bonefl or ribs — myxo-chondromata, osteo-chondromata. and cbo 
sarcomata — arc much larger, .softer, and luore vascular, 
prenent the appearance of pure cartilage ; only a few islets. 




will be distinct in the soft grayish tissue, which is not separated by 
any capsule from the adjacent tissues. 

Cbondromata most frequently grow from oonimon connective 
tissue and bone, very rarely from cartilage. About three-fourths 
of them start in connection with bones, growing either centrally or 
tubperioateally. Their favorite seats are the bones of the fingers and 
toes, the lower end of the femur, and the upper ends of the humerus 
and tibia. Much less often the ribs and the hip-bone are attacked. 
Vi*-«hDw has shown that islands of cartilage not uncommonly remain 
in t;lie shafts of bones ; and it is probable that many cbondromata 
spring from such islands (p. 143). The tumors generally begin 
be£V>re the ossification of the epiphyses, whilst the bone is actively 
gro-wing and vascular. 

^dost of the remaining fourth occur, in combination with other tis- 
sues, as "mixed tumors" in the parotid and testicle. Cohnheim 
suggests, as the source of cartilage in the parotid, an aberrant bit 
of tlie rudiment of the jaw ; Virchow, a piece of the pinna. In the 
tes-tis a portion of the rudiment of a vertebra may have been in- 
clu<Jed. The intermuscular septa, the subcutaneous tissue of the 
hreast, and the lungs are occasional seats. 

Xiastly, cartilaginous growths may originate from cartilage itself 
(**5<shondro8e8). These are sometimes seen on the surface of the 
artiicular cartilages, in the larynx and trachea, and on the costal and 
intervertebral cartilages. They are simply local overgrowths of 
''y^a.line cartilage. 

Olinically, the cbondromata are for the most part innocent 
P^"Wth8. They are usually single, except when occurring on the 
^''gers and toes, in which situation they are more frequently multi- 
ple. The central growths of the phalanges and metacarpals occur 
"1 children or before ossification is complete : the graver, subperios- 
*<**/, forms are commoner later on. 

The softer forms, especially those starting from bone and glands, 
occasionally exhibit more or less malignancy, tending to recur locally, 
M»d, rarely, to infect the lungs and even other parts. 


The Osteomata are tumors consisting of bone, either compact or 

The osteomata are the result of the ossification of newly-formed 
connective tissue other than of inflammatory origin. They must be 


clearly distingnisljed (1) from the simple f>9»ili ration of normal 
iitfini} tiMuiH — (•.(/. coHtiil, luryugeal, or bronchial cartilages, it 
tions of muscles (rider's bone in abductor longus and the like), l 
membranes of the brain : and (2) from similar imtififatiou of inflm- 
niiiton/ tiii»Ui\ Hueh as nodes or general thickenin<j» of lM)nt<8. thr 
sharp stalactitie processes which may j^row uroiind a oarioiis joini 
or on the surface of bone, and the smooth round prominences whid 
almost encircle a joint in rheuniatoi<l arthritis. Thev must bcdi.*- 
tinguished. also, from ralcurruuii dr/xin'ty, in which tlnri' i« iin t«'ni 
formed (p. 100). 

nstcomatn are generally divided into two niniti varietiM.I 
Homologous OBteomata, subiiivided into exostoses .unl MioetocM 
according an they project from the surface or info tlic mciliiil«n 
canal of a bone. 2. Heterologous osteomata. 

1. Homologous osteomata : '/. Exostoses are dividt-d. noHirini; 
to the density of the bone of which they consi.<t, into two kind*— («l 
the compart, ivory, or ehurnated ; ami (^) the canrrUout or 'panjy- 

(a) The ivory exostosis grows from y)eriost.cum. It occur* nin»t 
fre<iuently on the external and internal surfaces of the skull: tlif 
orbit is an especially favorite seat. It is met with abw »n tlif 
scapula, pelvis, anri on the u|)per and lower jaws. In the la*1twmf<i 
situation it may grow from the dental periosteum. 

Such growths are smooth, low, rouixled, widc-ba«ed, covemi lij 
the periosteum, and continuous with that of the idd bone from »l 
they grow. On section they are throughout of ivory-like deni 
and they are usually well ilefined from the adjacent ti.<isue. )Ii( 
dcopically, the lamelln? are arranged concentrically and arc 
to the surface of the tumor; cancellous tissue is absent and Hi 
sian canals are few ami narrow. Some sftecimctis are less ile 
the Haversian canals being as numerous as in ordinary com|>act 1 
but less regularly arrangeil. 

{^) The spongy or cauliflower exostosis is really an oesH 
chondroma. It grows from cartilage, usually near the junctio^ 
an cpi|divsis of a long bone with the shaft. It is especially con 
at the lower end of the femur and at the upper ends of the tit 
humerus. Its outline is less regular than that of the ivory gro* 
but it is prominent, more or less |>edunculate«l, and, so long 
growing, covered by a cap of cartilage. When this cap 
growth ceases. A section shows that the nta-Hs consists of •{ 
bone, directly continuous with the cancellous tissue of tht 




[i«ace it springs, and surrounded by a thin layer of compact bony 
S8ue. The medullary spaces may contain embryonic, fibrous, or 
itty tissue. 

(h) The enostosis is a dense bony growth projecting into the 
Bodulla, and is very rare. 

2. Heteroloerous osteomata are very rare as primary growths. 
They have been described as occurring in the subcutaneous tissue ; 
but Malherbe has shown reason for believing that such growths are 
really sebaceous adenomata with ossified stroma (p. 188). Bony 
tumors have very rarely been found in the brain and cerebellum. 
Parts of fibromata, lipomata, and chondromata may ossify. The 
secondary growths of ossifying sarcomata connected with bone 
often ossify. 

The commonest secondary changre is inflamination. Osteo- 
mata may also become carious or necrose. The last change is most 
likely to occur in ivory exostoses, effecting their separation and cure. 

Osteomata generally grrow in conneclaon with bone (homolo- 
^us), commencing in the periosteum, medulla, or persistent islands 
>f cartilage ; but connective-tisBue tumors, apart from bone 
heterologous), may ossify. 

Clinically, the osteomata are perfectly innocent tiimors. Their 
?rowth is very slow. They rarely attain a large size. They are 
often hereditary and multiple, in which case they usually occur in 
«rly life. Osseous growths which exhibit malignant characters 
are either sarcomata or chondro-sarcomata, which have undergone 
partial ossification. From these true osteomata must be carefully 
^inguished (p. 178). 


The Lymphomata are new formations consisting of lymphoid or, 
*■ It is sometimes called, adenoid tissue. 

lymphoid tissue is now known to have a much more general dis- 
•"oution than was formerly supposed. It not only constitutes the 
'o'licles of the lymphatic glands and the Malpighian corpuscles of 
~* spleen, but also Payer's glands and the solitary glands of the 
""estines. the follicles of the pharynx and tonsils, the thymus 
llsnd, and the trachoma glands of the conjunctiva. More re- 
'^'"ly, lymphoid tissue has been found in other situations, as 
*rottnd the blood-vessels of the pia mater and of other parts, in 
»e neighborhood of the smallest bronchi, in the pleura imnie- 


Fio. 62. 


(liately beneath its endothelium, in the peritoneum, in t 
membrane of the alimentary canal, iiml in the niedtilla 

Wherever it exists the same general structure, that 
licle of a lymphatic gland, may bo taken as the type n 
physiological lymphoid tissue, but alw of that of | 
growths. This tissue consists of a delicate reticulum 
meshes of which are numerous lymi)h-corpu8cle«. The 
is a close network of very fine fibrils. Its meshes are 
enough to enclose one or at most very few corpuscles in 
fibrils usually present a more or less homogeneous ap|>eM 
nuclei are sometimes to be distinguished at the angles 
work. The lifmph-eorpuiti'li's, which constitute the groa 
the tissue, can in most cases be readily removed from t 
of the reticulum by the agitation of thin sections in wb< 
are identical in tlicir chaniclers wi 
cooytes of the blood. As usually 
death, they are spheroidal, pole. 
parent bo<Iies. varying considerably i: 
presenting slight differences in struct 
arc granular, an<l appear to |>« 
in others a distinct simple or com 
cleus is visible, which is usually also 
others, again, are much larger, and 
or even three nuclei (Fig. 52). 

The histological an<l physical chai 
the lymphomata vary according to the rapidity of their 
ment. In the rapidly-grotvina forma the pro|>ortion of oa 
great. Many of the cells are larger than those normally ra 
lymphatic glands, and contain two or even more nuclei. T) 
are of a grayish-white color and soft, brain-like consiste 
like encephaloid cancer — yielding abun<lance of milky jo: 
may reach a great size. The more »loicly-iirowiny tuiiti 
other hand, are less richly cellular. The larger cell 
almost entirely wanting. The reticulum constitutes a 
inent part of the growth (Fig. o3), and, instead of bei 
ingly delicate, is much coarser, and forms a network 
homogcneoufl or slightly fibrillated bands. As the rvtii 
creases the lymph-corpu.scles gradually diminish in nnrolK 
come arranged in smaller groups within its meshes (Fig. 5 
growths are much harder than the more rapidly-growing 

CcUii (hiiii * IjrmphiiUc 
PTiwtli III llip liver. 
Thoac to thr liR an^ tliu 
orillrtnry lyiii|ili for^tiiH- 
rlrt, which oonttltutol 
(he KTciitor i»n of ilic 
(niwtli. To lliv riKlii 
•re Dome of the Urgrr 
clemcnta. :■: 830. 



Fio. •">.'$. 

Lymphimm ^.-iiiiMi iif ii firm lytn- 
phomH nf the niinlluytliiiiin, shiiwlnfc n 
very thickencfl rftk'iilimi, withfn the 

*rc sometiiuos exceedingly dense, and are rarely very large. These 
Variations in tlio itroymrtifin of cells and stroma are precisely anal- 
mEotw to those met with in ly)nphatic glands us the result of acute 
uii chronic inflammation respective- 
It; but in many cases the relation 
Ix-tireen cells and stroma remains 
oormal. as in hyperplasia. 

The lymphomata do not undergo 
marked secondary changes. There 
ulittli-tfiiilriiri/ to fatty degeneration, 
caseation, or softening, such as occurs 
ia Bcrufuloiis glantls. 

The lymphomata originate from 
lymphoid tissue, being apparently °'™"«/'r»hi..h thel.vnlphoicloeu.«n.• 
uniform overgrowths of pre-existing 

lymphatic .structures, mainly of the lymphatic glands. They are, 
therefore, usually homologous. They may, however, he heterologous, 
either owing to the new tissue e.xteniliug considerahly beyond the 
wufincs of its origin, or to its occurrence in situations where lym- 
phoid tissue is not present normally. This hitter ciuidition obtains 
ill Ilojgkiu's disease and in certain form.*! of lymphona which are 

Ill smne cases of round-celled sarcoma, which may originate in 
•nv connective tissue, the matrix undergoes development into a net- 
work; till' growths spread and generalize like onliiiury sarcomata, 
«i)il »re called lympho-sarcomata. They may originate in lym- 
phatic glands 

In Considering the development of these growths it must be 
WTDe in mint! that enlargements of lymphatic structures are most 
frwjuently of an inflammatory nature, being due to some injury, 
•""I that, histologically, as already indicated, there is but little 
'""crunee between these inflanimntory growths and true lymjdio- 
"'*'>• The inflammatory growths, however, tend to subside, the 
*iinior» continuously to increase. Further, the development of the 
iTOtor* ;*eems. like that of the inflammatory growths, to be occa- 
'"'iiaily deteruiine<l by some injury. Thus, an ii»jury may give 
"** to inflammation and enlargement of the gland; but this en- 
lurijf'meiit. instead of subsiding with the inflammation, continues to 
""■ (See -^Etiology of Tumors.") 

Clinically, the lymphomata are, for the most part, perfectly 




innocent tumors. They originate niont frecjnontly in 
glands. wliii'Ji tIiereii|ion iin<loijr" u continuous int 
Sometimes, a.-* alrendy atat«!il. the enlargement of tli 
|iearH to be the result of injury. In mo8t cascH. hov 
Houree of irritation is discoverable. The giamli whicB 
eially prone to this diseasse are the cervical, the suhtj 
a.xillary, the inguinal, the bronchial and mediastil 
abdominal glands. Usually only a single ghind or a 
of glands is affected; Honietimes. howev<'r. the growth 
general. As the glands enlarge, they gradually unite, 
ultimately they may form very large lobulated tiimoni. 
occurring in the media.'^tinum they may invade nne or^ 
they constitute one common form of mediastinal tumo| 
phatie structures in the intestine may in the same wi 
larged, ami project so as to form poly|)i. 

The lymphomata occasionally exhibit malignant proj! 
is especially the case in those richly cellular, soft, rapidlj 
forms which are sometimes met with. Such growths ma 
infiltrate the surrounding structures, involve the neighbol 
phatie glands, and even infect distant parts. To these i 
forms the term lympbadenoma is sometimes apidinl. 

In the (Condition known as '• llodgkin's disease" and il 
mia lym|ihomatous growths are met with in various ^wr 

HoDOKiN-8 Disease. 

This disease is characterizol by the enlargement of I 
glands in various parts of the body, together with llipJf 
of lymphatic growths in internal organs, esjiecially in th 
and by a progressive diminution in the number of the 
puseles in the bltH)i|. The new growths are precisely sin 
tologically, to lymphoma. The disease wias first dr>*C 
llodgkin. an<l is called, after him, "llodgkin's disi-asc:" 
known as "amemia lymphatica." It is allied to li-uchi« 
differs fSHciifially froui it in this respect, that the nc« fijrn 
lymphatic tissue is not a.ssocialcd with any notable inc 
number of the white corpuscles in the blood. (Sc<e " 

The lymphatic glands are usually the earliest seafil 
growth. .\t first only a single group of glands raaj 
subsequently, however, the proe«'«s be<"iu«e« more 


gUuds throughout the whole body may be more or less involved. 
The groups of glands most often aflFected are, in the order of their 
frequency, the cervical, the axillary, the inguinal, the retro- 
Iteritoneal, the bronchial, the mediastinal, and the mesenteric. 
The new growth, which in the earlier stages is limited to the 
glands, gradually breaks through the capsules, so that the enlarged 
glands become confluent and form large lobulated masses. The 
growth may also extend still farther, beyond the confines of the 
gland, and invade and infiltrate the adjacent structures. 

This new growth of lymphatic tissue, which commences in and 
often extends beyond the confines of the lymphatic glands, is ulti- 
mately followed by the formation of lymphatic growths in various 
internal organs, but more especially in the spleen. The spleen is 
affected in a large proportion of cases. Here the new growth 
originates in the Malpighian bodies, and so gives rise to dissemi- 
nated nodules. These vary in size from minute points to masses 
M large a,s a hazelnut or walnut. They are usually more or less 
irregular in shape, of a grayish- or yellowish-white color, firmer in 
insistence than the splenic tissue, and not encapsuled. In addi- 
tion to these, wedge-shaped infarctions surrounded by a zone of 
'■yperaemia are sometimes met with, similar to those which are 
often seen in leuchsemia. The spleen itself is generally some- 
what increased in size, and its capsule is usually thickened, and 
often adherent to adjacent organs. In quite exceptional cases the 
>|>leen is not the seat of these disseminated growths, but is simply 
"mformly enlarged, like the leuchaemic spleen. 

The liver, kidneys, alimentary canal, medulla of bone, lungs, and 
"ibcutaneous tissue may all become involved, the new growths 
•scarring either as nodules of various sizes scattered through the 
"'g*n8 or in a more infiltrated form, like many of those met with 
"1 leuchsemia. 

Histologically, the new growths are precisely similar to the 
'y^Bphomata, and, like these, present differences in the relative 
P'^portions of cells and stroma. The richly cellular forms are 
*" and pulpy, whilst those in which the stroma is more abundant 
*'* firmer and more fibrous in consistence. Retrogressive changes 
'^fely occur. 

" ith regard to the pathology of the disease, it is undoubtedly 
otiscufe. The development of the new growths cannot in most 
**8e8 be regarded as the result of infection from a j)rimary centre. 


as the process is, for the most part, confined to the IrmpLatic 
structures, and many and widely distant groups are often siuiui- 
tancously involved. The disease thus appears to occupy a (lifferrot 
pathological position from that of the malignant tumors. It i< 
probable that there is some special weakness of the lympbitir 
structures generally which renders them prone to undergo the* 
active developmental changes, the process being determineii bj 
some unknown factor. The progressive anaemia which acvom- 
panics, but does not precede, the gland affection is possibly doe to 
the progressive implication of the lymphatic structures and to tk« 
consequent interference with the formation of the blood-corpu.4clec- 
(See " Leuchivmia.") 

The Lymphangiomata. 

The Lymphanfiriomata are tumors consisting of abnormtE '! 
large lymphatic vessels. It is doubtful how much of the growth * 
due to simple dilatation and how much to new formation of lyr"^*" 
phatic vessels. The divisions are the same as those of angiow-^^^ 
— simple an<l cavernous. A section of the latter would scarce^^J 
be <listinguishable from one of cavernous nwvus (Fig. 46), exce^0^ 
by the contents of the spaces. There is generally fat in the stroui ■"■ • 

Each kind may be congenital or ae(juired. Congenital dilat^s^ »' 
tions are found in the tongue (macroglossia), lip (macrocheilia). •n^t^d 
labium, causing hy|)ertrophy of the jtarts. They are also found ^^ '« 
other jiarts of the skin. 

Acquired dilutntion of lymphatics is found in the skin, e8i)eciilK' h' 
that of the thigh and thora.x. Tumors sometimes as large as ^aanu 
orange may be thus formed in the subcutaneous tissue. Dangen)«~ u* 
loss of lyni]>h nuiy occur from rupture of one of the vessel k 
Fibroid thickening may occur in the parts from which the Iv^^bd- 
|>hatics ]>ass to the tumor. 




The Sarcomata are tumors consisting of connective tissue of a 
Dore or less embryonic type, in so far, at least, that cells predomi- 
late over intercellular substance. But in central parts the process 
f development seems sometimes to proceed to a further stage, and 
illy-developed connective tissues, such as fibrous tissue, cartilage, 
' bone, are formed. In this way a mixed tumor may result. 

STRUCTtJEB. — All sarcomata consist of cells imbedded in more 
less intercellular substance, which varies in amount and cha- 
rter and supports the blood-vessels. 

The cells, which usually constitute almost the whole of the 
owth, consist for the most part of masses of nucleated protoplasm, 
rely possessing a limiting membrane. They vary much both in 
ie and form ; and though, in any given tumor, one form usually 
edominates, all may generally be found by searching teased 
eparations, which should always be employed for the purpose. 
Tten the different forms are pretty equally mixed in the same 
ovrth. There are three principal varieties — round, spindle, and 
7'eloid cells. The round and spindle forms may be either small 
large. The irregular, multinucleated, myeloid cells vary in size 
d in the number and size of the contained nuclei. One cell may 
v« as many as thirty nuclei. 

Xhe intercellular substance usually exists in but small quantity. 
intervenes between all cells, and is as closely connected with them 
in ordinary connective tissue. These points are often relied 
on to distinguish certain sarcomata from cancers, but they prob- 
ly do not always hold good. 

The stroma may be fluid and homogeneous, or firmer and gran- 
^f, or more or less fibrous, or even chondrified and ossified. On 

amount and nature the consistence of the growth depends. 
The blood-vessels are usually very numerous, and are either in 
*«ct contact with the cells or separated from them by a little 
*"illated tissue. Their distribution is very irregular, and their 
^lls are often formed by nothing but the cells of the tumor. 
&»ce, on the one hand, the ease with which portions of the tumor 


are carried away in the blood-strcain aud the tumor gener>)iied. 
and, on the other, the frequency with which the vessels mptBit 
and permit extravasation of blood into the substance of the growtb. 
Lymphatics are unknown. 

An examination of the growing border usually shows b gnat 
excess of small roun<l-cells over all other forms. These cells exttni 
along the connective tissue in all directions, and force thcmMWw 
between the essential elements of muscles, glands, and any adjicent ] 
organs, while these elements themselves become pale, undergo atro- 
phy, and finally disapi>ear. In the invaded connective tissue many 
cell-forms are seen, which may possibly indicate multiplication wf 
the fixed cells ; but it is almost impossible to obtain any pn>of tb* 
they help to form the tumor. (See " Modes of Sprrad of InflaO*- 

In an ordinary examination of a sarcoma the growing edge shuiaM 
be avoided, on account of the predominance in that part of »m»" 
round-cells over those most characteristic of the tumor. 

SECONDAKY CHANGES.— The most important of these » 
fatty degeneration. This always occurs to a greater or less ext*»»>t 
in the older portions of the growth, causing either softening or tl»' 
production of cyst-like cavities. It is frecjuently associatetl wi*'' 
rupture of the blootl-vessels and hemorrhaere ; the latter may gi '*"* 
rise to the formation of sanguineous cysts (p. 181). Calciflcatioin 
(Fig. ♦iO). oaeiflcation (Fig. HI), and mucoid desreneration a«^ 
less common. The occurrence of calcification, ossification. ar»<» 
pigmentation is influenced by the predisposition of the matrix fn»«» 
which the growth is produced ; thus, calcification and ossificati* •» 
are more prone to occur in tumors originating in connection »i*" 
bone, pigmentation in those originating from the cutis or eyeba 1 •• 

VARIETIES. — Though all sarcomata possess the same gener-^ 
characters, they present histological and clinical differences wbic"' 
serve as bases for their classificatifin. 

The principal features which are thus utilized are — (1) the l'"^* lonn of cell: {i) the nature of the stroma; and (3) thr" 
.>'«Tiiii<l;irv cliiingcs to which the growths are liable. 

( 1 ) The predominant form of <•<// enables us to distinguish fon^ 
ps — tlic round-celled, the spindle-celled, the mixed- ce l to d,^ 
uliich no special form pre<louiinates. and the myatoid-oeUtd. 



Strictly Hpeaking, this last group is a mixed-celled sarcoma, but 
though the myeloid cells can never be said to predominate, rhey arc 
frequently so numerous as to be the most striking objects in the 
field when examined microscopically. 

(2) The Htroma may be mucous, fibrous, cartilaginous, or bony ; 
hence we may have a . myzo-sarooma, flbro-sarcoma, chondro- 
earcoma, and osteo-sarcoma. 

(3) Sarcomata may undergo tecondary chdnf/es, which are justi- 
fiably described as distinct varieties, insomuch as the peculiarities 
ire reproduced in the secondary growths. The chief of these are : 
melano-sarcoma, characterized by the development of black pig- 
ment, and chloroma, a very rare form, with green pigment ; lipo- 
aarcoma, in which the cells undergo fatty infiltration ; and calcify- 
in? sarcoma, in which calcareous infiltration is marked. 

PHYSICAL CHARA.CTERS. — Portions of sarcomata which 
have undergone no secondary changes are soft, semi-translucent, and 
grayish or pinkish gray. These appearances are best seen near the 
Urotemg edge, which may be very narrow. The diagnosis — even 
»ith the microscope — between a sarcoma, especially a fibro-sarcoma, 
•nd the different forms of simple connective-tissue tumors may be 
Mcee«lingly difficult. This is due to the higher development of the 
wntral parts of the sarcoma toward one or other variety of fully- 
fonned connective tissue. Degenerative i)rocesses, such as fatty 
mftamorphosis, and especially hemorrhage, may greatly interfere 
*ith the usual appearances : the occurrence of hemorrhage may con- 
'^frt a solid tumor into a blood-cyst with a scarcely recognizable wall. 

As a rule, the growing edge is ill defined, there being no sharp 
line of demarcation between the tumor and the adjacent parts ; but 
l^metimea a slowly-growing tumor may acquire a capsule by stretcii- 
'"? around itself the connective tissue of the organ in which it 

Mode op growth and seats.— The sarcomata always 
pnng ffom connective tissue, and may occur wherever connective 
"8Ue ig present. It is doubtful whether they start from adult tissue 
"'' from gome embryonic remnant. Congenital warts and pigment- 
'l*t» often serve in later life as their starting-points (j). 142). The 
^■'■n and subcataneous tissue, fasciae, periosteum, medulla, uml lym- 
I'hatic glands are the commonest seats of .sarcomata. 


CLINICAL CHARACTERS. — The wrcomaU occur mort fr^ 
<|iiently in earlv iitul iriidiile li(V, timl lire auionj; the nioHt ui:h 
of new foriiiutitiiis. Thev are cspt'oiHllv cliiiructoriwMl l»_v thru 
tendency to extend locally and to infiltrate the surrounding ntnic- 
tiircs. so thnt tlipy nre exceedingly prone to recur »'« lorn after renunaL 
Butliri has shown that sarcomata of certain jiarta altuo»t always affrc^ 
lymphatic glands at an early stage — vik. sarcomata of the testi*. 
ton)«iK lymphatic glands, and some faseire. Those of certain otbw 
jiartR show no tendency toailect lymphatic glands at all : so that, oa 
the whole, sarcomata present a contrast to cancers in this re»f»ct. 
Like cancers, they are very liable to become generalixtni Tb« 
secondary growths occur most freijuently in the lungs. Thr Jinrr—i" 
nation IK I'lf'ertfd hy iiu-an» of the blood, and is a natural r(*«ult o» 
the thinness of their vessel-walls and the immediate contuct of th 
with the cells of the growth — conditions most favoraMe to the 
trance of the cellular elements into the circulation. The di 
nation of the sarcomata is, on this account, sometimes more T%f> 
than that of the carcinoniata. In thr cdrrtnouiata rrtrntiion in f 
fiirhf utiufi- litki'H plftcf hy tfii- b/mphatirg, an(l dissemination hy i 
blood occurs later in the disease. The si'condary .«iareoinata ii!<tial 
resemble the pritiuiry growth, but in exceptional cases the aer 
varieties may replace one niujther. 

It has already been pointed out that the different varietie* 
sarcoma |M)s8e88 very different degrees of malignancy. As a rul 
the sotller Jiiul more vascular the tiinior, and the less its tendency 
form fully-devciopetl coivnective tissue, the greater is its mnlignitnc- 
The soft fotind-rAlfd and Inrye tpindh-celled varieties are th 
usually much more malignant than the finner »m<iU gpindlrirli 
growths. .Many small spindle-celled tumors after removal ue* 
rocur. whilst others recur locally several times, and ultimately 
duee themselves in ilistant parts. Asa rule, largeness of the spiai 
elements and the existence in many of them of more than one nude' 
are together evidence of N|>ecial malignancy. Central Barcumala 
bone are much less malignant than the subperiosteal varictir*. 
latter, with sarcomata of the tonsil and testis and melanotic aa 
of skin, being among the most malignant of tumors. The p: 
of a capule limiting the growth must also be taken into accunat 
judging of the degree of its malignancy. If must, howevi-r. 
l>orne in minil that even in a growth distinctly eucapsuknl the mm 
matous elements may invade the adjacent structure*. The mvrloi 



Fig. 54. 

IJimifl •■.Itc.I sfiri'iinio. \ 
Cbiu soi-ti(-iu ot' u HinuU 

growths are the least malignant ; they may in exceptional cases give 
rise 10 secondary growtLs* in internal organs, but " complete " re- 
moval gives a very good chance of non-recurrence. This .sometimes 
occurs with growths having every appearance of malignancy. 

According to Cohnbeim, the very varying maligii;iiicy of sarco- 
uialoua tumors goes far in proving the necessity for that diminished 
physiological resistance already alluded to (p. 140). 

Roitnd-ceijLBd Sarcoma. 
This is of soifter consistence than the spindle-celled growths, and 
from its frequent resemhiance in physical charactei-s to encephaloid 

I it is sometimes known as "medullary," 
'* encephaloid," or "soft" sarcoma. Histo- 
logically, it is elementary embryonic tissue, 
consisting mainly of vound-cclls imhodded 
>n a. scanty and usually soft, homogeneous, 
•>"■ finely granular intercellular substance 
(*'>g. 54), The cells usually resemMe 

»^^t vith in the most elementary embryonic 
tissue; less frequently they are bigger, and round-ceUod Mrromii of the 
•^'•ntain large round or oval nuclei witfi 

origljt nucle<}li. There is an almost complete absence of fusiform 
^cells and of the partial fibrillation which is so frequent in the 
•nore highly-developed spindle-celled variety. 

■ The round-celled sarcomata are of a uniformly soft, brain-like 
****i8istence, somewhat translucent or opa(|ue, and of a grayish or 
reudjsh-white color. On scraping the cut snrface they yield a juice 
_ which is rich in cells. They are exceedingly vascular, the vessels 

■ ofteti being dilated and varicose, and from their lialiiiity t<» rupture 
Vthey frequently give rise to ecchymoses and to the formation of 

■ sanguineous cysts. (See "Blood-cysts.") They grow from the 
V *^'^tis, the subcutaneous cellular ti.ssue, the periosteum, the fasciit!, 

■Dt» the connective tissue of organs. They extend rapidly by 

V'^r^'pheral growth, infiltrate the surrounding structures, repnuiiice 

^''(^noselves in internal organs, and often involve the lymphatic 

P'ftnds. From their clinical and physical characters these tnniors 

We verv liable to be confounded with encephaloid cancer : they are 

•Jistinguished by the absence of an alveolar stroma and by the 

|*netration of the intercellular substance between the individual 




GLIOMA. — This is a viirietv of rouiid-fflled sarcoma giDwiiij 
from tlif iieurojjlia or connective tissut- of nerve. It cousisi" "i 
very small round cells imbcddctl in an e.vceedingly scantv, honnv 
gencoiis. granular, or sliglitly fibrillatt-d intercellular aubstanci' 
(Fig. 'm). Some of tbe ceils uiav possess fine prolongations wLicb. 
by communicating with one another, form a somewhat reticulstd 
.'Structure. These tumors jiri' of soft consistence and of pinkisb- 
gray color. 

Gliomata occur in the gray and white substance of the brain, in 
the cranial nerves, and in the retina. In the retina a glioma uaaalljr 

Fio. 65. 

Snn-rimatou» tuniore (Vnm thu bnlii : a, a KlIonM uf the cvrehtiUnin. abuwlng lbi> «| 

miifi' onUniirlly prfstnleil liy tticsp prfiwllis; It. n niniptinitlvi'ly mri' is>nii of Hiroinm. 
flSthiK ttf liifKc riurh'iiti*"! rcUj* iTiolose*! within lln* mi-^hf* t'f u vnx-iiUr iielwnrt t"*** 
4lcvi'li)imn!Ut of llils tuniur took idari' in lliu liralii KulMc'qiU'ntly lo llmt of epInillC'Ccll*™ 
HTuwthn— jirimiirily in thf thigh and seconiiarlly In llic \nwf. X 200. 

commences as a minute nodule, which may gradually increase nDti' 
it jirojects as a large fiinguting tumor from the orbit. Altltoiigk 
gliomata grow slowly, they are not encapsuled, and. although tlie5 
may occasionally infiltrate the tissues in which they lie anil c»ni?* 
seconrlary growths in their imiiu'ditite vicinity, they very nn\y 
reproduce themselves in neighboring lymphatic glands or in distan* 
organs. They are liable to small hemorrhages into their structure*- 
anil sometimes become more or less caseous. So often are thes^ 
growths clinically " innocent " that by some they are dasstnl ** 
a variety of connective-tissue tumor of a "neuroglia" type, whicl* 
may occasionally become sarcomatous. 

LYMPHO-SARCOMA.— This is a round-celled sarcoma, in 
which the matrix has developed into a more or less perfect reticulum, 
like that of lymjihoiil tissue. It may begin in lymphatic glands »i 
in connective tissue anywhere. It is distinguished from lymphoma 
by its more rapid course and by tbe formation of secondary growtbi 
by embolism (p. 169). 



Fio. 66. 

AJjVEOLAR SABCOMA. — This is a rare form of round-eelleJ 

ffc*rcotuii wliieb was first (lescribed by Billroth. 'I'lit' cells, wliicb :ire 

Iwgc. sharply defiued, round or oval in shapie, uuil contain round, 

prominent nuclei, are separated from each other by a more or les.s 

marked fibrous stroma. In some parts this stroma forms small 

»lvt!«)li \^ithiu which the cells are grouped, but careful examinatiou 

will always show that in most parts of the section the stroma really 

l/ieuetnites between the individual cells. This last-named character, 

Mogrthcr with the nature of the ti.ssue from which they arise, serves 

'At ilistiiigui."!! these tumors from the can- 

crs, with which, in many ctkses, they may 
RiKily be confounded. The accompanying 
Irawing shows their microscopic charac- 

ltj* (Fig. 06). The stroma is often much 

more delicate, and the cell-masses are 

.occswionally much larger, than in the 

-drawing. The cells are generally in close 

[wnnection with the stroma, though ves- 

mIs never pass in among them. In this 

latter respect they resemble epithelial 

growths, Ziegler says the alveolar struc- 

''ire may be due to the transforni.Ttion of nonniil intcrva-scuhir tis- 

*if into sarcoma-cells, whilst the ve.-^.icls with the neighlwriug cou- 

"•'^V'e tissue remain aa septa. 

A/velor .sarcomata are met with principally in the skin, bones, 
""'tnuscies. In the skin, where they are often multiple, they leail 
I " ulceration. They tend to recur locally, and also to produce them- 
in internal organs. 



Alvenlnr iiarrnma ((hiro a tu- 
mor »r the skiM). X 200. Ktml- 
\w. 1 

Spindle-cblled Sarcomata. 

'^*e tumors, which include the growths described by Paget in 

lAb>>la.f„{ ^ " fibro-plastic " and "recurrent fibroid," are the most 

"iiniii**!! of all the sarcomata. They consist of cells, mainly 

'P"'**lf8hapod and fusiform, separated by only a little homoge- 

llimiis 411- slightly fibrillated intercellular substance, and nftcn form- 

['"R whorls round the vessels. The cells contain well-marked oval 

nticlei ^jij, QQp or more nucleoli. They are arranged in bundles 

'™«> pass in all directions through the growth, anil often give it 

r^ appearance of a fibroma or myoma. In those portions of the 

Aon in which the bundles of spindle elements have beea cut 



transversely or obliijuelv they prexent the appearaure of maod'V 
oval cells. The cells vary cnnsulcrubly in size in liiffereut tumon. 
Lence the division into small and lar^e spindle-celled growths. 

Fio. 67. 

are small, often not more than ps'ojy inch in length, and the inl«T* 
cellular substance is occasionlly im|*ffNi*y 
fibrilhited (Fig. 57). These growrtli"" oppn»A 
therefore the confines of the fibniiuata. an* ' 
histologically they must bo regarded u (icr«ii-i 
pying an intermediate place between 
bryonic and fully-doveloped couneetive 
sue. They grow from periosteum, fabric. 
connective tissue in other parts. They 
usually Krm and whitish or pinkish white, 
present on section a translucent .•■omew] 
fibrillated appearance. They are much more freipiently rncajM 
than any other variety of sarcoma, but they are \ ery liable to it 
trate the surrounding structures and to recur locally after renins 

menta in these tumors are much larger than in the precedi 

SuisU >|>lliiUr-ctflIC(l 
Mirt'MtiiH (fViiiu M tiitiKir 
••f the leg). •: a». 


Fio. 68. 



tiinp'«|iliuUr cclU-<l »«r>'ciin>. T>> ihr left ilir <'<-Uh tiavi- brcn cv|<«riiU'<) hjrl 
tlm( tlit'lr ItuUvlilunl (umM arv apiatn'iit : to tli« riKl>>. ilify itv In tlii-tr lutunl ill 
puslUoti, rarh u wmilil tw wen In ii tliln aertlon of thr tumor. ( Vlrrhow.) 

The cells are plumper, and both nuclei and nucleoli are i 
prominent and frequently multiple (Fig. 58). The interwlh 
substance is more scanty, and there is a complete absence of i 
fibrillation. These growths are much softer in consistence tbaal 
small-celled rariety. They are of a pinkish-white color, and 



often stained b}- extravaf^ation of blood, and in purt^ are sometimes 
almost diffluent from extensive futty degeneration. They grow 
rapidlv and are usually exceedingly malignant. 

MELANOTIC SARCOMA.— This is ii variety of siircnma in 
which many of tLe cells contain gramiles of dark-colored pigment, 

Fiu. 69. 

* li)«luiii||i: •nniiiun 'if tin- penis. .1, nei'tlim uliowlng tho (jcncral arrangement of tin- 
**'*'"il», ■■. a*i. B, avi'Iliin from the iM-riplii'nil piirt nf Ihe (trowth, xliuwing the "ludlfler- 
'^^ <^IU." iiiiiunic«t wlilrb tire xmutl iKolnteil pignHMiteii elements. At a a blood-veMel U 

^*». > jn ('. some of tticcIemenlH si'iHirnted by te<l^ing. In these the plgment-gianuleo 
**• Wfltieen . Jim 


luito distinct from tin- ]iiginent of extravasateil Mood. By far the 

igToater number of melanotic tumors are sarcomata, and most of the 

IStmlis, which were formerly described as " melanotic cancers," 

j'>tlcjng in reality to thi.« class of new formations. 

I The luelanotic sarcomata originate |)rincipally in two .-iitiiatious — 

I*** the choroid coat of the eye and in the su(ierficiiil integuments. 

'U both of these situations jiigment is a normal constituent of the 

''sHries. and this tendency of pigmented structures to originate 

"it'laiiDlic growths is exceedingly eluiracteristic. These tumors 

ttauBlly consist of 8pindle-9ha|)ed cells (Fig. 51»), and hence they are 

'U«&«:rihed in the present section; but in fiome the prevailing 

'yi>*iif cell is rrumd or oval. The pigment which gives to them 

»*eir distinctive characters consists of grunides of a brownish or 

'lark aepia color. are mainly distributed within the cells 

(•^ijf. 59, V), but are also found in the intereellular sub.stance. 

'rwjoently, only a very small proportion id' the cells are pig- 



NvrRirioa increased. 

moiitcil. whilst in other instances the pigmentation is much niorr 
universni. In all ca^es a large number of the elements will lie 
foiiuil to be ((iiite free from pigment. 

These melanotic tumors are !im<tngst the most malignant of the 
sarcomatous growths. Although thev show comparatively litllr 
tunilciicv til exteuil h'l-iillv, thev are rapiilly disseminateil by mean* 
<if I he blood-vessels, iiml occasionally also by the lymphatics: thev 
tints reprndiice themsches, often very rapidly, in distant tissue. 
Although the secondary growths almost inviiriiibly maintain tbcir 
melanotic character, the degree of their pigmentation varies con- 
sidenibly. Whilst many of them may be perfectly black in ruinr. 
others may be much paler — perhaps only streaked with jtigiuciit. 
The seconthiry growths are soft, usually distinctly circumscribHt 
and often encapsuled. They may occrir in almost every orgiiu "f 
the body : the liver, the spleen, the kidneys, the lungs, the heart, 
the brain and spinal coni, and the lymjihatic glamls and taV 
cutaneous tissue, nuiy all be simultaneously involved. Whrn 
occurring in internal organs the |>ignientatioir is not always liiuiifi 
to tlu' secr)udary iKwiules, but many of the cells proper to the organ 
itself are filled with granules of similar pigment, which in niort 
iibunditnt in the cells iuiniediately adjacent to the new growtli. 
This pigmentation of the ceils of the organ often extends for .'i<iiiio 
distance beyond the confines of the tumor. 

OSTEOID SARCOMA. — This is a variety of sarcoma whif^" 
was foriuorly known as '-osteoid cancer." The growth (uRUttll> 
spindle-celled) is either more or less calcified or partially convert*'" 
into true hone. \n a primary growth it is met with almost cxd**' 
sively in connection with bone, growing either from the periostoutf 
or the medulla; but the osteoid characters are usually reproduce^* 
in secondary tumors occurring in the lungs and other parts. 

■ Valfiticaliuii is much more common than true oHsifiratloti. Enct* 
of these processes may occur separately, but they are often com" 
biued. Bands and patches of granubir iippcarance, in which tlit* 
outlines of cells may still be visible or in which all structure bn.« 
disappeareil, and which stain but slightly, show where calcifica- 
tion ha.s occurred (Fig. (!0). In other parte, especially near tin- 
bone, spicules having the structure of more or less perfect bone — 
Haversian canals, lacunji?, anil imjierfect eanaliculi — will be seen 
penetrating the growth (Fig. t>l). The spicules are generally 

vertical to the surface of the bout. In some cases a skeleton of 
ibowy spines radiates from the bunt- through the growth. 

.,„„„ I rrnni R KiH'onctary tumor iif the Iiuig). ohowlnir tin- ralclflcatlnn of « 
"lUili unrl till' r'>riiiiitii>ii nf Imuiil luiuits iircnlcilU'il hitcn'oUulur material 
.. ,..1 r. which contain rouml ami oval i-clU. ■: JU. 

Both calcification and ossification may be very complete, but n 
thill mnryin of atirauna-tUme is always present. A sini)ile osteoma 

Ki<( 61 

— 1» 

^ ** ■ Mfcoma uf lowt'r Jnw ■ *, 8iin'omA-llsRiii* ; /», Ixtfu'. i^rowiiiK from J»w, of whirb the 

Hull in^ '" '''''''^ l)TiI''al . p. \«i\M of oommelirini! owlrtciitloii. Only ntu'lrl of I'cIIi art" 
^^^ : eli«e til the boii« the itrornu is vurj- Abroiin. • ^O. (Boyd). 

'" *l Iiavc cartilasio or perio.steiim on its siirfVicf and would he of 

"^" **ln\*er growth. It is most imjiortant to recofruize this differ- 



Myeloid Sarcoma. 

*. which is the well-know n " myeloid tumor," is somewhat 

V»i the !<pindli'-felli'<l jrrow tliM. If jjossc-tses, however, ccrtiiiii 

'^giciil |ieciiliiiritit'.>' HJiiidi probnblv dcpoiid upon tlic rliii- 



racten of the tissue from which it grows. Myeloid tumors nmrlf 
always wear in connectiou with b<jnc. and niuHt frei(uentlr orixi- 
nato in thi- uieduliiiry cavity. They contain many of the laryr. i 
multinucleated cells already described as "myeloid cells," wiiiiii 

Kio. «2. 

Myeloid urfinia. iVItvhuw.) 

resemble the cells of the medulla in a state of excessive nnt 
activity, together with numerous fusiform cells like those mc 
in the spindle-celled varieties. There are also some smaller 
and oval elements. The large myeloid cells which gi\e to 
tumors their distinctive characters are usually much more nan 
in those growths which originate in the medullary ca\tty fbi 
those which sjirinp from the periosteum. These various for 
celU arc nlini».*t in contact, there being very little interc-ellular i 
stance (Fig. 62). The growths are sometimes so vascular u 
give ri.'^e to distinct pulsation. They oftrn contain cyst*. 

Myeloid tunmrs almost always grow in connection with boBf. I 
ends of the long bones being their favorite seat. They are 
frei)uently met with springing from the fR-riosteum of the 
and lower alveolar processes, where they constitute one 
epulis. When originating within the meiluUary cavity the i 
tissue of the bone becomes "expanded " over them, and thov ' 
often communicate to the fingers, during examination, the ftruM 
sensation known to surgeons as " eggsht-ll crackling." TrueM|! 


*ion of bone is, of course, impossible; really, the old bone is ab- 
sorbed from within by the tumor, and the periosteum lays down 
ii«w bone on the surface ; absorption is more rapid than new forma- 
tion, and the thin surface layer of bone yields and crackles under 
pressure or is actually wanting at spots where pulsation is marked. 
These tumors are for the most part of firmer consistence than the 
other varieties of sarcoma. Many of them are firm and fleshy ; 
others are softer, more resembling gelatin size. They are not pulpy 
and grumous like the soft sarcomata, neither do they present the 
fasciculated appearance of the spindle-celled varieties. Their cut 
surface has a uniform succulent appearance, often mottled with 
patches of red. This red-brown or maroon color varies with the 
number of giant-cells present, and is very characteristic. The 
tumors are often encapsuled by the periosteal covering of the bone 
from which they grow. They are rare after middle life, and are 
the least malignant of all the sarcomata. 


The name Cylindroma is applied to a group of tumors in which 
the cells are arranged in hollow columns or globes. The interior 
of these structures is frequently, but by no means always, occu- 
pied by a blood-vessel surrounded by hyaline material. Accord- 
itig to some authorities, these tumors are really myxo-sarcomata 
"^m the first. In the opinion of others they are sarcomata in 
*liich the adventitia of the vessels has undergone mucoid degener- 
ation, while the vessels themselves have developed varicose dilata- 
tions. Ziegler, to emphasize the large size and number of the 
^esselg and the general character of the tissue around them, has 
'"ggested the name anerio-sarcoma myxomatodes. In all prob- 
ability several forms of new growth have been included under the 
"awe cylindroma. 


^*»inor8 are occasionally met with into which so much hemorrhage 
»«8 taken place that their real nature is masked, and their appear- 
ance U that of blood-cysts. The nature of these blood-cysts has 
oi»iy recently been understood. They are now known to be in the 
majority of cases soft round or spindle-celled sarcomata. They 
**>'*8iiit of broken-down blood-coagula surrounded by an ill-defined 
^y*T of soft sarcoma-tissue, which is, as a rule, clearly revealed by 


the microscope. These growths are exceedingly malignant. wA 
hence the recognition of their sarcomatous origin is all-importut. 




The Papillomata arc new formations resembling in structa."^ 
ordinary papilhc. 

Tliey consist of a basis of connective tissue, which sends tovx* ■"*' 
the surface numerous papillary processes, each supfwrting bliw »•*" 
vessels wliit-h end in a capillary network or single loop, the wh« »'* 
being enveloped in a covering of epithelium. The {mpillie may •»* 
short and siuiplo. as in an ordinary wart, or thev may be lor* !£• 
delicate, branching — g'^'ng "ff secondary and tertiary offsets — *»»•' 
very numerous, as in rilhiux tuinorn. The covering epithelium '" 
skin-growths is thick, hard, and stratified, and may actually bi»»« 
the papilhe into a solid mass; but on mucous membranes the slend ^r 
vascular processes are covered by a small amount of delicate ey»' 
thelium, and in consecjuence they are easily lacerable. Warts <■»•» 
serous mend)ranes are often covered by a ninffle layer of endotheli*' 

llcuiorrha^e and ulceration resulting from injury can hardly b* 
classed as secondary chaneres. The only important change is tb^ 
possible conversion of a papilloma into an epithelioma. Inawa'' 
all the epithelium is on thi- mrfaci\ no matter how irregular tb at 
surface may be. As soon as the epithelium begins to invade tf»e 
tixsiD-H hfiiiiith it the wart has become a cancer. I*iginente<l wirts 
not uncommoidy forui on tlie face in old age. and it is well to witc*h 
but not to irritate tlicui. 

Four varieties can be readily <Iistinguishcd : 

1. The ordinary skin-wart with its covering of hard s«|U8IB<>*'* 
epid«'rmis. Condylomata and veneri'al warts, due to the irrit»ti*>'' 
of the secretions of soft .xores or jronorrhcca, deserve special m^*' 
tion. These, tiioujrh coveretl by s<|uamous epithelium, are iiii>*-_ 
softer, more vascular, and more luxuriant in growth than the of** 
nary skin-wart. Tliey affect warm, moist parts. 



2. The Boft warts and villous tumors of all mucous surfaces. 
Tliesc nre usually fbarticU'ri/.fd I)y \<n\^. delicate compound papillse. 
iht tongue, cheek, laryux, and bladder are the parts most often 

Fig. 63. 


Bon iif w»rt <iti skin of nlKlimuMi : r, I'pltholliim : <•./. connective tiitsue coiitlniioiM with 
aif (Utl <'Uli» . <. •c'cnmul«tii>iuir>r horny t'|>lilcrml»<li-cp down livtwecn the iHtpUIa', 
^tiK in (w-Uon Ukv Urxv nvstii. v 10. (Boyd.) 

•ffecteil. The papillary enlargements of the synovial villi uliich 
}«re common in chronic arthritis may be inclmled in this group. 
3. Corns. — These i-ommcm;' as papillnuiata. but. as tlic ejiidcrmis 
I thickons and is pres.>»ed by the boot into the .soft parts, the paj)ilUe 
"'Umatcly atrophy. 

■t. BoniB some inches long occasinnally springing from the skin, 
ihes* consist of epithelium and sebaceous .secretion, and originate 
iroiu sebaceous follicles or from a sebaceona cyst. It is said that 
'"";? papilln> project into their bases, .so they seem to be allied to 
*«rts. The base must be removed with the horn or the latter will 

'o the naked eye the ordinary wart is a hard, abruptly-elevated 
''Mle inatts. a|>|iareiitly formed of epithelium. It presents an irreg- 
"'•' ("wartj'") surface, often divided by dee[> fissures. If the 
'Ovcsting epithelium be abundant or the papilhe be very short, a 
""iiided luass having a merely furrowed surface resiiltf<; but as the 
l*'pilla> lengthen and the ejiithcliiiin tiiiiis the growth presents first 
* <^i«liflower. then a branched, and finally a villous, a]>peurance. 
">"■ liiitiT ajijjearance is best seen on jducing a " villous tumor" of 
""" bladder in water, when the long delicate papillie float up. They 
•** txcM'dingly vascular. On section of a papilloma the relation 


bftttccn stroma and epitlieliuin, above described, can be seen orcn 
with the naked eye (Fig. *!:!). 

Pnpilhmiiitii alwiiys originate from skin or from mucous. stTim*, 
or synovial membranes. They most frequently grow from pre-e.tisl- 
iiiji; pajiillic; sometimes, however, they occur where no papill*- 
exist, springing directly from the subepithelial connective ti.*«ur: 
this is the case in the stomiicb ami larynx. As all new growths no 
free surfaces tend to become " papillary," this form of tumor is 
probably the result of pby.sical conditions. According to this 
view, a wart is simply a fibroma become pupillary i)y an nccidcDt 
of position, and piapillonuita as a class should therefore disappwf. 

Clinically, warts, .so long as they remain warts, are i|uifc innc- 
cent. They are common in childhood and early adult age, e*!*- 
cially upiin the liands anil face. They may be single, but n\M 
tbf liands they arc coinuionly multiple. They generally dis»pj»'»'' 
after a time, tlnoigii ihey may persist for years. Wart.s on luiif""' 
surfaces give trouble, and may cause death by bleeding: in tbf 
bladder difficiilly may arise from id»struction to the inflow or not- 
(low of urine, the entrance of the ureter being a favorite »ci»l- 
Lastly, the tendency of warts anil warty surfaces {irht/it/o*U limjit'^^ 
to become epitheliomatous in advanced life must be remembere<l. 


The Adenomata — or, as they are more commonly called, grlaa^^ 
ular tumors — are new fornuitions of gland-ti.ssue, more or It?** 
atypical in structure, having an abnormal relation to the tiss*** 
around, and incapable of jierforming the function of the gland tL^* 
imitalc. Their ducts do not enter those of the glan<l whence tb*^^ 
In structure the adenomata resemble either the racemo.w *^' 
tubular glands, and are <livided into two corresponding varietiff^^ 
1. The racemose adenomata consist of numerous saccule* «^* 
acini lined with small epithelial cells. The«e usually form a siujc**^ 
layer, though tbey may be two or three deep. A section cut \ft^^ 
oblii|uely through the wall of one of these acini will, by cuttii*.^ 
across adjacent cells at different levels, give the appearance »' 
superimposed layers. The acini communicate with each other »ti *^ ' 
are grouped together, being separated merely by connective tissut^' 
in which are contained the blood-vessels. The connective tissue- 
varies in amount; when iimcii in excess of the normal the growtf^^ | 



calloil an adeno-flbroma. Sometimes, in the most rapidly grow- 
hivg forms, tlif stromn is riclilv cellular, consisting of roiui<l and 
swindle elements : the histological distinction between such growths 
»u»l sarcomata is impossible (Fig. 64). 

\11 growth.^ originating in glandiiliir organs may be associated 
«ilh more or jess gl.-iDdiilar structure. In tjie niiininia, for cx- 

Fui. fW 


Adenums of mninms. >: 300, reduced J. iCautlle ) 

•Tie, parcoma, myxoma, and other forms of tumor are often so 

'Diormingled with the gland-ti.nsue of the organ that it becomes 

•iifficolt to say which is the predominant structure. In many cases 

It Is evident that the development of such tumors is accompanied 

V an increase of the gland-tissue amongst which they grow. 

•''iJtecl forms are thus produced — adeno-sarcoma, adeno-myxoma, 

*''^- Adenoma is, bv itself, an insufficient nauir for these tumors, 

''*<*Uso their stroma is different from, or in excess of, that found in 

""ftOnl gland-tissue. 

— The tubular adenomata grow from mucous membranes, and 

f "'♦•tst of groujis of tubules lineil with epithelium. Tlicy will lie 

[•""^i^.J ti. hereafter. 

'^■*e adenomata almost always originate ftom pre-existing 
SlWiciB. They generally grow slowly, and possibly from some 
liitttfTto quiescent congenitally misplaced rudiment ; otherwise it is 
^iiracult to explain the complete encapsidutiou and separation from 


yuTitmoy lycREASED. 

the normal gland which distiiiguish an adenoma from a localanf 
enlargement. The latter swelling remains in intimate relattoB witi 
the gland, and is probably often of intlannnatory origin. 

The mo."ft frei|uent secondary change found in these tmuiTui 
fatty degreneration of the epithelium, which may give rii« 

I'lo. t'.6. 

Aileno-fllironM of ni" 
iHU*. X too, iwiucvd |. 

_ -I 

formation of Mmaii caseous ma.s.«es in the growth. Dilntxtion of 

.faccnle.'* and tiibule.s into cyats and mucoid eofteninflr ar* ^ ■ 

crMiimon. The origin of eaneer has several times been traced l»i ■ 

adenoma. J 

The word ndenoina has been used loosely, as already pointed •» ^^ 

to include all new formiitinns of gland-tissue. ] 

Adenomata occur in the following organs : | 

Mamma. — This is much the most common seat of adenoma. 

rather of adeno-fibnuiia : for a glandular tumor which is structural-^ 

indistingiii.-<hable from normal is very rare (Fig. ••4). 

arrangement of the epithelium, the number and •ise of tlie ^ 

the proportion of stroma, and the number of cells it cmtain* »• 

more or les.s abnormal (Fig. tJo), hence the name adeno-fibroma 

generally moat applicable. These tumors arc also called " chrobi 



Inittuiuiary and " adenoid." They are cncapsuled. are round, oval, 

[or lobiilated, and lie in or on tlie breajst. Tliey are of liard ela«itic 

Iconsihtence. Their section is convex rather than cuj»]ieil. It is 

[cither lobiilated and fibrous-looking, or shows distinct slits and a 

iTacfmose structure even to the naked eye. The(<e tiituors are most 

[common in early life. They may be multiple. Many adeno-fibro- 

Imata contain cysts, which may be very numerous, and vary in size 

I froni slight dilatations of ducts and acini to cavities holding some 

jounces. cysts contain yellow, mucoid fluid, which may l)e 

reildish or brownish from e.vtravasated blood. Many are lined with 

cylindrical epithelium like that of the gland-spaces, but others 

appear to be formed by localized soften in;;.'* i)f the stroma. .\t first 

they appear on section tike irregular au<l braiieht'd lissures, then 

like spaces full of fluid: in other ca«es they are almost completely 

filled by papillary fibrous growths projecting inward from the wall 

Fio. (16. 


WU«iy (tnnrth IilsIiIc iin tivnriiiii i \-i. |.r.iji i link- from its waU (wl. U I'nii.slKis iif loose 
"■ '•"•tlvp ijiotiu' iri, viiiitnlnlnic iniiny bnincluil cv\U ifrivt'n"<l by ii layer of coluniDur celU 
^""'"Inry proci'iuwM iirc iiunit-rnus (jn. ■ 4<i. ri'iliiced i. (Boyil.) 

•*"• Covered by cubical epithelium. These cystic growths are called 
''^^c adenomata, or, if the stroma is richly ccdlular, cystic 

''"' non-cystic growths must be distinguished from local and 
general hypertrophies of the gland. 


Ovary.— Many compound ovarian cysta are reAlly cystic tubular' 
adi'iioiniita. und often contain pajiiliary jjrowthf (Fig. ♦»•>). 

Testis. — Xo pure inlcnoMiuta occur, but only mixed tuuiutx liia 
those in the parotid gland. 

Prostate. — In advanced iigi- sonic of the tuiuor!( Mbich form iB 
thi.s body contain gland.* a.« well siS muscle and eoiirifctive iiwiie 

Thyroid. — .-Vpart from the hypertrojdiy of en<ieniir piitrr tni 
Graves s distinct encapsuled tuiuori* having the structure <•/ 
the normal thyroid may occur in the substance of that gland. 

Parotid. — Purr glan<lular tumors are infre<|Uent, a«fi the glsorf- 
opitlieliuui of such tumors as do occur is genemlly very atypinL 
Fibro-adenomata are commoner. The oniiiKiri/ "parotid tumor ' i* 
*' mixed." containing cartilage, mucous and other ti»8ue«i. Thciitbw 
salivary glands are still less frpijuently nflVrted. 

Liver. — Small encap-sulcd tumors having the structure of the li** 
have been described. 

Glands of Mucotis Membranes. — ninnd-tissue enters U: 
into the struct\ire of some of the '•mucous" polypi, which 
spring from any mucouB membrane, especially in cAtarrhal sts< 
In some case."* it is probable that the glands primarily enlarge. tl»' 
project, and finally become polypoid. In other cases it in sup|: 
that locali/e<l increase of connective tissue from iuflauimuiion 
lead to increase of the e|iithelial structures in relation with 
Polypi of the nose, stomach, intestines, rectum, and utervA 
examples. The connective tissue is soft and <i-<lcmatiiu.i ; the 
face is covered by the epithelium of the part. 

Sebaceous and Sweat-glands. — So-calle<l adenomata of 
glariils are iiniforui enlargements rather than tumors. Fig. 67 »i 
a small portion of a sebaceous "adenoma" from the chin of a cli* 

.Amimj: secondary changes are calcifloation which may af* 
the epithelial masses, and ossification, which may take place 
the fibrous stroma. Tumors undergoing the latter change are 
and have been called "osteomata " of the skin (p. 103)- 

Adenomata nffonl further support to (^ohnheim's view roocrrni 
the nature of maligtiancy (ji. 140). Adenomata and adeno-fib*^ 
mata are alinoMt invariably innocent. ( )cca.sinnally cbmi 
which clinically and microstopically appear to be ordioarr 
mata, but which re<-iir locally after removal. It is no explai 
to call these .sarcomata. Again, there are several 0M«8 on 



of the generalization of ovarian udenoiiiata as well as of tumors 
having the structure of the normal thyroid glaml. 

The lumina of racemose adeiionuttii are sometimes filleii up with 
epithelial cells; it is then impossiFjie to distinguish them micro- 
scopically from scirrhus in its earliest stage — that of multiplication 

Fio. 67. 



' -i^ ' V : •' i 



l^'bulp gf a scUarpoUB Hdonumii ; r.r ciintiepUvc liSKiie cnntniniiiK iniiiiy ii'Ms fiihI rnnnini; 
"lUe >uil iM-'ptn : r. B«i-iMiIc ftiU uf t-iittliL'Unl pelln, few (if which «h<i\v sliftid <if futty ili'^i'ii- 
(Unri— « i-leHr xjiact-, )iiuliliig niirliMiii nsldc. In larger Mfi'ules di^i'iiiTiitioii is more 
l»Oer«l and extreme (/. '.) ■ aoo. iBoyd.) 

epithelium. Indeed, the origin of cancer from adenomata has 

<'n proved several tiaif.'», both microseojiicallv ami clinically. 

Aa sarcoma-tissue passes insensilily into fihrous. it is often im- 

I'Wsible to say with certainty which name — adeno-fibroma or adeno- 

*»rcoina — should be applied to a given tumor containing gland-tissue. 


^VThe Carcinomata, or Oanccrs. are, of all new formations, the 
^feust atypical. They are made up of cells of the epithelial type 
^^""ped irregularly in the alveoli of a more or les.s dense fibroid 
r«troma. The "epithelial type" implies origin from epibla** or 
'•ypobliist anil the absence of intcrcellulur substance; it doc« ui»t 
""I'l.v any specific form of cell. 
Tilt- alveolar structure, as seen in sections, has CMUcd it to be 
•111 that cancer is an atypical gland-structnrc. Etctt taaor i» 
">'pical mor|ihologically and pbysiolDgically ; almost all arpMVtroe- 
"i^lly. In cancer we have epithelial cells, often «f the 



abiinriiiiil form, filling up the liiiniiin of g1;in<l-tiilH*!» (tfit 
from u ;;liiiiil). )>iir!<tiiig through their'mi-nt or liiuiliD^ 
brane and ramifying in the s|iace of connective tiraue. Th 
type for such a process as this is the development of a glsnj 
the liver) by the growth of s<did hypoblast ie rods into a mcmt 

(ktli tram n •rirrhoi of 

STRUCTURE.— In rli-iding with the microscopic Btnic 
have to describe, first, the e|iittielinl cells; ami. secondly, tbc 
which form» the spaces in which they lie. 

The cells arc characterized by their large sijse. bv ihr "31 

of their forms, and by the magnitude and ]>roniiueuce of 

nuclei and nucleoli (Pig. 08). TIm 

''"'■"''• round, oval, fusiform, caudate, or jwl; 

^jA'^^^ — exhibiting, in short, every iliven«ity 

^I^L ^9 BBl line. These variations in form arc priui 

owing to the mutual pressure tu which, ii 

growth, they are subjected. The nm 

large and prominent, round or oval in 

and contain one or more bright uiicitfnli 

nuclei are perhaps most frei|uenily i^ing 

two are often met with, and in the s«jft 

more rapidly-growing cancers there may be more. The « 

loosely in the alveoli, and no stroma passes between thrni. 

rapiilly undergo retrogres.sive changes; hence they usually 

molecular fat. Sometimes so many have been destroyed th 

free nuclei are visible than cells. Cells precisely similar to 

are mot with in other morbid growths and al.«o in the nnrtnal 

There is thus no »pfcttic ■"cancer-cell." 

During the last few years the minute structur© of c»nc 
be<'n subjected to a very rigiil examination in scarcb for anv 
site that may be present. Nearly all observers are agree< 
when suitable {strtions of cancerous tissues arc harden 
stained by special tuethods pecidiar a|tpearances, the signi 
of which is still in di.spute. an; to be seen. These are kn 
"cancer-bodies" or "cell-enclosures." They vary greatlj 
Iteing on an average sontewhat smaller than red corpuscles, 
arc encapsulated, anil for the most part spheroiilal : they 
sharplv-dcfincd outline. They possess staining affintLic!* ho 
different to those of the ordinary cells of the growth. Thoir 



i» geuerallv roiiinl (ir oval. There is usually but one, ami this may 
be ciiurn'Cieil utlh the t«.'ri])her_v bv faint rays (.Figs. 69/', auiiIiJ<'^ 
The I'uiHHT-bodies eoinmouly multiply by binary division: the 
occurreiiee of sporulntioii. Jiltiiou^ili .'iffirtnetl by some, is dcninibv 
most. TLey are usually Ibuiui enclosed in the ordinary cells of ibe 
growth, but they have been described in the alveolar spacee outside 
the cells, and even m the lymphatics of the alveolar walls. Tlirir 
position has no ascertainiihle influence on their general char«cti'r»- 
As a rule, no cancer-cell contains more than one of them. Tlic 
cancer-body may occupy only an insignificant part, or it niay fill 
nearly the whole of the cell and displace the nucleus to the [pe- 
riphery. Still umre rarely these bodies may be found, singly "f in 
numbers, in the nucleus itself: in this case they are gcncnillj 
smaller than when found elsewhere. 

The cancer-boilies are most comnion in growing edges uiiil in 
secondary deposits, and are rarely, if ever, found in degcinTsicJ 
parts. On the other hand, there is no evidence that thoy oxciw 

Kio. 71. 

/■ P 


Canc'irlxvUi's xhowltit; jinilmWc mi-thoda of repnxliictliin : (r) yurloiis of |*r»»l* 
dlvldlUK, and Ihu coriuwtlTiK tliri-adn are shown. ■-; ti«10.— <«) DlvUilon of nuclrtiit aJi'l 
w»U Ik cumpli'tv. v. film.— (hi 1'iirui.lii' Kli<>wini;K''i>nuUii> at the ptTiphory of the ci-ll. 
—(f) Coninicnrine tn'urmi'iitnltoii <•( |>imu>lti-. Bhowlnit a acaUopfil luanrln. each 
which contains a iKirlion of Ihi- frntintMited niieUnu. X HKKI.— irt) Cell niiitalnlni a ell 
of Hmall iwrHBllcrt, prcHiinmlily n laicr Mn^v of the proovKS soi'U In (rK V Iijii— OiIDl 
thcuc with drawing of malarial [laraiiltcii. (Spvclnif n and drawing by Dr. Kulhr.l 

any unusual activity of growth in the cells containinir them, '* 
they degenerate they lose their sharp contour : and Ruffer !»** 
drawn attention to the fact that this not iinfrei|uently bsppe"^ 
when a leucocyte invades a cancer-cell already occupied by one o* 




[these "cancer-bodies."' The imture of these boilies is discussed 
[on p. 11I5. 

The Btroma varies considerably in iiitiounf. being much more 
I abiindaiit in some specimens than in others. It consists of a more 
lor less distinctly fibrillated tissue arranged so as to form alvenli of 
I various shapes and sizes, within which tiie cells are groujied (Figs. 
1 7'2 and 74). It is not closely connected with the cells, and none 
l)enetrate between them. These alveoli communicate with one 
■nother, so as to form a continuous cavernous system. The cha- 
! racters of the stroma vary with its rate of growth : if this is rapid, 
[•' ■will contain some round- and spindle-shaped cells (see Figs. 76 
i»ndSl); if, on the other hand, it is slow or has altogether ceased, 
"»e tissue will contain few or no cells. 
"lij will be denser and more fibrous in 

Eiararter (Fig. 74). The latter is the 
ndition in which it is most commonly 
et with. 
In the stroma are the blood-vessels. 
aese are often very uumentus, ami 
foi-ni a close network round the alveoli, 
rin-yare limited to the stroma, and never 
■i)ti3s into the epithcHal This 
Histriljution of the blood-vessels is im- 
Bportant, as it serves to distinguish the 
^ can-inottiata from the san'omatu (p. 1 (»!)). 
To alveolar .sarcomata and tiiiiiors s[irtng- 
ing from endothelium this ride, however, does not apply. 

Lymphatics citmmiinieate freely with the alveoli. This explains 
the great tendency of cancer »o infect the lymphatic glands. In 
"•'t. the alveoli may be regarded a.s dilated lymphatics, fur the 
•"Iiithelial columns grow along lymphatic spaces — the lines of least 


Ttie alvt'olar stn^ma from a 
acirrhus of tin- niumrnu. The 
I'lMls liMvu boon ri'iuiivi'il !)>• pcn- 

cuiing. X aoo. 

ORIGIN. — The question of the genesis of carcinoma involves 
tlim nf the genesis of epithelium generally. It is iii;iintiiiued by 
"•""l liistologists that epitheliuiu can originate only fnuti epitltelium, 
*iu that the epiblast and hypoblast are the sources from which all 
'puhelium is .subsequently derived. Others state that epithelium 
"iiT originate also from connective tissue. A like dift'erence of 
cpinion exists as to the source of the epithelioid cells of cancer. 




By iniiny tliev are rririinli-d as (iri^inntiiig only from |»r^-ipv 
e|iitlii'liuin. Otla-rs muitituiii tliat tlioy luay b«' diTivcil •!«> 
cells belonging to the connective tissue. It is aUo bclicTcd bt 
some tliiit niiiny ciiru;ers originiito from tlie endotlifliiim of tli» 
lympbutics — /. c 8])cuiuliy.etl connective-tissue corpuscle*. 

Nearly all nioilem observations tend to support the epillifliil 
origin. This renders it impossible for true cancer to arise in «o« 
mesoblastic structure. Cases have been re|iortetl of primsr)' vncrt 
in jynijibatie glands, in bone, in the nienibranei> of tbt> brain. io<l 
in other places. Of these cases there are three possible expliw 
tions: (1) some snnill primary jjrrowfh, which g.ivi- rise lo n 
tom.*. may have bei-ii ovf-rlooked ; (2) some ubn<irriiality in 
existed, such as a detaclied piece of mamma lying near the axill«7 
giniids or the ftetnl iru'liision of an epitlu-liiil rtidimcnt ; ' 
growth may have been one of those sarcomata which can I" 
guishe<l from true cancer only by the closest examination ami k" 
i-areful inquiry into their development (alveolar sarcomata, cjlin- 

Epithelial cells are said to occur round a cancer quite iwUl**' 
from it. They lie in the connective-tissue spaces. The isoltttiun '» 
very ililTicult to prove, and <loes not necessitate the origin of tB"" 
ci'll.H front connective-tissue elements, for the cells may havt* b»«« 
carrietl by the lymph-stream, aifled by the spontaneous mo't' 
ments ntited in cancer-cells by (.'iirnuilt. (Iften delii-ate cluittf™ 
cells oui- or lwi> inches long havt- bet-n traced bftween a w*'" 
growth and an apparently isolated nodule: such a chaio tui^* 
easily be interrupted. It is worthy of note that very few ctM* '" 
so-called primary mesoblastic cancer are nitir reported. 

It is most probable, therefore, that a cancer originatos eithi 
the growth of a resting embryonic epithelial rudiment (fob 
or in the multiplication of some epithelial cells. (Mher eondi' 
being favorable (p. 14rt), the cells grow through any basemC*^ 
membrane that may exist, and s|iread in the connective tissue 
lymph-spaces and channels. At this stage the epithelial 
actually lit- in the lymph-current, where they wouUI nat 
multiply very rapidly, being bathed in nutrient flnid. In thi» 
glan*lular infection is easy to explain. Where resistance is 
the growing fcll-coiinuns nn- narrow : where it is sliirlit tbrv 

The connective-tissue bundles of the part .••re at first the 



of tbe stroma, but round-celled infiltration, probably 
nf more or less intense intlauiniatiun excited by tbe 
Invasion, soon appears, and is followed by fibroid tissue 
Tacts. At other elements of the part nuiy also pcr- 
etrowa — ('. (/. fat-cells iti the breast and tiHisele-fibre.« in 

mode of growth tbe Cttrcinomata never beeome enciip- 
jraduiilly infiltrate Hiirroiiudinu striietiires. This j)roe.e8S 
ion i.< very eliaracteristie. and is more markeil iu cancer 
iT of the malignant growths, A zone of small-celled 

is wen for .some di.stance around the confines of the 
liat there is no line of demarcation between it and the 
ucture.s (Fig. 73). 

at jiresent no general agroeiiienf concerning the nature 
,ncer-bodies " before describi-d. or tbe jiart tliey take in 
and growth of cancer, lltiffer coni[)are.s llieni to the pro- 
ilnria (see " Malaria "), and by many observers they are 
he parasitic. Tbe evidence in favor of this view may be 
iri/ed : (1) their occurrence within the cell a.s a distinctly 
fetaoce; (2) their appearance, so strongly suggestive of 
leil structure: ('^) tbeir staining reaction.s. .so distinct 
I presented by the normal contents of cells; and (4) 

analogy to well-known species of sjMjrozoa recogni/ed 
P.S of epithelial proliferation in the intestine, bile-ducts, 
>f certain animals, — all point forcibly to the conclusion 
liodies, though not necessarily eoecidia, arc nevertliel<'ss 
Dd are parasitic in cancerous epitlieliuui.' But tlieso 
\ no means jiass uncballcnged. It is niaititained that 
*.«ie so-called parasites arc nothing mitre than the appear- 
nced by the invagination of a part of one cell by the 
ft substance of another, as might be seen in a section 
Igh the invnginating cell [larallel to. and just below, the 

ugh which the indieddod cell enters (Fig 70, <•). It is 
y others that enclosed leucocytes and ilegenerative 
ve in like manner been misinterpreted. A still more 
Ipported suggestion is tiiat these bodies are really due 
I0U8 formations in tbe originul cancer-celU. This may 
\r from an arrest of the process of direct division (ami- 
Vm some irregularity in that of indirect division (mitotic, 
kalluwny •. Morton IjW-tiire, Bvil. Hftfl. Jnurn., vol. i,, 1S93, 



karyrikinetic). Round ji detacheil portion of chromatin » cell 
forms ami grows rapidlv, but remains a daugbter-Cfll within iLf 
substance of its parent. If this be so, it is difficiih to see «bT 
(laugUttT and parent .should present any marked difterence.s from 
one another in their staining reactions. 

These various objection.s may doubtless e.\{>lain many of tiir 
appearances described by over-zealous advocates of the pnmsilic 
the<:>rv. but there remains a considerable residuum not so ea.sil_v Jis- of. In the nicjin time mucli of the argument depends on it* 
experience and authority of the difl'erent observers: and until thf 
existence of c!)!(r!ictf'ristic spores has been definitely made (iiil. "f 
until there is forthcoming stich cotifiriuiitory evidence a.s cheniisirv 
!iiid iuoculiitioii and cultivation ex]>eriu]ent8 can alone supiiWfp- 
145). the iiiter[)retation of the ii)>pearances described seems likfh 
to remain more or less in dis|uite. 

SECONDABY CHANQES.— The most im(K)rtant is fctW 
degreneration. This occurs in all the varieties of carcinoiiin. The 
more rapid the groxvth. the earlier does this retrogressive cb»iig* 
take place and the greater is its extent; hence it is usunlly m"*' 
marked in the riirr/ilmlni'il form. It produces .softening of '■"' 
growth, uliich is often reduced to u l>ulpy cream-like cnusislcnC'J- 
Hemorrhage, pig-mentation, mucoid and colloid degenerate*''' 
may also occur, with cyst-formiitioa. Cysts may be due al^' 
blocking of ducts — c. </. in the manume. Calcification atul t*^* 
ossification are very rarely met with. Formation of an abaoefl* ' 
rare, but important. 

VABIETIES. — The varieties of carcinoma are arranged on •^ 
anatomical basis. The cells vary markedly in character accor J •'^' 
as they spring from stratified epithelium, columnar epitheli «• 
or the epithelium of acinous glands. They inherit, to a gre*** 
or less extent, the form and temlencies of the variety of epithel*** 
from which they ofigiuate. Thus, colls of cancers springing ft'*' 
stratifieil epithelium tend also to undergo the .same epithelial evf»" 
tion. ending in cornification ; anil in many eases they show priclc ' 
cells. Columnar epithelium id'teu retiiins its typical form and «-• 
tinues to surround open s]jaees; but in other cases the cells mill 
ply so Hs to fill the spaces, the outermost cells generally retaining 
cylindrical shape. Cells of acinous glands undergo no evoliitioC* 



Y muUipIicatiou thev produce cells of their owu kind, which may 
much iiltfrt'tl ill nhape by raiituai pressure. Upon this reti-ntion 
>>y the celln of ancestral unatouiical ciiaracter.s the (•iiief varieties of 
cancer are based. Thus we have tlie squamous epithelioma, the 
columnar epithelioma, and the acinous cancer. But ancestral 
peculiarities are not always retained. Certain cancers sprinjijing 
frnui Kirntified epithelium — perhaps from the .hiiiiiII glaruls in rela- 
tion with it — undergo no evolution and are imlistinguisliable from 
wirrlnis, while tumors springing fmni (•iilnnrtiav epithelium are in 
raanv |mrts exactly similar to acinous cancer. 

In all varieties of carcinoma the secondary growths tend to repeat 
tlie pcctiliarifies of the primary, especially in epithelioma. In scir- 
rhiw the secondary growths in internal organs, though sometimes 
rwcmbling the primary tumor, are often more rapidly developed. 
Further, they are softer and more vascular, so that, in accordance 
*ith till' artificial distinction between scirrhus and encephalnid (p. 
201), fhev must be regarded as belonging to the latter variety of 

The name epithelioma was given to cancers springing from the 
*I"tlu'lia in opposition, a.s it was thought, to the cancers of connec- 
ti'Miwue origin. The distinction of the forms is of iniicli less 
iitifiortance now that the epithelial origin of all is couiing to be 
more and more recognized. Still, the histological differences 
■"^'wei-n well-marked cases are sufficient to justify a separate 
'Iwcription of the above varieties. 

'arciuomata are accordingly divided into two groups — acinous 

cancer, with m-irrhuuii or rhronic cinicrr and ctirrfiliuhiiil or nmti' 

fitnfer as subdivisions; and epithelial cancer, including Ki/tiiinKnix 

*^'i cnluinniir i'f>it/ieliointt. Of these, coluiunar-celled epithelioma is 

""*' allied in structure to inlcnoma. < o/lniil or jii'lutlni/unn i-an- 

'''■• due to colloid degeneration of the ciini cr-eells, was formerly 

'•'^ardcd as a sid)division of aciuoiis csiticcr or even as a separate 

'■"■ifrty. but all the above varieties may undergo tliis form of degen- 


^^tJNICALi CHARACTERS. — Cancers occur with increa.sing 
'J'lcDcy after the age of thirty-five; below that of thirty they are 
** tumors. The primary growths are almost always single. They 
' *nioDg the most malignant tumors, there being little ground for 
'Ce between them and the .sarcomata as regards their mortalitv. 



As a }»ro(ip the cancers grow rapidly, widely infiltrate aurroumlinj; 
jiiirts. curly iiiffct lyni[ihiiti(; ^I.'iiuls ((). 193), and idtimately hfcoiiio 
difsouiiuatiMl gfiienilly tlirouglmiit the system, liiless ejcciseil very 
early and very freely thov recur in loco. They freouentlv lirctk 

• • * • (la 

down and give rise to very offensive sores which bleed rt'inlily. 

It will he reuR'uihered that while the sarconmtii us a «;roii|Ml"iint 
infect lymphatic ginnds (p. 172). they are siip|)08ed to genrmliir 
more early and more readily than the carciuoiuata. The rensnu It 
this is that the surcoina-cells fvcijitently form tlie very walln of ti» 
blood-vessel, whilst the cells of'euucer.s do not even come int» eim- 
tact with tin- walls uf the vessels. 

Just as the sarcunialii vary in malignancy, so also do the carciii"- 
mata. On the wliole. cnceplialoid is more speedily fatal than wir- 
rhus, owing to its more rapid growth, greater vascularity. andnnTf 
active epithelial elements. Colloid degeneration seems to diniini^li 
malignancy. Every now and again an encapsuled tumor i.* nici 
with, especially in the soft palate, showing no sign of inaligiwnfy. 
yet having the structure of acinous cancer. In the variety kiio»r 
as atro])hic scirrhus the duration of the disease is not uncommonly 
from ten to twenty years and the e.xtension only local and glandnl**"' 

Epithelioma is, jmthologically, mncli the least malignant oft"* 
cancers. It extends locally, breaks down early, and often inf**^** 
the neiirhborinjt Ivnipliatics, hut it comicirativelv rarelv reprodu*^*- 
itself in internal organs. Thi.s is jirohably owing to the sixe *** 1 
clianicter of its epithelial elements, which render them much ■* ' ( 
liable to tnmstiiissioii by the blood- and 1\ mph-streauis than *"_ ' 
cells of the other varieties of cancer. Its malignancy v**** 
curiously with its seat: thus, on the skin of the face epitheli*^' 
ha.s genendly a very chronic course, and rarely affects even 
glands: on the lip early excision gives a fair chance of cure: 
the tongue its is often so rapid, aflection of the gland* 
enrly, and citchexin and death so .speedy that it must be rankc«» 
one of the most nuiligiiant timiors. 

1. CHRONIC CANCER or SCIRRHUS is charactcrixed ]'- 
be anioutit iind density of its .stroma and by the slowness of ■ 
growth MS ccimp:ircil wiih that of ence]ihiiloid. The latter fH**** 
arohnbiy accounts in great measure for the peculiarities in its stri**^ 
tiirc and physical characters. 



Tlie epithelial growth, although Jit first it may be luxuriant, 
"Quickly subsides. The elements soon atrophy and undergo fatty 

Fig. 73. 

'*»-lrThu« nfthe miimma : « ii««tlon tbinuBh the vCgv of ttii' tumor, nhowlnK the DmaU-oeUed 
^aaitntliiii iif thv niuwulnr ntinA unrladlpuau tiwuv in thu iii-lg)ib<irhoo<1 i>r thi; kIauJ. 

"i-V aw>. 

metnmorphoHis. They are most abiiiidiuit in die external portions 
^^ t\n' tuninr where growth is tali lug phiw ; in thu funtral jxvrtion.s 
'bey may be almost entirely wanting. Figs. 73 an*! 74 show the 
»p|H>nrance8 presented by scirrhus of the mamma in the earlier 
•ittjL'fx of its development. 

Tbe defeneration of the e])jtlieliiil elements i.s prohiihly tine to 

"Miteration iif the vessels by tlie seiir-like contraction of the stroma, 

*'i)cli ijuiekiy becomes hard and indurated. In this way growth 

"' thut part of the cancer is arrested. The whole of the central 

/"^rtions may thus ultimately consist of dense fibroid tissue, amongst 

"•Tr»i„„ ,,f II,,, i„»iiiiiiii H pi>ni>iii of iIh' junior Koincwhat internal to that represented In 
* •'■'. (hoMlng thp C'banirtorlatic alveolar strucluru of tlie i-aucer. - auo. 

"'cli are scattered groups nf atrophied ejtithelial cells and fatty 
I ,. *•■>» (Fig. 75); but even in these ca'ses tlie epithelial structure is 
^ ***'tictly visible at the periphery. The amount of atrophy and 
I **-t*artion varies considerably in ilifTerent cases. 
, I * «»e physical characters of scirrhus are in the same way due to 

^ *«.bHudance of its stroma. The growth is firm and hard, and is 
*«*lly depressed in the centre, owing to contraction of the fibroid 

^Uv and atrophy of the cells. Thi.s is very characteristic of 



scirrhiis of tlic breast, wht-rc it causes retraction of the nipple irnl 
puckering of tin- skin. Tliu growth is verv biinl and i'r<'aks as il 
is cut. TLe surfucc of the section i.s generaliv " cupped." nnil'if 
grayish-white, semi-translucent appearance (" like an unripe }H'ar / 

Fio. 76. 


SoliThiiBnr ihr mitniuiii: a m-cUon frimi the more centrni inirtlonsof tho turoor.tho»"< 
the utrt'iihy of tin- epHlicltul I'flls.thertliuiuutloii liuliv iti/i' of tlu- alveoli, Ihe BliwM 0»»»'. 
luul iIr' rutty ilObrin. u, rurliur stage; b, luon.' lulvimi'ist. v 'JUU. 

It is more or mottled with dots and streaks of opaque vrll''*' 
due to fatty epitbeliuu) in alveoli or milk-ducts. The latter W*J 
be cystic. The central part.s are pale and fihroid : the more extern** 
are pinker, because contraction lias not obliterated the vessels, ***' 
less finn than the central portions of the growth. They yicM. '* 
scraping, a juice which is rich in nitcle!ite<l cells, free nuclei, *** 
granules. The outlying parts of the tmnur can he brought •' 




view by the local application nf a /"> jier {'cnt. solution of nitric fc^ 
Opa<(ue white lines murk the affected areas. 

By far the commonest seat of scirrhus is the female breast, t * 
also found in the mule breast, the stomach, the liver, the pancr 
the prostiite, the skin, and the mucous meinbriiues. where it «i 
from racemose mucous glands. The .secondary growths to wbict*^ 
gives rise are often encephal(ii<l. 

•2. ENCEPHAIiOID or ACUTE CANCER differs from 
preceding in the greater rapidity of its growth, and in the oon^-^- 
<]Uently smaller amount of its stroma and greater softness of its 
sistence. Eiice|tliiiloi(l and scirrlius uiinttot be regardeil as in a - 
way constituting distinct varieties of carcinoma. There are mas 
interuieiliate st;iges between them (scirrho-cncephaloid), and all the 
structural and clinical difl'crenccs arc accounted for by differcuccii 
rapidity of growth, which probably depends upon the vascularity c^^ 
the part in which they arc situated. 

The cfiitliclial growth in encephaloid is rapid and abundant; ll^ 
cells, which may be either larger or smaller than those in acirrhu^* 



Kiii. 7(>. 


quickly undergo fatty tlegeneratiou, so that often there are more free 
nuclei visible tlian cells. 

The j)rop(irtioii of stroma is very bidjiII, lunl. owinfr fi> tlie nijiidity 
of its growth, it i.« much less fibrous than that of seirrhuB and does 
not undergo a similar cicatricial omtnictioii (Kig. T'i). The blood- 
vessels are often very abundant and the tissue supporting them is 
»oft and non-resistant. Hemorrhage 
into these growths is therefore fre- 

Encephaloid cancer is of a soft. 

brain-like consistence, the central 

portions, where fatty degeneration 

IS most advaneed. often beinj; com- 

pletely diffluent. The tuniDC is sonie- 

titnes more or less lohulated. On 

w?otion the uudegencrated (larts are 

S^^y, pinkish, soft, and translucent, 

''hilst the degenerated form a white Emcph«i..ici ...nrer ifr,m.«i*eeondury 

l"'lpv mass much resembling brain- '''nnr „r thu Uvir. shcwinif the iur»e 

. - 1 • 1 ■ r 11 "''"^ "^ ""•■ "l*'*^"" ""'1 'he thinmsas of 

»'« "Stance, which 18 often irregularly ihi-irwaUx. in the iihut small. wu are 
«aiued with extravasated blood. " '■'»"''^-'- J^'' ''"i:"^'!''"'''""! "'i'' »«> 

-C'nccphaloid is much less eotnmon phmis. •: ax). 
*uau scirrhous cancer. It is most 

n"e«^uently met with in internal organs as a He<-ondary growth. It 
'^ Sometimes jirinian/ in the testis and mamma. It may fungiite and 
oleecj (fungus hicmatodes). Many growths formerly described as 
cocephaloid cancers were really soft sarcomata (see p. 173).' 


1- SQUAMOUS EPITHELIOMA cnnstitntes a tolerably dis- 

j?***^t variety of carcinoma, but tiansitioital forms between it and 

^'*~*'liu8 arc occasionally met with. It always grows from a surface 

overed by squamous epithelium, either cutaneous or mucons (the 

J^'Hction of the two being a cuninion seat). Its epithelial elements 

ciosoly resemble those of s(|uamoiis epithelium. 

•he cells (Fig. 77) are often coiisiilerably flattened and distorted 

?*' "bape, owing to the pressure to which, in their growth, they are 

l*uhjpeted. The cells grow dnwn from the surface epithelium into 

"^ lymph-spaces of the conneetive tissue, and. [lUshing their way 

*lotig these, are formed into solid cylinders, which twist about, branch. 



Via. 77. 

ami intercommunicate — ^swellingoiitatsome ))ointsnnd liccotniug con- 
stricted or even iiiternipti'd at otliers. Single epithelial cells nwj 
be recognized here and tiiere, evidently swept ou by lymph. Tlit 
rods cut acro.ns a|ipear as round or oval nntt^seH of cells, of whieli tiit 

oiiterniuHt are usually large, irhilxt tb» 
eentral are more or less (<i]namous ami fnrtii 
a yellowish oiiiou-like ma.«s. Sonii'iimw 
the central cells a|)pear large and vesic- 
ular, the outermost are scaly ind 
llattened. The.><e concentric mnsm-s of 
cells are culled '■'■ coticmtric i/l<^»" of 
'■^ 4'fiitheh'(i/ tirstit." ani\. though not Ji*- 
tinctive or essential, they are cxcccding^J 
characteristic of epithelioma. The «*W»m«nc.pUht.ll»m.oftl,e fo,.„ii„g il,„„ ^^g „„,„11^. ,„„^ „„,] ^»V 

lip. .< JIM. ^ • • _ 

be so closely packed as ultimately tu »■»*' 
come hard and dry like of the nails and hair: the globe** ■ 
then of a brownish-yellow color and of a firm consistence. T^* 


Fio. 78. 


E]iillK-Uuinu III lla- Up, sliiiwliit: llii.' iiiiiuunlrk' k'u'i^'i »' epilliL'Uul rvlU 


globes are often lar;ie enough to be readily visible to tlie naked vy 
and. owing to the onion-like arrangement of the cpidennii- *'•*!( 
they usually present a fibrous appearance. 

The stroma presents every vtiriiition between nipidly-prowin-j: 
embryonic and an inci)nii)letely-fit>rill:ite<l tissue. It may be tolera- 
bly abundant or almost entirely wanting. It rarely forms siicli a 
mni'ked alveolar stnictiire as that wliicli cliaracteri/.es tlie ntlier 
vuiclies of carcinoma, and consists siin|dy of tlie fibi-ous tissue of 
the part more or less intiltraled with small round-cells, which may 
Itf nltimately replaced by eormeetive tissue (Fig. 7!l). 

The development of epithelioma is due to the down-growth of 
tlie surface epithelium of skin or of certain mucous membranes into 
the connective tissue and deeper parts, as is described on p. 184 

I'Ki. 73. 

'^«tk«||oni» nt ihe toti^if : ■ vertical UTtlon, nhnwinR exceailve e|iltlielfal growth u|ion 
*r ***»"li»oc .if the i>iiiUn»' unci fXtru.Hli.ii uf the celln Into the aulijiioi-iit oumieetlve tluiir. 
«*"'*'''""•■""' tlwiK' U liiHllrul«-i\ wilh siiiull cfUa, uiiiiiiin: wliirh are single epithelial 
'*"»'«tnl"ooneenti1i'(tlo)jc»." •; 100. 

*^'R. 70). The tendency of epithelinma is to bnak ilown at an 
'"7 stage: this is due to fatty degeneration <A' (he cells, and not 
'" 'f flammation. 



Epitbelionia usually presents itself as a small hard ulcer, or ii 
an iii(liirii1i.'<l fissure, or as a subcutaneous nodule wliieli siibw- 
((ueiitly breiiks down. The surface of the ulcer is irregular, and 
may be sloughy. It is often clean, and covered by large, firm, 
hhiish-red {iranulations, consistiuj; largely of epithelium ; more 
rarely the surface is mnrkcdly warty. The tumor itself is firm in 
consistence, often more or less friable, and on section present* ■ 
grayish-white gruiitilar surface, sometimes intersected with linefl of 
fibrous tissue. The cut surface yields on jire.ssure a small ijuantity 
of turbid !i((iiid. In many cases a peculiar, thick, crumbling, curdy 
material can also be expressed, which ofYen comes out in a worm- 
like shape, suggestive of sebaceous matter from the glands of the 
skin. This niutcrial is very characteristic. It is composed of fatty 
epithelial scales, and on being mixed with water it does not difTnse 
like the juice of other cancers, but sepurates into minute visible 
particles. If it is very abui)(biiit. the cancer is soft and friable. 
and the material can be seen on the cut surface as small scattered 
opa(|ue dots. 

Irritation has more to do w ith the cau.sation of epitlieliomn thau 
of other kinils of cancer. Some, such as cancer of the scrotum from 
soot and e{)ithelioma of the arm in workers with tar or paraffin, 
appear to be due simply to irritation in people the phy.«!iologic«l 
resistance of whose connective tissue is diminished until invasion 
by epithelium is rendered easy. Other epitheliomata occur at 
points where, the process of develo])mcnt being complicated, errors 
;ire likely to have <u-cuvred. These places liave been alreadv enu- 
merated (p. 142). Miiny of these are points exposed to irritation. 
S<|iiauious epitlieliouia usually infects the lymphatic glands, bat 
rarely occurs in internal organs. 

Rodent Ulcer. 

Rodent Ulcer deserves a short notice. It is a form of epithe- 
lioma beginning as a pim|de ujion the nose or check, and liable to 
freipient irritation from rubbing or picking. After a time it breaks 
down, and (he ulcer thus formed slowly .spreads, destroying crcry- 
thing that it meets, including bmies, and jjroducing the most hid- 
eous deformity. This may go on for many years, the health re- 
maining good and no gland being affected. It differs from ordinary 
eijiiiimous epithelioma cbielly in the small size of the cells, iu the 
absence of prickle-cells, in the slight tendency the cells show to 



lome scaly ami to form iiostts, and in the case with which the 
[epithelial coluuius can be traced (Fig. HO). Some believe that 

^^ KcMlonl ulcer of n>wv, Tbc patlunt hnd ■iiinll rodent ulcvra of the nose and cheek and in 
rl> v|«llli«Iioum iir the Up. ^ 50. iBoyd.) 


rodent nicer lu-gins in the root-sheatliN of the hairs or in the gland- 
©pitlieliuin of the skin. In some case.s liuving the elianicferistic 
history of rodent ulcer the struct utc is that of tyjiicnl eijithelioma. 

CA_NCEB. — These terms are applied to those forms of epithelial 
c&ncer which grow from mucous membranes with columnar (cylin- 

Fio. 81. 

rjrllndrlcol epltheUoma (firoia the colon), x 2D0, reduced (. 

tiricul) epithelium — ^. </. the stomach and intestines, and especially 
the rectum and uterus. In these tumors the epithelial elements are 



vsimilar to those of the mucous menibniiie from whieh tV 
They are cylindrical iu Mliape. ami are arrangeil perjivnii;- 
the walls of the alveoli in a manner precisely aualogotie to tliat of 
the columnar epithelium on the mucous surface (Kip. 81). Tli« 
slower the growth the more typical the glaiul-formatiun. In rmpid 
growths and reeiirreuces the cells are small and the lumiua iinper- 
feet. The latter may be filled up. and the growth !)»• indii<tingui«ii- 
able from acinous cancer, except by its edge, where u low culumnar 
or cubical form usually iiersists; hut this too mny W lcM>t. Tbr 
growths are of a soft and ofken gelatinous consistence; thov show • 
marketl tendency to undergo colloid degeneration. Tbi?MJ tiuuon 
cause secondary growths in the lymphatic glands, and somctiaci 
in the liver, luugs. and boucs: the secondary tumors po wacat the 
same characters as the primary cancer. The distinetioii Wtwccft 
adenoid cancers ami simple adenomata de|)eud8 u|K>n the inri 
of the neighboring tissues by the former. 

OoLLotD Cancer. 

Colloid or Qelatiniform cancer is simply one of the pnwedilig 
forms which has undergone u mucoid or colloid change. S«m>- 

Kio. «. 

r'nU')t<l ranrvr. ihnwlnic ihv Iktiiv iilvcuU within whipli te ounMaed Uw | 
tnaliTlnl < :nO. (Klm1l1ct»cti.| 

matou* anil other non-cancerous growths may undergo the 

The alveolar structure in colloid cancers is very marked. T 
alve«>li have verv thin walls; tbcy are large, distinct and more 


less spherical in shape. The large size and distinctness of the 
alveoli are owing to their distention by products of degeneration. 
These products form a gelatinous colloid material which is glisten- 
ing, translucent, colorless, or yellowish, and of the consistence of 
thin mucilage or size. In the main it is perfectly structureless; 
within it, however, are imbedded a varying number of epithelial 
cells (Fig. 82). These cells present a peculiar appearance: they 
are large and spherical in shape, and arc distended with drops of 
the same gelatinous material as that in which they are imbedded 
(Fig. 82). Many of them display a lamellar surface, their bound- 
ary being marked by concentric lines. It wouhl appear that the 
colloid change commences in the cells, which become gradually 
destroyetl in the process. 

In other cases, similar to the naked eye, the cells, with the ex- 
ception of slight fatty metamorphosis, arc but little affected, and 
the substance distending the alveoli is more viscid and mucoid in 
character. This is due to a mucoid degreneration (p. 82) of the 
intercellular substance rather than to a colloid change commencing 
in the cells. 

Colloid cancer is most frequently met with in the stomach, intes- 
tine, ovary, and peritoneum. In the latter case it is either second- 
ary or the growth is a sarcoma. The tendency of abdominal 
tumors to undergo colloid degeneration is at present unexplained. 




These tumors are congenital. They occur chiefly in the sacral 
region (coccygeal tumors) and about the head and neck — points at 
which double monsters are united — but they may be internal. Some 
of them are due to the inclusion and imperfect development of one 
foetus within another ; others to the abnormal development of the 
tissues of a single foetus. They are mo.xt complex, and may con- 
tain all the tissues of the body up to ganglion-cells more or less 
«'onfuse«lly mixed. They may be very large at birth or may not 
attract notice till later. Dermoid cysts belong to this group. 




In addition to the new growths already described there is n I«rgt 
clashi lit' foniiations. raany of which canuot be regarded as " tmunr'" 
in the .strict iijtiilication of tliis term. These are the cysts "f 
"cystic tumors." 

A cyst is a cavitv cnntiiining lifjiiid nr jiiiltaceoiis nmifrm). 
which i.s sejianUed from the surrounding structures bv a mnrc nr 
less distinct cafisule. It may be (1) a new formation, or (2)Bp»- 
exiating structure which ha.s become di.«tended either by it.* "»" 
.secretion or by the extravasation of some other fluid into it. ••nlj 
the former comes within the category of new growths; but forth* 
sake of convenience it will be advisable to consider them both i" 
the present chapter. 

There are thus two principal modes by which cysts origiDit*- 
The first and most frequent is by the gradual accumulation of job- 
stances within the cavities of pre-existing structures. These *a\>- 
stances arc, fur the most part, jiroducta of the parts in which thej 
are fnund. being it) some caaes a secretion and in others a oeU* 
growtii. The second and less fre(|uent mode of origin is bytb* 
independent formation of a cyst in the tissues. 

The accumulations of secretions and of other products 
within pre-existing cavities may be effected in the three following 
ways : 

Ist. By the retention of the normal secretion, owing to the rlosaK 
of the excretory ducts, as so often occurs in sebaceous glands. 

2d. By excessive secretion, the cavity being unprovided with »" 
excretory duct, as in the distention of biirsie. 

3d. By the extravasation of blood into the cavity, as iu hieBi*' 

The independent formation of a cyst may take place — 

Ist. By the softening and liquefaction of the tissues in eoD** 
particular yiurt, owing to mucoid or fatty changes. The ti»u*'* 
arouml the softened mutters become condensed, and ultiiuate'5 
form a kind of cyst-wnll, 

2d. By the collection (tf fluid in certain connective-tissue sp«cc*' 
and the subse(|uent enlargement and fusion of these spaces. Tp* 
surrounding ti.'*sue becomes ct>ntle!i.><ed and forms a cyst-wall : »'>** 
this may in some cases become lined with flattened connective-tis*"^ 
bUb (endothelium). 


CYSTS. 209 

3d. By the formation of a cyst-wall round foreign bodies, para- 
ntes, or extravaaated blood : the wall consists of fibrous tissue and 
is the result of a chronic inflammation. Smooth, heavy, sharp- 
edged foreign bodies are particularly liable, during the process of 
"healing in," to produce cysts of this character, especially when 
the parts are not kept at rest. Salzer has suggested the artificial 
introduction of such substances when adhesions are feared or a 
hlae joint desired. 

Straoture. — The wall of the cyst will vary in its nature accord- 
ing as it is that of a pre-existing or a newly-formed cavity. In the 
/brmer case it will possess an epithelial lining which will present the 
same characters as that of the gland, serous membrane, or other 
structure from which the cyst originated. If the cyst is of inde- 
pendent formation, there is at first no endothelial lining to the 
fibrous capsule, but one may develop later, as in false bursaj. The 
cyst-wall is sometimes firmly connected with the adjacent parts, so 
tliat it can only with difficulty be separated ; in other cases the 
anion is much less intimate. Instead of being a distinct structure, 
it my simply consist of the surrounding tissue, which has become 
tleoiie and fibrous in character. 

The contenta of cysts are very varied, and may serve as a basis 

for their classification. In the retention-cysts they will vary with 

tlie nature of the normal secretion. Serum, sebaceous matter, 

saliva, milk, seminal fluid, and other substances are found in these 

cysts; they are more or less altered in character from having been 

retained in a closed cavity. In the exudation-cyst-s serum is the 

roost frequent constituent; and in extravasation-cysts, blood. In 

those cysts which originate from the softening and breaking down 

of tissue the contents are formed from the products of retrogressive 

tissue-metamorphosis, such as mucin, fatty matters, and serum. 

Cysts may be simple or compound. A simple cyst consists of a 
"Ogle loculua. A compound or multilocular cyst is one consisting 
01 numerous loculi, which either communicate with one another or 
'^'nain isolated. Another variety of compound cyst is one with 
nidogenous growths, or, in other words, a large cyst with others 
powing in its walls. A compound cyst may become a simple one 
■y the destruction of its walls. 

Cysts are frequently associated with other growths, hence the 
'*nn» "cystic sarcoma," "cystic cancer," etc. It is especially in 
''"Xe growths which originate in glandular structures, as in the 


innuiina, testicle, and uvarv, that this combination is met with. 
The cystic devt'lojiuu'nt nmy iiluiost entirely obliterate the .'triic- 
ture of the tuiunr in wliicli it takes place, so that ultiuiatelv th>- 
latter may btcome couverteil iiitci a mere congeries of cyst*. In 
other cases large jiu[iilliirv masse.H of the tumor grow into tin- n»iii" 
cavities (" coin]ioiiii<i ]iruliferou8 cysts"). Considerable difficNiiv 
in determining the nutiire uf the original growth is thus not iofir- 
((uently ex|)i.'rifiic(.'d. 

Secondary Changes. — These may take place in the wall of the 
cyst or in its contents. The cyst-wall itself may become the wat 
of new growths, and produce secondary cysts, villous, glandnlnr. 
and other structures; this process occurs in many conipouml 'i>»- 
riun cysts. It may also be the .seat of an inflaniuiatory procrs* 
which terminates in supjiuration and granulation: by this towns 
the cyst frc(|iiently bewmi's nlilitcniteil. its contents being filher 
absorbed or dis<-liiirj;fd f.\tenii«liy and the cavity closing by gran- 
ulation. Calcification and ossification of the wall may also txxor. 
The contents of cysts undergo varinus changes, owing to tiieir 
rt'teiitiou in a closed cavity. The secretions become altiTtnl »" 
character, thickenetl, and viscid. Epithelial elements aDiii'n?" 
fittty changes, and so give to cholesterin crystals. Calcifi*^' 
tion of the contents is also eoninion. 

CLASSIFICATION. — Cysts may be most conveniently class'**^ 
accordin'T t<) their mode of nrijiiu, thus: 
1. <.'yi>t» foriHid III/ till' <tc<-utintliition of Hiifwtiifuti'S irithhi the caC*' 

of prf-exufiiiy gtriu'ttiren. . 

A. Retention-cysts. — Cy.sts resulting from the retention 
normal secretions. These include — 


a. Sebaceous Vu»ts. — These are formed bv the retention of 

cretions in the sebaceous glands. They posses.s a v" ^ " 
thin connective-tissue wall lined by stratified epitheli •* . 
(Fig. 83). They contain a mass of fatty epithelium *•" 
its products, cholesterin and nuinrphous debris. 

/3. Mufous Ci/ntn. — These are formed by the retentinn of setT*" 
tious in the glands of mucous membranes. 

y. Oi/»t» from the retention of nerretiottg in other parts, includi**^ 
— ranuhi, from occlusion of the .-salivary ducts; encifff*" 
hi/tirnrele, frout occlusion of the tubidi testis; nuimiHttrr 
ei/gtt, from obstruction of the lacteal duct«: nimple it0*" 


the (jrnafiiin follicles; and simple ci/stn of the liver ami 
kiiliwyr. tVom lociil obstruction. 
B. Exudation-cysts. — Cvsts resiijtiuji from excessive secretion 
in cavitii'S iinprovidoil with an excretory iliict. These 
iuclmle hurna;, ifiini/lia. Iii/ilnicrli; mi-niuffoeeles, cystic lironcho- 
rcUf, and many i\>f»t» in thf hrund /iffumoit. 
C. Extravasation-cysts. — Cyst* nvsitlting from extravasation 
into closed cavities. These iixhide hirmnlovele and some 
other forms of sanguineous cysts. 

II. ('\i»t)i iif itnlvfu'tiilriil (irifpn. 
■K. Cysts from Softening of Tissues.- 

-'riipsc arc especially 

Fio. X3. 

, I*"""!* rjfii: r /. Ihc llilii fiiimeHivi-ti.sBii. 11. IIiiimI liy i» thick 

■''■■Hum. Tho t»«UT I'ftllfl of thUi an- .luim-whul t-uljifiil . tlit-ii. |His.<»lne (nwiinl, 

iliiLtt'fiiMl ; nnd flnully tlH*y cnUrjifi' r^iiiHldtTHbly, U't-nini' fMtty, and rHther 

-■> niLr III iitiiln. They art- fuccwdoij liy futty di^brls {/>»'< •'<ini|irv'w<-d at to have 

^•^•"I.Tt. lUofd.) 

common in new formations, a.« in chondroma, lipoma, sar- 
coma, etc. 

• Cysts from Extravasation into Solid Tissues ; <: //. into 

hrain or soft new-irrowtli.*. 

• Cysts from Expansion and Fusion of Spaces in Connec- 

tive Tissue. — incliitU' — 




The term anoemia has no very definite connotation. As generally 
employed it includes all diseases of the blood which are character* 
ized by a deficiency in the number of the corpuscles or a diminu- 
tion in the total percentage of haemoglobin. Other expressions 
with a more precise significance are sometimes used. Thus a 
diminution in the number of red corpuscles is known as oligo- 
eythatmia or aglobulitm, and a deficiency in the haemoglobin as 
aehromatotit. These results may be produced by temporary con- 
ditions. Thus, anaemia is common during convalescence from 
acute fevers and after severe hemorrhages. It may also owe its 
origin to deficiencies in the ingesta or to that which produces the 
same practical result — stricture of the oesophagus or of the pylorus. 
In cases due to these causes the number of red corpuscles is always 
reduced, while the leucocytes may be either slightly diminished or 
slightly increased. Not only is the total percentage of haemoglobin 
below the average, but the amount contained in each corpuscle is 
Ivss than normal. Anaemia following acute fevers or hemorrhage 
rapidly disappears, the exact rate of disappearance varying with 
the nature and severity of the disease, the recuperative power of 
the patient, and the general conditions of convalescence. 

To two varieties of anaemia special reference must be made. 
These are (1) Chlorosis, and (2) Pernicious Anaemia. 

I. Chlobosis. 

Chlorosis is mainly a disease of girls and young women. It 

^Ises its name from the effects of its most marked feature, which 

'* the deficiency of luamofirlobin. This is so great that the skin 

'"d mucous membranes of the patient assume a very pale and 

"'gutly green tinge. In extreme cases the haemoglobin may fall to 

Oe-eighth of its full amount, and in most it is less than a third. 

'^ fill! in red coipuscles is by no means parallel. In mild 

»k^* they may average 3,500,000 to the cubic millimetre, and 

Y>" seldom fall below 2,000,000. The corpuscles are, on the 

^le, distinctly smaller than usual. Some of them 

are verv 



Binall, Hinging down to A/i in tliiirauter (niicrocytes); a few »re 
large, with a iliiiUK'tcr up to \'2n (matTocytes); wliile otheri* vritb 
an irrt'griliir outtinc are occasionally f'oimii (|ioikilocyte»). TUc 
Bpeciflc gravity of tiit- blood may fall ten to twenty degrees, thii* 
furnishing rcliahlc evidence of its "watery" condition. In some 
few cases where death had occurred the heart mid liirge arteries 
were unHSually small. Other morbid conditions secondary to the 
changes in the blood rnay coexist. .Viuong these are dyspmca tnd 
the occasional dejiosit of fat. both resulting from the deficient oxygen- 
carrying power of the blood; slight oedema, probably from defectire 
nutrition of the ve.ssel-walls: and varir)us auscultatory signs, due to 
the lowered .specific gravity of the hlooil and defective action of tlie 
inadeijiiately nourished heart. 

PATHOLOGY. — No generally-acccj.ted e.\pIanation of the 
changes in the blood has yet l>een found. Virchow first drew Htten- 
tion to the small size of the heart and large arteries. »n<l attributcJ 
it to defective ilevelopnient. He regarded the disease as the ex- 
pression of III! iuabiiity of (he l)bK)d-forn]ing organs to meet ih* 
demands made upon them during a period of rapid development — • especially liable, therefore, to occur in iu whom tb«w 
parti^ arc congenitally defective. In many cases the generative 
organs are also backward in their dcielopment : and this fact un- 
doubtedly affords some sufiport to Yirchow's theory. Still. A* 
enormous freijuency of tlie disease, its practical limitation tnnne 
Bex. its ready curability, and the want of jiarallel between the jjre** 
fall in h.T?raoglobin and the slight fall in corpuscles, point to a mof* 
transient and less organic causation. It is unquestionable that g^^" 
tralgia. gastric catarrh, gastrii; ulcer, rniDstifiatwn, defective hygitn'* 
surroundings, and irregular habits are frc((uently associated with tb* 
condition, aud that in niaiiy extimplcs of the disease the admini't'** 
tton rif iron fails to effect a cure until these be relieved. Ihi «•* 
other hand, it is no less certain that the relief of these condiiioW* 
without the adTuinistration of the iivm is ineffectual as a cure in*' 
hilt the mildest forms. Now, it is notorious that hiemoglobin, wliic"** 
contains a very apjireciable amount of iron, is the progenitor off'?' 
ments which contain little or none. The amount of this Bic<* 
excreted in the f;vces and the urine is excessively small, and i« "'* 
appreciably increased in aujetiiia. It seems reasonable to supix*^ 
that the iron thus left behind is utilized by the newly-forming haMBO^ 



globin; aud iF, therefore, the hemoglobin in the blood is deficient, 
it Would .toem luore rutioiial to look tor a ctmsi' tlmt interfores with 
tlif syiitht'sis of hjetiKtjrlobiii t'rom the aocniiiiilutiiig stock of iron, 
nttlier than for one which leads to anv loss iu the total amount of 
iron coiitnini.'il in the body. Any supply of iron, in addition to that 
already storetl in the liver, needed to meet the demands of growth 
and waste, must clearly come from the footl. Much evidence is 
'■vailnlile to show that most, if not all. the iron iilKS<>rbc<l or excreted 
is absorbetl or excrete<l in nrgnnir forms only, though it is impossible 
lo deny that it may exist in an inorganic form in the portal vessels 
nd bo retained and recombined iu the liver. 
According to Bunge. the iii)tiie<tiatc precursor of hivnioglobin is 
ttiatogen. a nnclein containing iron, phosphorus, and proteid 
•tt^r. He suggests that the sulphuretted hydrogen develojied in 
•<? alimi'Ufary tract of dyspeptic and constipated persons seizes on 
It' organic iron (hsematogen) in the food and cmiverts it into sul- 
fide, which is in4!apable of absorption. Thus the body is starved 
iron, and cidorosis residts. The success following the adminis- 
tion of large of iron he explains by siipjiosing that the 
^traction of the sulphurette<l hydrogen for the iimrifauif salts is so 
e»t that the organic compounds are undisturbed and allowed to 
on into the body. Sulphuretted hydrogen is very diffusible 
l«d is very readily absorbed. Its destructive action on organic iron 
'impounds is therefore not necessarily limited to the intestine, but 
night easily be exercised in the blood itself Stockman has pub- 
«»h«r«l some eases in which sid|jhide of iron enclosed in capsules to 
protect it from the action of the gastric juice was followed by dis- 
tmct benefit. The sulphide could not have attracted any of the sul- 
pburettcd hydrogen away from the organic iron. The failure of both 
uinnuth and manganese to act in the .same way as curative agents 
*i*o iiwts adilitional doubt on the sufliciency of Bunge's theory, as 
uiio does the success which has attendcil the subcutiineous injection 
of very small doses of iron. 

Among other theories may be mentioned Landwehr's. This ob- 
•ener is of opinion that at the age when aujeuiia is common there 
•* « tfndcnry to the exce.«sive formation of animal gum (I he carbo- 
''.'farate constituent of mucin), which is needed for the euibryo. 
"ii*. wlu-n present in excess, may interfere with the foruuUion of 

*aniler attaches much importance to a supposed deficiency in the 


hydrochloric acid contained in gastric juice. But this deficiencT is 
not uniform. The gnstric juice of some case.s of ciilorosi.>i contain* 
a large excess of bvilrocljioric acid, which is perhaps partlj ru- 
sponsible for the occasional development of acute gastric ulcers. 
Further, the luluiitiistnition of this acid Uiin no curative value in 
aiuemia. This disease is therefore unlikely to be due to » «!iiii 
of it. 

II. Pernicious An.£mia. 

Pernicious ansemia differs from chlorosis in many particular*. It 
does not show the same preferences as regards age and sex, beiag 
commoner in older jjcr.'ions atid in males. It is. moreover, generally 

Pernicious anwmia may be the apparent result of hapmorrhage 
after cliildhirtli or of any of the ordinary antecedents of anwnii* 
alreadv iiientioncd. More often it has no obvious cause. 



APPEAKANCES. — The blood in pernicious ansemia is very 

different from that in chlorosis. I* 

^"i-^^- differs from it in three especially 

* M ^^ ^ important particulars : (1) In chlo- 

^ • ^. rosis the most marked feature i« » 

^ ^ ^^ \ ^ drop in the pciccntaife of hxuto- 

globiu, whereas in pernicious »nw 
miu the most markeil feature i." 'b' 
diminution in the number of r©" 
corpuscles. Thus, although *'"■' 
total amount of hipmoglohin is* '"' 
variiibly diminished, yet the aiiioiH'' 
contained in each corpuscle v>»}' 
even be in excess of the iuirm«' 
The fall in the percentage "f "'"^ 
corjiuscles is enormous. Blood with only :}(M|.0(l() red corpuscle* '" 
the cubic millimetre has been described. (2) The next most fban"" 
teristic difference is the ri'oi|iien<'y of changes in the form sud stf* 
of the corpuscles. Sometimes there are found, a.s well as iion""' 
blasts, enormous nucleated red corpuscles (20/i dia.), known *■ 
giganto-blasta (Fig. 86). According to Eichhorst. the micp'cy'*'' 

' I'erchloride of mercury, 0..5 grm. ; chloride of siMliiim, 1.0 prm. ; niilpbMf "' 
iKxliiim, a.O grni. ; distilled water, 200.0 c. c. 

Pernirioiu anmnlii: blood.onrpiu>rlc!i 
sliowInK polknocyu-s Ifi), mlcrocytes (i«). 
and iiticleated porpti8<!lL.fl (nit*giilu<*ytoK) 
in). !*rrM«'rvu(I in Huyem's fluid.' (Sjicri- 
men mid ilmwInB by Dr. Molt.) 


e not only much more numerous than in chlorosis, but have a 
jry characteristic appearance. They are spherical, granular, and 
ighly pigmented. The number of leucocytes and of blood-platelets 
i somewhat diminished, the tendency to the formation of rouleaux 
8 less marked, and the coagulating power of the blood is feebler. 
3) The total quantity of blood is most markedly diminished. At 
ft post-mortem examination the vessels are almost empty. If this 
fact be considered in connection with the percentage-fall in. red cor- 
puscles and the diminished specific gravity of the blood (1028), 
some idea can be formed of the enormous extent of the change so 
far as the blood is concerned. 
The marrow of the long bones is generally red, and contains less 

Fig. 86 


Y'oIcIoiu ansemla : fresh marrow from humerus. Appearauce of yeUow marrow is not 
™"lke that of raspberry Jam. Ordinary marrow-cells arc shown ifl.m.c). The shaded cells 
^I'lgoented marrow-cells forming blood-corpuscles : the larger are megaloblasts and the 
"**"*' normoblasts. The cells marked (/) show multiplication by flssion. those marked (p) 

°'"plIaition by gemmation. Marrow treated with Hayem's fluid and teased. (Specimen 
*M<lrtwingbyI)r. Mott.) 

"' than normal. Large numbers of giganto-blasts are found, and 
^"Wc is also an increase of normoblasts, and often in great numbers 
*' microcytes. The red marrow contains pigment, giving the iron 
Action (see below). The finer bony trabeculse occasionally become 
The changes in the liver are of considerable importance. In 


flie centre of the lobule there may be an excess of pigment, ami in 

the j)ori|>lieral zone inm so loosely combined with orgimii" uiaiicr 
that Ji liiiitinct hliie cnlorution can ho obtainoil on treutiuj: .st'Ciiow 
of ihe organ with ferrocviuiiik' of potns.sinm and dilute hydro- 
ehluric acid. The cells in tin.' immediate neighborhood of the iotn- 
hibiihir veins arc occiisionaily fatty. 

The heart tinil siiiallcr blood-vessels, and occasionally the iiitinii 
of the large ai'tfi-it-s, slicyw extensive fatty changes, fmm which tlif 
.skeletal muscles ai'e practically free. The changes in the heart »rf 
particularly well marked. In the left ventricle the fatty intftn 
80 distinct that the terms '" thrush-breast" and '* tabby-cat" bsve 

Fio. ST. 


:\ o 

Pcrntclons iinirmia • tmme miiiTow «« in Fig. Sfi, but Imrili-iied In Mullrr't fluid •" ' 
n-Uoldln. Somf hnlftlo/x-n fat-vi-sloK-« arc seen, with tlie InteneniQi; cji|)illi>c! 
ililnted. These roulaln iKinniililnsIs wllli nwetteil inielel. The smallest eells »miiiir-N ■ 
those i>f Inteniieillste slue «re ^niiiilnrliKikiMK reil eiirpusele*. i Fnim u spcolmt'ii bj l" 

been used to denote them. The subcutaneotis fat is very genemlW 
increased. The skin acquires a faint yellowish or " old-wax" color, 
suggestive of slight jaundice. Small hemorrhagres are common in 
manv ports. Flamc-slia[icd hemorrhages clustered round the di«k 
are particularly frci]uent in the retina, and are an important aid to 
diagimsis. E.xacerbations are accompanied by fever. The urine is 

Mv dark. *i n -'ssive amount of urobilin is e.Kcreted. This 

II liv ibo ii-band at F when the urine i^ examined 



PATHOLOGY. — Besides the flifferences above tncntioneil, which 
mar Ih; lieliJ to tniirk off chlorosJ!* from pernicioii!' iinii'iiiiu, there is 
»hc ailditionul evidt-uce which is gained by the aduiiiiistration of 
iron. This drug, which effects a cure in clilorosis, is utterly useless 
m pcrniciiius nnieinia. 

Tlie increase of iron in tlic liver and marrow ami nf urobilin in 
tie urine affonls evidence that the disease is due to the excessive 
liwtruction of red blood-cells — hiemolysis. The changes in the 
marrow of the lonfj bones an<l the existence of nucleated corpus- 
vieu in the blood is uo argument against this view, as they might 
fie due to increased phj'siologicul, not to pathological, hoeuiogenesis. 
This explanation is the more probable as repeated bleedings of 
aniiDKls produce similar effects. A somewhat .<iuiiljir condition 
J Jima been produced in the liver by the aduiinistration of ri.lnydeue- 
Mliamine. This discovery has led to the suggestion that the iliscase 
ris tine to the absorption of to.xic products from the intestine. If 
this be correct, the "poison" must be some definite substance or 
H|nrjsanistn which very rarely finds its way into the blood; for. while 
^■ulceration of the intestine and all manner of decomposition of it-s 
^Prnateiits are common enough, pernicious auicniia it.^elf is compara- 
tively nre. The gradual and persistence of the condition 
»« also much against a purely cliemical cause, unless it be the prod- 
i«ct of some organism which takes up its abode in the intestine with- 
[***•* prodacing any local irritation. Two observers have described 
^'gnuisins, but their results have not yet been confirmed. 

It ii worthy of note that while in phosphorus-poisoning the fatty 
''^generation is almost universal, in pernicious aniemia it is far more 
'narkeil in the heart than elsewhere. Mott has suggested that while 
'hf fwling of languor so characteristic of the disease iuip<vsos rest 
'•Pon the skeletal muscles, tiie <leficient quantity and diminished 
""ygenating capacity of the blood necessitates ' increased work on 
'■'<' port of the heart. The balance of work and repair in the 
^'gaii cannot, therefore, be maintained, and ilegeueratiou ensues 
* a much greater extent than elsewhere. 


Leuchsemia, or Leucocythremia, is a disease characterized by a 
**">si(l,.rable and permanent increase in the number of white cor- 
PUsfl,.^ ijf j|,p hlood, bv a climinution in the number of the red eor- 
'"**cleji, and by enlargement of some of the lymjihatic organs. The 


Ivtnphatic organ mui^t freqiientlj involved >8 the splevn. Tlii« \i 
enlarged in the great majority of cases (splenic lencluvmiai. T\y 
eulurgement of tlie spleen is sonietinies iiesociatetl with eulargcmc 
of the lyuiphutic glands, and sometimes, although mnch lra> 
ipiently. uifii changes in the medulla of bones. In very rmnji 
the lymphatic glands only are involved (lymphatic IcuchiPmia), ii»«i 
cases have been described in which the tisscous medulla i» |irii 
pally affected (myelogenic leuchicmia). The lymphoid tissav of tl 
intestine may he hypertrophied. In most cases of louch«nii« 
overgrowth of lymphatic tissue in other organs occurs in the o»a 
of the disease. 

Leucocytosis. — Before proceeding to the consideration <tf 
chieuiin it will be well to allude to that slight and temporary n 
erease in the number of white blood-corpuscles which bu 
termed "leucocytosis."" This differs from leiichii'miu in thr 
respects: that the increase in the number of white eorp«»<"lr» 
only tetnporart/, is not necessarily as.sociateil with any diniiiiutio 
in the number of the red, and is never so market! as in Ivurhi 
in which there are always more than one white to every twenty; 
corpuscles. Moreover, in leucocytosis the increase is nlmnst limiti 
to the mvUinuch'ated leucocytes. A slight and temporary iac 
in the number of white blood-corpuscles occurs in many coDiiiti 
Physiologically, it occurs after a meal nntl in the later nioutlMi 
pregnancy. In pyiemia and in many of the acute pyrexiol 
es|>ecially those in which there is acute swelling of lymphatic «trTM 
tures, such as typhoid and scarlet fever, there is often u m«rke-« 
excess of white corpuscles. The same change ha» been dewrrib 
in tubercidar diseases and in conditions accompanied iiy suppur 
tion. After large losses of l)lood, also, there is an increase. o»it 
to the pouring of lymph into the blood to make ap its moM. 
cocyttisis does not seem to interfere either with the circulation 
with fh<' general health. 

PATHOLOGY.— The pntliology of leuehn»niia iit still exe 
inglv 'discure. and will probably remain so until our know ledp'* •"_] 
the physiology of the blood and the origin an<l fate of the M" 
corpuscli-s is more complete. Physiologically, we know that \r»* 
white corpuscles originate in the lymphatic organs, fn>i" •'"'^ 
they pass into the blood, either ilircetly or through the lym|>l»»'* 
vessels. Owing to the enlargement of one or more of the Iv' 


pba.i\c organs which always exists in leuchsemia, it has been sup- 
posed that the increase in the number of the white corpuscles 
irliich characterizes the disease is due to their excessive production 
by the enlarged organs, such as occurs in some cases of leuco- 
cjt:osi8. Inasmuch, however, as there is not only an increase in 
th^ number of white, but a diminution in the number of red, this 
hypothesis is insufiScient to account for the change. Further, lym- 
ph xk. "tic organs may become enormously enlarged without the pro- 
dncs'tion of any leuchsemia. This occurs, for example, in the spleen 
in ISplenic Anaemia, which disease, but for the fact that there is no 
incirease in white blood-corpuscles, is similar to leuchsemia. It also 
occsiirs in the lymphatic glands in Hodgkin's disease. The other 
vie^w, promulgated by Virchow, is that the transformation of white 
corpuscles into red is diminished. Hence the former tend to accu- 
mulate and the latter to disappear. Against this view it may be 
urged that there is no constant proportion between the increase of 
the white and the diminution of the red. and that many of the 
leixcocytes show evidence of active growth, not of diminished vital- 
ity. It must also be remembered that the origin of red corpuscles 
from leucocytes is by no means certain, while it is quite certain 
that they are the offspring of the nucleated red corpuscles found in 
the red marrow of bone. It is quite possible that the different 
varities of leuchsemia have each a different pathology. 

APPEARANCES. — ^Blood. — The increase in the number of 
white corpuscles varies very considerably in different cases. A 
proportion of one white to ten red is quite common, and often there 

Fig. 88. Fia. 89. 


j^chamlc blood (from a young man Blood from a case of splunlc ana-miu (from a 

" enonnoua enlargement of the middle-aged man with great enlargement of 
•PMien). X20O. the spleen). X^MO- 

we as many as one to three (Fig. 88). This increase gives to the 
blood a paler and more opaque appearance than is natural. In the 




earlier stages of the disease the i)ro|)ortion may not be inowtl 
one to twent}'. 

In sph'iiir leucocythannia it is the large uionouiicleHted corpi 
which arc particularly aljuutluiit, and in Ij/itiphatic leiieoci/lhinnin 
the smaller lyiiijihocytes. In the >tit/<lofffnic fonn the ntttiirc "f ilie 
new cells is less certain. Among the new element** found in iIk 
Mood in this variety are — (1) large mononucleated neutrophils cell* 
closely resembling "■'marrow-cells;" (2) nucleated red corpujclw 
suggestive of iicirmolilasts : unti (3) eosinophile cells and celi> «ii^^ 
'^mast-cell" granules. ^H 

It ii!is (iften Iiecn iiffirmcd that the new corpuscles, when eiduniw^ 
on the wiinii stage, show no iiwueboid movements. This ohservatinn, 
together with the liict thnt I'iitty degeneration has been occnsiunalh 
observed, has led to the belief that the majority of the leiicticvto 
are dead. Muir has lately pointed out that the absence of l(lov^ 
ment is confined to the large mononucleated variety, and tli»l MJ 
multinucleated leucocytes present exhibit their normal motility. 

The red cnr|uiscles, like the white, vary in their numbers. Tl 
may be reduced to a half <ir a ipiarter the normal. They »" 
usually natural in jippearance, but sometimes they are distinctly 
paler tliiin in lieahli. Occasionally they «()pear to be uniisiulh 
soft, and exhibit a tendency to .stick together, instead of forming 
the natural rouleaux. In the case of uphnic anamia rcferrnl lo»o 
]). 224 these characters were especially marked (Kig. K!)). The 
diminution in the number and the impairment of the i|uality of tlif 
red corpuscles, which e.xist not only in leuchiemia, but in mo* 
cases of great splenic enlargement, account for the anxmin wdii'ii 
exists in these conditions. In addition to tiie re<l and vhite W" 
pusclcs, nucleated red corpuscles have been found in leucha'niic ' 
blood, and minute, colorless, long, slender octohedral crystals of ||^B 
nlbuuiinou.s dianicter have been diseovereil in the blood, liver. '"^n 
spleen. The coagulating power of the blood in leucluemia is ni"*"'' 
diminished, juul when this liquid is alloweil to stand the white <-'*"■ 
])uscles fortii a cri'iiiuy layer n|Kin its surface. 

Spleen. — In this, which is mucli the most important organ i» 
jiroduction of leuchtcmia. the change is characterized mainly 
increa.sed growth. The organ l>ecomes enlarged, often enormoi 
so. The enlargement is uniform, so that the shape of the or; 
but little altered. The capsule is often thickened, and therr 
usually adhesions with the adjacent viscera. The consistence 


the spleen in the later stages is firmer than natural. The cut sur- 
face is smooth and of a grayish or brownish-red color, while thick- 
ened trabeculae can often be seen marking it as whitish lines. The 
Malpighian corpuscles, although they may be slightly enlarged in 
the earlier stages of the disease, are seldom prominent, and they 
are often invisible when the splenic enlargement is advanced. In 
exceptional cases, however, and especially when the lymphatic 
glands are involved, they may form prominent growths. Some- 
times wedge-shaped masses, of a dark-red or reddish-yellow color, 
are seen near the surface of the organ. These are probably infarc- 
tions of embolic origin. 

When the spleen is examined microscopically its structure is 
found to be but little altered, the enlargement being due mainly to 
»n increase of the splenic pulp. The trabecular tissue is also in- 
CTeased and thickened, and this change advances with the continued 
fnlargement of the spleen. The Malpighian corjiuscles are but 
little increased in size: sometimes they are atrophied. 

Lymphatic Qlands. — The enlargement of the lymphatic glands 
IS much less in splenic leuchtemia than in tho.'ie in which the 
glands are primarily and principally affected. In splenic leuchaemia 
one or more groups of glands are slightly enlarged in about one- 
third of the cases. The glands are rarely increased in consistence, 
»nd are usually frecl}' movable. On section they are of a grayish- 
^ color, and are often mottled with hemorrhages. Microscop- 
iwlly, the enlarged glands show increase of the pulp and blocking 
»f the lymph-channels. 

The red marrow found normally in the bones of the head and 
'fonk of adults and throughout the limbs in the foetus is a blood- 
forniing organ. In leuchwrnia it may become more highly cellular, 
•id consequently softer and grayer or yellower in color. Further, 
Hereas in normal growth the red marrow is replaced by yellow 
Progressively from the toes and fingers up to the heads of the 
'SOora and humeri, in this disease the opposite change occurs, and 
""^ yellow marrow is progressively transformed into red from the 
'""'ik toward the extremities of the limbs. 

^he follicles of the intestine may become so much enlarged as 

^ form distinct projections from the mucous membrane, although 

'* is less common than in Hodgkin's disease. 

^^ther Orgrans. — In the course of the disease masses of lymphatic 

^'>e or of lymphoid cells usually appear in places otherwise free 



from tlu'in. These masses are principally found in the liver tm 
kidneys, less frequently in the lungs antl muscles. The new growth 
in these organs sometimes forms distinct tumors, but much mure 
commonly exists as an iufiltrtiticm. How far these lymphoid growtlu 
lire the products of a hyperplasia of the cells in the iuterstiiiaJ 
tissue of the organ in wliirli tliey are situated, and bow far thev 
are the result of cmigrHtiori of the leucocytes which exist in unci 
large numbers in the blood, is unknown. The former, howerer. a 
probuhly the riio.<t iniportiiut factor in the process. 

The org;iii which is most frequently affected is the liver. Hiw. 
in IfiichuMuia. ihe vessels gencrtiliy are enlarged and <listeniif<i 
with white blood-corpuscles. Accumulations of cor|iuscles »nil 
lymf>hoid tissue are seen between the acini and extending »l«ii| 
the intercellular network into the acini themselves, so thai iIk 
lobules are sometimes seen to be clearly map[icd out by n gravisb- 
white interlobular infiltration. As this the liver-telli 
become compressed and atrophy, until ultimately the lohulw vm\ 
be entirely replaced by it. This is well shown in the liver from 

Vu.. iK». 

Livpr fW>in a r^e of itpleiin' uiiiL-tnin, !«tiiiM iiiK inv cxinialvc i-i-lluinr Inrtltretlct; : 
the tntiTt'oniilur iK'twiirk. The nriiau wHx greutly calariiTd, niiil lliv urn lUtur u 
to the nuked oyo between the Hclni. X^IX). 

the case of s))lenic anafmia (Fig. 90), the blood from whioh * 
re|)rt'9entcd in Fig. 89. Associated with this infiltration tlit'r^ '* 
often a formation of small, round, whiti-^h lymphoid no<lules ?oiP 
what resembling gray tubercles. These are 8ituate<l in ^^ 
inlerlolmlnr tissue. Owing to these changes the liver becouiw »P*^ 
considerably increased in si/,e. 

In the kidneys, which are also frei|uently affected, thf cli»n^ 
is similar to that in the liver. Here it consists for the tn*- 
part in an infiltration with which may be associated the furniatio*^ 
of roundish nodules and masses. 




The efficiency of the circulation depends on the maintenance of 
& correct relationship between the action of the heart, the size and 
elasticity of the blood-vessels, and the quantity and composition of 
the blood, as well as on the maintenance of a healthy lining mem- 
brane throughout the whole of the vascular tract. It is altogether 
out of the scope of this work to deal fully with the many ways in 
vhich these various factors may deviate from the standard of 
health. Practically, in disease they are nearly always combined. 
Structural diseases of the heart, arteries, and veins, together with 
their results on the general circulation, will be dealt with sub- 
sequently. We shall here limit ourselves to a brief review of the 
causes and effects of both dimunution and increase in the blood- 
supply of a part, and then deal at greater length with the phenom- 
eua of mechanical congrestion, dropsy, thrombosis, and em- 


By local anaemia is meant diminution in the amount of blood 
in a part owing to deficiency of the supply. It may be partial or 

CAUSES. — The causes of diminished arterial supply comprise 
*" those conditions which either narrow or completely close the 
'omen of the supplying artery. The lumen of an artery may be 
•I'lninished by disease of its walls — atheroma, calcification, or syph- 
'htic thickening ; or by pressure exercised upon it from without, as 
•>J new growths, constricting scars, inflammatory exudations, and 
Biechanical effusions, especially in unyielding tissues, as bones or 
tendon-sheaths. Complete closure of the vessel may result from 
«>nie of the foregoing conditions, or, more commonly, from throm- 
bosis, embolism, or ligature. In some cases the supply of blood 
18 diminished by an increase in the natural resistance from irrita- 
tion of the vaso-motor nerve. This occurs in some neuralgic and 
other nervous affections, or from the action of certain substances, 
«uch as ergot of rye and opium, or, again, merely as the result of 
a Jow temperature. It is sometimes attributed to the presence in 


the vessels of j>rodiict!' of metabolism, either in excessive amount or 
of abnormal cluirauter. Anivmia of one part may be secondarr to 
hypenvmisi. of other parts, such as an;i'mia of the brain and skin 
in congestion of the abdominal viscera, or it may be due to a general 
dimimition of the total ijuantity of blood, as after hemorrhage, in 
which case the distal parts suffer most. 

RESULTS. — A part with a diminished arterial supply is ususllr 
[lalcr. lest* tense, and of a lower temperature than natural. lu 
nutrition and function also are impaired, so that it mar underjM 
fatty degeneration, atrophy, or death. These results have hwti 
exemjdificd in the chapters on Fatty Degeneration, Atrophy. Bfni 

Obstruction of a large artery causes rise of pressure (triincieni 
under healthy conditions) everywhere except in its own area; awl 
this increased ))ressure endangers the .safety of delicate or di.scswil 
vessels until the extra blood thrown into the suddenly curtailed ra*- 
cular system is accominodtited in some way. The heightened lire.*- 
sure affects the vaso-inotor centre, and this speedily producer ilil»- 
tation of vessels sufficient to restore the normal pressure. But tl* 
vessels which dihitc most miirkeillv and persistently are those going 
to the auiemic part and anustomosing with liranches from the tnins 
beyond the obstruction ; this is probably owing to some ol)!Wttre 
vaso-motor mechanism, excited, it may be, by the aiuemia. Tliea* 
"collateral" vessels become Inrger, longer (tortuous), and thicker 
until the circulation in the part has again become normal — «'■«"- 
collateral circulation is established. At first, all vessels hatiog 
anastomoses with the obstructed one probably dilate, but those wliicl' 
enlarge jtermarieutly are almost invariul)ly branches on the mm*' 
side as the obstruction — e. tj. the ritiht inferior thyroid and vertebr** 
arteries dilate after ligature of the rti/hl carotid. The prira»ry 
anaMiiia, the blush and heightened tem|(er:iture of vascular iliUt*' 
tion, and the final return to the normal can be seen in limbs afte^ 
ligature of main vessels (p. 257). 


Hyperemia, or Congrestion, is excess of blood in the raorf or 
less dilated vessels of a part. It may be (1) active (arterial), or 
(2) mechanical (venous). These two varieties must be considered 



Active or Arterial Hyperemia 

Active livperii'iuin luouiis excess of arterial hlood in :i part, with, 
in most cases, acceleration of How. 

CAUSES. — 'I'lie iiiiuKxliute cause of active hypernemia is in all 

diminished arterial resistance. 
Diniinisbe<l arterial resistance may be produced pathologically — 
Ist. By certain agrencies which have a weakening' or para- 
lyzing effect upon the involuntary muscles of vessel-walls. 
Fntiifuf from previous prolonged contraction has this efl'ect. as seen 
in thfi liypera'TTiiaof the hands which follow suowhallin>;. Warmth, 

I to", in generally placed under thus heading. Injuriv* of all kinds, 
then iiol acting su<ldeuly and with extreme severity, produce a 
rpflex hyperivniia by their influence on sensory nerves. This occurs 
In-fore the /rue inflammatory dil.itation sets in. and must be included 
m llie next group of cases. The dilatation f/tarncterigtir of iiijl/im- 

j mafwi is ilue to direct ilamage of the vessel-wall, an<l therefore falls 
stiller this beading, and. so long as it is more than sufficient to 
ft'nnli'rbnlancc the increa.scd resistance which always aceomjmnies 
it (we" Inflammation"), the quantity of blooil passing through the 
part is greater than normal — /. c the part is hypenemir. The 
»ut\dai remoriil of jtrrgxiirf is another of hypera'niia. Thus, 
wogMtion of the abdominal ves.sels follows the removal of much 
«»<:itic fluid or of a large ovarian tumor: bleeding from the pleura 
"ccnr* when the cavity is ra|>idly emptied by aspiration or strong 
•Jlihon-action : bleeding may also toUow the complete emptying of 
» cliroiiically distended bladder. The muscle of the vessels, accus- 
'^nied to much su|>]Mjrt, ha.s |i>st power ; so. when the supjiort is sud- 
'iciiiyrfinoved, the ve.'«sels dilate fully, and small one.s perhafis rupture. 
2<l. By the removal, either directly, or reflexly — /. *•. by in- 
Wbitjon — of the vaso-tonic action of the sympathetic. — Thus, 
"''tiVf congestion follows pressure uj)on the sym]>athetic — as in the 
"wk—by an aueurysm. Certain drugs, taken internally, are be- 
''«*«! to directly jiaralyze the vaso-tonic nerves — e. if. nitrite of 
""vl, alcohol, tobacco. 

Tlic fffUx process is generally due to stimulation of sensory 
flwu's, the diminution in tonus thus produced being more or less 

«cnirately confined to the region supplied by the nerve. Friction 

iDrl slight irritants in the early stages of their action i)roduce by- 



penpinia in tliiti way (se« nbove). It seems that vascular dilai 
of deep organs may be produced reftexly by tin? applicmttu 
stupes to the skin over them. 

Anamia of any Inrpe part, a« of a limb compressed by Esmarcb' 
bandage, or of the skin fruiii cold, necessarily cause* htfftfnrmm 
otlier parts — compensatory hypereemia. But all parts do 
suffer enuully. as tliey would do were the bypera'nua the rc»ai 
simply of increased arterial pressure : certain vesaeU, as the gnr< 
abdominal veins, dilate, showing that the vaso-motor system ami 
for the accommodation of the surplus blood by producing 
diminutions of vascular resistance. After extirpation of one 
its share of blood passes mainly to the other. 

3d. By excitation of vaso-dilator nerves, such as the cl 
tympani. — Nothing is certainly kiu)wn of this as a cause of I 
Kmia, but the hyperiemia u.'«sociate<l with facial neuralgia and| 
of the thyroid in exophthalmic goitre have been refernnl to 
dilator neuroses and also to iidiibition of vaso-fonir nerve*. 

RESULTS. — Tlie results of active hypera'mia nn- prinfi|l 
Buch as might be expected from increase in the amount of ar 
blood, and in the rapidity of its flow, in any particular oi 
tissue. The symptoms in a superficial pnrf are — increased 
and pulsation, a subjective sensation of throbbing, some in* 
in bulk, and nuirked elevation of surface temperatare nntil 
approaches that of internal organs. If the hypenrmia be of 
duration or frei|uently repeated, the small arteries remain 
nuuit-ntiy enlarged, their walls gradually thicken, ami the pjiitk* 
Hum and connective tissues of the part increase. This mi 
Boen in the papillary thickening round a callous ulcer of thfl 
and the occasional spread of ossificntioii from the tibia inb 
granulation tisane. The ability to work is increased, and M 
trophy will follow if the<l work is maiittainc<i (p. IISV 
bypenemia of the nervous centres we see great exeitabilityj 
trathesiK of sight and hearing, and even convuUion*. In 
glanib, such as the kidneys, secretion is increased, the nrine 
water V and sometimes albuminous. 

Mechanical or VeNons Hyperjbmia. 
In venous hypenvmia the excess of blood is in the Tei« 
capillaries, and the flow, iuAtcad of being accelerated, is 


This is so frequently pnxluced b_v some obvious mechanical obstacle 
fo the return of hlood through the veins that it is often ealled 
oechanicekl hypersemia. The eongestiou of a finger jiroduced by 
8 moderately tight band tied round it may be taken as tiie type of 
«uch cases. 

CAUSES, — Anything which weakens the forces carrying on the 
venous circulation or which opposes iinusuai resistance to this cir- 
culation must tend to produce venous hypers«uiin. Such causes 
nii»y exist in any part of the vascular system — heart, arteries, 
I'spillaries. or veins — some having a local, others a general, effect. 
They may be arranged under two headings: (1) tliose which liimin- 
i»h the vis a tergo, or propelling force ; and (2) those which intro- 
•iturr a vis a fronte. thus placing a direct impediment to the return 
"f blood by the veins. 

1. Chief in the first group is diminished cardiac power. The 

heart may act so feebly or be so damaged structurally (see " Endo- 

<^Ti|iti«'") that too little h]oo<l enters the arteries at each stroke, 

»inl generally at a pressure less than normal. As a result the 

' •'Serial supply of all parts is diminished, blood lags in the veins, 

"»<1 a less i|uantity than normal returns to the luMrt during each 

"lastule. This is very evident in prolonged febrile diseases, such 

** typhoiil, and in those degenerations of the walls of the heart 

*hich lead to dilatation of its cavities.. In whichever of these 

I ^wjt's the via <t ti'rgu is diminished, that diminished fulness of the 

lartcries and overfulness of the veins wliicli are so familiar clin- 

lically ns the result of cardiac failure will be prodiued. If this 

|«>nditiou be of long duration, there is necessarily so much in- 

P'*»"fer('nce with the oxygenation of the blood, with the functions 

|of the blood-forming organs, and with the processes of digestion 

[ulifl assimilation that the blood itself l)eeomes deterioratetl. and 

|t'»ii» Iiy its lagging in every tissue the nutrition of all suffers. 

In the arteries the driving force may be weakened (1) by total or 

V*rti»l oli^truftion of an arterial trunk ; (2) by dilatation, arising 

"■"m simple atony or from those general fatty, atheromatous, or 

"liroiil changes of the arterial wall so conimon in advanced life ; 

or (8) by ritjidity. in which case, owing to loss of arterial elasticity, 

the heart's force is wasted against the walls of rigid arteries. 

Obstruction tn the circiilattim in capillaries arises mainly from 
/injure of inflammatory and serous effusions on capillary areas. 



AVith regard to veins tlic circulation will l»e slowed b_v (1) nbsenrr 
of muscular contractions, especially in the lower extremity ; (2)sucb, 
ililiitiition iis [irodiices incoin|)etenee of valves, thus reudering mo 
cuhir action useless as an aid to circutiition ; and (3) by »nvlliin;r 
vvliicL. diuiinisliinn; the elastic force with wliicli the lung tendsi to 
drjivv away from the pleural wall, lessens thoriicic as|iiratioD. For- 
cible expiration will replace the normal wjtWM^-pressure within the 
thorax by a /i/«x-iiressure ; thris, playing wind instruments im|ii?<icj 
entry of hlood friMu veins into the heart. Emphysema, effiisiKU of 
air or fluid into the jdeural cavities, and large new growths of tli» 
lung act similarly. These causes might fairly rank tinder the 
second heading. 

When, by various combinations of the above conditions. Ihecirca- 
lation is much retarded, hypostatic congestion occurs. The com- 
monest seats of this are the [losterior edges and bases of the limp, 
the skin over the sacrum, and any jiarts kept constantly dependonl. 
Slowing of the circulation causes distention of the veins and in- 
crease of the intnnenous [tressure. In iiny such jiart which is»l.«o 
dependent the intravenous, and therefore capillary, pressure is 
further increased by ijravitif. Tlic force of gravity is in projiortion 
to the vertical distance between ttie highest point of the bod\- Pi 
the time being and the part in t|iiestion. If the patient is so we 
as to be unable to change his position, this ])ressure constantly v^ 
upon the same veins and ca)iillaries, diluting them, and <i\'- ' 
increasing the tendency to leakage through their badly-noui:-! • 
walls. Thus the part is redder and softer than normal, and * 
a'domiitoiis {p. 238). In bedridden patients breathing is often ve'TT' 
shallow, and the effect of expiration in ilriving blood on to thel«?" 
auricle is therefore (liminished. (Sec "Hypostatic Pneumonia.') ■•'' 
people who are walking about dropsy from heart disease gcncrft'*!' 
begins in the logs. This is due largely to the action of gravity- 

2. Examples of direct impediments to the return of blood by '""^ 
veins are numerous. Tlius, congestion of the chylopoietic vit**^ 
from coni]iression of the portal capilliirii's occurs in cirrhosis of '^ 
liver; congestion of the lung follows mitral constriction or regti*"^ 
tation ; congestion of the systemic circulation results from jne»" 
cicncy of the tricusfiid valve; and in the lower extremities theii**'^ 
result maybe due to jiressure of the gravid uterus on the iliac xe***— 


RESULTS. — Whether there be a direct impediment to the retm 


Mood by the veins or n failure in tlio forces of circulation, the 
ins ami capillaries dilute, and the hlood. iiiovini: with diiiiinislRul 
ocitv. tiocuuiuliites in them. Tlie .lubseciuent cliauges will depend 
^bc degree of obstruction tn the venous return and upon the 
wis! presiiure — in other wurdss. iijmn the injury sustaincil by the 
Bewails from impaired nutrition uud upon the of pres- 
^H the veins and eH|)illaries. In addition to the immediate 
cts, such as the <limini>ihed .secretion of urine, the most imjiort- 

of the more gradually induced changes are the exudation of 
iin. the escape of red blood-corpuscles, hemorrhage, fibroid indu- 
on, thrond)osi8. und necrosis. 

. Exudation of Serum is one of the most important results of 
:iianical iiyper:eniiii. It i.« disiciissed un p. 23t). 
- Escape of Red Blood-corpuscles occurs when obstruction 
the venous return is very great: they transude with the fluid 
n the veins and capillaries. The blood-stream in these ve.ssels 
ipletely stagnates, and the red corpuscles become packed into a 
Went which iiscillafcs to and fro with the arterial pulsation. 
•n. suildenly. .some of the red corpuscles peneti'ate the walls of 

small veins and capillaries and escape into the surroumling 
ues. This seems to occur without rupture of the vessel, for if 

ligature be removed the blood again circulates in a perfectly 
mal manner. The corpuscles rarely escape in great numbers. 
bag been suggested that they pass through the stomata which 
;klingbausen ha.s shown to e.xist between the endothi-lial elements : 

<it> plasma coidd easily |iass through openings large enough for 
^krpiLscle, and as the transudation-fluid differs markedly from 
•ma. Oohnheim considereil that the existence of these stomata ia 
iccessary to account for the escape of corpuscles. 
s Hemorrhage is another residt of mechanical hyperiemia, and 
ally occurs only when the obstruction to the venous current is 
y great, and when the nutrition of vessels and tissues has suffered 
n long congestion. Healthy vessels can bear very heavy strains 
bout giving way. Those vessels which are the least sujjported 

the first to give way. Hemorrhage into the stomach in cirrhosis 
he liver and into the lung in mitral stenosis is a familiar example 
tbi* result. 
. Fibroid Induration is due to a gradmil increase in the connec- 

tisHue round the blood-vessels, and is one of the most important 
ilt8 of long-continued mechanical hyperteraia. The interstitial 



growth was forraerlv siijiposcd to lead to atrophy of the higher 
structures, and thus to imjiainiipnt of the functions of the org»D, 
In the stomach it was said to [>roduce atrophy of the glamlnltr 
structures; in the kidney, compression of the urine-tubes; aud in 
the heart, diminution in motor power. It is probable, however, thi\i 
the atrophy iu tliese cases is primary, following the deficient siiji|ih 
of oxygenated blood, and that the increase in the stroma is dai? to 
the fact that it is the only tissue [iresiMit that can thrive mi ihf 
material supplied. The alterations which this change ppxhuw in 
the physical characters of the organs — viz. induration associatrJ 
with alinoniiul redness, due to the excess of blood or pigmentatinn 
from hicmatoidin — are exceedingly characteristic. 

5. Thrombosis (see ]i. 240). 

6. Necrosis occurs from mechanical hypericmia only when the 
obstruction is very general and complete (fip. 35, 3H and 44). 

To sum up. long-eontiuued mechanical hyperemia leaiis to 
impairment of vitality and function. The tissues gradoillr 
undergii retrogressive changes and atrophy, although from tli'' 
amount of exudation aiul blood they contain their size and nl^ii- 
hite weight may be increased. This form i>f hypertvmia hw no 
temlency to cause multiplication of tissues other than of the con- 
ni'ctiiu-. an<l, in the case of catarrhs of mucous membranes, of the 

which were actively liy[ier;einic during life frenuently show i*** 
fligns of it after death ; for, if coagulation does not occur immftl >• 
iitely, contraction of (he arteries or of the elastic capsules oforg»«** 
forces the blood on into the veins, finis rendering the recogniti*"*** 
of arterial or capillary hypen^inia impossible. Further, uiil^ 
the influetiee of gravity abiue tliiiil will tend to run to the itio ^"* 
dependent parts, and thus a liyperremic organ — whether actively ^^ 
passively so — may be emptied of blood, and may thus appear p»lc^ " 

IJiit dependent parts, on the other hand — the posterior jiorlioi 
of the lungs, the lowest coils of intestine, the skin on the jio.'rtorit 
surface in dorsal decubitus — which may have been healthy durii*-^ 
life, now become full of dark blood. It is oflen diflFicult to say li""^ 
much of the congestion of the base of a lung is ante-mortem an*^- 
how much fiost-mnrteui. 

.\ further source of error exists in the post-mortem staining oi 



psrti, especially of the fiKlocariliuni, tbo linings of great vessels, 
and the tissues round veins, siieli as is met with particuliirlv in 
wpticivraia. The redness in these cases is aiufonn, and no uiag- 
nifiation will show that it depends upon distended vessels, while a 
cimpit.' lens will generally show the capilliirj nature even of an 
«[ip»rcufly uniform /ti/pera'inic redness. 

When large veins arc hyperremic the injectiou is said to he 
"runiibrm," from their branching form and dark-blue color. In 
the intestine, skin, and kidney hyjierjcmia may appear [lunctiforui 
frnm the arrangement of the vessels in villi, papillie, i>r Mulpighian 
("rjmsck's. as the case may be. Minute punctiform hemorrhages 
must uijt he mistaken for such ciises. 

I'igmeutation (slate-gray, black, or brown) from tlie altered 
hwmrjglobin of disintegrated corpuscles generally remains after 
fliriitiic hypenemia, as is nften seen in the stomach nnd intestines 
ifter portal congestion, and iu the bladiier and the lungs after 
flironic catarrh (p. 235). 

Mechanical Hypeb.«!mia of the Liver. 
Long-continned mechanicii! hypersemiii of the liver invariably 
g'ves rise to the condition known us Nutmeg: Liver, which so 

Fio. 91. 

»»r OestTiirllnii of llu' HviTi-rlls uikI |iii^iiL-iitiitioii nf llip ii'iitrnl |Mirtloni' of 

I •rinni; nrw ),'ruwtli of luiirn'ctivi' ti»Hiii' at tlic jifrliiluTy. l, luiMitli' vein ; /'. (nirtnl 

<S" Wlivti more highly mttgtillifd nuiinniiis mirlcl «rir ncen In the |>«rl|ilii'n>l 

uttlro Utniio. In ilil* ttpvcimvn thvre In more now tluuo >t the periphery lb«n la 




J V 4 


fre<|iiently results from oiinliao inconi]>etonce. The chu 
chanicteri/.i'fl by a large ao'iiuiiilatiixi dI" MkchI in ilu- siiblii 
ami iiitraloliiilur voinx, whicli ililati' and thirkrn ; bv stropkf 
the hepatic cL'li» in the central ])()rtion8 of the lobules : tinil nuclj 
by increase of the interlohiilar foiiriectiv*- tissue. The impfili- 
nient to the return of blooii by tiie hepatic vein8 lemla to atmiili; 
of the cells in the central portions of the acini iind to the ivfmi 
of piprnetit, so tlial, when examined microscopically, thc-e pin 
of the acini are seen to consist of broken-down cells and gri 
P„, 92 of pigment {Fig. yi). The 

",^' lobular veins nud their radicle*' 

are much dilated, and filled 
red blood - corpuscle* ( Fiji. 
Their walls arc thickened.^ 
there often appears to be < 
mure or leB« thickening ofr 
intercellular network which tsi 
mediately surrounds the centra 
vein. Owing to thiw thickes 
of the central \fin ami nf tfc 
Nutni.Ti iiv.r T'..rti.m ..f kik. !»i. m-0r jaeenl intercellular network 

n'litnil tii'iMtlr vi-Ui i IT. ninn' lilKhly miiK- 

iiinoi.ithuwinKthi'itiirki'niiiKor the vrini to the destruction of the 

.mllh.«.-.u.nul«ll......f r,-.n,l.>.Kl,...rim.- .,| j,,^. ,„„,, ,.^ , , j^ 

rim wUlilii tlioiu. .- MU. ' 

the acini in advanced sta 
the disease may present a fibrous apjiearance. This i- • 
much less marked in injected specimens, and is tht r. : 
due to atrophy of the cells and distention of (he vesacU. 
peripheral parts of the ai-ini new interlobular growth is o« 
ally seen insinuating itself between the almost unaltered liverH 
This new interlobular growth is less nucleated than that inet^ 
in cirrhosis of the liver. 

In the earlier stages of this affection the liver is smootl) 
often considerably increased in size from the large amount of 
which it contains. On section it presents a peculiar mottJet] ap 
ance. the centre of the lobules being of a dark-red cfdor. »hi 
peripheral [K>rtions are of a yellowish-white. This latter a{ 
ance is occjisionally inereaseil by fatty infiltration of the peri| 
liver-cells. The appearance of such a section is not unlike thaTi 
a nutmeg. I'ltimately. the organ may undergo a gradual 
nutiou in size, becoming more or less irregular on the av 



' This is due to atroy)hy of the central cells of tlie lobules, mainly 
from inaluntritiou (p. 231). but |iiirtiy from prt'ssiirc uf the dilated 
cciitnil veins and the coutructin;; interlobular ;'rowth. 

Mechanical Hyper^emia of the Lungs. 

In tlip lungs long-continued mechanical hypcnemia produces that 
pMiilinr induration and pigmentation which is known as Brown 
Induration. Thii? must frequently results from stenosis and in- 
sullicicnoy of the mitral orifice, 'i'he alterations pnnluced in the 
puhiiiinary texture consist in the Hrst place of elongation ami dila- 
tation of the pulmonary capillaries, so that even in nninjectcd prep- 
trations the alveolar walls appear abnormally tortuous. The epi- 

Fin. m. 



^liwnlndunitlon iif IIk! hint;, filinuiiii,' llir ■ilinnruiiil miuilx'r of .snolti'ii i>lKHifnU<l I'pl- 
"*"«1 cells wiviTinj! tlU' nlvi^ilnr wnUx. Iht ilii-n'iue iif ironniTllve tUsiiu arDUiul Ihe blixxl- 
'■"''•.n. will the large niiaiiOty uf piiciiK-iil ; (», (lie alvoolor ciivily. ■ Jii 

Uieliiil cells lining the alveoli become snolJcTi, probal>ly multiply, 
siiil iii^. jjpeu ill large numbers, filled with dark-brown pigment, 
"JVuriiijj the alveolar walls (Fig. 03). They freipieiitly accumtihite 
*'lliin the alveolar cavities. These changes are followed bv an 
'UtTeiwe in the interlobular ci>Tinective tissue, by the formation of 
'"?P i|imntitie8 of pigment, and often by a thicken- 
'"gof the alveolar walls. The bronchial mucous membrane is dark 
*l"i the small peribronchial vessels are dilated, Sttmctiuies these 
*M«el8 rupture and blood is extrava.sated into the tissue of the lung. 
(See '• Piiliuonary .\poj)le.\y.") 

hiings in which these changes are at all ailvanccd present a more 
'" 'ess uniform brownish-red tint, mottled with brown or blackish- 


colored s|)ecks atnl streaks. Tker are heavier and tougb 
natural, less crepitant, and iiptjn squoezinj; tlioin tin* pitlmoa 
sue IS foiiiiil to be denser and thicker tliuii tiiat nf u liei 


The normal tissues are continuously bathed in. and noarii 
the lymph, which derires it» nutritive properties from the I 
and passes on info that fluid the prnduct* if receives in exd 
from the tissues. These j>roducfs find their way, either 
veins or by the lymphatics, back to the heart, and thenrt 
lungs, skin, iimi kidneys. In all probability the vein.'i 
as much tiie soil-pipes of the tissues a.s the lymphatics. To 
in all parts of the Ijody a constant circulation of lymph t 
from the capillaries and returning by the lymphatics is ma 
is justified by our present knowledge. In the dop, at any 
know that during rest there is no flow at all fr<im flu- lyi 
of the limbs. The lymphatics seem to perform most of th 
during active exercise or in other local c-uicrgencies. 

Lymph varies both in amount and in comiMtsitinn. ' 
factors which arc mainly operative in dctennining thntc i 
the excess of the pressure within the capillaries over that 
tissues immediately around them : and (2) the special propa 
the c*lls of the capillary walls. 

1. The capillary pressure is, in general terms, a sort of 
between the arterial and venous pressure. It usually folloi 
closely that in the veins. If either the arterial or the 
pressure rise or fall while the corres|>onding reaoua or 
pressure remains cini»tant, the capillary pressure will rise 
too. as the case may be. If, however, one of them, ei 
arterial or the venous pressure, rise or fall while the otlif 
in a rovtniri/ direefion. the residfing capillary pri'ssure nd 
remain constant, or fall. I'uder such circumstances the " 
pressure is diflicuh to estimate, for there is no method 
measurement. Most often, as has been said, it ftdlows tha 
veins. A statement regarding flic arterial pressure alone i 
a safe guide to that in the capillurics, partly for the mH 
stated, and jiartly because the arterioles may inter|>o»e an a< 
in<lcfcrmin.'ible factor. 

2. The influence exercised by the capillary walla upon 
duction id' lymph has been supposed by Heidenhain and « 



be of the nature of an active secretory process, but by many it ia 
Rtill regarded as a passive tiictor, the efficacy of which depends only 
on the efficient nutrition of the vessel-walls. According tn this 
Kcoad view, a vessel-wall is said to be more or less " permeable " 
in pro|)ortion to (1) the readiness with which it iil!>)«s fluid to trana- 
nde (sensitiveness to pressure), and {'1) the resembliince which the 
tnnsuded Uuid bears to the ]dn.>:Uia of the blood. Thus, so long as 
thf pressure remains constant the jn'rim-nhiUty of the i:ai)illarivg is 
the measure of both the amount and the composition of the lymph. 
For example, the capillaries of the liver are said to be more per- 
nivsblr than those of the intestine, and those of the intestine than 
tbo,«o of the limbs. By this is meant that a similar increase of 
pressure imluccd in such case will not be fidlowcd by a similar 
result, but that there will be a marked increase <>f the lymph-flow 
friiin flie liver, a let's increase from the intestines, and the smallest 
iiierease of all from the limbs, and that in any case the lymph from 
the liver will contain more proteid matter than that from the intes- 
tines, and that from the intestines more than that from the limbs. 

The saline constituents are the same in all cases, aiid correspoird 
in amount to that found in the blood-piasimi. It is well known tlint 
tscitic fluid contains more albumin than cedematous fluid fnim 
the Ifgs. ancl that this is so under all conditions, and docs not 
depvnd nn the disease producing the dropsy, Dumaifv — such aa 
dipping a limb into very hot water — increases the permeability of 
the capillaries, and therefore both the nmoiint of fluid transuded 
anil the resemblance which it bears to blood-plasma. It is jjrobable 
•J^t a somewhat similar but less pronounced change may be caused 
h.v gradual alterations in nutrition, due to the circulation of defec- 
tive or vitiated blood, and that increased friction and greater perme- 
•kility may result, 

lleidenhain found that by introducing certain sub.stances into the 
blond he could produce an increase in the flow of lymph. These 
""Wtaiices he called •*lymphagogues," believing that tliey in some 
*•; stimulated the supposed secretory power of the capillary walls, 
'ttrling' has, however, by very ingeniously contrived e.\))orinient8 
"hown that in the case of dextrose the first eft'ect of its introduction 
Mtoeauijc ft reabsorption of fluid into the vessels, and a consetjuent 
"lerensc in the total qimntity of fluid they contain. This, in its 
'"rn. pruduces a rise in the venous, and therefore in the capillary, 
' Juumai of Phyaioloyij, 1S94. 



pressure ; and to this increased pressure, ruther than to any »ii«ijI 
secretory process, he uttribiites the additionul lymph-flow. Stwiiaj 
further shows that if uu amount of blood c(|unl to the cxptrtMl 
ab8or|ttion — caused by the introduction of the dextrose — be pn- 
viously withdrawn, no increase in the total amount of blood, niirM 
of the venous pressure, and no addition to the onlinary lymph-io* 
will occur. It seems, therefore, that perinenbility should rtill W 
regarded as the pos.session of a special power of retention rttW 
than as an active secretory process. 

By dropey is meant the retention of lymph, either in co»n^fm^ 
tissue spaces or in serous cavities, though by some it is ucwl odIt 
with reference to the serous cavities. The term csdema u liimte' 
to dropsy of the connective-tissue spaces, while nnnnnmi MW 
«ilema of the subcutaneous tissue. Thus we speak of "pMtA 
dropsy," "a-dcnia of the Inngs." "anasarca of the legs." 

It is tolerably certain that the causes of increased lympb-ll(>»M» 
also the causes of dropsy. It is quite certain that the most mark^i 
examples of tlrnpsy are. in practice, associated with enonnou«m- 
crease in venous pressure acting over a long period. .\m"n£ 
these local obttniction to the return of venous blood plays the chiff 
part. This may be caused by the pressure of cicatricial tissue fir » 
tumor, or by thrombosis. Itufficient action of the heart, such •» 
tliat occurring in late stages of valvular disease, causes a &ilit 
arterial, but a rise in venous, pressure, with a conseijuent slowinj; 
of the circulation. As the veins become distended their v»lit* 
become incompetent, an<l the action of gravity on the eniarjpJ 
blood-column adds enormously to the pressure in the capillarirt of 
the legs, and thus produces anasarca. A slighter form <<f fledtta* 
of the legs, in women whose occupation involves much standing,!* 
duo to the combined inHuence of constipation, garters, and grv 
In all these cases the mechanical congestion may mtl impn«bi 
increase the pennrability of the capillary walls. The certainty 
the increased venous pressure is the cause of the dropsy rwta 
on the constancy with which the dropsy ilisappcars when the inci 
in pressure is removed, liwrfunfd arterial preitturr is )M>mel 
credited with the production of dropsy, but it is uncertain wbi 
in the absence of increased venous pressure, it is a sufficient 
In that form of chronic Bright's disease known as granular kr 
there is a marked increase in the arterial pressure, but no opi 
until the heart's action begins to fail and the venous preMuro 

DROPSY. 239 

y rises. Possibly in such conditions the contracted arterioles 
artially neutralize the effect and act as a guard to the capil- 
An experiment of Heidenhain's shows how fallacious it is 
it to arterial pressure as a guide to that in the capillaries, 
struct! ng the thoracic aorta this observer enormously reduced 
terial pressure. Notwithstanding this reduction, he found that 
)mbined lymph-flow from the intestines and liver together 
d no proportional fall, though the lymph obtained included 
preciably larger amount of proteids. Heidenhain's inference 
lat no process of mere tissue-filtration could possibly explain 
suit. Starling repeated this experiment, but took the pre- 
n of measuring the pressures in the portal vein and in the 
)r vena cava as well as in the femoral arterv. He found that 
lormous fall in the arterial pressure was accompanied by a 
lerable drop in that in the portal vein, but by a distinct me 
it in the inferior vena cava, so that, though the pressure in 
testinal capillaries was almost niU the pressure in those of the 
ffas probably increased. He further showed that the flow of 
1 from the intestines ceased, while that from the liver (nor- 
the more concentrated) continued, as might have been inferred 
the pressure conditions. In this way the changes in capillary 
ire were found to explain the alterations in both the quantity 
iaracter of the lymph. 

; second great class of dropsies are those associated with 
unation of the kidneys and deficient urinary secretion. 
»e cases there is no ascertained increase of venous pressure, 
true that the pressure in the arteries is often raised, but the 
ears no uniform relation to the oedema. It has been suggested 
n these cases there are substances circulating in the blood 
; like the experimentally injected dextrose, and that these 
mces produce a condition of plethoric hydrnemia and a con- 
nt general rise of blood-pressure, followed by oedema. Against 
iew it may be urged that in the experiment referred to the in- 
jd flow affects only the abdominal viscera, whereas the oedema 
ight's disease is distributed over all the loose tissues on the 
» of the body. We know, however, practically, that improve- 
in the quality of the blood is followed by diminution in the 
Bt of oedema. 

cardiac failure there must be some hindrance to the exit of 
1 from the thoracic duct, and this may be an adjunct in dropsy 



due tu cardiac causes. Lucul [tiessure un the Ivmphatics Jov* o4 
usually produce icdeuia, though the occasional jtresencc of chrlf a 
the urine or in the pleural or peritoneal cavities is gcncmlly attnU 
uted to hlockiug of the respective lymphatics by growths or puv 
sites or to rupture of the thoracic duct or rcccptaculum chyli. 

In anicniia, neuralgia, cxoplitlialuiic goitre, tumors of thr ipinal 
cord, and other diseases slight degrees of a-deoia are occwinDilij 
met with. Section of the spinal cord produces ra«o-courtn<l«r 
paralysis, and tumors probably act iu a similar manner. In t^ 
other ca»ea vaso-motor derangements are common, and. iLmii^ 
their cause is less definitely ascertained, paralysis of ■ 
strictor or direct action of vaso-dilator nerves is probaLi.. -■- 
would furnish a sufficient cause. Experimental aiiiemia gives w 
to nn increased lymph-How. but it does not foiluw that ili-fccti'c 
blood acting over a long period might not increase the permcsbilin 
of the capillaries. Experiments on the spinal cord and un ti* 
splanchnic and vagus nerves have hitherto faiUsl to afford atti*- 
factory evidence of the existence of any nervous cftUM of ftkBt 
apart from vaso-motor changes. 

ThrombosiB is the coagulation of the blood within the v«*A 
during life. The proiluct is called a thrombus, in oppoaitioo «"• 
coa^ulum or clot, the result id' |)ost-morten» coagulation. Tlifu»" 
bosis may occur in the heart, arteries capillaries, or vriun. 1* ** 
in the reins that it most frei|uently occurs. 

CAUSATION. — Thrombosis is generally said to be ilnr t- ■'=*'-' 
or more of three causes : damage or absence of the lining of t"** 
vessel-walls, retardation of the blood-stream, and cbaog«« w v>^ 
blood itself increasing \tA coagulability. These cuiuoi we >b**^ 
now |)rocefd to discuss. 

I. Damage or Absence of the Lining of the V( 
wall. — The most striking points arc — first, that blooil rirrwlsti 
in living vessels remains Huid, while blood drawn from the Ui**. 
coagulates; and. secondly that when coagulation of ctmilati 
blood occurs it is usually upon some obviously disossed suKaee t^ 
in some place where the blood-strc-am has been mach r«(anl«^ 
Krom tlu'.'.e fact.i it has been inferred that the hcaltbT rc(»«U' 
exercises an inhibitory intluence upon the coagulation of Uw 


preventing the changes (whatever they may be) which lead to the 
formation of fibrin. It is probably more correct to say, with 
Lister, that blood within normal vessels does not tend to coagulate, 
the vessel-wall being, so to speak, neutral or passive so long as it is 
living and healthy. In this light the normal vessel-wall may be 
compared to greasy and viscous substances, like vaseline, paraffin, 
and castor oil, in which blood may long be kept fluid, and yet be 
ready to coagulate normally as soon as it is brought into contact 
with solid matter. Contact with ordinary solid matter, on the 
other hand, induces coagulation more quickly. When drawn into 
t basin, blood usually clots in from three to eight minutes, but 
Lister saw blood remain fluid for a long time in the angle between 
an amputated sheep's foot and the skin raised in a flap from it. 
Moreover, extravasations about simple fractures and into the cav- 
ities of the body are often long in coagulating, though they vary 
much in this respect. Coagulation occurs more rapidly on a rough 
surface than on a smooth surface. 

Although the integrity of the vesgel-wall has been spoken of, the 
integrity of the endothelium is alone necessary. Fatty and cal- 
careotis changes of the deeper structures do not cause thrombosis, 
whilst atheromatous ulcers, foreign bodies, and nodules of new- 
growths — all bare of endothelium — may; moreover, severe injury 
of capillaries, which possess only endothelium, causes thrombosis in 
them. It may therefore be concluded that damage or ahgence of 
the vascular endothelium is an essential condition in the production 
of thrombosis. This damage or absence, as already stated, may be 
due to many causes. 

1. Iqjuries may destroy or injure the endotheUiivi. Among the 
most important of these are section, rupture, ligature, and torsion 
of vessels. In section and rupture thrombosis starts from the dam- 
aged intima, and constitutes the means by which hemorrhage is 
naturally and temporarily arrested. By ligature, torsion, and 
other operative proceedings surgeons can also temporarily arrest 
hemorrhage which the natural processes are insufficient to stop. 
Cauteries and caustics furnish other examples of the effect of 
'Bjurr in producing thrombosis. 

2. Diseases of the i'es»e.l-walls may affect the endothelium. 
'^^, thrombosis may occur on atheromatous ulcers, bare cal- 
careous plates, or an intima damaged by syphilitic inflammation 
01" by the extension of spreading inflammation from other parts. 




IiiHaniination \vii!» formerly regardeil lu* tlu< innin. if not the miIt, 
cuuKi- of thrumbosis ; bouue throiiibosis iti veiiw* i» frttinriidt 
tcrmud " plilebitis " eveu at the jircsfnl dny. InllMtnniatiiio uf 
vciu» i» rurc lus n prinimy condition, but it may be due to extrntuia 
of inflatuiutition from neighboring tissues, and not infre<juentlj 
re»ult* t'niiH tlie formation of a thrombus. 

The thrombosis wliicb occurs as an occasional complimtioti of 
acute specific fevers is explained by the obwrvution nf I' • ' ' 
that in thef<e dit«ea!«e8 desi|iiumiitiiiii of endothelium miiy iMim 
large areas of vessel!^. 

fti tfir hi'iirt inflammatioii of the endocardium enti.«e:« drsirnftinn 
of its endothelium, followed by the growth of granulation tueuf m 
the op{>osed surfaces of the valves: thrombosis fre<|uently cam* 
upon these vegetations. (See " Endocarditis.*') 

Fio. 94. 

' fcetlno or • IhromboMMl pnpllli'iil nrh'ry • fnrtiilKhl »Arr U(Mur», ■tio«ia( , 

■Iniait Ihp wtaiilv i>r tbv Inlltnii. The thrumbun liaii bcvn torn ih>in Ih* veawl-valL IlkM- 

8. Imperfect blood-supply nf a part raimwif liim-atr nf ikf n*'**' 
vtilh fill iiii/ifi-ffct nutrition. Here slowingnf the circulation ia •■* 
iudireet, and deficient va.seulnr 8U[)ply the iram<Hlijne, cause. It* 
probtihly not a very important group, as there are rossons foraf 
picking the nutrition of the vessel-wall depends on the circnUlJoa 
in the vn.-ia vasorum. and not on that in the afTcctetl v«wel (Fig- W; 
see " Inflammation of Arteries"), and there is uo Decosaarr rtla- 


hip between these two portions of the circulation. This cause 
iefly operative in the case of the smallest vessels. The con- 
is affecting the blood-supply will be considered in a subse- 
t section. 

The presence in the vascular »ystem of substances not covered 
dothelium. These comprise such things as needles, horse-hair, 
re introduced into the sac of an aneurysm ; pre-e.xisting clots 
mbi or emboli) ; parasites which have penetrated the vessels ; 
lew growths which project into the interior of veins. In all 
instances the clotting first takes place upon the foreign sub- 
e itself. 

Retardation of the Blood-stream. — Sometimes abnormality 
rface is insufficient to cause extensive clotting until retardation 
c blood-stream is added. For example, in the aorta we some- 
i find calcareous plates uncovered by endothelium, but with 
or no adherent fibrin. In aneurysm, too. the wall is always 
rmal and the circulation somewhat retarded; but sufficient 
ng to effect a cure may not occur until by treatment we still 
er reduce the current, and thus prolong the contact of the 
1 with the abnormal surface. 

I the other hand, retardation, or even arrest, seems quite unable 
tsclf to produce thrombosis. So long as the endothelium is 
fairly nourished within the vessel the stagnant blood will not 
iiiate. Blood within a tied-off turtle's heart does not coagulate 
the heart dies. The time preceding the occurrence of coagu- 
a in the jugular vein of a mammal is longer in proportion to 
are exercised in laying it bare and applying the ligatures ; and 
is operation be done antiseptically, coagulation may not occur 

IV are these very different results to be explained ? Impaired 
lation in a part means damage to all the tissues supplied — to 
ascular endothelium among others. It is of course possible 
diminishing the rapidity of the blood-atream may have no other 
;nce than that which it exerts in this direction. There are, 
ver, rea.sons for assigning to it a more direct action. All parts 
stream flowing through a tube do not proceed at the same rate, 
lentral or axial part of the stream invariably travels faster than 
peripheral or periaxial, for it is exposed to less friction. If 
particles be suspended in such a fluid, those with a specific 
ty most closely approaching that of the fluid will move most 



luiiidly and inuintuin their position in the axial !<tre«ni tiu'rt cuily. 
If the rate of flow bo climininhoil. tlic leii<lency of the m;-- -' ' 
particles to remain in the axial stream will also diniiniijii. 
will be in pro|H)rtion to the difference between their n-sjiwtnf 
specifie gravities and that of the fluid in which thev »■ 

In most arteries und in many veins the periaxial str. 
only plasma and a few leucocytes. But directly the stream *l*ckra» 
the leueoeytes fall out more rapidly than ever, anil Ian lieliiml fW 
to the walls, while even the red corpuscles maintain lew piTt'cfl]' 
their axial position. The hlood-plateleto (blood-plale<<. binnK^ 
blasts) j»enerally occupy the axial stream, but fall out wion ^f^n■ 
and from the same cause as the leucocytes. Now. whit'i'f ■' 
attribute to the leucocytes or to the platelets the chief fiiiH: 
the production of the thrombus (p. 24G). it is cjiiite evident iwt 
thoujrh the lining membrane of the ve.isel be diseased, yet tbf i»- 
creased IViction thereby j)roduced may be insuflicient to caum- »ii' 
practical slowing of the blood-stream at that point, bikI iiwuffioifoi. 
therefore, to bring either platelets or leucocytes into rotj' ' 
the damiiged part of (lie wall. In this way we mn_\ have .n. 
mal endothelial lining without any resulting thn>mbn»is. 

On the other hand, when the current is slow, a.* in the vi-iiu. ili* 
leucocytes and platelets will readily come into cuntnet with tbf mi1« 
of the vessel, and may proiluce clotting even though the •l»iu»i.i' '* 
vessel-wall be comparatively slight. In this way wo find that neilk** 
damage to the endothelium nor slowing of the circulation ncf<l I* 
followed by thrombosis, and that the furmer is the more i»i|i'irt*i>l 
cause of the two. because there are many plBci>s where the bl'W^ 
stream is naturally slow. 

A tendency to stagnation of blood may be due to many cam* 
of which the most importattt are cardiac weakness, general ilimin*" 
tjon of vascular tonus, and ililatation (varix) of veins. .\ll tl"^ 
may well !»«• combined in a single case to retard the circiilatiou. »"'' 
thus to produce an abnormal vessel-wall and prolonge<l contact "« 
the same blooil with it. They are conditions which give rv» 
" marasmic clots " of Virchow. These form in the mi-»t <irf 
Print — f. </. those of the lower limb, pelvis, or back ; in fh< 
rein* ami »inu»i!M, where the venoua circulatioD ia ordiitarily 
slow and difficult; ami in those part* of the heart in which 
tends to remain when the organ first fails to contract eflicirn 
r. g. the auricular appendices, the apices of the ventricles, and 


spaces between the trabeculee. In veins these clots begin just behind 
the flaps of valves. The force of the venous current is so slight or 
the resistance to it so great that it no longer opens the valves com- 
pletely; the blood consequently stagnates, and after a time coagu- 
lates behind the cusps, Such clots occur in the course of many 
exhausting diseases — as phthisis and cancer — in which thrombosis 
is materially facilitated by the (juiescent state of the patient. Care- 
ful examination of the sites of recent thrombi is said to have dem- 
onstrated absence of endothelium, but this is hardly proof that 
alteration of the endothelium was the cause of the thrombosis, for 
the cells may have disappeared secondarily. 

In varicose veins, which are frequently the seats of thrombosis, 
the circulation is extremely slow, and the endothelium, owing to im- 
perfect nutrition, can scarcely ever be healthy, though it is not 
always so damaged as to excite coagulation. 

III. Certain Conditions of the Blood favor coagulation and 
promote the occurrence of thrombosis. It is said that the tendency 
to coagulation is increased during the later months of pregnancy, 
after profuse hemorrhage, and in certain acute inflammatory diseases, 
such as acute rheumatism, erysipelas, pneumonia, and pleurisy. To 
whatever cause it may be due, an increased tendency of the blood 
to coagulate is probably never more than a predisposing cause of 
thrombosis. In septic fevers thrombosis is not uncommon in places 
taving no direct relation to a wound. This has been attributed to 
the breaking up of leucocytes in large numbers, for it has been 
shown that injection of leucocytes into the circulation of animals is 
followed by their rapid disintegration and local or even general 
thrombosis. In all these diseases a failing heart and flagging circu- 
lation — the causes of ordinary marasmic clotting — are present, 
whaps desquamation of endothelium (p. 241) occurs, and it is 
possible that organisms may play a part in the proce.xs. The pres- 
ence of organisms seems particularly likely in those frefpient cases 
'f Tenons thrombosis, often going on to puriform softening and 
"ewndary phlebitis, which occur side by side with erysipelas and 
Pyemia, and which have gained for " phlebitis " a place amongst 
"hospital " diseases. 

« is well known that the presence of calcium salts is essential to 
™* coagulation of the blood, while the addition of oxalates will 
neutralize the effect of their presence and prevent coagulation. So 
*''o among the products of cell-action substances allied to nuclein 



ai<l coa{rulntion. whilo albumoson hinder it. We do not tei 
the bearing i)f these f'nets tijwn the phenomena of tbroinbosi 

ooagula in the heart are generally fxtffi/. The thirknei 
pule layer varies ilireetly with the time whieh elapses h«l 
changps in the hoart-substanee allow coagtilation to begin, w 
position inilieates the part that was iipi)crmost after lienib. 
mortem clots are red. soft, watery, and never adherent. 1 
not JiH the vessels, and can be easily drawn out of thetii i 

Clots formed in the heart Just before death difl'er imi 
from the preceding. They are partly due lo the •■ nhippi 
the blood by the chordie tendineue and other structnrcB. 
oceiir in ca.^es of slow death, when the heart is too weak l«i 
its cavities an<l the hlooil tends to stagnate. As wmilil be ex 
they are more or nniformly dccolori/.ed. and. thongh n^ 
rent, are often so much entangle<l among the ehordar and tm 
that they cannot reailily be removed. From their longer di 
anil more complete contraction they arc firmer and totigh< 
true jKist-mortem clots. 

Thrombi or ante-mortem clots are of two kin«l« — r 
white — according as they originate from tfuietcirtit or rire 
blood. In the former case, as seen in an artery or veil 
ligature, more or les.s of the (stagnant blood on either sidt* 
knot coagulates into an onlinary red clot — soft, unifonn on i 
and adherent to the ve.ssel-wall where this is injured. The 
bus. still atlhering to the wall, then contracts, becomes d 
less elastic, but still remains red. This is the state in wi 
thrombus is generally found. 

Kut y> hen coagulation occurs in blood whirh i» ttill rireiii 
in the sac of an aneurysm or on a cardiac vegetation, a w 
mixed thrombus results. Zahn studied the formation of su( 
in small veins irritated by a small crystal of salt in their ne 
hood. .According to this observer, the abnormal surface 
eai'b successive ipiantity of bhutd which passes to |i>ave up 
little fd>rin and some leucocyte!*, whilst, if the blood-»t| 
languid, soiue red cor[)uacles remain in the ihrombuii. r«>nd 
mixi'd. Hut later observers have sliown thai innumerablu 
plateleta, and tiot leucocytes, are deposited upon a thread 



ngb H vessel, and alsn. in the case of a severed urtery, upon the 
lilvenlitiii within wliieh the cut vessel bus retracted. Moreover, an 
txaiuiuiition of old clots in aneurysuis lias convinced <.)8lcr that 
they, too, consist of )dutelets, and he, consequently, regards leuco- 
tyti's lis of little inijtortanre in the formation of thrombi (p. 'lAA). 
These throiubi are grni/ig/i-whitc or reddimli, Jirinli/ aiUii-rvul to (he 
wall, and it U pveuliar to them t/iat they are often atratified. This 
is probably due to variations in the rate of do|iosition of the fibrin, 
in the bloiid-pressure to which it is subjected, and in other physical 

E' tins. Fretjuently white and reddish layers alternate. 
rombuB may be "parietal " or "obstructive." causing ]<artial 
plete occlusion of the vessel. Once formed, it extends by 
liepofiition of umre fibrin on its surface. As a rule, this extension 
i»checke<l by the rapidity of the blood-current at the junction of 
the first large collateral branch in each direction ; but sometimes, 
jgMcially in veins, thrombosis becomes " c(;ntiniied." and a clot 
^^bztentl from the foot to the vena cava. Both in arteries an<l 
'VW!i» extension is most likely to take place toward the heart, 
ih it may occur in an direction. These thrombi 



1 III lui arterUI tliroinbiM thtrty-«evc-u dnys old : a, new blood-rcssels : 6, leuc-ocytoK 
ItUiiiioaliiii ccllii. iKIiidHoltrh.) 

»Ily adhere to the wall throughout their whole length, but 
Smea they <lo so only at their jiointa of origin. 

hhe capillaries coagulation occurs ordy as a result of necrosis 
>ve injury of the capillary walls, for they are »n small that, so 
,'""6 M they are living, their intliienee in preventing clotting will 

Ipon the whole of the contained fdoud (Lister), and conse- 



f|iiently tliromhosis docs not extentl into tlicui »o lonjj a# tLcrcu 
sufficient blood-siipiily to kevp tbein alive. 

LATER CHANGES IN THROMBI.— These arc— dccoloni*. 
tion (when reii). rcHoliitioti. or;^anr/.iitii>n. calcifiestiuii. soAniiBg 
(ninijile mill infeetive), and piitrefacfinn. 

Decolorization. — Tlic first ehange in a rod throinliiut is % brak- 
ing down iif the red i'"r|iiisele8. Their stroniata beconio unrwof- 
iii/uhle. and the h:enio;:li>bin in set free and in great part ahwrbtJ. 
though some may remain at* granular hnematoidin. A* a mult thf 
throniliu.t limes its deep-red eolor and accpiires a finely mouM 
reddich-gray tint. The procos!< begins in the centre, and tdM 
weeks or inonthH before it is coinpieteii, 

Resolution. — That many thrombi dinappear is certain. f<»r »lmi 
it wa!< the ciihtoni for venesection to be yierfornied at regular luif- 
vaU the repeated bleedings were lVe(|uently effected from the muk 
vein. Ill UKiderii times. aJHo, re-establishment of the eirt-uiatmii 
is known to have occurred through spermatic veins and il 
the supi-rficial veins in tin- leg in eases where thronibrMiis i ■ 
doobtedly taken place. The steps of the proceiw are nol knn"*- 
In some eases of death from septic poisoning appearanc*vs founil IB 
vessels which have been tied indicate that thrombi, (••rni.-il )»(i\n 
the on.oet of the fatal disease, have brokeit down. 

Organization has been mainly stuiiied in thrombi forroiii); in 
ligatured ve.ssr-l.s. The effect of the application of u ligBliiff •» 
usually to cut through the miildle and internal coats of the «(W>> 
the ends of the divided coata c^tntract and retract aomewhat. tarniDf 
up and down into the lumen of the vessel ; anil the coii-' ' " 
external coat is all that is left in the grasp of the noose. Ii 
hours a red thrombus forms, conical in shape, and adherent by it* 
bajte 10 the iineried inner and middle coats. For two or tbr 
<luys it extends, until it finally reaches the junction of the I 
collateral branch^-often, for some unknown reaM)n. stopping al 
of this lUi the distal siile. .Meanwhile, it has become firmer. ilri<*i 
and more widely ailherent about its to the artery. Tht 
of adhesion progri-s-ses. as the thrombosed piece of veMel coni 
upon the clot, until it becomes universal. By the seomd lUy * 
luiffy nodule tnay be seen in the base of the ilee|»-r€<«l throml 
anil this rapidiv increa.«es, so that in a week or two the color of 
clot has disappeared. .Vfter some weeks or months this ilecohu 



Fui. 9f.. 

i>und to have been replnccd by connective tissue intimately 
Uritii the artery, wliieli Ims tin- appearance of a firm fibrous 
The microscope gives the t'oliowing explanation of the ]iro- 
Thc red thrombus couisists of red corjotsscles. witli a few wliile, 
» meshes of a fibrin-con^rulnm. The biifly nodule which grows 
the base of the clot is formed of ^uiuil r«>ui)(l-cell.x. wliieh at 
»re undoubteilly leucocytes migrated fnou the vusa vasorum 
wi by the ligature. But there is a diflVnuie nf opininn as to 
rigin of those formed atVer (say) the tliird dtiy. By this time 
ells of the part iiave recoveretl from tiie injury <\u)\v thi'in by 
'Qund and ligature. It has been niainttiincd i)t:it tin' new tills 
Jl It-iiroriftrii '</• t/irir protjnii/. Si-liftU-beu Sfciin'd hctuvrii 
le ligatures pieces of vessels and put them into the abdomens 
bbits — an experiment which is 
ically repeated in the bits of 
1.1 wiiieli lie hei/oiid the liga- 
in all aseptic stumps. He 
1 tliat they became filled with 
fctive tissue containing well- 

f I Spindle-cells. It is, how- 
no means certain that 
' spindle-cells were derive<l 

E)cytes (p. 120); and even 
ere. the ability of white 'aJ 
1 to form the new ti.isue 
|^>ot exclude endothelium 
Hp doing 8o as a regenera- 
^■peas* A more probable 
Bnon is that the organizing 

{' les from tiie endothelium 
the deei>er layers of the 
The iiitima is often found 
, and the internal elastic 



LiMiiritiKliniil Kvctliin of the- Uifntiirpil 
eml (If llu- I'rurni iirtcry of a ling tlRy 
ilnyn nftcT thr nppUcaliDii nf lUc UKUtiirr. 
^hor•rillK till' iiHwly-fitriiifd vi*!«ho1s in tla* 
thrombus ami tlu'lr I'omniunti'Ution with 
imultaneOUSly obscured or thv vun vasorum; n. Ihrmnliii!!: jtf. 
_ n 1.1 iniiM'iilHr riiul : Z, pxtt'ninl null iiikI VRim 

IB op. Processes can he triice<l 
y^ lining membrane ilis|)la(-- 

^■riginal clot. However formed, the cell-mass is penetrated 
lood-vessels, which form us in granuhition tissue (p. 128). 
become spiuille-shaped or briiiit'lu-d 4 Fig. DU); fibrillation 
litbcr in them or in the ground-substance between them; 

vusoriim. ■ 20. (O. Weber.) 



many cells (lisHp|iear aii the fibres increase ; the latter contnrt i»l 
iMiiiiy vessels are oblit'Tatcd. the result beinp the fil>r<>u» c<»nl ilnnt 
mentioned. This is called organization ol' a throntbos. but ii » 
evident that the original thrombus disappears entirelr. and Iw 
nothinj: to do with the proeoss which goes on in the n>nt 
muss the origiii of which we have discussed. The ve!*fl .;_.. .. 
ex>nverted into fibrous tissue and blends with that of the riot. 

In certain cases channels are formed in the new tissue: tb»» 
communicate both above and below with the lumen of the vtwfl 
and thus tlie circulation is more or less completely re-esti»l)li»kf(i- 
They are probably due to dilatation of the vessels of the thromKw 
(though «hy this niiould occur in some cases and not in ■•'' 
unknown), mid give rise to the »iiiii»-likr (hijrniTiitiim of Hoki! 
It is espceialiy fret|uent at the junction of the common iliac \rM 
ill cases of •' white leg." and leads to more or Ie«8 perfect recortri- 
It is rare in .irteries. 

Organixiition is most frequent in uniform, unstratifim) ihrmn'"' 
and especially in those occurring iti arteries. But longchtt- 
kind, such as occur after ligature of the lower i>arl of the .... ■ 
as well as large laminated thrombi, like those in aneurysm.'. o»»J 
remain as more or less granular masses of non-irritant fibrin, witbo*' 
any sign of organization. 

Calcification. — This occurs in some clots, giving rise to phl«***^ 
liths. These are especially common in the prostatic plexm- 

Softeniiier. — 1. Simple. — A fhronilms which undergoes none 
the prev ioiisly described changes often softens. This, in the tu«jnr»*? 
of eases, is due to the chemical changes which the constitueut« *^ 
an a.septic tliromliiis undergfi when no organization or-curs. Tl»*^ 
result in the forinntion of u more or le.>ts Hiiid, pappy substaii< 
which has a red<lish-gray color, varying with that of the ihromb 
which is undergoing ihe change. To the naked eye ihr fluid oft^ 
looks liki- pus, and the process is still spoken of as the jtHiifnf' 
»oftfiii)ii/ of a clot. Itiit N'irchow pointed mit that the fluid f<>l 
sisted of the d(^ris of corpuscles and fibrin — albuminous, fatty, atf 
pigmentary granules. Thi-re may be a few reeognixable white e» 
pii,-«'b's in it »lii<'li have prolialdy niigraieil from without. In 
of constriction of the mitral orifice of the heart, with con!»e«|a« 
dilatation of the left auricle and slowing of the circulation. I«r; 
cloi.s undergoing this change may be found in the auricle*. Tbtr 
consist of little more than bags of thick, grumous fluid. The oatn 


lamioic generally form a firm case for the softened central part, and 
if the softening approach the surface, this case is often thickened 
at that point by the formation of fresh protective clot. Not infre- 
quently, however, the encasing clot may be perforated and the con- 
tents discharged into the circulation. The larger particles may 
form emboli (p. 255) probably too minute to cause syuii)tonis. 
When occurring in an artery or vein circulation may be thus re- 
established through the thrombus. This process constitutes canali- 
Kklaon of a thrombus. 

2. Infective. — But certain cases of puriform softening similar, 
so far as the naked eye can detect, to the above are accompanied by 
all the symptoms of septic poisoning. Acute suppurative inflamma- 
tion of the vein-wall is shown by the microscope, and any portions 
of the clot which enter the circulation are so intensely irritating as 
to cause suppuration wherever they lodge. (See " Pyaemia and 
Septiciemia.") The difference between the two cases is, that in the 
latter form of softening micrococci are constantly present, and it 
is to them that the infective properties of the broken-down clot are 
due. In the great majority of these cases the veins affected lead 
directly from a wound, and then the mode of entry of the specific 
micrococci is evident. In a small number of patients also with 
wounds the thrombosis and softening occur in veins having no kind 
of direct connection with the wound : here, too, the organisms have 
entered by the wound, and in some cases at least the thrombosis is 
•^condary to a general septic infection. Finally, there remain a 
'*f instances in which no pathological breach of surface can be 
Wind for the admission of the germs ; it is thought that in these 
"■^y must have passed into the blood through the alimentary or 
''^piratory mucous membranes. 

^trefiiction. — This rare change is due to the entry into the clot 
f the putrefactive bacteria from some very foul, and often gan- 
S'^Qous, surface : the growth of these organisms converts the throni- 
"* into a stinking yellow-red fluid which is highly irritating. 

. *^8ULTS. — The results of thrombosis comprise certain changes 
*he walls of the vessels, more or less obstruction to the circula- 
""> and embolism. These must be considered separately : 
1- Ohansres in the Vessels. — More or less alteration in the wall 

01 th^ Tessel is an invariable con8e(jucnce of the formation of a 
"^^bns. When the thrombus undergoes a process of organization 


it becoinca, as alreatly <l<'9criin'(l, ititiiiintcly iinite<l with the' 
wall. The Intter, in tlic first jilin-c, l>c»«iiie!* infiltrntr<l *>id 
and fonsiilcrahly tliiciifiHMl, hm iiiiiiniiti.-lr, ti);;f»lifr 
thruinbns, gradually iitrupbit'S. It is wlieu tin- thronibun U9 
a process of inffrtive /iiirij'urtii Koftrtiitii/ tliut llir niii)«t in 
vhiiiigcs of an acute iuflnmuiatory nature tiiki- )ilace in tht 
They are due to the irritation of the deeoiuiMJiiin^ ihromt 
are most frequently observed in the veins, 

where i«fe<-tivr I 
h 11 vein are eonoi^ 

thickened, so that to the nuked it resembles an artrrjl 
inner surface has lost its tranflliiccncy, and is of a dead] 
color. The ndventitia and middle (roals are iuje<Tted audi 
numerous heUKirrliiigic points, which are often visible ihrol 
intiiua. The swelling of the wall ia, under the niicro»cope,l 
be due to dense infiltruticin with leucocytes, which cDnceaUJ 
mal structure (Fig. I'T), while the innermost cells die aud ai 
into the lumen of the vessel. Small collections of pu» mav 

Fio. 97. 





ikptloii iirna* • |>irtul I'luwl In a , . • ^ , > IrphlfliUI* arlalus la { 

Mitli " iiinliillral pyarmU." The vcln-wiU ( K) I* converted Into (Tmnulatlnn « 
<if vi'lii 1» IK-Iiin on III)' li'ft. iHoyil ) 

in the externiil un<l middle eoal.-«. The neighboring tiMue | 
become involved. acute inflammatory changes in n 


stitute what is known as suppurative phlebitis. Although most 
freq^uently due to thrombosis, they may also occur as the result of 
extension from adjacent suppurating tissues, in which case the 
tbroxubus, which also undergoes puriform softening, is gcnondary to 
the phlebitis. Similar changes are observed in the arteries. Septic 
arteritis, attacking a ligatured artery in a putrid wound, was for- 
merly a most disastrous sequela to operations, being the commonest 
cause of secondary hemorrhage, now so rarely seen. 

2. Obstruction to the Circulation. — The consequences of the 
obBt;T*uction to the circulation resulting from the formation of the 
thrombus will depend upon the rapidity and manner of its forma- 
tion, the nature and size of the vessel obstructed, the situation and 
nnmber of the collateral branches, and the force of the circulating 
• current. The rapidity with which the obstruction is effected is of 
considerable importance, inasmuch as the more gradual the process, 
the longer is the time allowed for the establishment of a collateral 
circulation. For this reason the interference with the circulation 
<*ttsed by thrombosis is, for the most part, less marked than that 
'thich results from the more sudden obstruction caused by embolism. 
In the veins, when thrombosis occurs in a vessel of small size and 
^oen collateral branches are numerous, as in the prostatic or uterine 
P'^xuses, the circulation is but little interfered with, and no symp- 
™ttjs of obstruction result. If, however, the main trunk of a large 
*'**•*», as the ilio-femoral, becomes obliterated, the obstruction is 
***«Owed by mechanical hyperaemia, the extent and duration of 
"^'lich will depend upon the facility with which the circulation can 
^ i"e8tored by the collateral vessels. It must be remembered, how- 
®^^i", that the valves in veins, when they exist, may, by preventing 
"*cIc-flow, offer a great impediment to collateral circulation. Throm- 
|*08ia in the ilio-femoral vein frequently occurs, as already stated, 
I** the later stages of many chronic debilitating diseases, especially 
'** phthisis; also in the puerperal state, where it gives rise to the 
'^ontjjjjQj, known as phlegrniasia dolens. As the femoral is almost 
**** only vein which carries blood back from the lower limb, the 
*«ect of suddenly blocking it is marked. At first cyanotic, the 
'**>i6 becomes swollen, pallid, white, painful, and too tense to pit, 
*^<l there is more or less tenderness along the rf/n, which feels 
enlarged, hard, and knotty. These symptoms vary greatly in 
*''aonnt, and to them are sometimes added those of lymphangitis 
*^d cellulitis. The extent of the thrombus, the number of col- 



lateral bniiulics which it blofks, ami the streiifrlli of the iirculniM 
will do niiK-li to uceoiiiit for the uuiount of ilmIciuu: ami it i» protw- 
blc that the more acute iutlauuiHtory symptutnti arc of septic ongn. 
The eirciilutioii is. in nioHt cases, ultiiiiutely restored; but iflbe 
iuipeiliuH'iit huH been of a lung iluratiMU. (he tiaiiues become thickdtnl 
anil the limb remains hard, indurated, and somewhat enIarg«<L 

The re.sultti of obstruction in arteries will be considered •! tti« 
end of this cha|)ter. It is in tissues with "terminal " arttriwtlul 
the interference is most marked, and here heuiiirrh!i)ri<- infanliiiu. 
tvhich so often results from embolism, may occur, nlth<Mij;b. oiitf 
t«i the more gradual obstruction of the <Mrciil!ition. it i.s Ie-*s likfh 
to do .Ml (.•'ee iielinv). 

8. Embolism. — Tortious of the thrombus may be corrii'd »to 
by the circiilatinn. thus coiistitutinf; enilxdism. This, which i« Ik* 
most important result of throndnisis. will be considered ui tl>f 
following section. 

Embolism is the impaction of solid substances circulating iu tk* 
blood in vessels which are too stnall to allow tiiem t<i pa». Tbf 
Flo. 68. soliil substance-s are termed emboli, and art- of 

very voried nature. 

By far the most frequent Bources «>f erol-'l' 
are thrombi, jiortions of which ore carried ffw 
the seat of their formation by the circulali<ii»- 
Many other subettknces, however, may ut 
emboli, .\montr these are — (1^ vefretatioii' 
ciilcareous or atheromatous ma«^»eii sepanttiii fi 
the valves of the heart or from the innrr 
face of arteries: ('!) portions of new pr^i 
as .sarcomata — which, having perforate*! i 
... ., , .. sels, have been carried awav bv the ciimeirt : ("l 
••i>h<-iii>u> vrin. iihow. parai<ites which have made their war into 
rru.l;rr:;:.^l int-Hor of vesseU: (4) liui.l n.t wh^ch h» 
iiinimiiiiK Into (III- mil caped from the fat-cells and entered open \\ 

• ■ml vi-««'l .«. uphv- , , . , 

pbatics — an occasional occurrence tu 
and contusions: antl {'A f>ipnient-jrri»nnle4. 
.\ thrombus may produce embidi iu va 
ways : (1) It may soften and break dowii. 
its fragments be distributed by the bl 

nttu* v<-ln . T. throm- 
hiu ''. I'onlriil <''■•! 
prajortlnff Into f«-iii<>r.«) 
%*'ln. At r, f, iip|M.»i!*- 
Ihip valvt«, thn Uinini- 
Im* l» •(>(Um<Hl. (Vlr- 



Fig. 99. 

rtions of a parietal thrombus, not filling the vessel, may 
by the passing stream. But, on the whole, the most fre- 
; (3) that illustrated by the accompanying diagram. A 
tally ceases at the junction of the vessel containing it with 
e collateral branch. The cardiac end of the clot, how- 
.xtends as a firm conical projection into the lumen of 
i"ig. 98, C), and the strength of the blood-current, which 
factor in preventing the further extension of the clot 
heart, may break off this projecting end and sweep it 
eral circulation. Some sudden movement or exertion 
lines in these cases the separation of the fragment 
brm the embolus. The veins are the commonest seat 
s, and venous thrombi are common sources of embo- 
ins of the low^er extremities and the 
s being the most frequent sites. Em- 
cardiac thrombi, whether attached to 

projecting from the valves, is also 
common, and is produced in a similar 
3 frequently arterial thrombi give rise 

come arrested in the first vessels they 
are too small to allow them to pass, 
refore, the seat of impaction will be 
lation of the vessel or at some point 
the giving off of large branches, the 
lishes suddenly (Fig. 99). The par- 
! so small as to pass through even the 
ries, and not give rise to any symp- 
Y may pass through large cajjillaries, 
i in a finer set beyond ; but, as a rule, 
lacted either in the first set of capil- 
;h they come or in some larger ves-sel 
set and their seat of origin. Thus, emboli originating 
lie veins or in the right cardiac cavities will most com- 
e arrested in the ves.sels of the lungs. Emboli origi- 
e pulmonary veins, the left cardiac cavities, or the 

be similarly impacted in the systemic arteries and 
•specially in those of the spleen, kidneys, and brain, 
oli originating in the portal venous system will block 
he portal vein in tlie liver. With the exception, there- 


Embolus Impac-ted 
at the bifurcation of 
a branch of the pul- 
monary artery, sbow- 
inK the formation of 
thrnmbl behind and 
in front of it, and the 
extension of these as 
far as the entrance 
of the next collateral 
vessels : E, embolus ; 
tX. secondary throm- 
bi. (Virchow.) 



fore, of emboli oripiiiiitiiig in the portal .syHteai tbe »e«t of arrK u 
the artc^ie^< or cii|iillarieK. 

Eiuholi are carried usually in the direction of tbe main curmi; 
hence tlidse <-nrrie(l hy the iiortic xtreani pas(« int'> the thoracinotu 
more commonly than into the carotid or subclavian v(«iM>b, uil 
into the left carotid or left renal artery more often than into lb* 
corresponding artery of the op|K>»ite »ide. (iravitation bU» inRii- 
ences the direction in which they are carried, cspecinlly \\wym «f 
large e\7.c. which move somevNhat luore slowly than the blu«4- 
8tream ; hence they are more common in the lower VAtr* auJ po^ 
terior parts of the lungs than in the superior and anterior iMirtiow 
of these organs (p. 268). 

It is not uncommon to find that the small vcsselo nf an area <^ 
which the supplying artery is plugged also contnin enihuli. Tli" 
may be accounted for in two ways: Firttl, if, a* i.« fro^nrtdh i^ 
case, the mrrcst takes place at a point of bifurcation, the ruMt 
may partially fill both bninches. allowing ii small stream "I ' 
pass; this imiy iireak oft' portions of it, and so produce m :.. 
emboli, which become impacted in tbe smaller divisions of tlf'W* 
main trunks. The »eeond mode is by the detachment of wTffw 
small emboli from some distant source, which subscifucntir yifltb* 
mash large i>nougli to stick in the main trunk. It r-. founil ijpt**" 
mentally that small bodies injected at intervals into the jnj;uItr<M> 
are sometimes swept into the same division of the pulmonai 

The amount of obstrtiction which immediately follows k • 
will de|ieiiil u|>on the naturf of the embolus as well a« upnn itttf* 
and shape. If the embolus be from a soft, recently-formed ill'*' 
bus. it will be at once moulded to the cavity of tbe veMrl, »k** 
will thus be immediately and com|>letely plugged. If, on thr i>^*^ 
band, it is irregular in shape and firm in consistence, as whelfH 
rivetl from a calcified cardiac vegetation, it may not complelel^^ 
the vessel, hut allow- a snuill current <if blood to pass it. 

The arrest 4)f the embolus, and tbe conseiiuent obstruction tot^ 
circulation, are followed by the formation of secondary throiri* 
behind and in fmnt of it, which extend ».>< far :is ihc juncimn ofiW 
first large collateral vessels (Fig. 98). If the emhtdus dcie« not ttnr 
plelcly (ill the vessel, thrombosis leads to the dc|M>sit of Kucvcanvt 
layers u|sjn its surface until the occlusion of the veftsrl is o«>iap]ct(« 
and then the secondary tbrombos vxtends, as in the ffirmrr a 
until it meets with a current of blood strong enough to anreat il 


progress. If the embolas is a portion of a soft thrombus, it will in 
most cases be impossible to distinguish it from the secondary throm- 
>a£ which surrounds it. If, however, it is a calcareous mass or a 
>OTtion of an old thrombus, it may usually be distinguished from the 
aore recent secondary coagulum. 

Emboli may, in rare cases, become absorbed. They may also, 
rhen derived from thrombi, soften or become organized. The 
hsnges in the secondary thrombi are similar to those already de- 
cribed as occurring in the primary (p. 247). 

XESULTS. — The results of embolism are — (1) those depending 
ipon obstruction to the circulation, and (2) those produced by the 
irritation of the emboli. 

Trom the facts disclosed in the preceding paragraphs it may now 

be inferred that embolism of either the pulmonary or the systemic 

veins is practically a mechanical impossibility ; but that in any of 

the remaining vessels — arteries, capillaries, and portal vein — we 

may expect its occurrence. As embolism of the arteries is followed 

by very different results to that of the capillaries, the two conditions 

must be considered separately. For our present purpose the portal 

Tein will be grouped with the arteries, from which it differs mainly 

in its lower blood-pressure. 

Abtbbial Embousm. 

tile circulation depend chiefly on the extent of the arterial anasto- 
moses in the affected part. 

Sudden and complete obstruction of some arteries, such as the 
™ial or a second or third branch of the mesenteric, is practically 
without effect upon the circulation, which is carried on through the 
■"ge vessels which anastomose with those branches of the obstructed 
"'siy which are given off below the seat of the obstruction. Yet 
''pture of the common carotid is occasionally followed by cerebral 
•onening, easy though it would seem, when only one of the arteries 
'applying the circle of Willis is blocked, for the cerebral circulation 
^ '^ efficiently maintained. 

"> other cases there is some, perhaps even very great, difliculty in 

•fleeting the re-establishment of the circulation. This is owing 

*'tiier to the small number and size of the vessels anastomosing with 

"'e bruiches of the obstructed vessel, or to some disease of these 




vessels interfering witii their normal power of ililntation. Ihilip' 
ture of the fenionil artery the limb becomes pale ttn<l it* «orf»f»- 
temperature falls many ilegree.s. In this condition it remain' w^rnl 
faoDrK; then, if all goes well, the superficial vctioelM dilnto. thccirr*- 
lation through them proceeds with undue rft|iidit_v. and thi' «.iirfK<i«- 
t«'niperature rise.s some ilegrees higher than that of its fell'>«. Thii 
reaction gra<lually disappears, and ultimately the part may rrnnii 
abnormally cool. 

On the other hand, the part deprived of its blood-supply nuTJit 
en vuttmif. Between the two extremes of recovery and death tliew 
are many possibilities — from death of a single too upward. Tbf 
part which ultimately dies may remain pnic and bloodlcsv, U'l 
gradually mummify, but usually it becomes more or htm »mtlleii 
with blood driven into it by a pressure insufficient to send the lilwJ 
right on through the veins: fluid ami cells jiass into the ti»i«». 
organisms thrive and invade the part, and moist gangrene result*- 
Similarly, embolism of an ultimate branch of the roesenteric, vitk 
secondary thrombosis obstructing the vessels on either wdc, «iU 
lead to a partial necrosis of a small segment of bowel and be^lo^ 
rhage into its lumen (vide infra\ probably ending in recovrry: 
but embolism of the main trunk of the vessel caufleit gaiigrenr o< 
the whole intestine. 

Infarction. — This seems the best place to discuss infaretinH, » 
process often produced by embolism, but not infreijuenlly dae "' 
other causes. In some organs, such as the spleen and kiduey, tk' 
arteries have capillary, but no arterial, anastomoses with the nfij^ 
boring vessels. Such arteries are called end or terminal art*ri<* 
Each of these arteries supplies a conical compartment of ih' ■""'' 
in ijuestion. The base of the cone is r)u the surface of ih. . _ 
while its apex points toward the centre, and corrcsjionds to ' 
jioint of entrance and exit of the artery and vein rfsjKH-li» 
The possible lueans of access which the blood has to such a por 
of tissue are — (1) the main artery and vein just mentioned, (2) 
small vessels ])assing from the capsule into the cortical part uf 
organ, anti (8) the capillary anastomoses with the neighboring^ 
sels on each side. 

If by means of embolism or thrombosis the main artery suppl] 
«>ne of these conical segments of tissue becomes blockitl. nc 
and other degenerative changes will occur in it. for the cmp 
vemeU and the lateral anastomoses together are nnable to ma 


nutrition of the part. As seen post-mortem these cones— or, 
hey are then called, infarcts — when cut from base to apex have 
ery typical triangular section (Fig. 101). Two varieties are 
cribed : (1) the white or ansBinic infarct, and (2) the red or 
norrhaeric infarct. A white infarct is pale yellow, and has its 
e level with or depressed a little beneath the rest of the surface 
the organ. A red infarct is blackish red, and has a slightly 
»ed base. Recent infarcts of both kinds are surrounded by a 
peraemic zone. Red infarcts are common in the lungs, spleen, 
i kidney, and are occasionally found in the intestine. White 
arcts, when primary, are found in the brain, retina, and the mus- 
ar walls of the heart. 

Microscopic examination of a tohite infarct will reveal coagula- 
n-necrosis and fatty degeneration of its tissue-elements. Some- 
les transudation from surrounding parts supplies sufficient nour- 
ment to keep alive the connective-tissue stroma; the nuclei then 
in with logwood (Fig. 101). 

In the red infarct the tissue is so crammed with blood-corpuscles 
It the degenerative changes are often obscured. 
Some white infarcts contain granules and crystals of altered blood- 
ment. These are considered to be a later stage of red infarction 
which the rest of the hemorrhagic extravasation has disappeared. 
It is very important to remember that all tissues do not equally 
ist the effects of anaemia : those of the skin and muscle are most 
'stant ; those of the brain and intestine least. A piece of strangu- 
ed gut dies more rapidly than a tied-off ear. This power of 
■stance is not the same in all individuals, 
i/essation of function soon follows cessation of nutrition. The 
«tg of this may be extremely serious : thus, plugging of one of 

larger cerebral arteries is generally followed by sudden loss of 
isciousness and paralysis ; plugging of the pulmonary artery, by 
den asphyxia ; and plugging of one of the coronary arteries, by 
den paralysis of the heart. 

"athology of Infkrction. — Very different explanations have been 
red of the exact manner in which infarcts are produced. 
Arguing from the above data, Cohnheim offered the following 
lanation. In his opinion, the first effect of the plugging of a 
ninal artery is the stoppage of the blood passing through it ; the 
rides contract and empty them.selves, but, being deprived of 
r blood-supply, they subsequently dilate, and the pressure in 



Fio. 100. 

thctn is fluis reduced to nil. Venous pressure, though low. if'n of this, and so Idood regurjiitatt's froni tlie veins to fill 
cajiiliaries ami lU'tfriole.s on tlu' jieri])lii'rul side of the plug, «sid 
be seen with the microscope in the tongue of a frog one of whi 
linj^iud iii'ti'rifs has heen tied. The arteries rouiiil about the »r' 
dilate and their capillaries become full of blooil : but even «iililk** 
assistance the blood-pressure in these circumferential capilluriH 
still insufficient to force the blood through more than a few of t 
outlying capillaries of the ob.structed area. Consequently such 
area will be dark from the presence of stagnant venous blowl. \^ w 
surrounded by a ring of arterial redness. Later on. the csca|>t 
red corpuscles itito the tissues will darken the mass still furthi 
This occurs without any rujtture of vessels, just as happcn-t 
venous congestion (p. 231). Finally, secondary thrombosis of t 
vein and other vessels is said to occur in the area (F'ig. I'M'). 

The changes which usually result from deprivatinn of an*f 
blood were studied experimentally by Cohnheim. If the e«r o 

rabbit be cmj)tied of blood, ligatiireilut 
root for eight to ten hours, and the W' 
be then allowed to circulate, the org»ii 
comes exceedingly red, swollen, ami n'J*^ 
niatous. When examined microsropiral'J 
the ves.sels are found to be dilati^l, »«" 
numerous white blood-corpuscles arc 
to have escaped from them into the J" 
rounding tissue. The longer the pf 
deprived of blood, the more abnn<l»nt 
the subsei|uciit infiltration with leucocyt 
and when the obstruction has lasted I**"', 
four hours small extravasations of 
cor[)usclcs also occur. If the ligatiiri" 
«!nii.iiiii» 1.); r. vi-in Hiif.i with main cin for forty-eight hours, the earJi' ..f lufnrr. «i,i,.., (, la- t <dnilieim Concluded that when blood-T^ 
.•umiiiK rtisiiii.-vniii'') ; -'. •rca gpja with their vasa va.soruni are depf 
tatc-rai byix-mmu. «*. wobtT.) of errculatmg blood for a sufficient 

of time they lose their power of retaJ"' 
the blood, and allow first the liipior sanguinis ami leucoeytc* 
subseipientlv red corpuscles, to csca[ie from them, the esea[ie t."»k' 
place only through the capillaries and venules. The whide pp"^" 
can be watched in the tongue of a frog to the base of which a I' 


ton-l : »i. urtery oMiliTiiU'il hy itn 



ture hsti been applied. For the walls of bloo«l-ves8cl« to be thus 
altorcil. interference with the eirciilation must be verv eoiiiplete, :i 
very little VHScnbir supply serving to prevent the above phenuineua. 
Still, it is a wide-reaching fact, wliicb must always be borne iu 
minii that imperfect nutrition, however slight, is a step toward 
<l«ith, and must render tissues less resistant to injury. These 
obMrvatiims explain all the changes, from wdema to moist gan- 
grene, given above, which may follow ligature of the main artery 
of a limit. 

dilinheim thought that when iiiilioli binekcd terminal arteries the 
Kttilt was almost always hemorrhagic infarction. In his opinion, 
eicejitiiins to this rule were due either tti the veins of the part 
b«iii(j vulved or thrombosed, so that regurgitation was prevented, or 
to tlie part being so placed that gravity strongly favored the return 
of blood by the veins. In the»e cases the area remained [)ale and 
bWless. He considered that stmio fipparcnt exceptions were owing 
to tbu existence of fine arterial anastomoses with certain arteries, of 
»liich the greivt majority were ri'tiflt/ terminal. Tlina anastomoses 
of tile bronchial artery with the pulmonary might sometimes ward 
off infiirction in the lung, and the presence of branches of the 
hepatic artery might similarly prevent infarction of the liver re- 
«altiii;i from embolism of a branch of the portal vein. One reason, 
Kconling to (.'ulinlieim, why infarcts are so much commoner on the 
Mrfac« than in the substance of an organ is. that in the former 
situation the whole base is almost absolutely cut off from collateral 

bitten disputes the truth of Oohnheim's explanation of the whole 
prooesjt of infarction. He shows that the infarction of the kidney 
*liich fiillous ligature of the renal artery cannot be due to regurgi- 
•»titm from the renal vein, as it is most intense when the renal vein 
" iticlf simultaneously ligatured. Under these conditions the 
kidney s\v<dls, becoming first congested and then infarcteil. The 
wnj^tion begins in the subcapsular /.one of the cortex and at the 
''Mwof the pyramids nearest the attachment of the pelvis. This 
<»tig(>sti(>n is due tn the continued supply of the organ by small 
Woriesinow much ililated) which spring from the liunbar, supra- 
■*"«!, and phrenic, and pierce the capsule, as well as by others 
'luch spring from the spermatic and run up along the ureter. If 
"•* renal vein is left open, the kidney swells more slowly, because 
*tii6 t)f the blood entering from these arteries can then escape by 



the vein; the venous stream is therefore away from, not tonard,' 
kidney. But the coni[>lrti«m of tlie proof that ih»' infarctiou isi 
to HU|i|tly throii^rli tliest; nrtfriox. uiitl not lo vt'iioiis rt'tliix, is i 
hy an experiment which shows that when theMc are detached iuG 
tion ihies not oeciir. Oin- kidney is fhelli-d out of its hi-ti of 6? 
and its artery is tints rendered pfally termimil. The rrtiwl urtpnw 
CD both sides are then tied, while the veins on (>otb sidcsi arr Irft 
patent. The "shelled" Icidncy now hcconit-s slightly rong 
but, as a rule, no vi-nmis refriirj;itatioii occurs; the organ remt 
lighter and sninlier tlian its fellow, and docs not beeoiae engui] 
with extravasated corpuscles. In the opp<}»ite kidney typical i 
farction occurs. It would seem, therefore, that in many ca.-*!-*. «i 
the H)uin artery and its small collutenils are tied, the prc«tar«J 
the renal vein is not snfficient to overcome the resistauw in 
capillaries and to distend them with venous bloo<l : much Icj*!' wo 
it be able to do so when the capsular arteries ore piiaipiuj 
into the cortex, and thus increasing the intracapsular 
If by coughing or vomiting the pressure in the renal vein i»' 
infarction is more likely to occur, and it is iiroibiced in ii« i 

Fio. 101. 




;'/-A » ,^- 


AInvr, •«! Ihi- lefl, H • rvprtwnlnilmi ituliiml •Iwi nf n M-rtlnn tlirouch • .. 
of the kliliH'y Um rtrrlr innrka fiiiKhly tlif i«n miiiriiltli'd iiml ilnn ii (m Ih* «u 
IK>lnU to bmllhy kMiirjr ; nm, u(a miniiul Mnll'ln'ilnn tnfl : r. to Hii »t< ■ it 

Arv rininiiirit viUh r»*<l n*»n»»t"*'l''* ""** th** Omih-* on* uuiri- ur lr»% •'■ ■ •m 

kl<lD*T •iitnUiii* «iiU ■ MnlplKhUii lurt whiob urv Um <lcKiiiii<nlx |« >kiiii> . »vil.> 

form by clamping the vena cava inferior above the entry of thr i 
vein. These observations were extended with similar results I9| 
spleen and lung. Since then amemic infarcts in tb«* sple<»o 



Imu foimd associated with thrombosis of the splenic veins without 
miv iibstnictioii in the artery. 

lu the great majority of cases, wlieii a truly "terminal " artery 
isblocke*!. mj infnrction occurs. The area formerly supplied by it 
remains pale and miieniic, ami microscopic examination reveals no 
trace of red corpuscles. This* is seen in cases of euiboliism of the 
cerebral arteries (while softening) and of the central artery of the 

When iin artery of some part (c ij. limb) in which the veins are 
vabwl liecomes blocked, no reflux can occur, but infarction may. 
Such infarction is rare, because these parts generally have a rich 
»rt*ri»] supply sufficient to carry (ui the circulation ; it is most 
likely to follow blocking of the iiiniii artery (p. i.'iS). 

Litton agrees with Cohnheim that the red corpuscles escape by 
iliapedesis, but considers that this i.>< due to the distention of the 
cspillaries and small veins by the mechanical congestion. It almost 
immediately follows the application of the ligature, before ansemia 
lin-H hail titne to effect any niarkeil change in the vessel-walls : and 
"idecd, if a ligature be placed on the artery of a "shelled" kidney 

Fio. 102. 

Il<i ktdnt'S' ifrnni * cue of ancnryim of the ftbdomiiml uurtji: muiiy sunall ypllow- 
rwchra wen* •••■ItertKl tlirouBh ttio I'nrtlci'n of the orKitu*). B'si-ntlul roll* thttlly 
^^"oriAmcd. conncctivo-Usauc cell* «tin c-iiiMitili' nf BtnliiiiiK. x 3X1. 

*<"* retnove<J after four hoiirn, no fresh blood enters and no escape 

« <:'>rpus<des occurs. 

" »ould seem that the true reason why red infarcts are found so 
'f(i<|uently on the surfaces of the organs in which they occur is not 
wit the base is almost entirely cut off from its blood-supply, but 


that there the sroall capsular arteries enter, nnd that throuf^fa thm 
blood is still driven into the area. 

Litten's experiments are conelimive .•»o far as the kidiicv u a* 
cerned. Cohnheim's ret/unfitalion theory probably holds {;ikh| bt 
a few cases, and in its favor it must be reiiienilien*d that in (lit 
majority of cases in which simple embolisms from rnrdinr riltn 
occur there is " back-telling" (p. 84) upon the lun>rs and rrno«i 
pressure is abnormally high. Nor should it be forjfotten '' 

resistance oftcred to regurgitation from the veins by the cu) 

of the tongue or ear is probably much less than that offereti b_T 
those of the firm kidney within its elastic capsule. 

has, such as a bit of non-infected fibrin or a fragment of • csin- 
reous plate, causes slight irritation of the vessel where if ' 
Such an embolus, with its secondary thrombi, will iisn ' 
absorbed or become organized. This irritation may oecawioiuJI.* 
cause so much inflammatory softening of the vessel-wall tb>i '* 
yields before the blood-pressure, and an aneurj-sm results. (S«« 
"Arteries.") This is now held to be the pathology of nm* 
aneurysms occurring in people too young to be suffering fro* 
atheroma or acquired syphilis; and, as the emboli are nsually ♦!!»»*' 
or of moderate size, dilatations from embolism affect <'H|K><"iall* ••*• 
cerebral arteries and the smaller arteries of the limbs, from the M** 
of tlic briichial downward. 

An infective embolus is one which has brought with it from ■' 
source organisms capable of growing within the body — at all evn» 
in the dead or gn-iitly depressed tissues of an infarct — and wh» 
thus gives rise to bacterial changes at the point where it is a: 
The result depends upon the intensity of the irritation whick ft 
particular bacteria can excite: in cases of rheumatism they o(k 
seem to render the embolus but little more irritant than ainf 
fibrin: but in pyicmia the micrococci cause secondary suppontk^ 
(See •• PysBmia.") 

LATER CHANGES IN EMBOLISM.— These depend npon 
two considerations Just discussed: (1) the extent to wliidi tlte 
culatiou is intcrfere<l with, and (2) the amount of irritation 
by the euibdlus. 

1. Small Infarcts. — In the case of tinall red infarctt, if 


embolus is free from organisms the coagulated blood gradually loses 
color, becoming brown or yellow, and absorption proceeds slowly. 
lo the case of amaU anaemic infarctg the tissue-changes are more 
clearly seen than in the red infarcts, where they are obscured by 
the extravasated blood. In these white infarcts lymph reaches the 
part by transudation from parts around, the cells swell, lose their 
nnclei. and blend — in fact, undergo coagulation-necrosis (p. 39), 
and thus form the well-known white wedges. The more external 
portions of this mass of coagulated blood and necrosed tissue 
become infiltrated with leucocytes. In this area fibrous tissue sub- 
sequently develops ; this contracts, and ultimately a depressed scar 
may be all that remains to indicate the change. For some time, 
whilst these secondary changes are taking place in the infarct, its 
most external portions are surrounded by a red zone of hyperaemic 
tissue. This is exceedingly characteristic. 

2. Large Infarcts. — In the case of a large infarct the central 
portions may disintegrate and soften. This may subsequently dry 
up and leave a depressed scar. 

3. Infective Softeninsr. — If an embolus is derived from a part 
where an infective inflammation is going on, it sets up a similar 
inflammatory process, both in the vessel within which it becomes 
impacted and also in the surrounding tissues. These septic inflam- 
matory changes lead to the formation of abscesses, which are 
known as embolic or metastatic abscesses. Microscopic organ- 
wms are almost invariably found in these abscesses, and it is to 
them that the infective properties of the embolus are probably due. 
No more suitable nidus for their development can well be imagined 
""in a tissue in which infarction and necrosis have occurred, and 
'hich is kept moist at the temperature of the body. Infarction is 
lot an essential antecedent of a metastatic abscess. If the metab- 
olism of the tissue in which the embolus lodges does not destroy 
»e organisms, but affords them suitable pabulum, inflammation will 
«Mae. This subject will be considered further in the chapter on 
"Septicsemia and Pyaemia." 

4. The other possible results of embolism have been referred to 
«" p. 258. 

Capillary Emboli. 

yi'Me generally consist of fat, masses of organisms, clumps of 
"••te blood-corpuBcIes, pigment-granules, or air. In fractures. 



contusions of subcutaneous tissue, ruptures of fatt^ liter. ««» 
osteomyelitis, anil otber morbid conditions in wbirb fi»t-rell« ir» 
broken up luid the fat set free the droplets lire nljsorbnl bj '►<» 
lymphatics and veins, especially when pri'ssnre in the |i«ri » 
increased by inHanntiiitory effusion or beinorrbiiffe. t>n ^ 
the right side of the heart they are carried into the puii.. ..-. 
arterioles and capillaries, where their presence may n»i\j W 
demonstrated by staining with osuiic acid (Fig. 103). t ►ne h« oM 

Flo. 103. 


y»\ cmbotlani nf Iiiiik ilViiiii iMii r<mi|iniiiiil fmi'Hirc ofli-n atul mitvM' •ulx'iitiinf "' ■ '" 
tkml. Till' tilnck iiiU!i!><-s uri' ilrKi"* "f •*". "tiiliiol wlili mmlr mltl, lylnir In rufllliin" *='' 
•tUTtiiln i>r nlvi'oliir HnlU ■ 4"!. iBi>y>I.) 

these soft and easiiy-nioiilded plii^rs are swept on to tiie left m'"* 
of the heart, and di.stribiited by the systemic circulation t" nl'*'* 
off^ans, in which also they may be very numerous. For t ti»* 
fresh emboli are constantly reachin)j the lun;:s. but when thia ««••* 
the fat-masses are passed on to other orj»ans and elimiuate<L tB ^^ 
at least, through the kidneys. This fat-embolism is beiievfJ 'f 
some to be the cause of death after simple fractures — a renr r^ 
event. But. as large i|uantities of fat may exist in the lunps »*•' 
other organs of animals without causing any symptoms what**'** 
some skepticism is justifiable. If a sufficiently large niimbentf *" 
capillaries of the lung or any other organ be blocked by &(. 
functiiin will of coiii-se be interfered with, and in the case of st 
organs this would mean speedy death. It is probable that *' 
lungs always coiitMiii, proportionately, many more emboli thai 
organ supplied by the systemic circulation. It has been 
that half the puhuonary blood-path may be obstructed withootj 
turbiiig the circulation at large (Cobnlieim). We most th 
suppose that, as a rule, the passage of fat on to the systemic 
lation keejts the number of plugged capillaries below the poi 


mger. In acute osteomyelitis it is probable that the fat-drops 
ay serve as carriers of pyogenic cocci from the seat of inflamma- 
Dn, and cause their impaction in vessels which they would other- 
ise pass through freely. 

Clumps of leucocytes form emboli, and therefore petechise, in 
iptic fevers (Huter). Air entering the veins may give rise to 
nbolism. Here, as in fat-embolism, the air-plugs have little 
Feet: to cause death, air must be injected so quickly and in such 
laDtity that the blood in the right heart is churned into foam, 
pon which the viscus fruitlessly contracts. Pigment-granules, 
robably parasitic in origin, have caused capillary embolism in 
alaria. (See " Malaria.") 

Thrombosis and Embousm of the Brain. 
Thrombosis and embolism are the most common causes of 
irebral softeninfirs. 

Softening frova Thrombosis. — This is commonly the result of 
heromatous, calcareous, or syphilitic changes in the cerebral 
■teriee. Such changes favor the occurrence of thrombosis, caus- 
g diminution in the lumen of the vessels, roughening of their 
ternal surface, and impairment of their elasticity and contractil- 
'• As a result of the interference with the supply of blood the 
wbral substance undergoes a more or less rapid process of 
wosis (p. 76). 

Thrombosis may also occur in the cerebral sinuseB and veiiis. 
irombosis of a sinus may be primary, and fall under the heading 
narasmic (p. 244), or it may be secondary either to (1) disease 
some adjacent part, such as of the bone in inflammation of the 
iddle ear. or (2) to extension of a thrombus along a vein — as in 
e case of the orbit — from an inflamed part to the sinus into 
liich it opens. The result is great distention of all veins opening 
•o the sinus, oedema of the area whence they draw their blood, 
'Bote hemorrhages, especially in the vascular corte.x. and .soften- 
g from impaired nutrition. 

Softening from Embolism. — The .softening resulting from 
loolism is, for the most part, entirely dependent upon the 
"triiction to the circulation caused by the embolus and by the 
'"Iting thrombosis. It is rapidly induced, and is often attended 
!■ Ae extrava.sation of blood in its neighborhood, when it consti- 
'tes one form of acute red softening (p. 78). If the interference 



with the circulation be slight and there be no extravasa^ 
blood, the softened portions are white in color (p. 7rt). Thfl 
most IVeiiiiently blocked is the middle cerebral arterv, and 
majority of cases it is that of the left side. In altuoHt all 
which softening of the cerebrnl substance re.«iilt.H frnui einl 
is duo to arrest of the embolus in one of the ve»sel9 
circle of Willis, because here the circalation cannot b« 
rc!Stored b_v the collatenil vessels. Softening, however, do 
necessarily follow the blocking of a cortical artery, for coiim 
tion between these branches is freer than is often supposed. 
Engorgement of the area beyond an obstruction in a c 
artery is an exceptional occurrence, but it is sometime* s" 
as to cause rupture of a large artery beyond the obstruction aii4 
hemorrhage some days after the embolism. For rrasons just] 
this is ii fjir more likely occurrence in obstruction cif corticaU 
of larger or basic \essels. When interference with the circu 
is attended by vascular engorgement and extravasation of bl< 
softened portion, in tlie early stage, is either of a uniform d« 
color or presents numerous hemorrhagic jsjints. The softefl 
most marked in the centre, whilst the hy|>erR>mia and rcdh< 
extend for some distance around it (p. 7H). The surmundir 
laries are dilateil and filled with coagula. and granular cor 
envelop their walls. In a more advanced stage all trace uf 
structure is lost: the softened mass becomes decolorised, aad| 
from a dark-red color to a chocolate, brown, yellow, or cv«i ' 
It muv iiiiuefv, and form a cyst with clear contentj« and a 
wall. More commonly, however, it is gradually absorbni,^ 
replaced by fibrous tissue, which contracts; and ultimately ai 
with hienuitoidin crystals, may be all that remains. 

Inpakction op the Luko.— Pulmonaby Apof 
This condition is sufficiently distinctive to merit sefuir 
sideration. The so-called infarcts of the lung are most con 
met with in cases of mitral stenosis, and to a less extent in til 
tnitral regurgitation. They are found in the lower lobes anj] 
lower iin<l outer parts of the U|)per lobes. In most owe* 
irregidarly conical, but occasionally nearly globular. In ili 
they vary from a fraction of an inch to that of an entir 
Illackish-red. firm, with well-defined margin, often iuulti|i 
occasionally continent, they present sujicrficial rraembla 



Inoinrs on the one hand and to lobular iint-iniionia on the other. 
Fnitji the former they are distiri;j:iiisbed by tlit'ir c()I<)r, shape, posi- 
tion, and the conditions under whicli tliey occur ; from the latter, by 
their nnmber, .shape, darker color, and better-defined limits. They 
m' not iufrei|iiently the .starting-points of a hypostatic pneumonia, 
•oil iirr then ies.s easily reeogni/.e<l. In such cases the mljucent 
portion of the visceral pleura is roughened by the iuHummatory 
Mmlation on its surface, while by the same factor in the suhstunce 
(if the organ the maasea are welded, the color mottled, and the edges 

Mode of Formation. — There can he no doubt but that these 
BiMso.s consist mainly of c.xtravasated blood, but there is consider- 
»ble difference of opinion concerning the reason of its upiiearanco 
in the tissues. They are regarded as the several products of embo- 
liam, thrombosis, or rupture of the pulmonary vessels. 

Infavr of embolism id' one or more branches of the pulmonary 
irtcrv may be urged — (1) the frequent existence of a thrombus in 
the right auricle; (2) the di.soovery of iin emlxdus in tfie largest 
•riery entering tlie infarct ; and (3) the general resemblance wliich 
thtw nia.s!<es bear to infarcts of tlie spleen and kidney. Agaiimt 
embolism us the sole cause are — (1) the not infre([uent absence, in 
the* casses, of thrombosis and all other known causes of embolism 
«ilhcr in the systemic veins or in the right auricle: (*2) the still 
Bwrr frec)uent failure to find an endwliis in any branch of the pul- 
luiinary artery itself; and (;i) the eotnplcnicntary facts that embolism 
lB«y be found without infarcts and that artificial embolism in animals 
Ms to produce infarction. 

Tlmt thrombosis is, at least, nn oernsiomil cause of " pulmonary 

iluxy " is inferred from — (1) tfie existence, in a few of the I'ases. 

eroma in the pulmonary artery ; (2) the presence of a throm- 

without any sign of embolism) in the nuiin artery supjdying 

W^nfarct: and (3) the extreme retardation of the blood-current at 

ime the "infarct" is formed. On the other hand, all these 

nnu-na may exist without any infarction. 

I ii(|iicstionably, the most constant condition present in these cases 
'» Ik ionjr-continiied anil t7iarke<l increase in the pressure in the |>ul- 
Bwiiary veins and capillaries. The numerous anastomoses of the 
•""iichial vessels with the pulmonary veins, and the weak action of 
Wi' hourt which usually co-exists. ci>-operate with the increa.sed 
pfwmirc in distending the vessels and in lowering the nutrition of 

270 FEVER. 

the vessel-walls, and thereby increasing their liability to rapton; 
while the enormous strain thrown upon the parts in coughing tap- 
plies an exciting cause. The chief objection to this explanation Hm 
in the fact that all these conditions so frequently obtain withont m 
infarction occurring (p. 55). 

Grawitz has formed the ojtinion that all these " infarcts " are doe 
to the rupture of newly-formed vessels. A careful e.xaminatioii of 
some fifty ca.scs showed that the structure of the aficctetl parts it it 
all cases similar. In the parts supplied by the bronchial Tcswlt— 
i. t: the subplcural, peribronchial, and interlobular tissue — Gnwib 
found numerous large, tortuous, and, in his opinion, newly-fomfd 
arteries. In the neighborhood of these he thought he could true 
commencing hemorrhages. But the most important of his rwallt 
seem to have been his success in protlurhig infarctions. Thi» ii« 
accomplished by simultaneously compressing the bronchus an<i the 
pulmonary artery. The infarctions took some weeks to develop. 
He explains those ca-ses in which emboli and infarctions havebeea 
found a.Hsociated by the suggestion that small peribronchial htemito- 
mata may so invade and damage the walls of the adjacent arteriet 
as to give rise to the gradual formation of a thrombus, which be 
thinks has often been mistaken for an embolus. 



Bv the term •• fever " is meant an abnormal rise in the tempff- 
ature of the body, together with other changes due to incre«<* 
c<mibustion of the ti.s8ues. 

TEMPERATURE IN HEALTH. — It is usually stated that the 
normal temperature of the body is WA° F. It must, however, h* 
remembered that the temperature not only varies in different p«^ 
of the body, but also varies slightly with the time of day, the »P 
(if tlic patient, and the surrounding temperature. The norm" 
tfuipfrature of the nurfarc of the body is always lower than th»' 
of the intirniil partx. Moreover, it is lower in pro|M»rtion u *' 

FEVER. 271 

the trunk toward the periphery, as well as more liable to 
from change in external conditions. To ascertain the 
re of the body for clinical purposes a thermometer is 
ween folds of skin in the axilla (or, in the case of children, 
, under the tongue, or in the rectum. If results are to 
'ed, it is essential that all observations be made in the 
e, for the temperature in the axilla is generally half a 
rer than that in the mouth, and that in the mouth half 
ower than that in the rectum. Again, the time of the 
tt must be stated, for the temperature rises during the 
les its maximum between five and eight p. m., and falls 
night to its minimum between two and six A. M. Further, 
e temperature of an infant or young child is slightly higher 
of an adult, and in the aged it may be slightly behw the 
the adult. The full range between all these extremes is 
ne and two degrees. 

;ulating (thermotaxic) mechanism is less easily disturbed 
Ivances. The temperature of young children is easily 
lepressed : an attack of crying may cause a distinct rise. 
, on the other hand, when oxidative processes are feeble, 
rature is more easily depressed than raised. For this 
;ht rises of temperature in the aged are of much graver 
:e than in the average adult, and in the former even 
OS of inflammation may be present without any accom- 
rise of temperature. The effect of food is to excite 
n in the large mass of gland-tissue connected with the 
! tract, and to cause a slight rise of temperature: the 
food may therefore quicken a rise or retard a fall. The 
>rdinary exercise is slight, but tends to produce a rise: 
Tcise, such as prolonged running, may cause a rise of one 
;rees, or even more. Mental exertion tends in a similar 
and it is evident that the activity of all protoplasm must 
be greater activity of the tissues and the combustion of 
a are the most obvious reasons for the higher temperature 
e day. The diurnal variation is, however, said to occur 
confined to bed and deprived of food, so that the expla- 
y lie in the diminution of tissue-activities during sleep, 
that in those people who are in active work during the 
are asleep during the day the normal course of the tem- 
s reversed. 



SYMPTOMS OF FEVER.— Since the introduction ul' at 
cliiiii'ii! tLt'iTiKiiin.'ter the term "fever" has come to he almuS 
gvnonyinoiis with that of rise of temperature. This latter coiiili- 
tion is certainly the most easily ascertained, the most rwiiilt 
recorded, and. i>n the whole, the most reliable symptom of imt- 
The course (»f the temiieratiire in all febrile attaekft is tlivi>itJ« 
into three stages: (1) the (mmt. or period of rise; (2) the «iw. 
fastigiiiin, or stationary period, during which the temperjturf is 
more or less at its height ; and {'6) the fall, decline, or iirtici "f 

The onset may be middcti, the temperature rising three t 
degrees before the end of the second day ; or it may be ;/ 
rising every evening, and falling slightly every morning, until ^ 
full height is reached, as is seen in typhoid fever. The smW™ 
onset is frequently accompanied by an intense sensatiiiu of mi 
and a violent attack of .shivering, known as a rigor. The ieiii|*t- 
ature is at the time high, the ves.sels of the skin are contracted, w' 
excessive lo.^s of heat is thus prevented. In children, in xtbomtbf 
controlling power of the nervous system is less dcvelopdl thiw"' 
later life, a I'oni'uhion often replaces the rigor. The gradual on*** 
may be marked by .flight chiliness, but very rarely by rigivr*. 

The fastigium, or second stage, may be over in a few hours "t 
may last for weeks. The temperature may remain at a fairly cot*" 
stant level nr it may oscillate several degrees each day. 

The final stage of fever, like the onset, may be sudden or gr**" 
nal. When sudden it is said to end by criaiB. The drop i* oft«f' 
acpomjianied by '" critical " swciiting or diarrhcea. Sometinip' '''*" 
fall ia so r.xpid and so marked that the patient may be in dnngft w' 
dying, and may even die, of collapse. When the fall i.-* gmuo** 
it is said to end by lysis. This is analogous to the corresponJii*^ 
form of onset, as the tenipernture falls by a series of morning drof*» 
broken by slight rises in the evening. The special types uf ffv** 
characteristic of some diseases are in all probability dependent t**" 
peculiarities connected with the growth of sj>ecial parasite*. (^^** 
"Malaria.") When fever ends in death the temperature genenl'.*' 
rises just before this occurs, and may occasionally go on rising f***" 
a short time afterward. 

Febrile temjieratures almost alway.s exhibit a tendency to rhytb- 
mic daily variation like the normal temperature, being higher lO 
the evening than in the morning. Sometimes the opposite « ^ 

FEVER. 273 

ttise, and the tempersture is then said to be of the inverted type. 
When the daily variation does not amount to much more than two 
degrees the fever is termed continued. When the variation is greater 
than this the fever is remittent ; of this type hectic fever, which ac- 
companies chronic suppuration, is a good example. When the drop 
between two maximum points reaches or falls below normal, so that 
there is a fever-free period, the fever is said to be intermittent ; of 
this variety malaria is the type. 

The extent of the rise of temperature varies greatly. Certain 
terms are sometimes employed to express the average height of the 
temperature. It is however, quite easy, and always better, to give 
the figures themselves. Above 107° F. the fever is called hyper- 
jyrtxia, and a temperature at or above this point enduring for any 
length of time is usually fraught with the greatest danger to life. 
When the temperature of the body as a whole reaches 109° to 110° 
F.. prompt measures are necessary to prevent death. As in sun- 
stroke, this termination is possibly due to some decomposition of 
the tissues. So called paradoxical temperatures, even up to 128° 
F., have been recorded as occurring in hysterical individuals, and 
in a few of them the most careful watching has failed to detect de- 
ceit. In some cases very high temperatures have occurred again 
Mil again. They are often quite local, the temperature on the 
opposite side being, for example, practically normal. They are 
»«ompanied by few or no symptoms. Wasting especially is ab- 
*nt. Hale White regards these cases as of central origin, due to 
perverted action of supposed calorific centres, comparable to the 
derangement of the motor centres in hysterical hemiplegia. Hys- 
terical persons are very liable to disturbances of body-temperature. 

High temperatures are generally accompanied by cloudy swelling 
"f the tissues, and, if prolonged, by fatty degeneration : poisons 
tirculating in the blood have very likely a share in producing this 
"suit (p. 79). 

Apart from rigors and chilliness, which are usually associated with 
">e onset, the earliest symptoms, as regards the nervous system, 
>fe headache, incapacity for self-application, general sluggishness 
*' mind, loss of self-control, and byperaesthesia of the special 
""ses. Then comes delirium — at first at night, and for short 
periods only, but later on often becoming more marked and even 
Wiwtant. Vague muscular pains are common in early stages : 
e^en in their absence unwillingness for exertion is marked. The 




muscles waste rapidlv and their movenu'rit!* hecomr ««k iixl 
tretnuluus. The nervous svHteui ha.« a large 8harc in pnxlanaf 
tremor and proHtration. and is resjionaiblc far such « evmptoa as 
constant picking at the beti-clothcs (carpholniry). In fever thcfrf- 
ijuency of tlie heart-beate is increased. This result run he obtainni 
experimeutully by flie ajiplieution of heat. Yet tiie rapidity of tbf 
pulse bears no reliable proportion to the height of the tenipenitnrf. 
It is uiueh jtreater in some diseases than in other* — fur • ' 

scarlatina than in typhoid. The heart, ainon^ other ii< 
progressively in quality and power, and n» it docs so it« beat I 
more frequent and less effective. Here, again, the nen'<ni> 
may be partly at fault, the inhibitory influence of the vagu- 
impairod. Similarly, arterial tone is progreiwiTely Wt. Th» 
result iif the progressive failure of the heart-force and arterial to« 
is that the pulse, which in a healthy inilividual at the comnK-ot'r- 
nient of a long fever is quick, full, strong, and often jnclin»<i to 
hardnens from high itrtcrial tension, becomes, ns the discaj«c |ir»- 
gresses. quicker, softer, and fuller, though no further rise of ten- 
porature has occurreil. The softness and fulnes* of the pulwirr 
due to loss of arterial tone while the heurt-bent is still strong: lk» 
softness increa«ca ».s the arterial tone yields. liitter on il 
diminishes as the still more rnpiilly-bentitig heart fails to i 
veMels. Ultimately, the pulse is very small, soft, nnd frequent, «r, 
as it is termed, threaihi. Increasing frequency of puW with • 
steady or falling temperature is often regardcfl as thr sigjj of • 
failing heart, though the ''quality " of the first sound really alToni* 
an earlier indication of its approach. 

Respiration is quickened. This change, like th«- iuereaMHl fr»- 
quency i)f the pulse, is possibly in some meitsurc due !<• the efrrt 
of the rapidly-heated blood — in this ease, on the respiratory cwitr*, 
as it can be induced experimentally by similar means. The "Xyj!*" 
absorbed and the carbon dioxide exhaled arc both increase*!. •"B^ 
times in exact proportion to the rise in teni|)erature. 

Digestion is impaire<l. for secretions from the glund.>> difccbnr;ii"i 
into the alimentary tract are diminished. Appetite is lo*t (»'•'*• 
rezia). and its place is taken by thirst The tongue is liry •!>" 
often furred. There is usually constipation, due probably lo si"?" 
giikhnes.^ of the intestinal muscle, to lack of secretion, and }>erL«!* 
to absence of some of the normal stimuli to contraction. Exct** 
tiOD, as tested by the rapidity with which eertnin ingesta 'I'C*^ 

FEVER. 275 

the urine, is said to be slow in fever. Although the amount of 
id taken is larger than in health, the urine is small in <}uantity, 
1 a high specific gravity, yields a copious precipitate of urates, 
i contains an excess of urea, uric acid, potassium salts, and pig- 
Bt (pathological urobilin). The chlorides arc diminished. With 
excess of coloring matter in the urine may be taken the fact 
t in fever there is a progressive decrease of red corpuscles, and, 
Qfding to some, corresponding increase in the amount of iron 
linated in the urine. According to Hayem, both hfematoblastH 
red eorpuHchs are less numerous during the stationary period 
Fever. Directly the fall in temperature begins the number of 
natoblasts increases, reaching its maximum a day or two after 
disappearance of the fever. During the following week it grad- 
ly sinks to normal. An increase in the number of red corpus- 
I and a .simultaneous diminution in the proportion of hcpmoghbin 
V contain closely follow the in the hsematoblasts. The 
' in the percentage of haemoglobin completes the return of the 
A to its normal state. 

fhe excess of urea is one of the earliest changes, and may even 
cede the rise of temperature. The excess is generally absolute, 
netimes it is only relative ; that is, more is passed than would be 
reted by a healthy man confined to bed on a similar diet. There 
soally a marked increase at the commencement of defervescence : 
I is most likely due to an accumulation of its precursors in the 
«1 or tissues. 

:emperature often occurs after death, especially in those dying 
denly or of acute diseases. It is most marked in cases of fever 

to the presence of a ferment in the blood, or in cases where 
th occurs with a high and rising temperature. Tetanus is prob- 
1 the best example. The explanation is, that cessation of the 
on of the heart is not accompanied by immediate extinction of 
oe-change. Thermogenic processes continue for a longer or 
fter time ; and thus, while the production of heat ceases grad- 
'y, the loss of heat, being largely dependent on the respiration 

circulation, is cut down so suddenly that the rectal temperature 
8 for a brief interval, and then falls as usual. 

'ATHOLOOY OP PBVBR. — The foregoing account has shown 



that the css«>ntial condition in fever is increued thfrnio|rrii<!>i* 
to incrca.scd brcakiiip down of the tis<f«ii(>!«, niid I'-iitfcinlU «f il»* 
niiisclfs ; for the functions of the glands, the second gn-nt hf-at-pro- 
ducing organs, are almost in sbevance. Ah rtr have nlreadr indi- 
cated, by increased thermogenesis we mean ihnt ii fehrile |MiU(Ot 
will produce more heal in a given time than a healthv periuib npaa 
the same diet and under Kimilar circum!<tnnce!< — mil neccMuilT 
more than a healthy person on onlinary diet, though rren lhi» m»T 
be the case. While the febrile patient takes le** food, he »\tti>ih» 
more o.xygen, and the increa-te in iieat he product-* i.* due ti> tke 
excessive combustion of his tissues. Traube held that diminiibed 
loss of heal tiHik the greater share in the niaintrnnni'c of tli< 
temperature in the body of a febrile pntieut. and tlint tir 
brought about by an energetic contraction of the viwsels of xhr dtia. 
But wuch a contraction of vessels is by no means constant, .ih : 

it occurs is nut (d' long persistence. Moreover, a high tcin|u: 

»ud a freely-sweating .skin often occur together, and calnriioffnc 
observations have actually demonstrated the increaseii ihenatigeii- 
esis. If stipport is required for the view that fever is depeiHlent 
on increased destruction of tissue, it is found in the projM'rtiotiitrlT 
increa.sed discharge of urea and carbon dio.xide. 

Some physiologists believe that thermoereneeiB ik iinil<r im- 1"»- 
trol of a cerebral centre or centres which control other tbrtiB*' 
centres in the cord; but in the present state of kno>»leilg« it ^ 
impossible to speak certainly of the position of these centrw. <»* 
their function (excitor or inhibitory), or of the paths of their tSntr* 
and eff«-reni fibres. The effect of curarizing an animal ' would wn^ 
to demonstrate that, normally, heat-production in muscle — likeo**^ 
traction — takes place nuly in to a .stimulus along a thenui 

' Mnc.'MliMer khowol thai the wnrk-perforniini; «n<1 hntl-produring 
miUM'le are to » certain exitriU ilixtiticL Siiiiiiilulioii nf a niiwular 
ililntalioii «f it* veMnels, Utmpnrnry rtiiitrai'lion of tlii< muM-lr, untl 
diu'tiuD 'if tirnl. FaliKiK- nriil ifilil t>i>lli iiiUTri-ntl willi tlii> llifrni(^i(«<nir I 
I<in|{ ln'firin' llioy jiii|>iiitv<l tlii' (Kiwcr i>f c-oiitrnction. • tn the ntlior Uaod. | 
!>v niranr — which .•"•l» nu ihi- iHTv<--<'niiiii|p. in miwvlr— (laralrwd |J|» 
lh<'rnii>|^-iiir fiinclionN i<( the tiiui(.-l« Binniltaneoiuil^. If an antinal 
mainlaininKa fairly uniform U-ni[H-reture i lumioiotkn-mie \ be |K>iwnicd with < 
ttcoomc* ineapalile of niaint.iininK it« t«ni{)«ni(un!, whii-li mimitlipi^W rBriai < 
thni of ihv nunuunJing uiwliiini i poikilolhermie), al(houf;h the rirculatkm t4 lW| 
blood ia unim|mirr<i nnil ihe normal rate of rexpiration it kept up. ^laxiri; r^Li 




(caUibolic) nerve; but it does not prove the iinijossibility of directly 
ttiiDiilatiiig the tnuscle to proiliiuo heat, es|ieciiiily iis we know it 
can wiitmcf alter its motor nerve is deiid. It is evident, therefore, 
thtS tliv causes of fever may induce the increased tliermogcnesis, 
cither by acting lUrectly upon the tissues or by acting on them /«- 
(ilin-tiylkrnu(/fi l/ie nervous Kifgtem. In certain cases — <•.(/. nervous 
or hygtcrical fever, it seems impossible that the cause ciin act ujion 
till' tiwiies otherwise than through the nervous system : but, in the 
majority of cases, it may act either way, and until recently it has 
pwruliy been assumed that the action has been ilirect from tlie 
blood upon the tissues. 

Still, as we have already shown, thermogenesis may be increased 
euormoiisly in health without any rise of temperature, ami we must 
therefore consider that fever aLso involves a disturbance of the heat- 
rcgiiiating lueciiaiiisni. or thennot»xi8, whereby it fails f<> maintnln 
the balance between heat-production ami heat-loss. If tliis balance 
»cre maintained as in health, we should have a stable temperature 
«t » higher level than the normal. Hut the chief characteristic 
of the temperature in fever is it.s variiibiliiy. fold, food, excite- 
ffli'iit, effort antipyretic drugs, all afi'ect the temperature in fever 
much more markeilly than the temperature in health. As Mac- 
Alister says, the ttderably regular daily tluctitatiou of the tenipera- 
t'lre ill fever shows merely that nil the thermiil processes are not 
atterly disturbed, some which are rhythmic in health remaining so 
in diwane. 

hike intlaininations, fevers may be divided into the infective and 

non-infective. The infective fevers are those due to the multi- 

(ilicstidii in the body of a micro-parasite. This explanation serves 

for the group of "acute sjjecific fevers," malaria, and febrile dis- 

flVnin which there is no inflammation present, at least in the early 

(»r» of their course. These cimstitiited the old groups of primary 

or essential fevers. In some (typhus, niahiria) there is no intlain- 

niation ; but in many an intlamniatioii tippi-ars (of throat, nose and 

eyc», skin, intestine) — too late anil often too slight to account for 

the fever present. There are also the cases of fever secondary to 

Koiind through which organisms liiivi> gained access to tlie body 

f.if. Septic infection, pysemia, erysipelas, and lymphangitis — and 

lie large grouji of fevers .secondary to infliiiiimations (inflammatoir 

ircrs), practically all of which are infective. In most of these 

secondary" fevers the pyrogenous materials are manufactured b\ 



nrgnnisins in some definite part oi the fxuly. nml nre tbHI^B^int* 
fli»' lilood. 

In the non-infective group wo liml. Hr»t of nil. two w ouutl iii«»— 
e»ses : (l)sini|)le trmitniitic fever, nnd (2) it« tiiorc inienm" fnm. 
iiciite septic poisoning or sRpneniia. (See " Septicjeuiin.") Simple 
traumatic fever ensues upon "simple" injuries (eontiisionj' (n«i 
fractures). It is penenilly slight, and is most probably due ti> tb*- 
absorption of fibrin-ferment (and very likely other pyrogenun* 
bodies) from the sent of injury: ptissibly, irritation of nerve- '-^ 
llie original injury or by fragments of b<<tie or tissue — may L.i> ■- 
some effect in causing the fever, though gtrong irritation of ti 
sory nerve causes de|>ression nf tem|)ernfiire. Aseptic inn 
fever, wliicli occurs in aseptic wounds, is |)robnbly due to thci 
c»uses as the simple traumatic. Nervous (hysterical) fever inoap- 
|iosed to be due to the influence of higher over lower thfrmal| 
centres. The rises of temperature which occur in ehihlrcn, parr- 
peral women, and other weakly adults, from varioun emotion* tnd 
oilier slight causes — e. jf, the rise which is so commonly fonml »fier 
an entertainment has been held in a hospital ward — »wm l" *»* 
examples of nervous fever. 

Further, eases of nervous injury or diseaso not unei»niroonlT 
occur in which one cannot help susfiecfing either that tlierm***' 
inhibitory centres or fibres are destroyed i>r that therniognii"' f** 
tre« or fibres are irritated. Hale White has broup;bt a nninbrf •" 
such ca-ses together. In a most interesting case of bullet wMjiid •" 
the bead accompanied by fever, not otherwise explained, it ••* 
found that the motor area of the cortex, corresponding to EulcBb**" 
and Laniloiss heat-centre in the dog. had been ilestniye<l. T*** 
inbibitorv influence of this centre may apparently be cut oS * 
destri>ved by sudden and extensive intracranial hemorrhaije, oT *'• 
hemorrhages, scleroses, and tumors of the brain so plsce«l u0 
dextroy inhibitory fibres or to irritate thermogenic tract*. It ""^ i 
long bt'cn kiniwn that injuries and tumors of the cervical w**"^' 

along which most thermal fibres must pass, are apt to eaiise __^ , 
fever. In a girl with a fnictiirrof tin- cervical spine Teale nt!or«»*'^i 

a tempenitureof I'iU'^ K., recovery iiltimutely occurring : Mime rrjr**^ 
this as an iustauee of hysterical fever. 

Lastly, there are many fevers of whose pathology we are >t''' 
ignorant — (•.</. the fever met with in various anivmic state*, i** 
lyniphadeuoma, and occasional cases of malignant dUease. 

lyFLAMMATlON. 279 



Inflammation may be defined as "the succession of changes 
which takes place in a living tissue as the result of some kind of 
injury, provided that this injury be insufficient immediately to 
destroy its vitality " (Sanderson). 

HISTOLOGY. — The exact nature of these changes was, for the 
most part, ascertained by the experimental researches of Cohnheim. 
The method of investigation consisted in the artificial production of 
inflammation in transparent parts of the lower animals, and in the 
observation of the process thus induced. The parts employed have 
been the foot, tongue, and mesentery of the frog, the tongue of the 
toad (the best for many purposes), the mesentery of the rabbit, and 
the wing of the bat. The similarity of the different observations 
i)as shown that the process is essentially the same in warm and 
cold-blooded animals, and by microscopic examination of the lip 
^J reflected light Hiiter proved that it is the same in man. The 
Procees of Inflammation is generally described under three 
keadings : 
J- Changes in the blood-vessels and circulation. 
2. Exudation of fluid and of blood-corpuscles from the vessels. 
''• Changes in the inflamed tissues. 

Though separated for purposes of description, it must not be sup- 

P<*8e(l that these changes occur successively in the order in which 

"*.V are placed ; on the contrary, they all go on together. 

1. Chanfirea in the Blood-vessels and Circulation. — Changes in 

^th blood-vessels and circulation are absolutely essential to the 

*'stence of inflammation. This is true of non-vascular as well 

of vascular tissues. In the former, which comprise the cornea 

**« cartilage, the changes occur in the adjacent vessels from which 

**8e tissues derive their nutritive supply. The nature of the 

"bilges may be studied in the mesentery of a curarized frog. 

*'iefly, they are as follows : 

The first effect of injury of the mesentery — mere exposure to the 
'**■ being sufficient for the purpose — is to cause dilatation ' of the 

With certain irritants, as ammonia, a short contraction of the arterioles may be 
tW first result 



arteries, which gradually extends to the veins and eapillarir*. Ti* 
dilatation of the arteries coinniencea at ouec. and ix not pni . ^ 
anv contraction. It increai<e8. steadily and slowly, for nlioii! • 
hours, and is accompanied by an increase in the len/fth »( ihir f»- 
aels, so that they become more or less tortuous. It affrcf* tb' 
arteries cliieHy, then the veins, and slightly the cupillane?. Tim 
enlargement of the blood-vessels is HKsociateil at the roninicn<Tnii>ni 
of the process with an acceleration in the flow uf blood, whirb, 
however, rarely last.-* more than an hour, except in the ontlvm^ 
partH. anil i» followed by a considerable retardation in tlir rir- 
culation. the vessels still remaining dilate<i. 

Pulsation is now evident iu the smallest arteries, niul thr »irj'-. 
is slow enough to allow the ubserver to di.^tinguish indiviJuuI '"r- 
puscles in the capillaries ami smaller vein.s — p<-rha|M4 even in li>e 

It ha.«, however, long been known that the ttccelemtion of ik« 
blood-flow in an injured part — the so-colled determination ofhlauJ — 
is not constant, and often subsides withioit the occurrence of »n)' •»( 
the characteristic phenomena of inflammation. Cohuheim c«ii?i«i- 
ered that dilatation of vesxels with increased veloeit;/ of the blooi 
current en.^uing immediately after the infliction of an injury i» »*^''" 
dental. In some cases it is followed by contraction, after »bi*» 
dlltitiitiiiii it'ith dimiuin/ied eelnrit;/ commences. This, on the otb«T 
hand, comes on slowly, is constant, and persists as long as the rao"- 
f>ihtliilii>ii irit/i diiniuixheJ lufixiti/ must be regarded as the bmbd*** 
vascular change of the inflaniinalion. 

Returning to the observation of the frog's mesentery, the reU»"* 
atiori of the circtdatinri in the dilated vessels is sometimes aeeO " 
lake place somewhat suddenly, and is u.iually first observable ia A' 
veins. As the stream gets slower increasing numbera of whiteoir' 
puscles are seen in the periaxial stream of the »mrt//rr rrtwa-^-riiUinjf 
slowly along, stopping here and there, anti finally coming to a .-itand- 
still. Thus the smaller veins become lined with leucMcyloi u 
with a spheroidal epithelium, often more than one cell in ihickntM. 
Some stick iu the capillaries. The time ut which the ehaogv oceun 
varies, The severer the injury, the earlier this layer of Ivuracytia 
is formed. The narrowing «if the vein* by layent of leucncytct, 
among which there an- no red corpu.scle.s, seems to inrrcaae tlie 
obstruction to the circulation, which becomes slower nnd slower, 
poasibly both on this account ami because the damage \* Itccaming 


^ter. The red corpuscles, with some white, accumulate in the 
capillaries, which appear as if distended by a red injection-mass. 
Actual measurement shows that they may be one-fourth larger than 
Datnral. After a time all onward movement ceases in the capillaries 
tod their contents sway to and fro with the pulse. This is the stage 
of oscillation, and it is succeeded by that of stasis, in which no 
moTement of any kind occurs ; but the blood, though stationary, 
may remain fluid — for as long as three days in the bat's wing. 
Finally, thrombosis or coagulation may take place, but not until 
the capillary walls are dead. Thrombosis puts an end to that escape 
of corpuscles from the vessels which will be treated of in the ne.\t 
These changes in the circulation may be thus summarized : 

1. Dilatation of small arteries, then veins, and lastly capil- 


2. Acceleration of blood-current, quickly followed by gradu- 

ally increasing 

3. Retardation of blood-current — first observed in veins — and 

simultaneously with this 

4. Leucocytes in large numbers fall into periaxial stream, 

and lag behind. 

5. Pulsation in smallest arteries, oscillation of blood-stream, 

and perhaps stasis. 

2' Escape of Fluid and Blood-corpuscles ft-om the Vessels. 
-The circulatory and vascular changes have been described as if 
My were the only phenomena of inflammation. But this is far 
rom being the case. Soon after the veins become lined by white 
^rpuscles the field becomes more and more obscured by the presence 
"f small round cells in the substance of the mesentery. At even an 
wlier period, though the miscroscope does not show it, the fluid 
»hicb naturally escapes from the vessels increases greatly in quantity 
"d changes in quality. As soon as the lymphatics become unable 
to carry it off, it accumulates in the connective-tissue spaces and 
eanseg swelling. These finally become insuflicient to hold it, and it 
therefore escapes on the surface, together with a number of the small 
round-cells. Here a coagulum forms, consisting of fibrin, small 
vand-cells, and some red blood-corpuscles. This false membrane 
an be removed and the fieM cleared for observation until another 
lembrane forms. 

a. Source of the New Cells. — If a small vein lined by leuco- 


cytc8 be carefully watched, the following cbangee will ht fteeo- 

baps at once, perhapi* not for norae tinif : Sonic of thr l« 
innncdiatcly adjacent to the wall gradiiHlIy sink into jL, Mi«l pa> I 
tiirough into the Riirrounding tissues. Various stHgv9< of tliotrfa» 

Flo. 104. 





Snbriitttnooiif tl<«ut' ••>tii<r •lUliinr-f nN>vr HchiX imhI 111 • CM< of •(■rntillrtf i 

Three Vulm inrkl'il Witll Inumylrs I'l.Ulllrh arv >«i'u|ihl|i fr%Ml>. I:>>llll<l 111! iflrrj'' 

thtn nrr uoiir. Uuulili- (he vtvu-U iimii) UrKvr cells ari' ff<-ii. X J*'- 

awe nmy be olK^erved. .\t first y>innli iMiitnn-xbnprd il. 
appear on the outer wall of the ves!»el. 'rhi-fc j;riidMall_\ ' 
until they assume the fonn of pear-^(haped bodie.s adherent brtlwi' 
Hnutll en«lM to the vessel-wiill, often sending out proceswe* "' 
attached, t'ornii and Kunvier say that if an aillierent Iciu - . 
torn from the wall and swept on, tiie adherent part is •*finjrf'<*'- 
and von Recklin-jhausen lias dt-.^eribed the part irithin the i*-**!!* 
n tailpole's tail) as sending out processes, litiniateiy. the 'O 

[K-dide of protoplnsiu gives way, antl the passage is complolc 

corpuscles remaining free outside the vessel. A similar wctpet**** 
place, but to a less extent, from the ca[iillaries. 

As a rule in iidlainmation the escape of white corpuscUf pwW? 
excee<U that of the re<l; but in the roost severe cases, iu whielil 
nation is in<luced in a large number of capillaries, the usual 
id' affairs nmy be reversed (Fig. 11-, p. liOfi). From such n{Ml1 
th« re<l corpuscles pass out in great numbera, occupy the inMnM* 


he tissues, and give the exudatioD a hemorrhagic character, 
the other hand, when " retardation " has not culminated in 
uis," most red corpuscles remain within the vessels and pass 
ig through the inflamed area, whilst the white adhere to the 
k The intensity of the injury and profusion of capillaries 
ermine the proportion of red corpuscles in an exudation. These 
ffl out chiefly from the capillaries, and several may escape in 
ick succession from one place, giving rise to a red spot visible to 
e naked eye as a punctiform hemorrhage. No rupture of vessel 
curs, as may be shown by injection. 

Both red and white corpuscles at first remain near the vessels 
lence they have escaped, but they are soon pushed away by other 
rpuscies or washed on by the escaping fluid. The white cor- 
acles have, in addition, their own peculiar power of locomotion. 
108 they may ultimately be found far from their place of egress. 
But are white blood-corpuscles the only source of the numberless 
nnd-cells which crowd the tissues in every inflammation but the 
Mt trivial ? Virchow advanced the view that they all arose by 
»ltiplication of connective-tissue corpuscles. Addison in 1842 
ferred from his observations that leucocytes passed through the 
88el-walls and became pus-cells, and in 1846, Waller actually saw 
em escaping. These observations were unheeded until Cohnheim 
1867 asserted that all new cells formed in the tissues as a direct 
'lit of injury were escaped white corpuscles which had migrated 
the 8j)ot where they were found. And, in spite of opposition, 
» view has held its ground, and all arguments and experiments 
vaoced to show that the small round-cells of aeute inflammation 
i due to the multi])lication of fixed tissue-cells have proved incon- 
sive. Experiments have amply shown that migration of leuco- 
<8 will give rise to all the appearance noticed, but it is diflicult 
Wclnde the possibility of the multiplication of the fixed cell.'', 
-^bnheim, however, believed that the subsequent regeneration 
tissues was also due to the development of leucocytes ; but this 
t of his conclusions is now generally disputed. 
I'hc following method has been adopted to .show that leucocytes 
■ produce an infiltration of tissue with small round-cells without 
aid of the fixed elements. A cornea or other piece of tissue, 
cells of which were suspected of multiplying, is excised, kept 
some days, rendered aseptic, and then placed in the peritoneum 
subcutaneous tissue of a living animal. On subsequent examina- 



tion clumps of small round-cells arc always found In {lositiim* 
normally occiipicil by tissue-corituscles. but multij'V *" ' 

latter, wliicb were prcHumablv (load, was clt-arly im; 
fixed counoctive-tissue cells lie in spaces and clefts, and the i*i 
cells, taking the easiest i'oiir><e open tn tliem. invade and accm 
in these spaces and arouml the fixed cells. 

The non-vascular tissues, and especially the cornea, were tl 
strongholds of those who maintained that these cells nri|rinatf<l tr-m i 
multiplying connective-tissue corpuscles. Biittcher showeil tiu^J 
after slight central injuries of the cornea with nitrate of aiU«f|^| 
which caused no affection of the surrounding vesaela. the site* nf 1 
the corneal corpuscles in the neighborhood were occupied by rlump^J 
of euibryitnic cells, which lie believed could have been fornini <>dI]H 
by multiplication of the fixed cells. Cohnheim pointed out tkittbe 
new cells might be leucocytes wbidi had tiiignited from tlif i-no- 
junctival sac. and ^enftleben jiroveil that this «as their *av,K*^ 
This observer succeeded in applying t4> a minute 8|M>t in thr cnti* | 
«f the anterior surface of the cornea a sciliitioM of chloride <•! 
which soakeil through the dense anterior corneal lamina «::■ 
destroying it. By this method he found it was fiossible to kill il»« 
corpuscles in a small central area of the cornea without uffr^tinf 
the marginal vessels. The spot remained clear, and no cliit!' ■■*^ 
embrvmiic cells were found. But if the spot irritated via* in- 
margin of the cornea, the neighboring vessels dilated and the «lM«»' 
ageil area became cloudy from infiltration with Ich' If •* 

the slight central injury first described a cut or stu i/hl^* 

anterior lamina was added, opacity of the cornea and infiltnUJi*^ 
of eorpiiscles from the conjunctival sac oc<'urre<l simultaneoittl*'"^ 
It seems, therefore, that Cohnheim was right in supposing that 
small round cells found in inflamed tissues as a direct result of iIm^ 
injury which caused the process were escaped leucocytes. A km 
of the cells may be due to lU'ip'twrativi- changes (p. 47). 

Moreover, in the less acute forms we find cells which are fonnrd 
by rfgenfratirt processes going on in the cells of the lissur*. bal 
these can ntnl must be sharply distinguished frotu those wc kaie 
been discii^^iiig (p. 28*!). 

^. Exudation of Fluid. — As before stated, one of the c«riini 

, ♦fTivfs of the vascular changes in inflajiimation is iiH . ' .l». 

tion of fluid. This was noted in the microscopic • •. i^ of 

the inflamed mesentery, but other experiments show th« proceas 


mucb better. Lassar tied a cannula into a large lymphatic of each 
Wnd leg of a dog. He then stopped the circulation in one leg, 
»nd dipped this into water at 130° F., thereby exciting acute 
inflammation. On removing the fillet the lymph-stream from the 
c&nnula at once exceeded the normal, and soon reached eight 
ima that on the sound side. At first the fluid was clear, but after 
a time increasing numbers of white corpuscles made it cloudy, and 
red corpuscles were also found in small numbers. Swelling of the 
foot began while the flow of lymph was free, evidently because the 
exudation was too rapid to be conveyed away by the lymph-chan- 
nels, even when fully dilated. Later in the experiment the flow 
diminished, partly because exudation diminished as pressure on the 
vessels (from effusion beneath the skin) rose, and partly from 
coagulation in, and consequent blocking of, lymphatics. The 
lymph collected difiered from the exudation-fluid in mechanical 
liTpenemia in containing a much larger proportion of albumin and 
in having a much greater tendency to coagulation. This latter 
property varies with the number of white corpuscles which it con- 
tains. The lymph differed from liquor sanguinis in containing less 
•Ibamin and having a slighter tendency to coagulate. The compo- 
wtion of inflammatory effusion, however, is not constant. In the 
■"ost acute inflammations it contains a large number of red cor- 
puscles; in less severe forms white corpuscles are greatly in excess 
of red. In the more severe inflammations the fluid approaches 
plasma in its composition and tendencies, wliil.xt in the less severe 
't becomes very like the fluid in mechanical hypenvmia. It also 
varies according to the part from which it comes. A mild degree 
of peritoneal inflammation will produce an effusion containing 
more proteid matter than a far severer inflammation limited to the 
leg (p. 237). 

3. Chaneres in the Inflamed Tissues. — Inflamed parts are soft, 
and the component tissues are blurred or altogether indistinguish- 
•We. Microscopically, the tissue-elements are at first separated by 
flnid and obscured by leucocytes and fibrin-filaments. The tissue- 
cells, when not obscured by leucocytes, are either structureless 
masses from coagulative necrosis or are undergoing fatty degenera- 
tion. The tissue-fibres are swollen and indistinct : they ultimately 
degenerate. Red corpuscles are found in even moderately severe 
inflammations. The changes in the escaped leucocytes and the 
actual destruction of tissue will be described subse(iuently. 



We must, however, liere point out that regrenerative 
arc 8onictiuic8 disco vorublc in the cells oi an iullunied am. mtAt 
I'oUowing experiment shows. 

When Senftleben (2><4) with chloride of zinc destroyed all etlh 
in the centre of a cornea without ndiuittin;; any white corf-'- 
to the area, the part remained quite clear an<l showtnl no i 
eye change. But on the third day niicroscapic exauitusluia 
^^howed that the corneal corpuscles around the damaged arc.i " 
.«liooting proce!*se(< inio it. Nuclei appeared on the proce-ti; ji -' 
plastu collected around thetu : and brunehiHl cell.« fomuMi. obidi 
apiin threw out rejienerative proi'es'se.f. and so the riiriirni ■ ■ 
puscles were completely restored. Had leucocytes bet'ti aiiiii i; i 
to the corneal tissue, controversy would have ariocn as to wbt-ibcr 
tlii'v also did not sprinp from the cells by multiplication: but, 
inllamnuitory |)li<-nomena being prevented, the regenerative prnciiMi 
coiilil be studied alone. In other ti.ssues alsti regenerative prwrtM*' 
occur, the more resistant elements endeavoring to make pxxi tlif 
lo.«s sustaine<l by the tissue ; but such attempts are found nininiv id 
clironic and subsiding intlamuiations. In these we must lu' pr^ 
pared to find evidence of cell-multiplication, which will I* nor* 
marked and commence sooner when the injury is slight. Tit 
greater the injury, the Mure marked will be the Jft^mrrttk* 
changes and the lea$ marked the regenerative. 

ing thus briefly described the succession of changes which nwur •» 
the process of inflammation, we may next consider how an >' 
produces them. An injury has been held to cause abnomol • 
ditious of the blood, of the tissues, of the nerves, and 4)f the liK"**" 
vcflsela. Ou one or more of these it must neci^sarily act. 

There is no re.ison for supposing that the blood is nec«K«rt»J 
damaged. We can see that while the circulation round a mi*^***" 
seopie inflammation proceeds in a normal manner, any corpo#^**^ 
entering this region rend to stick i<i each other and to the ti 
walls (p. 2H(I) ; but when they get through the part again tbeV" 
on toward the heart (piite normally, aa before. Further. bl<**^ 
drawn from an inflamed area behaves exactly like that frtiin oti*^ 

The tiflsue-elementa are certainly affecteil in ca«efl dn« to obvio** 
external injury, and probably in all others, but 




to show that hijurif to vesseU alone would give rise to inflara- 
ItioD. He injured the vessels of a part by witlHirawinj; the blood 
Dm them and then injecting them with iiTitatiiig i^idutions*. On 
Bowing blood to flow through the part again he found that all the 
ttt'iiDuiena of inflammation ensued. It is therefore possible to j)ro- 

Ecc inllnmmaiion Itv' injury of the vessels alone if we can be sure 
It in this experiment the irritant did not pass througli to rlic 
i*nvf H!id ilaniage t/icm as well. Conversely, injury of a uou- 
luciikr tissue which does not at the same time affect vessels is not 
lllowed by the phenomena of inHammation (p. 287). 

Sensory and vaso-motor nerves must ofttrn be affected by irri- 
ints. nnd no doubt take their part in producing those variations 
t calilire and flow which oflen precede the essential phenomena of 

liunination. But as all these latter occur with perfect regularity 
a part of which everything except the main artery and vein are 

vi4'il, nerve."* cannot be regarded as essential t<» tiie process. 

There remains, then, only the vessel-wall. That this is affected 

shown by the facts that the earliest plu'nouieua nf inflammation 

e VMcular ; that injury of vessels causes these phennmena ; that 
kjurjr confined to non-rascnlar ti.ssues does not cause them. 

'irtlier. Ryneck has shown tiiat stasis may be prodm-ed in the 
fog* neb in which milk or detibrimited blood is circulating in 
••oeof normal blood, and also that in vessels the vitality of which 
*» been completely destroyed by the injection of metallic poisons 
^ fiich stasis can be produced. In all spontaneous inflammntions 
* CftUHe is probably carried to the part bv the blooil, acting pri- 
fcrily upon the vessels and secondarily upon tlic tissues. 
There is no iletectable structural altcrnlinn of the vessel, how- 
*r: so Cohnheim sjjoke of the clniuge as " molecular," and 
f*f<led it a« fiossibly chemical in nature. To cover all that we 
f* know of the escape of fluid ami corpuscles, it is neces.sary to 
I^E that the molecular change not only increases the friction 
^^■t the blood and the ve.ssel-wall, but also that it renders the 
^^Bore " permeable " (p. 237). 

Explanation of the microscopic phenomena. 

p'' hen contraction of arterioles is the first effect of an irritant, 
'5 probably due to its action as a direct stimulant of the vessel- 
p'l ; but nothing is really known on this point. 
i^Uatation with acceleration of flow may ju-obably occur in 



two ways: (1) Irritation of a sensory nerve is >*rll known tel 



latatiuD ot till' urtcnoU'H in it» own area of ili»tn 
action of an irritant not siifliciently intense to pnrni\-)io tbr \tmti$ 
at once will stiuiiilate the s«'nttory nerves ami eAime this rrfirx IdkJ 
ililatittion. Tlic arterioles dilate, anil, the l.i|ooi|-|tre*!«nrr bciftj 
uiaintained. a larger i{tiaiitity of blood is adniilte<i to their rajiiJ- 
laries, which cannot diiat^i proportionally. The bIood-pre««nrr n 
the eapillarv ureas is, firtrrif /inrihim, rnii«e<l in propi>rtiou to ilr 
increase in the cross-seetion of the supplying arterinU';*. I'mkr 
these circumstances acceleration of the streaiu will acooni|MiDT ifali- 
tation of vessels. The wiill.s of the latter, being uuinjur*<l, miy 
contract after such dilatation. (2) Hut Cohnheini found that tl« 
same phenotuena occurred in the frog's tongue after i^ectipD nf 
everything exce|)t the lingual arteries and veins. Ther arc tka 
due, perhajis. to Jirt'ct artiim of tin- irritant upon t/ir lot-nl rturtlt 
nervous fi/»teni, which maintains a certain " tone " in the vtiwW 
even after section of the sympathetic. Dilatation of arterie* ilimio- 
ishes the resistance to the flow of blood; injury of eoil't' ' " 
increases it. If (he former is in e.xce8H of the latter, tii< - 
phenomena will occur. They are not seen in severe injurioBM' 
from the slow action of croton oil on a part. Tlie aecdvratidB i* 
most marked in the outlying parts of the intlnmed area. 

Dilatation with Retardation of Flow. — Keturdation noon fol- 
lows uj>on acceleration, though the driving fore*- ••onlinuc* 'f 
and no contraction of vessels has occurred. Alnmst the 'n. 
ceivable eaiu$o of slowing is, therefore, increased local re»i«t«Bi». 
<lue to alteration in the ves.sel-wall. It is one of the result* "f '!>♦ 
molecular changre. Resistance, and therefore retardation, imrr*-*" 
with the alteration of vessel-wall until stasis and evt-n thromboii* 
are reached, the latter, in the case of capillaries, probably mf^yf 
death of the part. 

Escape of Contents of Veeeela. — Nonually. the veMelt 1*^ 
tnit the escape of fluid, for healthy lymph, cerebro-spinal 8ii«»' 
and the fluid which tuoistfiis the pleum are all ilerived fr 
blood. These fluiil.* differ from each other in many par? 
These differences depend on that s{H.>eiaI quality which mt I*" 
apoken of as •• |>ermenbility " (p. 237). and which ll<i 
regards as an active secretory process. Directly an inflam-^ 
set« in. the normal fluid of the part is changed in pro|inrtion tntK 
intensity of the process (p. 285); the ifuantity of albumin riMa.tb' 


f to coagulate increases, and corpuscles appear, as already 
d (p. 283). All this is attributed to a molecular change, 
^nders easier the escape of proteids, as has been shown by 
5 solutions of such bodies, though the vessels bore the nor- 
od-pres8ure without bursting even after red corpuscles had 

generally stated that heavy particles are drawn into and 
along by the swift axial stream, and that, when the parti- 
such a stream are of different weights, there is a tendency 
lighter to be thrown toward the circumference. Thus the 
;e8, being lighter than the red corpuscles, consequently pass 
) periaxial stream whenever the current is slowed beyond a 
point. They lag behind because they are in the more 
loving stream. These phenomena will therefore most 
occur in the slower parts of the blood-current (veins). But 
ilanation is insufficient, as leucocytes weighted with particles 
ilion act in a precisely similar manner. Many observers 
n that the difference between the specific gravity of the sus- 
particles and of the whole fluid represents the tendency the 
i have to fall out of the stream (p. 243). 
regard to the migration or diapedesis of corpuscles, the 
re ill chosen as regards the red corpuscles, which can take 
? part in their escape. Moreover, it is plain that the force 
rives out the red corpuscle when lying against the vessel- 
II act also upon the similarly situated leucocyte. It was 
r thought that these manifested no signs of activity whilst 
re within the vessels, but many observers have shown that 
Further, von Recklinghausen has seen a pigment-cell in 
; frog work its way into a capillary and while there send out 
8. He argues from this that a leucocyte can work its way 
any rate, we must admit that leucocytes probably are able 
mething toward their escape. 

nfluence of intravascular pressure upon diapedesis is uncer- 
)ompression of the supplying artery will generally stop the 
ive migration. On the other hand, the arrest of the heart's 
n the tadpole has no such effect. The results of experi- 
jvised to show the effect of vaao-motor paralysis are also 
ctory. While in the majority of cases vascular dilatation 
iapedesis, there are many exceptions to the rule. Metch- 
>mpares the results of inoculating two guinea-pigs under the 



skin of t)ic car, one with tubcrfle bacilli, tlu- other with the 
Mi'tchnikowii : in the Hrst aniniul the dilatation will hv flight 
the (linpeilesi^ considerable ; in the second the dilAtation will be, 
marked, while there will be scarcely any diapcde*i» «t ■]]. 
frog's mesentery be moistened with a s<^liitinu '»f <)tiiniiir. 
tliapedesis will occur, though from their siibseijuenl behnridr ft 
can be shown that the leucocytes are not |iiirnly9ced. Hax tlr 
<|iiinine a repellent action on the leucocytes', or iloes it priMiuo 
some inex|ilicable resistance in the vessel-wall? The Utter vift 
IB opposed to all we know of the phenomena in i|rje)<tion ; ud 
MetchnikofT ac<"ordirigly ikmcjiIs the former exfdiinntion. nii'l O'n- 
siders that diai)eilesi.s nininly depends on some variable nualitv p* 
Bcssed by the leucocyte which causes it to seek or to avoid tl» 
vessel-wall. Others are inclined to attribute ilifTerenccs in lb* 
behavior of the leucocytes to differences in tJio chemical eonilitioM 
in the environment. 

DestructioD of tissue is due to the damage done by thr injifj 
to the element.s of the part, to abnormal physical and chemical wo- 
ditions produced by the exudation, to the pejitoni/.ing aition wf 
organisms, and to imperfect blood-supply in the more advanM^i 
stages. It is doubtful whether the leucocytes actuallv 
sue, or whether their only function is the removal i>t _ 
ar4> dead, and of such substances aa they may be unac< 
to encounter. 

rediirKt, heni, »wfllin<f, pain, nmi imfxiimd function. 

Redness and Heat may lie taken together, as they botli ikp'O'i 
upon the ipuintity of blood passing through the |iart in a unit ki 
time. Ab a rule, this quantity of blood 18 incre««e<l, the »x«» 
being most marked in the early stage of the pro<'ess. when tbf l*** 
is bright-red and hot. Its ves.sels are then fully dilatctl ainl ^' 
resistance but little increased. As the resistance grows, from n^"* 
marked molecular change and from pressure of incrt-.i ■ i" 

tiou the i{uantity of blood passing through the part i> ..:! '"j 
Cohnheim excited inflammation in one foot of a dog. aoii meail 
the blood returning through Itoth femoral veins afterward. All 
the delivery on the injured side was excessive, sometime* 
than twice the normal : but when suppuration or sluoj 
was induced the deliverr became markedly less than normal. 


must accompany such a condition, and such a part will be 
I if its vessels are dilated and full, but mottled or pale if they 
impressed by exudation. In most inflammations the internal 
external resistances to the circulation are not sufficient to 
terbalance the efi'ect of dilatation, and the blood-pressure is 
up; consequently, the delivery from the veins remains 
»ire throughout, and the part is red and hot. Both redness 
heat may be concealed if normal tissues cover the inflamed 
An inflamed foot may appear to be several degrees hotter 
its fellow, but its surface-temperature will never equal that in 
■ectum. An inflamed pleura is never any hotter than its fellow, 
may be colder. The local rise of surface-temperature is due 
ly to more rapid circulation of arterial blood : excess of heat 
t produced in the part. 

relling', beyond the most trivial, which may be due to dilated 
jIs, is the result of oxidation of fluid and corpuscles. It may 
ntirely owing to fluid, as in hydrocele, or entirely owing to 
1 round-cells, the fluid having been absorbed, as in orchitis. It 
s in amount with the distensibility of the j)art, being most 
:ed in such tissues as the scrotum and eyelids, and least marked 
me. When due to fluid (oedema) the affected part " pits," un- 
it is very tensely stretched. Swelling from cell-infiltration is 
does not pit, and is sometimes called "solid oedema." Swell- 
may escape detection in cases of slight inflammation, in which 
Tmphatics suffice to carry awav the increased exudation (see 

in is due to pressure of the exudation on nerve-endings; per- 
also to chemical irritation of them. It varies directly with 
«nsitiveness and the tension of the part, as well as with the 
ity of the effusion into it, as is seen in acute suppuration in a 
il tendon-sheath. It is often throbbing from the increase of 
»n produced by each heart-stroke. The eflfect of increase of 
are in producing pain is well shown by allowing an inflamed 
to hang down. 

pcured ftinction is due to the fact that every inflamed tissue is 
id. It is proportional to the damage of the essential cells of 
ITected part. 

lBIBTIBS* of inflammation.— The j9roce«« of inflam- 
' Perhaps " Degrees " would be n better term. 



mution is liable to no important vurintioo, but the rmc 
duced by injuries of different intensity aeting f"r difffrvnf 
of time tipon different tissues vary sufficiently to penuit of a i 
cloiisification being made upon this basis. It will be renirfl 
that the first effect of injury upon tlie normal exudntioo 
increase the (|iuintity of fluid which escaped from the va 
to render it more albuminous. Next, whiUt the rise ii 
of albuminous constituents continued, leucocytes sppearml 
creasing numbers, and the fluid became more and more 
Furthermore, with the leucocytes came a few red corpu 
these, in the most intense inflammations, were vastly in exe 
the white. These differences in the exudation may be foti 
passing from the spreading odge toward the centre ■>f an infl 
tioD such as that which constitutes spreading traumatic 
There is no break in the continuity of its producfinn ; the 
from .serous to hemorrliagic intlauimation occurs gradually an 
{lanKii with the increasing intensity of the injury. Oonseqi 
the following *' varieties " are to be regarded simply a« stepal 
process of intianiiuation due to variations in (1) the n*«i«tingj 
of the tissues (:!), the intensity of the cause, and (8) the dc 
its action. 

1. SerouB Inflammation. — Injuni SHi/hl. — .\s a ro*ul 
injury the noruial tninsudntiou from the vckM'U is iiic 
ijuuntity, and contains excess of albumin, but very ffw l«Mtc 
Conse(|uently, it contains very little more itll)iimiu than .••erumj 

the name), and does not euugulaie 
^"^■i^- most a few flakes form. The 

amjdes are chronic effusion* into 
cavities — the pleura, jointD. or 
vaginalis (hydroctde). In each 
lining of endothelium \» not 
.\n effusion of the same kind occ 
in the substance of a part, r«»n»ti 
inrtHLinwinry .iMiemn ..f .kiu. .. inflamuiBtorv oBdcma " (Fie. 105).| 

The UriB- «i«p« ■how II wi-rv • ... ' 

flu<ii •nil ihf cxu.ic<i fliiKi a j)art is swollen, " pit* ou pr 

<Km.... Mi-cluw" l-y Mr Boyd., ,^^^ y,.^^ ,^,j^^.j ^^j ^^ fp„„,| j,, 

t rated with excess of Bnid. 
occurs on a mucous surface such an intluiumatinn is calleil 
rhal." In this ca.«e the exudation contains mucin. In i| 
ished states of the blood, especially w hen the albumin is dinii 

INFLA MM Alloy. 


flammatory cxudiitions are liable to be serous, even when the 
•riicess is i»f considerable intensity. In the earlier stages of more 
ihlenso intlaiiiiuutions. where the emijjration of blooii-turpuscles is 
ftot fully established, as well as in cases where the injury t<» the 
■vessoLn, although severe, is rapid antl transient in its action (as 
tbiit caused by heat and blistering agents), the effusion is often a 
clear aud only slightly eoagiilable lii|iiid. With more severe dam- 
ajp the coagulating jiower of the exudation increases. Networks 
iif fibriu are freijuent in the meshes of inllamod connective tissue, 
and inrge flakes of it may come away in otherwise serous efl'usions. 
i'lrcst' inflammations are called sero-flbrinoue, and lead on to the 
next class. 

Fibrinous Inflammation. — Itijimf more Intcimr. — In this form 
tlie exudation is still more riclily nlbuininous and contains more 
leuciit'vtes : it consei|Uently has a much greater tendency to coagu- 
lite.und " lymph " forms on the inflamed surface or in the substance 
of the inflamed tissue. The most ty])ical examples are found cm 
serous membranes. On the surface of the visceral ])loura. for irritant jtrnduces redness from dilntntion of vessels: 
llicu fiillows exudation of fluid and leucocytes, with <lamage of the 
emliiilielial lining, and fibrin, funning upon the siirfiice. entangles the 
li'Hccintes in its meshes. Fi/n-in riintdiniiKj lfu<-iiri/te» conKtitiiten 
" injliiwmatori/ li/)iip/t." The white corpuscles may be very numer- 
"lu. iir only a few may be distingiiisliiible in a granular or obscurely 
filirilluted matrix. " Lymph" may now form upon the opposed stir- 
lucciif the parietal pleura, which becomes infected from the original 
f'fus, and the two ])atches blend. This is the first stage in the for- 
inMiori of an "adhesion " — /. c a band of connective tissue between 
"I* t«o surfaces. "* Ijviuph," formed in exactly the same way, is 
'1'* temporary uniting luediuiu in healing by the first intention, and 
'''■'< siiiiilar ■■ lymph " wliieh "glazes" the surface of an open wouiul 
* li'i hours after its inllictioii. In these cases the fluid escapes 
iroa file f|.f.p surface. When it ocnns on a niur'nus surface such 
■nfiiinunation is calletl '■ cnutpous " or "mendtranous." A similar 
eolation occurs into connective tissue as a result of chronic slight 
'nitation ; the fluid is apparently absorbed as fast as it escapes ; 
"'iriii prolialdy forms, but it soon disappears, and with it those leu- 
<iic_vte8 which crowd the tissue: while those parts of it which have 
"•fMi destroyed by the prinniry injury and tiic jirocess excited by it 
»re ^mtlually replaceil by prolifcnition of neighboring connective- 




tissue cells. Such itn iiilltiuniiiitinn nmy end in ivbsyrption — now 
leucocytes wandering into lyuipliiiiies and re-eutering the circulj- 
tion ; others, together with the filnin. laulergoing fatty changwiuiJ 
fiirniing an emulsion uliifli is* simiitirly alisorbed. 

Productive Inflammation. — Injury Sliyht, hut Lotuj Cotitmuni. 
— In many cases tlio intianimatDry process ends in the formatirm "( 
new tissue — infiauiiiiatory fibrou.s tissue ; and the inflamtnatioD i» 
then said to be productive. In this case the fibrin j)resent ilr ■ 

IH'ars. and the exiulation seems at this stage to consist of cl 

packed leucocytes in a scanty homogeneous luatrix. The vitalitv 
of these is maintained by vascular loops which spring from il»^ 
capiltiiries of the inflamed tissue and penetrate among the celi^ >n 
all ilirections: tliis is granulation tissue. It differs from infliun- 
iiiittitn/ hfiiijih ill possessing vessels and in having a honiogeoe<»u* 
instead of a fibrinous matri.x. It derives its name from the f*<?t 
that on the floor of a healing ulcer, which consists of this tissue, 
the young cells mass tliemselves round the apices of capillary liiiif»*. 
all of which project toward the surface, and wo thus get the fli****" 
macle up of ruundeil projections, about the size of a pin's he*«* 
which are called '"granulations " (Fig. 111. p. 303). The pltntit'**^ 
formation of rrgnt'ls in I'ttxtntidl to the r/ianffei) which thl» ti»»Hr umir-^- 
(joi't: in the prodiirtion if riiiini'rtire tinxur. In healing wounilsn^^ 
vessels have been found protruding from adjacent capillaries by it'*' 
end of the secntid day (Wywoil/nff'). 

To ascertain (lie exact development of granulation tissue in*** 
fibrous tissue, Ziegler placed chambers, formed of two slightly 
separated cover-gla,sse8, in the subcutaneous tissue of dogs. »o<l 
removed them at varying periods. U|i to the fifth day they «>»»" 
tained round-eelLs — some with one, others with a hi- or tri-p«r1it* 
nucleus ; then there appeared cells twice the size of leucocyte*, con- 
taining ft large vesicular nucleus, slightly contractile and capal'l*' 
of taking pai-ticlcs into their substance. These are called epithe- 
lioid cells, on accintrit of their appearance, and formative celte, !>•■ 
fibroblasts, be<-;itt SI' from them all new eonneetive tis.sue devr! !■ "^ 
As they increased in nniidier those witji divided nuclei ilisapji'i - 
so it is jirobablf that (lie fibroblasts feil upon degenerating leuco- 
cytes. After the twelfth ihiy giant-cells in increasing nnnil'i''^ 
were foiiml, formed afiparently at the expense of cells in tli'"''" 
neighborhood, either by their coalescence or by their aborli'' 
attempts at multiplication. Many giant-cells degenerate, but .<oiu* 

may develop into connective tissue. This tissue is formed thus : the 
fibrobliints assume various shapes — pyriform, spindle, ainl bniiR-hed 
—ami are closelv packed in a homogeneous intercellular sub.^tance. 
The protoplasm of the Hbrohlasts eitlier secretes or is itself con- 
♦erteil into a substance which fihrillates. By the union of bunrlles 
ffiitn different cells and by spread of the process to the intereelhihir 
nuiwtance there are formeil intercrossing fasciculi of fibres, to which 
adhi'W some of the nuclei of the original cells with :i little proto- 
plwmfFig. 10(i). 

Shwiiigtiin and Hallance repeated tliose ex|ierinients. with this 
additional precaution, liint they only left one .small aperture bv 
«rhicli cells coidd enter the s|)ace between the two cover-gla.sses. 
Tbey ngrectl with Ziegler that leucocytes were the first cells to 
enter this spnce. and that these were succeeded by fibrobhists. 
They differed from him concerning the origin of these fibroblasts. 

Flo. 106. 

^"""m of new growth reiiultlnii from chnmlc iullauinialliin of conncpttve ttuue : A,m 

"'•""I'l, a, • (ll.roSd, structure. .< •-'uO. 

'" «»me in less than twenty four hours after the cover-glasses 
*tff placed in position leucocytes had entered in considerable num- 
Wru iind had distributed themselves all over the enclosure. Hut 
"Mr the |x>int of entry were other cells — plasma-cells or fibroblasts. 
Thcsp Cells differed from the " ]iioneer " leucocytes in that they 
wn larger, more coarsely granular, and possessed a single dear 
on\ nucleus. In im case were transitional forms seen. The 
oripiial leucocytes were never ob.served to undergo any but de- 
generative changes. The fibrobhists, on the other haml, showed 
greater power of amtrboid movement and of enclosing corpuscles 
tliHU the original leucocytes. It .seems clear that the fibroblasts are 
he i>w't'fi)»<ir». hat not tin' prot/i'n//, of the small round-cells founil in 
lie t«rlieat stages of infianmiation. Sherrington und Hullance 


consider tbat the fibroblasts are one of the normal conatitucDtt of 
onnnoctivo tissue. Motcbnikoff maintains that fixcil c■onDl■cti^^ 
tissiu' cflls. c'liilotlipliiil I't'lls. ami tlii' l!ir;j;e nioiioiiticlenr variety of 
leucocytes havt- all the powi'r of (ievcli)iiing intc fibrous tismf. 
The exac-t origin of the fibroblasts must still l)e rt-ganled a>< ilmilii- 
ful. In thf mean time it may be observeil that the rcscmbLiiitr 
between MetchnikofTs large mononuclear leucocytes and Shcrrinz- 
tnn and Rallunce's plasma-cells is very close, both in appearand 
ami beliavirir. It is worthy of special note that in the eifxTV 
incnt8 of these last observers blood-vessels had not clevelofH-il be- 
tween the cover-glasses even by the eighteenth day. 

Tlic new connective tissue is calleil inflammatory or scar-tiseue' 
At first it is highly vascular, a recent scar being redder than tb^ 
surrounding parts; but tlie ttiulency to contract is characteristic of 
this new fibrous tissue, and as this proceeds vessels disappear, »nd 
the sear, in the course of some weeks or months, becomes white «u» 
compared with surroun<Iing parts. This contraction of scar-ti»*ue 
tnay produce serious results, such as the gravest deformities of 
atrophy of the essential epithelial elements of glands. (See "(Tir- 
rhosis of the Liver.") The contraction is most marked where tl>9 
tissues are loose, as uliotit the scrotum. It appears to be essentia" 
to the process of healing; for this will cea,se in a callous ulcer of 
the leg if infiltration of surrounding tissues and adhesion to dee|r>*' 
parts arrests contraction. A scar is always a weak point in cfc* 
system, and a tight scar is always irritable and very liable to lin?*»' 
down. The tendency of scars is to become fainter. 

But granulation tissue does not always develop into sear-tissi**- 
If the continued irritation become excessive or the vascular sii|i[»'.^ 
be deficient, the [irocess may be arrested at any stage, und J*" 
generation will follow. Deficient blood-.«upply may be due *** 
insufficietit lievelojimeiit of vessels, diminution of their liiininu {«•* 
occur in giinimata), or to pressure from too dense ])acking of tl»'' 
cells. It has been found thnt imperfect blood-supply is accow*' 
panied by tlic development of giant-cells ; they arc found in »'' 
really chronic inflammations. Thus, the typical structure of * 
tubercle is — a giant-cell in the centre, surrounded by fiiraiati*'" 
(epithelioiti) cells, whilst outside these and intermingled with the"! 
is usually found a /one id' ordinary leucocytes (Fig. lit"). In giiP'' 
raata and lupus-nodules sitiiilar structures are frequent. A Jec''"" 
through the thickened synovial membrane in a case of cbr«.>nii* *rt''' 


riti* often sIiomts the following appearances: Externally we find 
(iTdinary jjrnii Illation fi».>«uc. with j>oini' <levelo|»ing scar-tii^iie : pass- 
ins; townnl tlic joint-cavity, we fin<l next « layer of tVjnnative cells 
iawhicb giant-cells become increasingly numerous, ami even typical 
" tiiln'relest " may occur : yellow spots and patches of fatty degen- 
fration next become frequent, and the surface may be composed of 
pwmiiir debris in whicli cell-forms are no longer distinguishable. 
A liiiid looking like thinnish pus may occupy the cavity; it con- 
iiiiis however, very few pus-cells, but consists mainly of fatty 
jfniniilci' — formed by degeneration of the superficial cells — sus- 
[wmled in fluid. This is the change known as ••chronic suppu- 
ntion" of the knee. "Chronic abscesses " of similar nature 
inur form dsewliere. especially in cotinection with bone (caries of 
'frtpbr*). When starting from bone the purifonn fluid, formed by 

Fio. 107. 


> AVrrln frum a raw nf lii'irrculniil.i of »»• Uvpr. A miUtlnucU-alcd «l«iil-ceU ikrcuple* 
Itentittr kroiitiil l» nil ari'ii iirmmiiu-iwiim <°iuiriiliiin, uiiil. oiiUlilr this, n ujiie ('uiuUnUlIK 
v™«lt«ll> or nr.rv.tilii.t». an.!, t<) « \vm cxtpiit. nf lfu<'«>cjl«i. Tlie IcueocyUw are mo»t 
nuuniiu ,in tin- «iile wluTf Ihe <mif«l|iiii l> ini»l «<lvanc-o<l. ' 'JS*y 

liegeiicration of the granulation tissue, simply distends the tissues 

muDil »bout and converts them into a bag, the wall nf which yiehls 

I little pus. <tn the other liiiiid, increased irritation will destroy 

ffimcof the cells of the granulation tissue and will pnnitnH- inflam- 

vatidu of it, with free escape of corpuscles from its ves-sels — in other 

wonls. will cause it to "break down into pus." This is best seen 

when a healing aseptic ulcer with a serous discharge becomes septic; 

the Jischarge then becomes purulent. 



Interstitial is the tenri applioil to intintiiniatinn of politf orgiw 
when the uinuifestiktions of the process ure pritnorily liuiilr<i to cJw 
connective tissue between the casentinl element* of theorgBM. In- 
terstitial intliunniiition may he ncute. ninnin;: on even to fiiippunliniL 
but as a rule it is an ordinary proiliictive inflammation in wliifli 
there is but little exu<lutioit and a eonsiUernhle amouut "f wll- 
niultiplication. It is iieeompanied by secoiulary chnngw in tfc* 
essential eells, iluc to inferfercnee with their nutrition. In pano- 
chymatouB iufiiiintnutions the epithelial elements of the "rfcan ««■ 
to be primarily affected, becoming swollen, finely grnnuUr. or r»ni 
structureless and incapable of staining. These are probaW 
degenerative and tieerotic nature, mixed up with regeneratiu ; 
cesses (pp. 38. 79). The essential lesion of the inflammation mn*. 
of course, be of the vessels in the connective tissue; but the wsentiJ 
cells of an organ are much more delicate than those of it* oono**- 
tjve tissue, and show more (juickly the efl'ects of a strong irrit»»^ 
which causes engorgement of the vessels of the conneetire ti*^* 
and free escape of ceils and fluid into intercellular au<I intrafr**' 
ular spaces. I'nder the action "f very slight chronic irritants f***** 
liferntion of connective-ti.s8ue celU occurs, with but little or 
acetitiiulatiiin of leucocytes. Scar-tissue is thus fornn**!. «n<l 
nutrition of tlie essential cells is more slowly, but none the B 
snrely, interfered with. 

Suppurative or Purulent Inflammation, — Injun/ lutrnrt 
J'rolont/i^tl. — This is a \ery common form. In it the exu^ 
contains the same elements as in the fibrinous form : the pecoliar*^ 
of the process is that no coagulation occurs, no " lymph '" fo 
and no new vessels appear ; and even such " lymph " as may li» 
been formed at an earlier stage of the inflammation is de»itmy ' 
when suppuration sets in. The irritant is more intense than tb 
usually re<|uire<l to produce fibrinous inflammation*, and it is 
tial that its action l)e ]U'olonged, Serous ainl fibrinous stage* o{brf> 
precede the suppurative, showing that they arc minor grades of ibtf 
same process. 

.Suppuration may be either acute or chronic; with the latter wt 
have already dealt. Either of these may appear in s nrrum»erAed 
(ithtivmi) (Fig. lOH) nr in a iliffiim- form, either in the mf'stitncf uf a 
part or on tifrff mtrfarf — mucous membrane or skin. lu tlir latter 
case, when the epithelium is destroyed with more or Ie«s ofilir miI»> 
jacent tissues, the process is called \ilceration, but wbere tbe 





deeper layers of the epithelium remain it is termed a punilent 

Formation of an Acute Abscess — When we cotno to consider 
the etiology of acute Ruppiiration we shall find that, in all proba- 
kility, it is always due to the action upon the tissues of organising 
—most commonly the staph iilncurrug pi/oi/mu's tiitrciig. Some of 
thfoc organisms become arrested in the capillaries of a part, and, 
ifthteondtdoiiD are nultahle for their t/rowtfi, they proceed to ninl- 
tiplvand to give off the products of their mctabolistn. All around 
tliem appears a clear hyaline ring of tissue, «hicli docs not stain 
«nd in which all structure is lost. Obviouflly, some irritant, .soaking 
fwni tile cocci into the tissues, has destroyed the latter and they 
h«ve UQilergone coagulation-necrosis. In the course of a few hours 
a ring of leucocytes appears rnund this area and becomes increas- 
ingly ilwime : they infiltrate the necrosed urea irnd press in towiird 
lln' ceutre. whilst the cocci, on the other liimd. uniltiply and pass 

Kin. lOH. 

Ktf0 <u the tklii. The huniy lnyiT hu» lurxvly lUsaiiiiearecl, snd the MalpiKlilan 
T^'llVl upward l>y the subjnitnl utmci-ss (a). The raaes of piiSK-orpiisolos is Just 
'••k'lUrilnmi to f.)nn a ravlty. the- wh11» of which are thickly liillltrAtfil with siinilnr cclU. 
itomintj KIk. lifj.) iFiMin ■ ^iieclmi-n by Mr. lioyil.l 

'"'^- The cocci penetrate the tissue in all directions, lying e8f)e- 
*'*lly in lymph-spaces, and everywhere a layer of leucocytes is 
'i'nnod to oppose them — at first in vain {p. 315). However, after 
nuinv leucocytes have been either killed by the chemical products 
of llie organisms in the tissue or starved by the inaccessibility of 
lie necessary nutriment, the resistance to invasion becomes suc- 
H>sMfid, and by degrees the cocci are completely walled in by gran- 
iJafion tissue which everywhere intervenes between thein and the 
fslthj tissues. In rabbits, after injection of cocci subcutaneoiisly. 

the limitation be>:inH on the third or fourth <Iav. but is not oon 
ou tlic average till the ninth : in man it iiKtiallv occurs more sp 
At firnt a central yello\vii!>h mu88 uf uocrooed tissue infiltrated vitli 
cocci and leucocytes is found, surrounded by the layer in «liiek 
cocci and leucocvtcs are striiirtrlinc for the niiisterv. '■ 
central niahs Hnftenj*, and it ist noticed that the tissue-t 
Up and become indistinct as the cocci spread among them; I 
no fihrin forni:* in the fluid exuilation. All this in attrihntr 
peptoni/.ing action of the cocci which in acknowledged to txil 
energetic. 80 long as the process is actively spreading tu>] 
ves!«els form, but as soon as the leucocytes have got the tipiNrl 
vessels iijipeur and "granulation ti.'-isiie " is formed. Thus 
veloped ii cavity horderetl by li.'tsue infillrnted Mrith living 
This rnvity contains dead leucocytes, destroye*! and Ii(|nefie<r 
an<l exudation, as well as a few living cells which have^ 

Kio. 109. 

84**'ttt>li Oiroiik'li II ^nniii pov iHitiu..' liM' ii<>Mi> i.i>t-r i)\i-r iiii' {riilrr' i>t Ui« 
dUii|'[K'«rtsl, Mini tliK frt'f i'(Ik\> nn- ktiuwii. A niiiM it( rclU U Mrfti lit Ih^ lwmii4ii| 
UietMdlU'ii Mi>l|ili;l>luii U>ur ami th«r Iruv •lOii, miikliie iu wit)r li> llie Hirlker. 
■rtiml Inlmi U i>lliiiil<' wltnUy In ilw fpliliTiiiln, while ilir llnid »n<l r«ll« liair 
IVniii the derma, the tnirk bring uliuwii- (Oiinpain Kik UJS.) (Krom • Hi 



migrated from the surrounding tissues: ttiis fluid is ealle 
Once formed, such a cavity either enlarges or .<!hiftH it.* |)Oiiiti<i 
both. The extension occurs in the direction of rr«Utaa'4 
Its appn>ach is marked by thrombosis of the minute veMdft *J 
mnleciilnr disintegnifion of the cells they supply, by mizntlii 
corpuscles, and by exudation of fluid into the newly-fonued 
Its progress is not arrested until it reaches some free nor 
open cavity, upon or into which it bursts. We find on MXti 
the Willi of n sprendiiig ab.scess all the stages of inflammatt 
proof of the prolonged action of the cause. In the centre. 1 



ud in sncce^sion as we pass outward from this, thrombosis, stasis, 
rrtaiilatixn of (low, (litninisliing. and jierbiips giving plni-e to acctd- 
twliod. bidorc the normal circulation is reached. With hypcrtcmia 
exudation increases ; much of the fluid is taken oflf by lymphatics, 
hilt tli(' c<irpusclos acounudate in increasing luinibors. and red join 
tbt' wliitu outside the vessels as the centre is approached. This 
iccuiint explains how it is that we are led to the belief that sup- 
piiratioti has occurred when we find redness, heat, and inli'irui 
developing over a deep-seated swelling. 

•Vii ncute abscess almost always extends until it bursts or is 

ofn'in'ij; by either of these means tension, a great cause of the con- 

liniijiiiwof the inflammation, is relieved, while the pus and its orig- 

in.ll cause escape together. If the cavity is couiplctely dniiuetl aud 

kept ftt rest and putrefaction of the discharges is prevented, all pus- 

formarKiii cea-ses. Vessels i|ui(jkly develop in that fiart of tlieround- 

<*llt!i| inKltration of the walls iu whicli this hu.s not niready nccurreil: 

Ions tbcy become lined by granidation tissue. This grows and 

Wends across the cavity, which is often tliniiTiishiMl by sonic falling 

"• of the wall.>». Scar-tissue then develops, and thus the abscess is 

'•eale.i (pp. 128, 129). 

Diffuse suppuration is exactly the same going on over 

* *idc area. It is often more intense than when circumscribed, and 

•t 18 by no means uncommon to find shreddy slouglis in tlie pus, for 

effect of the injury on some portions of tissue is so great as to 

»8t> miliar death. Diffuse suppuratiiin is generally due to the 

\*^r«ptoeoccns p-yo(iene» — an organism id" whicii die peptonizing jiower 

P* more intense than that rd' tlie staphylococcus, which possibly 

[»ceom,t8 for the difference in tlieir airtion. (See "Micrococci.") 

I*U8 from a simple abscess occurring in an otiierwise healthy 

P*f8©n {liiuiliifile pus) is a thick, creamy, opaque, yellowish-white, 

*''glitly viscid fluid, having a faint odor, an alkaline reaction, and a 

[•pe«ific gravity of 1030 to 10:^;^. It contains 10 to l.'i per cent, of 

|*oli,| matter, of which two-tliirds an- albiiuiin and the rest fatty 

latter and salts, such as are found in blood. On standing it scpa- 

*'es into a dense yellow layer, /iit>f-ci>rfiiiiii'(<'i<. and a dear siipcr- 

**tant fluid, llijuor pur in. 

I*U8-corpu8clea are spheroidal bodies about t^Vj '"^^h in diameter. 

!■* «»oy are semi-transparent, more or less granular, aud motionless: 

•**v usually contain a hi- or tri-partiie nucleus, the .segments of 

'•*ich together are no larger than the original nucleus. Such 



Fin. 110. 

I'n* rorptiHrlc*) wt •*'♦•» nftor 

di-Htli . •!. iR'forv. >>, •flvr the 

dilllliiii iif diliiU! M«tle *cl(1 

division is therefore regarded as evidence of degeneration raflirr 
than of iiinltiplieiition and of growth. 

A small minority of the cells have exactly the appearanc* M 
Icucoeytes and j>erf(>nn iiintrboid. moveinentit. These are tin 
recently-escaped cell». Acetic acid clears up the cells and ru....- 
obvious the often-obscnre nucleus (Fig. 110). 

It is noteworthy that pus hits no jKjwer of absorbing sloughs'* 
sequestra ; //«•««</ cells arc rei|uired for this. A bit of bone, evfi ^v. 
ivory |K>g. surrounded by granulation tissue will be slowly tT'ili i 

but it may he in piu for months witlmctt 
losing weight, and suppuration is not likcW 
to cease until it is reinovtHl. The pr** 
vention of suppuration is therefore to ^ 
aimed at in all cases of necrosis and •• 
foreign bodies (especially aliHurbiiM. li 
tures) retaineil in wounds. 

Sometimes, though rarely in ihf ciLxf 
iin acute abscess, after a collection of pus has furmeil the irritat 
diminishes so much that granulation tissue forms mund the fluid 
develops into fibrous tissue. Such pu." may long remain eucapsiil 
its corpuscles breaking down into fatty d(^bri« ; but as a rule i 
fluid part is iiltsorbed. and a more or less dry, chccsj-looking ui 
et)nsisting of cell-d<^bris and cholesterin cryst^ils, is Irft in the t^^^m 
sule. The mass nuiy calcify. Such collections may lie harnil 
in the tissues for years, and finally become the centre* of ft. . 

suppuration. These changes are much more commuu in chroi^^*^ 

Ulcerative Inflammation. — Wv have seen that suppuretion 
the substance of tissues jiroduces nndeenlar disintegration of ih 
as a rule no distinct slough is found in pus. The same tnoleci 
destruction eating away the tissues on a free surface consti 
ulceration. I'uder the action of an irritant the su|KTficial layer oT" 
the fekin becomes soaked with fluid, and leucocytes esca|te in non- 
liers from the vessels and wander even into the epithelial cell*, whi 
they .seem to have arisen by endogenous niidtiplicatiuii. L" 
these circumstances the superficial cells do not become hornjr. •ad 
art- I'ttsilv brushed ofl". or the original irritant may ha<e destroyei 
their \itality and cohesion, and they are washed away by escaping 
fluid. The rete is now exposed, and the deeper tissues are liabks to 
irritation from slight friction, contact with chemical irritant*, or 



putriil liistchnrges. The inflainniutorv pntcfui* l>ccotm'»< inori' intense, 
the t'>ca|)e of IJiiitl and leiiencytes (Veer, ami stanis and tlirombiKsis 
occur here and tbcre. Portions of the pupillary layer and of the 
wvcriug epithelium die, disinte;irate rapidly, and come away in the 
(liMlarge. The process spreads by tlu^ j)rodiiction of limited stasis 
mil death of tissue ; if the stasis is at all widespread, a visible 
slough will result. It is common, indeed, to see tags of dead tissue 
»ilhereiii to the floor of a spreading ulcer. If the irritation becomes 
oure intense, these shrcfls will increase in size and fomu "•sloughs." 

Fio. 111. 

_®o o^^o, 





lilnf •iirfkrv : n, layer of pas , fc, Kniiiulaiiun ii».siii- with IiH<r« of blcxid-veaiole : 
< "■miiii;ririii|{ ili!V(-l4i|.ini'iii of thi- itrBnuliiiiiin tlnKUf liiln ii niirilliilfd ktructuri-. x 3X1 
(KUKWcUib.) Di«|{ri.mui»tic. 

ilcentioii passes insensibly into giini;reiic in proportion as death 
bcfoiuw tiw rapid to porniit. by lui-aiis of deirencrntion and the 
jctirtn of leucocytes, the molecular disintegration nf the parts as 
lliev file. The discharge in the spreading stage consists of a few 
ieucocTtcs and the debris of broken-down tissue suspended in fluid. 
JjiVe the edge of advancing suppuration, the margin of a spreading 
loer e.xhibits all the stages of in flaiuniation, from the mildest to the 


prodiirtion of molecular death. An alwceiis is often li 
closed iilrer When tlie chiisou of the iiitiiiuiniutiuii are 
riMind-celliMl infiltration of the floor increases ami becomes Mur*r 
Inrizcd into grnnulation tisfnio (Fig. 111). Sloughs arc det»rfa(>(f by 
the action of leucocytes which eat through their couuectutns titk 
living parts, and the base soon becomes covered with "granidation*." 
When healthy, these are bright-red. slightly-raised. roiin<leii rlr> 
vations, about the size of a smull pin's head, and consist of nil* 
grouped round a capillary loop. They contain no lymphatin mA 
no nerves, are not tender, and do not bleed readily. ho|>artrire 
from this type indicates disease of the granulations. 

The granulation tissue grows by multiplication of thr 
cells, and such loss of tissue as has occurred is thus replaci 
the same time the cells infiltrating the edges disappear, ami i 
sink gradually t" the level of the base. Epithelium now shooU 
from the cpitheliul cells at the margin, and three zones cannl 
be distinguished at this stage — an inner, dry, red zone, wherr tk* 
cells arc one or two thick ; then a wider blue zone, where th« 
thicker, but where no horny cells exist: and lastly, an opaipie «■ 
ring of sodden horny epithelium The deeper layers of thcjff''** 
ulation tissue are meanwhile becoming scar-tissue. contractin)( »■>*' 
drawing together the edges of the sore, so that the epitbeliuv 
less and less to cover; and tinallv the whole surface i* skim 
over and all granulation tissue is converted into fibrous Hf^ 
Contraction goes on even after this, and the re^tiilting acar it **? 
much ^<ul!llk■r than the original ideer (pp. l:iH. \2\i). 

Hemorrhaeric Inflammation. — This form of inflamuiatioP " 
characterized by an exudation in which red corpuscles are in ^r*' 
excess. So far as can be observetl. red corpuscles are the latest <*' 
all the contents of vessels to escape. In a case of .spreading ti*"" 
matic gangrene the ti.ssiies a »hitrt dintance alxivi' the wtiially g*''' 
grenous part were crammed with red corpuscles, showing that tat 
vessels couhl hold none tif their contents (Fig. 11-); hitfher uf 
there was a free escape of leucocytes and of sero-fibrinoiu) •fffiwi"* 
(Fig. 1<H); and hit/fur utiff there was effusion of simple wwww 
lluid only. <lf course the injury may be .so inten.on as to moM la 
immediate and free escape of red corpuscle* from the capilUrin 
The fluid which i»oaks the part in these cases is usually thin 
more or less deeply blood-stained. The grtwter the nam 
capillaries present in a tissue the more likely U an t* xiiiUtiaa to 


be hemorrhagic ; severity of injury is the other factor. There are 
gciu'rally many red corpuscles present in the exudation of acute 
[ineiimonia. The free escape of red corpuseleM shows that the 
cajiillary stream in the part is reduced to a niiniinuiu, that the 

Fig. 112. 



BwfiT iKjrur of ••litis i«n<l *ul)<'iilnn«Hiim fiit n sliort dlntanoe nbove llie dead part In a <•««> 
oripniniiiiix i(iiiiim-nv. Tin- liiUTstlres of the tlMtiex art crnmnicd wUli rfd coit'ispIc's mid 
«fr« Kblht; r, (, rtmnectivu liiviue; y, fHt-oullii; r. c, red cun>Ufit>l(.'S, •. lAX). vBuyd.) 

injury done to the tissue is a very grave one. and that stasis, death, 
•ml thrombosis arc impending, Too often gangrene is the terniina- 
tiw uf such iutlaiuiuatiou. 

'i«B, ii,(Ti"tM, and new i/rowth. 

!• Resolution. — This, the most freijuent and most favorable 

•♦nnination of inHammation, consists in the cessation of the pro- 

"**«»nil the restoration of the part to health. For this to occur 

" i» necessary, lirst, that tjjc t-xcitiiig ciiusu b<? removeii ; secondly, 

'Mttli« walls of the hiood-vessels he restored to their normal con- 

'litinii. in order that abnormal tran.Hudation may be arrested; 

'""filly, that all exudation be disposed of; and lastly, that any 

onMl or damaged tissue-elenienta be regenerated. Obviously, this 

fMtorntion will be more easily eftVcted in the earlier than in the 

more advanced stages of tiie inflammatory jjrocess. But resolution 

Isvcnof ''stasis" sometimes occurs, and may be watehed under the 

sicroitcope. The corpuscles of the stagnant blood move off, one 

IT another, till a slow stream is re-establis!ied through the 

iflajuod area. This stream ipiickens as resistanre diminishes, 

ctiDtraction of the vessels follows the gradual recovery of 




their muscular coat«. ExndatioD. first of corpiuicle». tlien of llaidL 
ct'asc». and tin* ciroiilntion ac;ain becomes normal Sentm. i»r»- 
fibrinous, and productive infianimatiood in their early ht^fu trv 
those which end in retolution : but if normal tissue has be«o one* 
replaced \t\ firiiniilntion tissue or scar-tissue, or has been tl» - 
by suppuration, ulceration, or gangrene, remlution is imiH.-- 
A normal con<lition of the walls of the blood-vessels is deiniil'T 
upon the proper circulation of the blood through them and ibftr 
va,sa vusortim. Whatever, therefore, favors the re-establishment wf 
normal circulation in the inflamed area will favor resolution. 

The last element in resolution is the removal of the int1atumtt'>rT 
products — fluid iind corpuscles, These are removed un 
lymphatics, but after restoration of the circulation al , • 
carried on to some extent by the veins also. In the later »Ujt« 
of the process any unabsorbed blood-corpuscles or fibrin iindftyi 
fatty degeneration, and thus the complete removal of the infl»»- 
matory producta is much facilitated. (See "Gray Iiepatiaati<iD-~i 
The process of regeneration in the various tissues has already bc« 
describe<l (j). 11!>). 

All conilitions interfering with the lymphatic or vaacular circa^' 
tion. such as the pre-ssure exerci8e<i by a large effusion in a mto* 
cavity or by a richly celluliir exudation in a lymphatic gland, m** 
retard resolution. It is generally believed that interference *'" 
the li/iii/)hatu' circulation tends especially to prevent absoqitK*- 
and interference with the circulation in the hhunl-rriinfU < 
vent that restoration of those vessels to a normal condition v: 
necessary to arrest the continued transudation. Recent nhnmritt* 
have, however, shown ' that fluid artificially introduce*! into ti« 
pleural cavity is mainly absorbed by the blood-ve.ssels : and it • 
possible that the absorptive power of the lymphatics ha> b«« 

II. Necrosis. — Inflammation may terminate in death of 
inflamed tis.-iue. Wcigcrt has shown that in all but the sligl 
forms of inflammation the inability to stain will reveal cells m^\A 
have undergone coagulative necrosis (p. 80). In nin«t inflaauna- 
tions the destruction of the tissue-elements is .siill more niarkeiL 
Clinically, we do not speak of necrosis unlfss nbviou* molar destk 
of tissue has occurred, a» lilstingiii.Hiii-d fpiiii the iitolrcular dg atf e- 
lion characteristic of sii|)ptinilion and ulceration. 

' Htarling ami Tubby, Juurnal i^f Pkyoiolugy, I8M. 



Tbe severer the injury, the longer its period «f action, and the 
cbler ihe rosistance of the tiswiies, the more likely is necrosis to 
B«U. It may be produced in the tbllowing ways: 

1. By direct injury to a part, producing, by its continued action, 
itl«Tninati>ry disturbance of the circulation, ending; in tiironibosis. 

tissues are affected by the injury siniuItaneouHiy with the 
i, and suffer also from the interference with the circulation. 

2, By an irritant conveyed to a part by its vessels, affecting them 
•rimsrily ami inducing in them changes similar to tiie foregoing. 
Ibe tissues are affected secomliirily both by the irritant and by the 
circulatory disturbunec. 

•1. By pressure of a neighboring inflammatory exudation. This 
ttraiigHJatcs the supjdying vessels, as in sl<Higliing of skin from 
WiWflcdeina. in necrosis of tendons in a whitlow, and in death and 
pgi'iitration of cells in chronic tiithimnmtinns. Death is lunrc 
kely fo be produced in this way when the cxudsitiou occurs in 
tyiitlding parts, e.specially in bone; here sudden dcatli of an c.xten- 
Vc exudation means death of the affectc<l part of the bone and its 
Jbcequent separation iit the foi-m of a sei(Uestrum. (8ee " Necrosis 
' Bone") 

lu all infective inflammations the irritant exercises its deleterious 
tfct upon the cells of the inflammatory exudation and tends to 
Wroy them. 

• Some causes of inflammation always lead to gangrene — e.g. those 
' carbuncle, nnilignant pustule, and hos[iital gangrene. Such in- 

mmations are sometimes called gangrenous or necrotic. 

The ulcerative process by which a slough or 8e<|uestrum is de- 
fliwl lias ah'eady been described (p. 40). 

III. New Growth. — Inflammations ending in new growth are the 
N»lled "productive"' intiunimations (p. '2!*4). For this to occur 
le inflammation must reach tlie fibrinous stage, must endure for 
Bie time, and must not pass on to suppuration. Moreover, the 
0(>d-supplv must be plentiful. 

ETIOLOGY OF INFLAMMATION.— riinicnl observation has 
[>wn that certain intbimiriiitions appear to have obvious causes. 
5h as blows and strains : these are called simple, traumatic, or 
Bnerogenetic. We shall presently see how few inflammations 
I entirely under this heading. In the vast majority of instances 
cftiise is obvious: these ma v be calle<l cryptogenetic, uUhough 




of lat€ years the causes of many sucb influiniiiations have b**" 
clearly demonstrated. 

It iiKist iihvuys 1)0 remembered, in considering the mode of pn*" 
ductimi of an iiiiluinuiutioii, that there are two /aciom in the pntf^ 
— the cause iiud the tissues njion which it acts. A* in (Lt'o*^* 
of other utorliiil foiidition.-j, tlif ciiiiscs of iufluiumation are ezcitiofi 
and predisposing. Sometimes no predisposition is necessarj. bi** 
often the exciting cause of sin inflammation cannot act iinlc* ll»« 
resisting jiowcr of the tissues to the irritant in question ha.' Ih^«» 
lowered. This impairment of resisting power is the work of llt« 
prcili'xponiiii/ causes, and it may be cither inherited or 8c<|iiirir<l 
(p. 2ti). It is obvious that in cases where preilisposition is ncci-s-'sry 
the condition of the tissues is as essential to the production nf •.«» 
inflamiuation as is the presence of the exciting cause: the M'fti«i»«J 
the yiiitiifi/f soil must come together to produce the jdaiit. 

Willi rcgiird to the nature of the exciting cause, it is alway.".*!!!** 
mechanical, chemical, or physical agency. The simple dcpriv«ii(»t> 
of liloiiil-siipply. which lends to injury of the vessel-walln nml the 
surmuruliug tissues, is enough. If these agents he of sufficiciit 
strength and be continued for a sufficient time, they cause Jwlhof 
the part; short of this, they ]iro<luce distinct changes toward dtito 
(p. 315), and in their sligiitest intensity they act as simple "licprt**- 
ants " — /. e. as predisjmsing causes of disease. Every condition "P* 
posed to the health of the whole or of part of the body will lie»^ 
finil its jilace. 

DifFtcult us it is to discover the cause of many inflamniatiow^ *** 
should bear in mind the very obvious fact that «<» infiaiumatiun c** 
arisi'H trithoni a oniJir, giinjile or complex. If an inJhimiiKtliff* 
ttprfaJn, its r<ni»e hati Hjiread he/ore it ; and pemititfuce nf itn iKJlitf**' 
mation [chronieity) implies continued action of its cause. 

I. Simple, Traumatic or Phanerogenetic Inflammations-—^ 
These lire due to the action of some very evident injurious i>{;tii<^.>- 
such as median iciil violence, caustic and irritating chemicals, «?<?*" 
sive heat or cold, electrii-ity strong enough to produce electrrtly**^ 
of the fluids of the ]*!irt, or prolonged local ann>nii» and con»f<|"it*'* 
privation of blood. It is characteristic of inflaniniation from tb*** 
causes alone that it iias no tendency to spread beyond the ftart or*!' 
ivally injured nor to pass on to more adrnnred statjes after thr en^*^ 
hail ceased to act. Every one knows how slight are the inflauunn'"''* 
changes induced by very severe siibrutaneous injuries, even ih"'^ 


bo broken and tbc capsules of joints torn ; and it is to be 

tiiat all will xooti bo cinially familiar with the absence of 

ilflamuiation when siiniliir injuries, i-cmmnnicatintj icith the atmo' 

tfktre. are treated in such a way (antiseptically) as to exclude all 

ondary causes. In animals thi' eft'ects of each of these irritants 

'wn be accurately »tudie<l. tliiter injected a ."> per cent, solution 

of nitrate of silver or a similar solution of chloride of zinc into the 

mnscles and other tissues of animals, and thus killed the part acted 

on. In a large number of the cases no sign of inflammation was 

(blind in the surrounding tissues. Other experiments were made 

br |ilitnging a cautery into a muscle (llailhauer) and bringing the 

prfvioiisly diviiled .skin together over the injured part, antiseptics 

Ijt'ing used. Only such changes occurred round the eschar as take 

pl»ce in the absorption of a simple infarct and its replacement by 

Hliroiis tissue. Here, then, we have examples nf the most severe 

luirbanical. chemical, and jdiysical injuries killing c<tiisiderable 

nia«ses of tissue, but only giving rise to the slightest forms of in- 

'I'tmtnation. In each case the action of the irritant, though intense. 

'» localized and of short duration. Certain parts are killed abso- 

I'ltely. and the surrounding damaged area is a very narrow one. 

^ .'«oon as the mo.xa has ceased acting the tissues tend of them- 

*«'vf» to recover; hence inHammation excited by such as the 

above reaches its height very soon after the introiluction of the 

"Tilant, and soon subsides unless .some fresh irritant is superadded. 

I 'his is frei|uently seen after the infliction and projier treatment of 
* clean-cut wound by a shar|) knife (|i. 1"27). A chemicnl irritant 
"lay enter the body at a distance from the fiart at wliich its chief 
"•^tion takes place; thus alcohol taken by the mouth causes cirrhosis 
'^f the liver, and turpentine or cantharides, inflammation of the 
Tender this heading come inflammations which arc referred to cold 
'•'*ti wet — •'rheumatic " and "reflex " inflammations. WlicJi a man 
K«ta conjunctivitis from the action upon his eye of a draught through 
* keyhole, the relation between cause and effect is easily comprehen- 
*''>le; but, except on the hypothesis of greater delicacy of nerve- 
"**»iie. it is not iiuite so easy to understand why inflammation of 
'•«" facial nerve shoidd ensue from exposure to cold, whilst a great 
_titit_>kness of superficial tissue seems uninjured. But this difficulty 
^P*^<^<)lnes much greater when internal organs (lungs, kidneys) become 
'^''ameil, apparently in <'on8equence of cold acting upon the surface 



or of wet feet. Pneumonia, which ay)peare<l to be an example of 
this, is now alinii^t j)rove(l to be an infective ili;$ease. In thisMs* 
any effect ]irodiice(l by cold can be regarded only as predi«poeiD|!' 
We know thiU surface cold drives the blood to internal orgmMud 
raises the hlo()il-j)ressiire. Ciiii this produce inflatntnution ? La»H 
plunged rabbits, shorn of fur. into iced water and tliorouvblv cliille 
them ; he found changes in all the organs, especially the lungs inJ 
liver. In these the vessels were often greatly dilated, the arlmi'S 
thrombosed, and the veins surrounded by patches of rouud-ci'll*- 
When the animals were pregnant the same changes were noted io 
fiietal oi-gans. He believed the changes to be due to the irritant 
action of cooled blood iijion the vessels of internal parts. I'erli»|« 
something of the same kind may occur in man. and a lui-u» mmri* 
irHi'stentitr must be assumed to explain why the kidney in one ow. 
the lung in another, is affected. Freijuent exposure to cold iniglit 
then be regarded as a cause of chronic nephritis, for the tempor«ry 
albuminuria induce<l in some people by a cobl bath shows thatiu 
them the kidneys may be easily damaged. 

It is held by srnue thai em'Kitii'e J'unrtioniil nctU'tltf is a din 
cause id' inflammation, eoujunctivitis from overwork being the usu 

Nerrotis hifluencr, too. called into action by irritative lesions' 
nerve-trnnks. is regarded as a direct cause, herpes zoster being tl>«-* 
favorite instance out of many which might now be quoted ».< lu*'*"* 
or less probable examples. The data are not yet sufficient in •liM-i"*' 
the ipiestion (p. 24). 

II. Cryptogrenetic Inflammations. — In a very large numbt-r •• ' 
the intlainniations met with in iiractice there has been no obvity*** 
iiiccbanical. chemical, or physical injury. Until recently the c»u** 
of such were obscure, and they have hence been called cryptogentt ** 
a better name than " idiopathic." 

In the ne.\l chiqiter evidence will be given which proves that m)*-* 
of the,se inflammations are due to the action of fungi. Thtwe m -^" 
act either as mechanical or as chemical irritants; essentially, the^*^ 
fore, they produce iiillatiimalicin in tlii' same way as do liie gn "^ 
lesions which have been nictitidnetl as of simple inflnmn^^* 
tion. But fuiijri vshich arc callable of jrrowth in the body keeii -^^ 
a continuouH sup[dy of the products of their life-action as long * 
the conditions are suitable for their development. The products ^^^ 
different fungi vary enormously in their power of injuring the I •*• 


—some producing actual gangrene, others varied degrees of 
mmation. It is for the production of those forms of infiamma- 
which require the prolonged action of an irritant that the fungi 
so peculiarly suited, for so long as they can grow a continued 
)ly of irritant is kept up. If the irritant is tolerably intense, 
'variety of fibrinous inflammation is induced, just as by croton 
p. 311); when a strong irritant can also peptonize dead tissue 
fibrin, suppuration results. If the irritant is less intense, the 
I stages of productive inflammation (p. 294) result, as in tuber- 
ind leprosy. The characteristic lesion of those and some other 
ises is a tumor-like inflammatory nodule developed round a spot 
hich parasites have lodged, and whence they may spread and 
:t neighboring and distant parts. Diseases characterized by 
; lesions are therefore spoken of collectively as the Infective 
milomata — a name signifying infective, tumor-like formations 
rannlation tissue. 

It it wonld be a very great error to suppose that the presence 
rgranisms capable of producing irritant products is sufficient to 
; inflammation. We have already pointed out that the resist- 
of the tissues must always be taken into account; and, 
ugh we are still probably far from knowing all the conditions 
1 influence these two factors — the germ and the soil — experi- 
al pathology has discovered some of them, often of a most 
ishing nature. 

e role of organisms in the production of inflammation will be 
snced by their detention in the tissues, by any local or general 
sposition in the tissues, by the anatomical characters of the 
and other considerations. These subjects are discussed in the 
ring chapter. 

ioloery of Supptiration. — No one now doubts that suppura- 
s commonly the result of organisms (p. 298), but the question 
lether it is always so. There is considerable doubt as to 
ler certain simple irritants cannot be so employed experi- 
illy as to produce suppuration. Nitrate of silver and similar 
when injected form albuminates, and probably soon cease to 
te ; but if glass capsules of croton oil or turpentine, which are 
bus neutralized, are placed aseptically in the subcutaneous tis- 
nd the capsules broken when the wound is soundly healed, sup- 
;ion results, and no organisms are found in the pus (Cheyne, 



Strauss, Klempcrcr, and mnny other recent observer*, on lli' 
other hand, using extreme prceautions to prevent the vntrj of 
organisms (ilnnjr with the nceillo, tmve coiue to the opposite eoncln- 
sion — viz. thnt under no conditions do simple chemical irritant* 
give rise tn tlie fnriuiitioti of pus. Cheyne, in summing up the evi- 
dence iifion the ((uestion. coiK'liidos that tiio difference of opinion i' 
duo to the fact tluit tiie putty-like \nma of 8lowly-«H»solving <\fd 
cells and fibrin, which some oh.servers have called ]>m. is ni>t 
regarded in this light by otbur.s ; and he agrees that true, crfamv 
pus is never seen in man apart from organisms. He mentinam 
however, tiiat (5 rawitz and Scheuerlen have produced acntr aipptii" 
(free from organisms) suppuration by the injection of cadaviTini' 
and i>utrescine, alkaloids sp|>arated by Brieger from putrid flr*li. 
which are not only irritants, but are algo the possessors of pepmnit- 
ing powers. 

The cnntliision is, that in practical medicine and surgery wfti* 
not meet with the formation of true pus as a result of the action »( 
" simple " 

an indnmuuition implies the previous spread uf it.* cause. No*, it 
is difficult to understand bow any of the nrdinary mechanical or 
physical irritants can advance from the spot at which they fining 
upon the body; and. although it is conceivable that some cbcnii»' 
irritant, dtie to a faulty luetabolism on the part of a group of reil< 
might soak from the morbid area into the surrounding ti.ssiic*. a"'' 
thus excite a more or less progressive inflammation, nothing '* 
known of .such a process ajiart from organisms. An infl»uiniatit>" 
which is characterized by a tendency to spread will always be foun'' 
to be of parasitic origin. Clinically, inflammations spread by con- 
tinuity of tissue, by the lymphatics, or by the blood-path. Tb^J 
third mode of ailvance, if not also the second, necessitates nn irt^B 
tant in a particular state, for ueitlicr a gas nor a fluid in the bl**** 
cttuhl cause a patch of inH:unau\tion at a distance from the priiu*'^ 
focus, but would irritate the tissues generally. Micro-orijanUm*'. "" 
the other hand, having settled at a spot, can spread thence »'^^* 
much as in the case of malignant growths. (1) They may p*** 
their way along the paths of least resistance as they grow, or '" 
carried for short distances by lymph-streams or by leucocytes wb'*"' 
have taken them up, sjiread of the inflammation by '• continnity •'' 



ihing in each case (Fig. 113). (2) They may be car- 
ly the lyiii])li-streiun long di.stiiTii'es from the primary focus. 
pyc<] in this way. they are usually arro.sted in the first lym- 
L' gland they reach. Here they often excite a secondary 
imation without having caused any trace of intiamniation 
m the ])rimary focus and the glanil. the organisms jia.ssing 

EDUgh the lymi»hatic vessel.-*, but becnniing ant-sted in the 
hannels of the gland, precisely like the particles of pig- 
L'h may be found upon microscopie examination of a <rlnnd 
k" central" side of any extravasatinn of Ijlood. (3) The 
|b may enter the blood-vessels and be carried about by the 
-Strejun until arrested, when, under favorable conditions, they 
udtiply and give rise to a secondary (meta.static) inflammation, 
H we get in pysemia in almost all organs or parts. an<l in 
|)s when the testis or ru-ary becomes inflamed. 

f un inflammation e-xciteil by one of the »imph is easily 

Fio. 113. 

r* niiui'U- Drar nhiiukU'r ifruiu n ciuv of Mtrcouia uS the ki'ml nf the 
Ul, ahiKrln)! jiaiwitKe n( shiihU roiiiiiI-oi'lU ipnihably iukrroinAlou« I nloni; the " Uiifo »f 
•Ulanoi-." »t In cliiTim- Innninniation. Wlieru tin- iwlbi are thickest tht- muw-k'tilirw 
nucil >ir Imve (lU«t>|iearf<l. i From > <p«i'tiiivn by Mr. Buyd.) 

HtxI. As BOOH as the causes are removed, the cells of the 
(fed tissues begin to exert their inherent tendency to recover 
injury (p. 3*2). Dead and dying cells are removed by leuco- 
anil their places are taken by new cells springing from the 



normal tissue-elements. But when once a brood of bacteria h» 
pained a fontlmid in the tissues and has begun to n)Mhi|ily mil 
spread, the iiillaiumatory jirocess also spreading pari /uintu.'n \t 
difficult to see how the advance is checked. Clinically, inflamun- 
tious spread rajiidly and widely, and yet, perhaps after cutuinjE 
gangrene of a large part of the body, become ultimately arrrKleA 
The fact is. that nil the time there is a .struggle for existence ]P)ing 
on between the eells of the body and the invading parasiti's. tnd 
the victory may lie with either, and may be won perhufis ciuily, 
perhaps only after a struggle of wliich the issue is for long iluubl- 
fill. It will be remembered that the first effect of an injury into 
cause dihifation of the ve.s.sels of a part, and Landerer »nrmi»» 
that this Hu.shtng of the j»art is often successful in sweeping am.v 
for destruction or elimination from the system bacteria which hvt 
.nettled and begun to exercise their nn.xiotis influence. If thisilo* 
not hapj)en, the germ.'* will probably liiid their way into the tiwac* 
and the inflanim:ition will sjiread more or less. In the case «f 
pyogenic cocci giving rise to an abscess we have seen (p. 29>''| tbii 
at first a zone of coagiihitive necrosis forms rotmd the microlx*: 
that this is infiltrated by leucocytes from out.side and by cocci from 
within; that it next softens and disappears, leaving the Icucocyti* 
and cocci more or less mixed up; but that by the eighth or nin''' 
day sections of the abscess-wnll no longer show this mim/Z/ni/ of tl"' 
opposing forces, the leucocytes now forming a compact wall n>upJ 
the central flui<l (pus), which contains both <lead leucocytes .■Jini 'lif 
cocci. Similarly, beyond the edge of an advancing erysipclaH'ii^ 
or other spreading iuflummalion there appears n cloud of thesv I""" 
cocytes, no doiibi exercising a corresponding function. .\s to thf 
weapons with which the war is waged, nothing very exact is kn"*''- 
It may be that the products of the two classes of cells flotiliiij: '" 
the same nutrient fluid are mutually injurious, and that tho»f '•' 
the body-cells tend to render this fluid unfit for the growth oft'" 
bacteria. .Vgain, it may be that the bacteria, as is usual with ro'i"!^ 
things, secrete or excrete jiroducta hostile to their own exislfDCf. 
and that these at last accumulate in such i|uantifie.« a.s to chcrk t"' 
growth of the organism. But there is another way in which micnil"'* 
:i])pi'ar to be destroyed, about vhich more facts have been accum"' 
lated. It iias long been known that micro-organisms., like "tin'' 
particles, are taken up by leucocytes; attention was finst drawn''' 
it by Koch in his account of mouse-septica>roia. In his p«()er <'0 


e Etiology of Tuberculosis, Koch has advanced the view that, as 
e tubercle bacilli are incapable of locomotion, the commencement 
a tubercle is due to the escape from a vessel of a leucocyte which 
IS taken up from the blood one or more tubercle bacilli. He 
presses his belief, founded upon numerous observations of micro- 
)pie specimens^ that this leucocyte soon sickens and swells up, 
8t into an " epithelioid " cell, then into a giant-cell, and that the 
cilli are short-lived, not uncommonly dying and disappearing 
tm a cell, but often maintaining their position by the production 
fresh bacilli. Metchnikoff has confirmed Koch's observation by 
rery direct method. He found that a little crustacean, the water 
a (Daphnia pulex), suitable for microscopic observation, was sub- 
ct to invasion by a fungus, the pointed spores of which penetrate 
intestine and enter its tissues, where they are at once surrounded 
amoeboid corpuscles like leucocytes. The spore swells and ulti- 
ttelj breaks into fragments, whilst the victorious leucocytes blend 
form a giant-cell. All this goes a long way toward proving that 
der favorable circumstances leucocytes may take into their sub- 
nee and destroy these vegetable parasites ; and it seems likely 
tt the beneficial effect of moist warmth in inflammation is due 
gely to the fact that it aids migration, and thus increases the 
ny of leucocytes upon which so much depends. 
Phasrocytosis. — Mention must here be made of Metchnikoff's 
planation of inflammatory phenomena in general. In his opinion, 
! whole process is the result of an effort made by the invaded 
;»ni8m to destroy any virus that has gained access to it. Thus, 
! dilatation of the vessels, the increased diapedesis, and the appa- 
it conflict between leucocytes and organisms are all automatic 
•rts on the part of the individual invaded, and not, as has 
herto been suggested, the purely passive results of ordinary 
cesses on damaged tissues. 

tietcbnikoff divides leucocytes into four varieties : 
. Small leucocytes with a single large nucleus. These are 
nd in lymphatic glands in large numbers, and are hence called 

. Large viononucleated leucocytes. These are full-grown lym- 

. Large, coarsely granular leucocytes with lobed nucleus, stain- 
with acid aniline dyes {eosinophile cells). 
Large, polynucleated leucocytes, difficult to stain (except nu- 



cleus), and therefore called ncutrophile cells. These ire 
numerono of nil. 

The meniber« of the second and fourth groups are phagttftn — 
i. e. ther attack and attempt to engulf any organism nr iitbpr {m^ 
eign substance to the presence of which thoT are niuMcnitWMd. 
The endothelial cells are also phagocvtes. 

According to MetchnikoflT, the phenomena of inflammation ir* 
directed to bringing the phagocytes into contact with the im^iiiau 
organisms in order that thoy may be able to enclose and destroy 
the invaders luflanniiation tiiay thus be either rrtntrttaruhir <a m- 
travastrular. The former has already been descrilxMl at length. Bj 
the latter is meant the action of the phMgocytes on any foreiim pi^ 
tides /// t/n' circulation. Wiien an inlluiuiiiatinii li-ruiinates br«r- 
ably. the phagocytes survive and the organisms disappear. U, 
however, the organisms are too j>owerful for the phagocyt«. th« 
latter will die and fall to pieces and the organisms will be set fr»»: 
this frequently happens in tubercle. Chemiotaxia (cherootazi»> 1» • 
term used to express the attractive or repellent influence wi 
environment exercises over the phagocytes that come un . 
influence. According as it attracts or is neutral or is rejiellrni it 
is caile<l |)ositive. neutral, or negative. In conditions of i 
chemotaxis the organisms are unmolested, and conse<|' — 
agate rapidly, but the phagocytes may become proof . 
condition and cease to be repelled. In this caHe the tinal uw* 
may be reversed.' 


Fermentation and Infectivb Diseasb. 

It has long been thought that the group of acute speciSc 
must have a very special cause. The characteristics of this jrroap 
are — (1) that they occur in epidemica; (2) that they are obvioiutT 

' For further inforniatUm on thevc |M>inl8 the uludenl in refemd to tli« aitirW <«j 
" PhnjforyliMiid " by Sidney Mnrliti, in ({iiiiin's Oietionory <^ Utiieimt, 1894, i 
Mrli:>inikoir« lixlurvit on ibe Vamjiamlitr Palhole^ (^ li^/kmmitliiiu, twariaiwi hj' 

t^tarling, iH'JS. 


coDtsgious and infectious; (3) that each member is absolutely dis- 
tinct from its fellows and runs a typical course ; and (4) — the most 
important distinction of all — that the poison which gives rise to each 
of them multiplies in a marvellous manner. Thus the introduction 
into a community of a single case of one of these diseases may be 
followed by the death of thousands from the same disease. For a 
long time nothing could be discovered to account for the appearance 
of these diseases, though they were obviously produced by some- 
diing which multiplied in the patient, which clung about his cloth- 
ing, and which could be carried through the air for considerable 
liigtances. This " something " was, and still is, called the " eon- 
\ tagion " of the disease, and for many years science has been en- 
l deavoring to discover its nature. It was soon recognized that no 
[ gas would meet the requirements of the case, for diffusion would 
I won put an end to its power for mischief. A fluid was still more 
I out of the question. Contagion was therefore necessarily regarded 
w a solid in a state of very fine division^— particulate. This con- 
tiigm is known to be insoluble, because it can be removed from 
Saids both by subsidence (vaccine, Chauveau) and by filtration, the 
poison not passing through the filter. These facts, taken with its 
power of multiplication, seemed to show that the contagion was some 
living organism, hence the origin of the contagium vivum or germ- 
theory of disease. In 1840, Henle clearly formulated the doctrine 
that living organisms, probably of a vegetable nature, were the 
causes of the acute specifics, and supported the view by arguments 
which have withstood all endeavors to refute them. Since that time 
an enormous number of researches have been carried on, to some of 
which allusion will subsequently be made. 

Long before 1840, however, it had been noticed that a close par- 
allel might be drawn between an infective disease and a fermenta- 
tion. It may be presented thus : 

Infection Addition of ferment. 

Incubation / VenoA during which nothing is 

I noticed. 
Fever, outbreak, and course of ( Rise of temperature and active 

disease "l fermentation. 

Decline of disease Gmduat oes.-<ation. 

Period of protection from same ( Addition of more ferment has no 

disease \ effect. 

It may be further noted that, except in cases in which yeast was 


added to tbe saccharine li<|uid, the source of the ferment iaoaaa 

of alcoholir foniifiitutioi) wsk* us in_vsl<Ti<>iis ns wa-i the #onrw of 
the jK)if*i>ii which gave rise to iiii epiilcinic of whooping cng^. 

ETIOLOGY OF FERMENTATION.— The nhove fiamllel wm 
gfiici'iiliy i'ci:oguizf(l, uiiii the cause of ferincntAtion. beinf^ nook i 
more open to expcriineut than the cause of infections (liMMe. w I 
iiivesti'tated first. Many kinds of fermentation were specdilr rto)^ I 
nized — hictic, hutyric, viscous, etc. — and tlie close relation»btp iCJ 
putrefaction to these ]>rocesse.< wa« soon acknowledged. In «aokl^| 
these organisms were found, and their relationship to the pncmm J 
has been the moot point between the uj)holiler!> of the nhil ur fom^^ 
thforif of fermentation and the Hup|)orters of the j>hif»ical (Am|I^| 
Alcoholic fermentation has been used as the tyyie of all. ^| 

The Germ-theory is adopted i)y the jfr«'at majority of »ricBt>l^| 
men at the jiresent day. According to this view, tht- sacehnnimrf^^ 
cerevisiiE (yeast-plant) is the rauKf of the alcoholic femienutioB. I 
Its food is sugar, together with nitrogen and .«ome in<irgnui(' tDat^ | 
rials, which must also be provided; the immediate pnKluct)> of it> J 
liftvaction are alcohol, carbon dioxide, glycerin, and !«ucrrnir *ri<i I 
It is supposed that the sugar (Msses into the cells, which takr «hit 
they r<'(|iiire for tlu-ir own growth and repair, anil throw back ml" 
the surrounding tiuid the products of tiirir activity. Thus a y«v»' I 
cell forms the above-mentioned sid)stnnces just aa a hepatir nil 
forms the constituent.-* of bile. Organisms which act in lhi» din** 
way are known as otyaiiuftl feniifnU. But there is another w»T « 
vrhich very similar results are produced. Instead of acting dirwdj. ' 
the living cell may act only through a "middleman." which alwajt 
forms the connecting medium between the organism and its char*f- 
teristic chemical products, but which does not itself nnderitu ta} 
change (p. 321). These " mi<ldlemen " are known a« ttm/ormti 
ffrniriitii. Thus, the diphtheria bacillus, resident in the fidsr 
mcmbranr, gives rise to a ferment which, circulating in the blooA. 
produces — mainly in the spleen — the toxic albumoses to which maaj 
of the symptoms of dipbtberiii arc due. 

The Physical Theory aflTirms tiiai fermentation is a " molemlar 
motion" transmitted to unstable organic compounds (fermcniablr 
substance) by albuminoid parti<'les (ferment) which are tbtsnadreB 
the seat of "motor decay" (»'.<■. arc undergoing decompomtiofiV 
The molecular motion of these particles may initiate, in a largf 


■ amount of a more stable substance, chuuges similar to those of 
I »hicli tLev are flii-msclvos the sent. Any portion of the sulistance 
I tu which thi* molecular motion ha.-* been eoiniutmieiitetl is eajmble 
I of traoMiuitting it to other suitable material, and thuH the ferment 
I (-lo/M lo multiply. The ferment communicates its vibrations to the 
I |iiirtidt>8 with which it comes into contact, and tlic^e again to neigh- 
I Uriug particle.s, much as a spark causes the decomposition of a 
I train of gunpowder. Rastian says that there is no proof of muiti- 
I |ilir«tion other than that which occurs in a sufficiently strong solu- 
I lion iif sulphate of sodiuuj when a crystal of the same salt is 
I ihroirn in. 

I It is very difficult absolutely to disprove the physical theory. Its 
I »iip|i<irters atlmit the frei|uent presence of organisms in fermenting 
I Suiils, but regard them as accident.s or a.s spontaneously generated, 
I betMiiiiie the same decorapositinns cun, m some instances, be effected 
I in tlieir absence. Thus dilute alcuhoi run over wood shavings or 
I charcoal so a« to expose a large surface to air is converted into 
I 'iut-gBf. But this is no evidence against the ability of the myco- 
I 'Iwma aceti ixlso to effect the oxidation as a vital act : and. indeed. 
I 'listinct differences exist between the two processes. 
I On the physical theory much was made of the fact that spon- 
I Uneous fermentations are always more or less impure — that is. there 
I We fountl III the fermenting fluid many germs <juitc different from 
I tkoM essential to the particular fermentation. Again, organisms 
I pxnctly corresponding in form were foimil iu fluids undergoing very 
I 'lifferent decompositions. From such facts it was argued that there 
I »M no constant relationship between any one germ and any partic- 
I "Itr kind of decomposition. The jin'iloiiunaurv of one character- 
I Litic form was accounted for bysup]iosing that the comlitions peculiar 
I l«cai-h kind of fermentation either favored the growth of a certain 
I organi.Hui or originated it «i«' novo. But it has now been shown in 
I »CTy niiinerons instances that it is possible t<> obtain a cultivation of 
I raeh of the various organisms fotiml in a ferment iusi fluid, ami to 
I demungtrate that a special decomposition does not occur unless one 
I particidar form of germ is present, all other forms being variable 
' anil uocideutal im|)urities. Ami it has also been shown that urgan- 
isms indistinguishable from vnv\\ ntlier under the inicrHscope may 
gire rise to very different eliemical jimducts wlnn gnnvn upon the 
ue culture-medium, and may produce absolutely different results 
rben inoculated u|ion animals of the same species. It is clear. 




tborcf'uro, that similarity of exteraal form does uut imply 

A pure cultivation of uii organism is obtained dy truti.<rcrriii^ 
minute (|uantity of tlic substiiuce containing it to Miaie tuaicria/ la 
or on which it will grow rt-iiJily. The tran.ofi-rfUte it* ■■:■■,■'■'• 
effected by means of a .Hterilizeil needle. Sometimes nolid a:. 
times Hnid culture-grounds are employed (p. SoO). For the prcfcu 
purpose a solid, transparent material is the best. (Uu-e pinctil iiB<Jrf 
favorable conditions, the organi.>'ui grows rapidly. From thenm'yM 
of the patch formed by it a fresh culture-ground is inoculated «itk 
a necflle in the same way as before. This procejw may be rcp«t<4 
any number of times, (ierm-theorists believe that they can tkat 
eliminate everything taken from the original fermentation eicrfi 
the organism which is capableof growth : and they have ei. 

to make this still more certain by the addition of further pn*.- 

0uch as (1) by washing the organism with sterilized water au>l niWr 
fluids incapable of destroying it; (2) by infiltration; and (3) kr 
drying. They show that even after procedures inoculation «f 
a suitable substance »itii tlic surviving and purified orgaiti»ii) *tiU 
ivadfl to the characleristic fermentiition. But it is pottiUe ^ 
"particles in a state of motor decay" may have been in •' ' 
and each succeeding instance inoculate<l upon the cultur. ^ 
with the organisms, and that they, too, may have be«tt praciioll.* 
multiplied by the conimunicatioii of their molecular wotidd tn ik* 
molecules of tiie culture-grounil.' 

Nevertheles.'N. germ-theorists have rendered it certain that ill''* 
" particles in a state of motor decay " adhere so closely lu ll 
ism which is constantly present that they are only able to inijui' - 
molecular motion to substances in which this organi<in will f^*' 
for if the organism dies no fermentation occurs. 

Moreover, the "particles in a state of niotor decay iii 
been shown to jws.seHH existence apart from organisms. ■"" 
"antiseptics," which are selected on account of their abililj '* 
destroy the biwer organisms, invariably check the molevalar isaiJoB* 

' Innnli- power of inrmutini; or ifmwinif U m>l oini-liisiTe nf lift). IJ«tiic H**^ 
oil! Ilisl n amall i|iiniility of ox:ilic arid will not u|ioii > very Urgv quuMit^ ^ ^^ 
Diidr. aplitling ilir IiiIUt tiilo oTitlir ni-iil niiil aiiiiiiutiiii : one uii|;til t»x Itiai, •"H'* 
with tuitaMr |inliiiliini, the nxalli' oc-ul itirrv.-i^-M jtHU'liiiitely. BaunupuMi <an 1^ 
diffiweni.'*' N'lHt-en lliv clipniii-Hl chango cli'rotttl br oxniir acid and \tj llriiif «IV^ 
ians b thai the forincr ai'ts liv juiitiimnilinn, ihu latb*r hy inhimitMtrtalum .- Um Mt Mf 
mean only juita|iOHition with Intentol tlMuei. 


be physical ferments; so also does heat sufficient to destroy 
luisins. In general terms, the properties of the physical fer- 
its are those of the organisms. 

'inally, it has been shown of several fermentations that the thin- 
c membrane or the shortest column of fluid is sufficient to pre- 
t the transmission of these supposed vibrations ; that direct con- 
t with the ferment is necessary ; and that sonorous vibrations 
e no influence upon fermentable substances. If a solution of 
;8r in a test-tube is divided into two parts by a plug of cotton- 
ol, and yeast is introduced into the upper, this part alone fer- 
nts, though fiuid continuity is uninterrupted. 
Although the physical theory may be theoretically possible, the 
igress of discovery has shown that its rival — the vital theory — is 
•■ truer one. To accept the physical theory one must set aside a 
fectly satisfactory and evident cause (the organisms) and j)roceed 
rapport one hypothesis by another. We therefore conclude that 
th processes comprised in the terms fermentation and putrefaction 
due to the action of vegetable organisms. 
Jew do these oreraoisms act ? The principal views are — 
I. Organisms, like all living cells, require certain materials for 
»th and repair. They take into their substance the organic and 
rganic compounds which are necessarily present in any liquid in 
ch they can grow, and they give back to the fluid the products 
their action. These are known as " organized ferments." 
i. Certain organisms produce " unformed ferments " (p. 318). 
? chief characteristics of these unformed ferments are — (1) that 
f seem to act by mere contact (" catalytically "), taking no part 
he decompositions to which they give rise; (2) that they act in 
remely small quantity ; (3) that they do not multiply, but, never- 
ess, can transform many times their weight of the fermentable 
Jtance, though ultimately they become exhausted ; (4) that they 
soluble and are always derived from living cells ; (5) that they 
require water or moisture to enable them to act, some preferring 
acid, others an alkaline reaction ; (G) that, like the organisms, 
r act best at a certain temperature; and (7) that while any 
ke<l deviation of temperature arrests their action, and any con- 
rable degree of moist heat destroys their properties, they are, 
a dried, as resistant to all physical and chemical agencies as 
es themselves. They arc complex albuminoiil bodies, and can 
xtracted by glycerin. Ptyalin, pepsin, trypsin are well-known 



exaiiinles fnnii tlu- liimiiiii boily ; t'Tiiiiii^iti (liititT iiliiiniiil) iitnl liui- 
tase (l)arU'y), from the vegotaljk- kingiloiu. Il is cfi-laiti iLnl wnir 
hacteria {v. g. putrefactive uu<l pyogenic cocci) form ilia»t»tic mil 
pej)tii' ferments, wliifli ciin tie se})ariite<l from, ainl act in thealwntf 
of, tbe or^auisms. Miisctiliis lias Mepurated from the raiiTrnvKois 
urpw a body cajvable of changing urea into ammonium ettrbiiiiate. 
The organisms of cholera and diphtheria furnish excellent c^a^lplrt 
of the power of a strictly lociilized orgiinism to give rise to pcncril 
cbaiige.s through the mediiitidii of " iinfornied ferments." 

3. Niigeli lias adopted the view to which Liebig seemed tcn<lin|j— 
that the life and growth of cells is necessary to fermenlatinn, iW 
chemical changes being always due t.n the transmisjiiun of lln' 
molecular motions of Uviiig ]>roto)dasm to the uuHtable comp'*iiDii> 
around it. 

Products of Fermentation. — In all jirivcesses bodies are fiimn^ 
which hinder the development of. iiiid ultimately dcstror, ^^| 
organisn)s which produce them. Thus, the alcoholic fermenlation 
is checked iiml ultimately arrested by the accumulatiun of .ilwbol, 
while putrefaction is himlered by the development of bodies iil« 
carbolic acid and crcssol. It will be remembered that animals p"" 
duee substances having a corresponding efl'ect — c. //. carbon liinxi'l''' 

If the analogy, pninttil out uri p, 'ill . between infective di*i"»»'* 
and fermentation were strictly true, we might at once infer tim 
these iliseases were caused by the growth and life-action of vc^'i'lsl'l' 
organ isius in the tissues of the Ijody. especially a.s uniny low I'"''''' 
of vegetable life have been found associated with Ruch dl 
But no one could nccept the eonclusion on the evidence of mi <iip"^ 
ficial a resemblance. The same stringent proofs mu.'it be nffuriiw 
in the case of each disease as were deuuintled in the case of 
fermentation. How far these proofs are forthi-(»ming will he ••'I 
in the concluding part of the present chapter. We shall now f' 
shortly what is known of the botanical position and life-hi.storv •> 
the vegetable parasites of man. 

The Bacteria or Schizomycetes. 
ganisms which have been found couueeti'd with the diseases i" 
man are all T/tnllnjifii/teg, or plants in wbieii no distinction bctwi*" 
stem and leaf exists ; and, as they are all destitute of chlorophvu- 
they belong to the class of Fungi, not Algae. The parasitic fnnp 


tie of three kinds — ^Bacteria, or Sehizomyeetes, Yeasts, or Blasto- 
ay:ete», and Moulds, or Hyphomycetes. The bacteria, besides 
causing putrefaction and several of the "fermentations," include 
almost all the organisms which are believed to produce the infective 
diseases. They are, therefore, by far the most important group. 

The Sehizomyeetes or Fission-ftingri are, with very few e.vcep- 
tions, achlorophyllous, non-nucleated, unicellular organisms. Many 
of them approach the limits of microscopic visibility, whilst all are 
wry minute. 

Form. — In form they may be said to follow, more or less closely, 
one of three types — the »phere, the rod, and the comma. The 
tpherical bacteria comprise those of any shape between a sphere 
and a cube. The rod-shaped bacteria may be short and thick with 
rounded ends, so as closely to approach an oval, or they may be 
long and thin with scjuare ends, or they may exhibit any possible 
combination of these features. The commas in some cases are long 
«ndthin, in others short and thick; they differ also in their degree 
of curvature. Spiral and dumb-bell forms are less common. 

Structure. — Bacteria consist of a peculiar form of protoplasm, 
n^oyrotein (v. Nencki), and appear structureless ; but it is very 
probable, from their great resistance to alkalies and dilute acid.s, 
'hat they possess a cell-membrane of some carbohydrate allied to 
«ellul(we. During the formation of spores and after the action of 
tincture of iodine, which stains and causes shrinking of the proto- 
pl«8ni, a fine membrane may be actimlly seen. It is very elastic, 
ttd seems to form the inner layer of a gelatinous envelope, by 
■Dore or less of which all bacteria are surrounded. 

Color. — Bacteria refract light strongly, and cause turbidity of 
Mj culture-fluid in which considerable numbers are present. 
Apart from artificial staining, a of organisms is usually 
colorless — /. c. white or grayish. Some organisms are green from 
chlorophyll : others are brightly colored, red, blue, yellow, etc., the 
tint being mainly in the envelope. Bacteria are stained with more 
or less difficulty by several aniline dyes, and many of them may be 
identified by their special staining reactions. The color proiluced 
is not always uniform. This irregularity generally depends on 
spore-formatioD or on degenerative changes. By some it is 
regarded as a possible indication of definite structure. Some 
forms are stained brown by iron salts in water. The starch reac- 
tion with iodine is not rare. 



Movement. — Single round-cells have no movement other thu 

Brownian ; but chains and colonies of them are said by Ogston to be 

capable of locomotion, thouehthii 
Kui. in. \ . . ^ n .^ 

opinion IS not generally acceptw. 

The rod-forms have often a mobile 
and a motionless stage, but some 
never move — e. //. B. autliracis, B. 
tuberculosis. In a few eases. *beii 
specially stained, one or more cili»- 
like filaments or flagella have been 
found. These seem to be con- 
nected with tlie cell - membwiie 
rather than the protoplasm, thus 
differing from true cilia. In some 
organisms one or more flagelU «re 
found at one end only; in others. 
as in the cholera spirillum, thej 
may grow from both ends ; and in a few, among them the typhfli<l 
bacillus, they are very fine and are attached all round. By metn* 
of these flagella movement is probably effected. No motionle» 
bacterium is provided with flagella, though on many mobile form* 

"BlHc-mllk" bacilli, stained by \as(- 
fler's method to show flngcUa. (From a 
specimen by Dr. Arlile.) 

Fig. 11.5. 

I>ia);runi to sliow )iietho<i» of re|irodii(ll(in by llsslon: n, t1st<iim iu one dirccti""' ' \^ 
iiients U'liiitlieniMK iis they divide; fc, fission in two dirt'ctions— «aoh seftment fu**"'. ^j,j 
ilividi's in tlie siime rlinction us in « ; c, Hssion in three directi<m«— in one direrti"" 
tali OS place in two paraliei |ilaiii's : (/. fission in three directions. 

none have yet been found: in these the mode in which motK"" ' 
produced is nncxplaiiied. Certain algae, larger and higher '" 


Kale than bacteria, move in a similar manner, but have no cilia. 
Often no reason can be assigned fur a change from motion to rest, 
or wee ver»d. A good supply of oxygen seems to be connected 
with the active motion of some forms. 

Reproduction. — 1. By Fission. — All bacteria multiply by 
transverse division. In the rod forms this occurs in a direction at 
right angles to the long a.xis. In the spherical forms it may take 
place in two or in three directions at right angles to each other. 
Thus, one cell may divide by a single act of reproduction into two, 
four, or eight equal segments. If two or more parallel dividing- 
planes occur before the separation of the segments takes place, the 
number of these will be largely and proportionately increased (Fig. 
115. c). A cell which divides in a single plane elongates as it 
<livides, so that the progeny retain the proportions of the original 

The first sign of division is the appearance of a fine transverse 
line crossing the cell, continuous at its ends with the cell-membrane, 
>nd often at first imperceptible until stained with iodine — a point 
to be remembered in estimating the length of apparently single 

The new cells formed by fission may at once separate from the 

P»rent, or they may for a time remain united to each other, end 

'oend. In this way pairs or chains of cocci and long filaments of 

■^'Is are formed. A mass of organisms lying side by side in more 

*"■ 'ess spherical colonies, and bound together by a viscid substance 

'ormed of swollen cell-membrane or of mycoprotein, is known as 

* ~foghea.^ Zoogloea; often combine to form constant characteristic 

Ca-ci and micrococci . Spherical or nearly spherical. 

t)iplococci Cocci in pairs. 

^Streptococci .... Cocci in chains. 

Staphylococci .... Cocci in groups like bunches of grapes*. 

tetrads Group of four cocci produceil by imperfect cleavage. 

*SarciiMe Group of eight or more cocci, similarly produced. 

^licrobacterium . . . I.iength not more than twice breadth. 
t)e8mohacterinm . . Length more than twice breadth. 

Bacillus Straight desmobacterium. 

^Spirillum and vibrio . Curved desmobncteria. 
SSpiroclwta . . . Flexible, corksi'rew desmobacterium. 

Jjeptothrix Long unjoined thread. 

2^oog]oea ..... Group of agglutinated bacteria of any form. 
Clostridium .... Bacillus with transverse projection, 
fipirobacterium . . . Curved bacterium. 



appearances by which the organisms may be recogni/.ed. even W 
the naked eye (Fig. 110). Lnrgu aggregations of hacteri* wt 
always slimy, owing to tlie zooglteju. The •• IVog-spawn " eoccu* 
(^Liuconostoc) may fill wliole vaf,s in sugar-factories: tVrtii4rij 
Kuhniana and Claduthrix ilifhutuma may block wate^-pipo^ aiid 

F>o. 116. 

(V>1oiiii'» of iHtclvriH. In thi^ (if^iri* tlit* eiiDriuotih ilillVn-iiri- lltul inu> t'Xii>l IvtftcfflU 
KTVupiiiK of OIR* nutaft of firKHnUniM uinl Itml i*r utltore is t^howii. i An^r StvrnU'rf I 

cover reservoirs to a ileptfi of several feet ; and a species of • 
giatna covers a large area at tlie buttoin of the Bay of Kiel. (.nlW 
the "dead" ground, because fisii avoid it: these few exumpl^ 
show how extensive may be the development of zoogltrw. 

The time occupied in division hn-s been variously given ni from 
ten to tliirty minutes; and, as the iifTspring proceed at oricf 
divide like their parents, a single biicterinm may in tweiitv-l 
hours give rise to a progeny which Cnbn estimates at 

2. By Spores. — Another method of multiplication is met »'"• 
among the fission-fungi — namely, the formation of sporefl. Spo«- 
bearing organisms have been divided into two groups — endotji»r«<i* 
and arthrogpi/ruun. 

The i-nJogpurous (/roup consists at present of certain long f"" 
forms (fiirrilli) and some spiral forms, liut it is more than likely tli»' 
spores will be futmd in species in which they arc not now kBii»f 
to occur. The spore forms as a minute point in the cell, enlarv'ii'P 
rapidly, and often attaining maturity in a few hours. It i.« 'l"^" 
a clear, round or oval, iiigldy refnvctiug bo<ly, which has eviilfD''/ 
grown at the expense of the «-ell-ei)iitents : the latter gradii'"/ 
disappear. A sjiore ennsists of [trotophism and fat enclowo '" 
a firm capsule. It is (|uite excejitional to find more than "i"" '" 
a single segment. S]>ores have often a very close resemblancf '" 


It was formerly supposeil tlmt s|iori'-tortiKitii)u was a result of 
*xl>iiu»tion of the aiibstratiiiii, iiiid ovidt'iiut', tlu'retorc. of lowered 
viUility. But it i» now known to take [iliu'e most readily when 
llie conditions of growth arc most favorable. Spore-forniation in 
»tithnix bacilli can be arrested by reducing the temperature of the 
orpjnisms below '20° C. or by introdm-inu (•ertnin nmdifications 
intn tin- culture-j^round. Fission ami spon'-iiiniuition may go on 

Th»( spore!' are extremely resistant to iinfavoniliU' surroundings. 
imttfi. nppareutly. to the ([tialities of tlu-ir tine liuiititi;; meinlirane. 
If after long periods of (|uiesceiice they are piarcd in favorable 
fiiiditiiins. germination takes ])!aee; their membrane swells, they 
lose their fine dark outline, and tlie new vegetative cell grows out 
in tin; direction of the long axis of the spore. 

In the iirtfiroHporiiiDt ffroiip no spores are found within the cells, 
Imt certain cells during the process of division by fission exhibit 
'iniistia! reju'oduetive powers, and are therefore regarded as spores, 
'^onictiines these arthrospores are larger than the rest of the cells: 
'" iifher instances no diff"eren<"e in apjiearatice can be made out. 

As an example of the first variety the fmg-spawn coccus may be 
'■hosen. It consists of chains of cells agglutinated into zoogbeie, 
*t>'i the zoogbea-forms are blended together into irregular masses 
*" large as, or larger than, a hazelnut. Here ami there a cell in 
'nechiiins becomes larger than its fellows, all of which die. The 
wge cell, if transplanted, germituites. 

All micrococci and niicrobacteria are believed by some to furnish 
tsiniples of the secon<l variety. No distinction can, however, be 
'Ifswu between the early and late stages of cocci, and it is better, 
iherefiire. not to include spherical forms among spore-bearing 

llatiy bacteria are monomorphic — /. *'. between their spore and 
tlieir fidl development they exhibit otdy one form, that of their 
«|<ore. Slight variation in the si/e and form of the cidl is the only 
Tariation that such organisms present. ( Ithers arc inore or less polt/- 
t>i"rjifiic — /. »'. in their life-history, rods, spores, fibitnents. and zoog- 
(Hx can be traced, succeeding each other or mixed up together. 

lere is often a marked contrast between the contiitious essential 
the more existence of an organism and those which are necessary 



if it is to grow freely. In this section will be tK)nsiflerc<l tlir iiiilii- 
euce which a few niodifirntioris in the environment htive mi ll" 'if^ 
and growth of orjiiiniMiis taken together. Kach variety of fmi^n' 
seems to diflFer from all others in its ff>od-re<juirements. tliouph «H 
must be sujijilieil witli ilie iiinterisils whence they can obtnin tiirelf- 
ments of whicti they Tiiese are curbon, hydrogen, tiiir«2<'"- 
[ihosphonis. sulphur, calcium, mngnesium. and potassium, Tbi-ln*' 
four are generally provided by carbnhydriites an<l albuminoiili*: the 
rest by inorganic .salts present in aniuuil and vegetable tissue*. tV' 
tain bacteria, however, can asr'imilate nitrogen and carbon froraniod' 
less comple.x sub.'^tances than albumin and carbohydrates when tin* 
are not avaibible. This i.f shown by the growth of putrefactive'* 
ganisnis in Cohn's fluid (phosi)hate of pota.«.siuni, .ii ; sulphni<- >■•' 
magnesium, 1: phosphate -of calcium, .05; tartrate of ammoniuiD. 
1 ; wafer. 10(1). For the growth of others the more compleT IkmII** 
are essential. Thus, beer-yeast will not grow unless glucose or siO«* 
body convertible into it is present. It is possible that such » fta><* 
and such conditions could be discovered for each fungus that it «l"n* 
would grow in them, Kaulin worked out the com|>osilion of MC** 
u fluid for a mould (Asjiergillus niger). and proved the vain* o» 
each constituent by estimating the iliniinution in weight of a speci- 
men of the dried plant yielded by a certain i|uantity of the flni«» 
from which the constituent uniler investigation had been witlulra*!*- 
Very slight differences in the t(>ni[>ositicin of the food-material ni»y 
favor the growth of one orgjinistn ninre than nf another. XSi»i*l* 
says that in n neutral fluid eontniniug .sugar, in which were uioulil** 
yeastJ!, and bacteria, only the latter flourished, causing lactic-«ct*l 
fernu'iitation ; but the addition of \ per rrtit. of tnrtarii' ici" 
brought the yeasts to the fore, with the formation of alcohul, Khil*" 
the addition of -f to ,5 prr ernt. of the sanu" acid caused the inoal«» 
to develof). The reactions of the fluid has a marked iutliience in 
this respect. As a rule, acidity is unfavorable to the developmeU* 
of bacteria, alkalinity favorable — the reverse usuallv holiiiii^ I***" 
yeasts and moulds. Very slight differences may suffice to prnpot 
the growth of a bacterium; for example, Koch was nnnhle to pro- 
duce any disease in (ir/it-mire with an organism which always P* 
duced fatal septicnemiu in hon»e-micv. Some similar diffcwn*^ 
would .seem to e.xist between two men exposed to the poison "f •** 
acute specific, one of whom catches it. whilst the other does D«'*- 
A very slight, practically imperceptible, change iu the metalx'l*® 


of the body or of a part may enable organisms to flourish there, 
even though they were quite unable to do so a short time before. 
Many chemical substances are inimical not only to the growth, 
but also to the very existence, of organisms. It has been suggested 
tiiatthe term "antiseptic " should be reserved for those substances 
wliich prevent their growth, but which do not cause their destruc- 
tion, while those which actually kill the germs should be called 
'•germicides." But the distinction is not an absolute one. The 
difference in many cases depends on the degree of concentration. 
Thus, most germicides can be so diluted that tliev act only a« 
"antiseptics," though the converse is not equally true. 

ilermrii' chloride is. on the whole, the powerful chemical 
germicide known. A solution of 1:1000 will kill any spores in 
kalf an hour. Its power is increased by the addition of salt or of 
hydrocbloric acid (five times as much), while it is seriously dimin- 
ished by the presence of an albuminous fluid, and absolutely 
destroyeil by the addition of alkalies, and therefore of .*!oap. 

A 1 : 20 watery solution of carbolic acid rapidly destroys fully- 
developed bacteria, but takes a few days to kill the more resistant 
spores. The addition of hydrochloric acid (half as much) increases 
'to germicidal value. On the other hand, anthrax spores have sur- 
vived for three months a 1 : 20 solution of carbolic acid in oil. 
Typhoid bacilli have an unexplained tolerance for carbolic acid. 
Saiicyhc acid, boric acid, sulphur dioxide, chlorine, bromine, 
'O'line, an<l a multitude of other substances have a weaker but 
•naiogous action. It is especially worthy of note that while 
^ood-elot in wounds is a substance on Avhich most bacteria thrive, 
ilitod-gerum in artificial cultures is distinctly inimical to the growth 
of many of them. 

It will be readily understood that the germicidal power of any 
*ibstance must to some extent depend — (1) on the nature of the 
"fganism ; (2) on the degree of virulence of the particular specimen 
'" <}uestion ; (3) on any physical conditions that may interfere with 
"nniediate contact ; and (4) on the presence of any neutralizing or 
'"Compatible substances. It must be remembered, too, that the 
"^pidity and extent of the efl^ect produced on organisms separated 
^^" cultivation from all the constituents of the exudations and .secre- 
"^na in which they are commonly found, as well as from other 
'•"danisms that may usually coexist, is no exact measure of the 
"Vets that will be produced when wounds, cavities, or surfaces of 



the body are concerned. Neither must it be forgotten that thi" 
very substances which are most efficacious in dcstroyinj: organiw" 
are generally those which interfere most readily with the nutritioj 
of the tisHue-cella. 

Water. — Nothing that is really dry fcrmi'tit.s, The presence or 
«"»«>• water is e.s.siontiiil to the dcvolopment uf nil fungi, for it iictjM 
the medium foi' conveying oxygen ;inil food-suljatance."* into tin- i-ell. 
It is easy to add too much or too lit lie for a given speeiee. 
moulds reiiuiro less tluin the ye:ists. and these, iipain. les» th 
hiscliTia. I'jion jam, driotl by aihlition of sugar moulds nfien grotj 
if less sugar he iuhlcd or more water left in the fruit. Hicnholic 
fermentation is comuinti, svhilat if the proportion of water be still 
greater, putrefaction may occur. 

Desiccation destroys many vegetative cells within n few liavsur 
hours, but many resist drying for niontlis, and spores of the t'nil'>- 
sporous group do so for years — it is impossible to say how lonfi- 
Thus, dried cholera spirilla die in three hours, whilst dried tvphoiil 
bacilli survive nearly as many months, and dijihtheria bacilli lonjef 

Oxygren. — I'asteur has divided fungi into two varieties — aerobic 
and anaerobic. The presence of oxygen is essential to the tnembfn 
of the first group, while it is fatal to (hose of the second. .Xiiiicr- 
gillus niger, U. subtilis, and Mycoderma aceti are examples of lU group ; the bacilli of tetanus and of malignant oedema Wfl 
to the second. By far the larger number of pathogenic orgnuis 
are able to live either with or without o.xygen, at least for a 
siderable time. An organism which thrives bi'»t in the presence^ 
oxygen, but which run grow in its absence, is said to be "acn 
and capably (facultative) anaerobic," and vice vrmd. The first( 
these two groups is the most important, and includes the hiicill 
anthrax trd)ercle, typhoid, and diphtheria. 

Oxygen under pressure may prevent the growth of. and »" 
months kill, even (f('V<'/i/<' organisms. Their spores also, according 
to Diielaux. retain their power of germinating much longer 
oxygen is excluded : if true, this may partly explain the act* 
of air as a disinfectant. 

Temperature. — Each organism flourishes best at a partiruU' 
temperature. All will grow, but less actively, at tempeml'i' 
somewhat above or below this jwint. Now, no organism can 
come parasitic unless the temperature at which it grows corresp*" 



to that uf some pari of the body to which it finds ttcces*. Hence 
it ha[)[ieii8 that all pathoirenic bacteria grow rcudily at about the 
li'm(iiT!i(iire of the hiiiiiau body. In some casfs tho ratigi' within 
wliicli iJirowth is possible is very limited, as in the tubercle bacillus, 
"hifli. while it thrives at f>!1° F. (-'iT" C), can grow with more or 
\m difficidty at any temperature ranging fi-om S2° F. to l')8° F. 
Fmm this it may be inferred that this bacillus is less likely to exist 
«5 »n external than as an internal parasite, and that when it does 
•fleet tile surface its growth is likely to be slower and its progress 
iiiore easily arrested. Other organisms, such as those of cholera 
smi typhoid, can in suitable media grow at a temperature of 00° F. 
and upward. These can, therefore, easily multiply apart from the 
l>i)dy The general statement iuay be made witli reganl to bacteria 
that reproduction ceases when the temperature is reduced to 40° F., 
•ud in the of luany org.Tnisms at a much higher point; but 
they do not neccs.sarily die. Though rendered rigid and motion- 
les!, some can survive extreme cold. The spore-bearing B. an- 
tliracis been frozen in a Huiil at — 11<l" C. without itijury. and 
the typhoid bacillus has survived tliree hours' freezing The nia.\- 
imiiin temperature at which bacteria can grow is in most cases 
Wtweeti 100° F. ami 120° F. By further rise of temj)eniture 
fijtidily and denth are induced — more easily in moist than in dry 
Conditions, and mucii more easily in the adult thun in the spore- 
form. The reaction and nature of the medium in which the germs 
We heated have a deci<led infhience. Boiling, and indeed a much 
liter temperature (140° F. ) than 212° F.. will kill the great 
Bajority of fungi, but solutions containing spores may need ex- 
["wiiire to a temperature of 212"^ F. f'ltr many hours before they are 
fninplctely sterilized. Thus, Tyndall failed to sterilize a hay- 
ittfttiiion by eight hours' boiling. This jirolonged resistance of 
•(wre-containing tliiiils to boiling is explaiued by sufiposing that 
frwh jrcneralions of adult orgiinisms are developed after the boiling 
ttoter from spores able to resist that temj>erature for a long time — 
• view supfKtrted by the fact that such fluids may be readily steril- 
iwd if boiled for a few minutes only on four or five successive 
occi«io»8 at intervals of several hours. 

Id like manner, alternate freezing ami thawing destroys organ- 
i''tt)s more rapidly than continuous freezing. Tyjihoid bacilli suc- 
cumh to this treatment in a month, while they resist continuous 
[freezing more than three times as long. 


•Some vegetiitive forms hare been fouod which withstnnd tviupen- 
turc3 higher tlian tliosc nnmoil. Ditclaux found sonic haeilii I';/'* 
////•/.(■ in choffiiv) whicli. wlifU siispcndt'd in (tlightly alkaliiu' liuid. 
were not destroyed by 100° C, but in acid medium were kilNia* 
minute: the sport's were not destroyoil l)y 11.")° ('. (hlicr 'in^ii" 
of sporo iiiivc bt'cn na-t with vvhidi have withstor)d a moist init •' 
even 130° C. 

Strciiining steam has n. more powerful jrermicidal nrtimi iliaii 
superheated steam. This is probably due to its grc.iter ilcsn'' '" 
moisture and its eonserpiently greater penetrating power. 

The (//•// spores of tfie R. antliraeis and of tlie U. subtilis arr n"' 
destroyed by less than three hours' exposure to 140° C. 

Best. — Fungi flourish better in a still medium than in one who** 
particles are constantly moving : wliilst the B. unthracis ilividt* 
actively in the blood-strcjini, luanv lither kijidsfmicrococcuaseptico** 
seem always to settk' befcu'c n)ulti]>lyiiig. 

Light. — Light, e-specially bright sunlight, has n destriicti*''' 
influence cm orgjiiiisuis. Tli«' rays from th<' viidcf end are siii"! *'• 
be the most powerful, those from the red end the least. All <irpin- 
isms do not sutler e(|ually. A few even multiply under the action 
of light llecorded exjieriinents on this subject are contnuliotor** 
The contradiction may lie due to the difficulty in exciutliiig tb* 
influence of desiccation, oxi<lation. and changes in the mo<lii »" 
which the organisms are phiced. Vomhhied with these, light iiininC*" 
tioiiably forms a valuable means of disinfection. 

Soil. — Ajiart from their degree of moisture and from the prescnc* 
of other orgunisms, the intliience of most soils on the growth *>• 
jiatliogeiiic bacteria does not seem to be marked. l\'at, howev«?*'> 
h;is a distinctly destructive influence over the organisms of cboirr* 
and typhoid fever (Dempster). 

These arc the essentials by wliich the growth of orgnuisiim r*** 
lie modified. Absence of growth does not necessarily mean ilea*' 
<if the organism. If the conditions are unfavorable, the cells »»• 
not develop, but they may not die. By making a compnnitivr" * 
small change in scune of the above conditions the developmriii, a** 
couse()uently the nctiun, of any given organism may be prevent 
This may often he possible when it is ijuite out of the i|ii«ti'in *" 
employ measures powerful enoiigli at once to dettroy the iirgani'*"' 


these microscopic vegetable organisms to be found ? A putrid 
wound swarms with them. Whence do they come? There are 
three possible answers : 1. They may find access to the body from 
some outside source; 2. They may exist in the healthy body, 
developing only under special circumstances ; 3. They may be 
spontaneously generated from the tissues. 

1. Earth, Air, or Water may be the Habitat of Germs. — ((/) 
Barth. — The soil is the principal .storehouse of organisms. Portions 
of mould taken from the surface and dropped into a sterilized cul- 
ture-fluid invariably infect it. Pyogenic cocci and the bacilli of 
tetanus and malignant oedema are among the forms usually found. 
In winter Koch failed to find any organisms, iit a depth of one 
metre in soil which had not been recently disturbed, which was not 
formed largely of decomposing material, and into which no unusual 
soakage of water had occurred. 

All .solids in contact with air, including the surfaces of animals, 
bavc organisms upon them. 

(/)) Air. — That dust contains much organic matter is easily shown 
by combustion, and by artificial cultures it can be proved that some 
of this is living. It has thus been found that spores of moulds are 
the commonest forms, then bacilli and their spores, whilst putrefac- 
five organisms are comparatively rare. Organisms of some kind 
«xist in the air everywhere except away from all lift — in mountains 
*bove the line of perpetual snow or on the ocean far removed from 
land and ships. In such places a sterilized fluid would not ferment, 
even if left exposed till it dried. But wherever life is found germs 
*fe found. They increase in number as the population grows and 
*s putrescible material becomes more plentiful. Ilesse found that 
*ne air in a hospital ward in Berlin contained thirty times as many 
■bacteria as the air out of doors. In some parts of London it is 
possible to pour sterilized fluids from one flask into others with the 
'^sult that but a small percentage will become turbid from the growth 
'^^ germs ; in other parts every flask will be infected. I'recautions 
*g*inst infection become more necessary as density of population, 
***<! imperfect ventilation increase ; and it is obvious that in the 
"Ospitals of large towns such measures to be successful must be most 
*t*'ingent, for here putrefactive organisms will be comparatively 

The air is kept supplied with organisms from the surfaces of 



objects over wliicli it jiassos. The dust left as tiic final n-xiilti 
putrefactive proeesfes is a fertile Hoiireu of eoiitaiiiitiatiou. I'crfw 
»till air becomes pure by Bubsidence of its germs. 

(r) Water. — All water, except such as comes from a p 
(artesian wells), cinitains orj:aiiisms. Kaiu-water sweeps tiic iiir. ami 
infects the soil with the germs which it carries iIowd. All snrfw*- 
wftter is infected frnm the ground tliruiigh which it soaks. Ri>rt- 
water is exposed to all (lossible sources i«f pidiutiun. It is ^nmU 
necessary to add that iiidcss the water contains suftieieiit orpiiic 
matter to serve as fund fur the fiiugi. no multiplication will lake 
place, and that, sooner m- Inter, tiie germs will die. though [xTlup 
not fur many weeks. The existence of many organisms in a Mtiijilf 
of water render much organic impurity probable. 

2. Do Organisms Exist in the Living Body? — They exist iff 
large uundters on its extcnml (.ikiii) and iniernul (bronchial anil 
alimentary) surfaces which are in contact with the air. On the skin 
they are most numerous on the /lamh — beneath the nails ami in ll"' 
folds of skin about the nails; and on finrtK jirovidol with Imiraii'l 
large iflanih — r. g. the scalp, axilla, and perineum. Special earei* 
therefore reipiired to disinfect these parts. Inhaled witli the hreuth- 
organisms are found in the larger bronchi, but the smaller futi« 
and alveoli are jtrobahly free, for Tyndall has shown that lliewinr 
plemental air is pure, a,s it causes a nondundnous gap in an elcftnc 
beam thrown across a dark room. Fiii'lher proof lies in llu-firt 
that *• medical " einpyeniata. communicating with the air tlinnijel" 
the linig. generally reuiain free from putrefaction, whilst surgiol 
empyemata, I'ollovvirig an external wound of the pleura. aN 

With food and drink manv living germs are carried into the »!>• 
mentary canal. .\ll kinds of fungi swarm in the mouth. Tbej 
grow fewer as the stomach is reached, for the acid gastric juicej 
unfavorable to the dtivelopment of most of them. Orpnni.sms 
plentiful in the duodenum before the food has become alkaline, 
the pancreatic juice swanus with organisms after impure fee'lil 
Indeed, the products (vf normal ])ancreatic digestion and th<»i'«< 
the ordinary putrefaction of albuminoids are practically the sa 
Throughout the whcde intestine, but varying with the product* i 
stages of digestion, euoriuous numbers of organisms occur, 
abnormal states of the mucous membrane or in too prolonged ret< 
tiou of intestinal contents the fungi may multiply and excite 



ana even jioisoning, by the proiliii't!- of their iu-tioii. Expe- 
siliows that allLT death piitrt-'f'actiou begins in tlie altilomen, 
ling from the alimentnrr cuiin). 

obtaining pure urine ilirectly fVoni tbi- iirethni Linter showed 
healtliy urinary tract is tree from organisms. 
!teri)i iin the skin and mucous surfaces mav fairlv be reganled 
muil to the body proper — /. e. to the tissues. Organisms are 
ill the ti-ssues in many dhrani-f : wc have now to in(|uire 
w tlicy exist in the /leult/ii/ tissues. Tliere are two routes iiy 
organisms may reanh the tinsui'S. One is tiirough the nkin ; 
lier tiirough the murniis tnembnateg, esjiecially the respiratory 
le alimentary. 

The Skin. — As a generiil rule iniinjiiri'd ejiiilcrnris is imper- 
ii) organisms, and in priictirc ncin-ly ;i!l mganisius that gain 
hy tiiis means enter tiirough wounds or slight abrasions, 
k's liavc. however, been produced by rubbing into the skin a 
culture of the stophylococeiis pyogenes jiiireiis. Inoculation 
Se .seems to have occurred through the walls of the liair- 
BB or the 8wcat-duct«. as it does in the case of acne pustules. 
The Mucous Meml>rane». — If organisms enter by the skin, it 
'ortinri. likely that they will also enter by the niiicoiis nieiu- 
I. To decide this (jiiestiod. s<» f;ir ii.s the respiratory tract is 
ned, animals were placed in an atmosphere impregnated with 
,X spores. Aiithra.x is a pMrtinilarly siiitalile organism to use 
Ht, from the readiness v»iih wliich it thrives in the tiornial 
I In an experiment of Buchner's out of sixty animals thus 
Ffifty died from antlirax. It is unlikely that the organisms 
iwallowed and alisorbed through the wall of the alimentary 
-first, because, while large numbers were found in the lungs, 
none were present in the spleen ; and secomily. because out 
ty-three animals fed on double the proportion of unthnix 
only four succumbed. These experiments not only showed 
the ease of anthrax the organisms can gain an entry through 
bcse miK'Oiis nieiiibrmie, but also that the entrance through 
■piratory mucous lueiiibrane is the more readily eflected. In 
Ig they are probably taken iiji like ("trhon particles, carried 
phatie glands, and thence perha|ts to the blooil. It is diffi- 
^cny that in many cases there may have been some slight 
Wt the point of entry. 
m animals are fed on putrid material living organisms may be 


THH vh:ai:TAtiLK parasivkk 

foiinil ill tlio iiritif. This is tlit- case wlioii it liiry 


\ml.sIm'i1 iiiitrfiix-live orgiiiiistiis i;- inji'cto<l into the rirculj 
Ortlinarily, as above said, frei>)i liiiiniin iirinc is stcrilr. 
goriiis. of coiirsf, are (•.•iiTitMl to otlirr or;:iiii)» than the kiditft 
arc foiin<l us vfllowish iiiii!<i«fs in tin* cu|jilluric»: tlicv are uuak 
thrive in the hcaltbv system, and die and dixappear in twoortbm 
vrt'ks — often much more nipidlv. Kmni the above data it i» piw^- 
able thiit iindt^r onliiiurv eirciimstanees or<!nniMn!« can pas* thrnnjk 
the miicoiis inenibrHne^ of man in i^mull tjimntitieH only, ninl tt>il 
any which do enter soon die nntl t|o not reaeh tlic tirine aliTc^l 

Kx|>eriments have been nnub- to determine \« hether or|;auifa(W 
liabitiuilly present in heullliy tissues, I'ortions of liealthy nrpu 
have been removed with precaiitiontt and placed under conditi««» 
best calculated to enconrn^re tlie growth of any or;:ani*rai' tint 
mi;j;lit l>e ])rescnt, as well nr. to prevent their contaminalinn fn« 
any extraneous source. The results have been contradictorj.' 

The balance of evidence seems to be distinctly in favor of tl* 
view that. </» a ruli\ no living germs nre to be found in linllk* 
tissues. But that the blood may contain liviiig pyogenic opcci il 
|irol»ible from the freipiency with which inflnmmution and »!•«• 
ri'sult from bruises occurring in depresse<l states of the t\*um 
(|). M48), but without any break in the continuity of the e|ii*lrrD<» 
(p. <'137). If cocci could onliimrily obtain accesa to the tiMow by 
means of the vessels, il woiihl be impossible by autisejitic trMlJM** 
(adapted to prevent the entry of living cocci t'rom without) to ^ 
vent suppuration of wounds from causes reaching theiu from inih»- 

Agdin. the rarity with which any collection of pulre*ii' ' """ 
in the body undergoes putrescence (notwithstanding the -^ 
of the temperature), and the certainty with which by care 
keep wounds -'sweet," seem to be strongly against the e\i 
of putnfitctiv fungi in healthy tissues. It is certain, hut 
that if these do gain access, tliey may survive for some Lot 
that the jiutrefuetion of removed portions of tisane, osnally attril 
uted to want of cnre, may .sometimes have been due to the {rcMftC 
of living genus in those pi>rtions at the time of their reuitMal 6w 
the body. Again, if a suitable ni<ius be provided for tiie do^B 
nient of organisms, they luuitiply and .set up their rhamrtiM 
ilccomposition. Thus, Ohauveau performed fii»tourtK2yf ttf » siterj 

' W>twiri ('h«Tne, 7Vaii<. PalM. Society of JjoiMlon, IH79 ; Mott aad Honigy.Jmt 
of Pk!f$Uilogti, ToL iii. 


testis— I. e. subcutaneous torsion of the organ and its main vessels 
—in one case before, and in another after, the injection of septic 
bacteria into the blood. In the latter case, in which the testis pre- 
inmablj contained imprisoned organisms, it broke down into a 
potrid fluid and excited much inflammation around. In the former, 
in which the injected bacteria were shut oflF from the damaged testis, 
the organ underwent the fatty changes known as necrobiosis. This 
is the invariable course when under normal conditions the operation 
is performed as a method of castration : it seems to show that, nor- 
maiiv, organisms are not present in the sheep's testes. 

Some organisms, however, seem capable of flourishing in tissues 
which are perfectly healthy — e. g. the poisons of the acute specifics 
and the B. anthracis. Even here there is some very obscure differ- 
ence between individuals of the same species or of closely-allied 
species which renders some of them suitable media for the develop- 
ment of certain organisms, whilst others are unsuitable — i. e. more 
or less predisposition is required even when a species of animal /« 
UaUe to a disease. Thus, some people do not appear capable of 
contracting the acute specific fevers ; children are more subject to 
Mute specifics than adults; Algerian sheep are immune to anthrax ; 
joung dogs are easily inoculated with the 6. anthracis, but old 
ones are not. One great diflBculty in the experimental study of the 
infective diseases of man is to find animals which are subject to 
them. Many organisms will thrive only in some particular tissue 
or fluid of the body ; thus, some multiply in the blood, others in 
lymph, some in bone (osteomyelitis), others in the cerebro-spinal 
meninges (epidemic cerebro-spinal meningitis). (See " Micro- 

To sum up : Organisms in great variety, but in very varying 
Bumber, exist in air, water, earth, and on all objects exposed to air, 
on the skin, and on those mucous surfaces which are in contact with 
*ir. Organisms can probably pass through the pulmonary and intes- 
tinal mucous membranes, but in small number ; and such as ordi- 
•"irily thus enter the tissues are unable to develop so long as the 
latter are healthy. The life of such fungi among the tissues is 
^oort. It seems to be a very rare thing for them to reach the urine 
«ive. Occasionally an organism which can develop in living tissue 
titers. The recipient of such organisms is in more or less danger 
of disease. Some fungi seem to find a suitable nidus for their 
development in the great majority of mankind ; thus, few are im- 



niiine to tlip vaccine vims. All m-jriinisnis flourish Ijest in ti«»M 
the vitality of which is im|iairetl : soiiif probably cimnol di'vtlop 
niilesH this is the case; and 8till another group cannot multi]ilT it, 
livini; tissues at all. Two preat ilivisions (clinical) of axpum 
are thus obtaineil: 1. The Patboerenic, or those «hich can invn 
and multiply in livin<» tissues, almost invariably j;ivinj» rise to di 
ease. 2. The Non-Pathogenic, or Simple, which can develop onl 
in (load tissue, and arc tlierefnre found chiefly on the surface of tl 
body, where slouglis and discharges are common. It i.s u verv raW 
occurrence for putrefactive fungi to find their way tiUre to an intM- 
nnl slough or piitrescible effusion, as they did in Chaiiveau'noxpvri- 
nient ([>. 8o<)). 

3. Spontaneous Generation. — The pos.sibility of organiitu 
originating </»• novo from the molecules of decoiuposiiip ' 
must be mentioned, but cannot be discussed. The great lua; . 
of observers are agreed that there is no evidence that it ocean 
They hold that if a fluid or moist solid be thoroughly sttriliifl 
and placed under such conditions that no organisms can enter from 
without, no organisms will ever develoji. 

We conclu<le, therefore, that organisms found in a putrid woiiml 
have entered it fnim iri'thout, and that the same is true of fiiii|.i 
found in patliologica! lesions within the tissues, the organ i.-suis hid- 
ing entered by a wound or through a mucous surface. For tb' 
present, at least, we uiii.'<t adhere to the belief that neither livin? 
organisms nor their spores exist nornuilly in the tissues, ami tlia' 
they are never eliminated alive by an excretory organ or bj • 
wound. ' 

This is of fundaUH'iitid importance in surgery. If orgaiii*m» 
couM enter n wound from the side of the tissues, aseptic treatrac»' 
would be impossible. As it is, we are sure that if we allow no liwf*" i 
hole for the entry of germs from without, our wounds will rem*** j 
free from feruient-proce.sses. Patietits are thus saved from the ila»'" 
ger of septic intoxication, of septic infection or pysemia. and **• 
other infective diseases. (See " Pyiemin and Septicemia.") Ob<^* 
organisms have gained access to the tissues, it is extremely diffict*'* 
to destroy them without also destroying the tissues. Improvemr*'* 
of the general health often enables the tissue-clement* to 
invasion succe.ssfttlly. (See " luiniunitv.") 

Products of Bacteria. — The chemical products which »"•»" 
from the growth of bacteria are both numerous and varic<l. *" 



ses they comprise a series of complex changes which are as 
imperfectly made out. To a considerable extent they 
upon the nature and amount of the material from which the 
a in question derives its nourishment, as well as upon the 
1 conditions by which it is surrounded. Thus, the cholera 
when grown in weak meat-juice produces a peptonizing fer- 
ut when supplied with a much stronger solution forms a 
; ferment instead. 

products of bacterial action have no pathogenic import- 
hese we shall not discuss. They include many pigments, 
ve of aniline dyes and certain fluorescent and phosphores- 
(cts ; many on/atnc acids, such as lactic, acetic, and butyric, 
er allied substances; a few gases, including carbon dioxide, 
as, hydrogen, and sulphuretted hydrogen. 
;hief products of pathogenic importance are — (1) unformed 
s. (2) albumoses, (3) alkaloids or torincs, and (4) caustic siib- 

coMPARiNQ Action of Anthrax and Diphtheria Fer- 


\gent, Ferment or Secondary 

iry In- 




Infective Agent. 



Anthrax ferment. 

Diphtheria ferment 
in membrane. 

Digestive Products. 


f Hetero-albumose. 
Albnmose -j Proto-albumose. 

I Deutero-albumose. 

Qlobulin-like body. 
Tryptone (peptone). 
I.«ucin and tyrosin. 
A bitter body. 


I>eiicin and tyrosin. 
Alkaloid (base). 

( Hetero- 
Albiimose < Proto- ] 

( Deutcro- 
Organic Acid. J 

• in the membrane, 
in the bodv. 

relation of these different groups to one another can be 
understood by a reference to the preceding table. The 
' Goulstonian I,ecturcs, liril. Med.Joum., vol. i., 1892. 


most striking feature it presents is the general similarit 
the products oi proteid digestion and those o( bacterial act 
processes are not so similar as they appear at first sight 
first place, the ultimate products are difiercnt. In choler 
loid is the final product : in diphtheria, an organic acid, 
more, the experimental inoculation, of animals with the ; 
produced by different organisms clearly shows that thc« 
albumoses are by no means identical, and that their clien 
tions, so far as at present known, give no indication of thi 
genie effects. Thus, in diphtheria the albumoses can 
degeneration, while the organic acid seems almost ham 
cholera, on the other hand, the alkaloid or final product se 
the real cholera poison. So far as is at present known, t 
tion of an alkaloid by an organism is not necessarily pr< 
that of a ferment. 

In connection with about one-fifth of all known pathogei 
isma ferments have been discovered. The nature of those 
already described (p. 322) 

Albumoses are common intermediate products in the se* 
bacterial reactions. In some cases they arc the mo.-it vi 
all the resulting c<mi]iounds. This is so in diphtheria and 
|H)ison. In anthra.x and cholera, on the other hand, they 
parativcly of slight importance. 

Among the varied products of bacterial growth are a h 
her of alkaloid suhstanees. Some of these are harmless, 
are poisonous. The latter are known as torines. E.xampl 
these varieties may be found in putrefying meat, fish, an 
They can be easily separated and their nature investigaJ 
virulence of both anthrax and cholera is due to the fori; 

Fate of Org'anisms in Livingr Tiesuea. — It by no meai 
that germs which have actually entere<l the tissues will 
and give rise to disease. Ju.xt as in the case of infective 
tions, so in all other infective diseases, there are tirn fad 
produetion of disease — the attack of the germs on the one 
the resistance of the ti.ssues uj>on the other (p. 307). 

Supposing the conditions to be favorable to their grow 
genie fungi differ nineh in the course which they pursu 
remain about the spot at which they first settled. Others, 
ferent degrees of rapidity, spread by continuity of tissue. 



a^in, are carried along in tlie lyinpliatios, settling in tliem here and 
tlii-re, or passing on until the nearest ghinils are reached. Another 
gnmp enter the circulation at once nn<i are carried in the blood nil 
over the body. Some species remain and multijih' in the blood, 
mil in tritnslucent i)arts may be seen in the plusrautie zones of the 
terns; others, again, re(|uire to be deposited I'roin the blood at some 
spot preilisposed to receive them. Escape from disease after expo- 
»iirc to infeetion is doubtless often due to the deiiosit of germs »t 
jpots other than " weak " ones. 

The spread of organisms in the tissues, like that of an absce.s.s, 
»lw«T8 occurs along the lines of least resistance. Fiirtherniore, it 
is not necessary that the organisms should inter the tis-siies at all in 
iinler to produce disease. In diphtheria the bacillus is confined to 
tbefiiise membrane: this becomes simply a manufactory of the fer- 
ment, which is rapidly distribiiteil throughout the body, giving rise 
in the tissues to the albunioscs alreinly referred to. In cholera, too. 
tile bscillus is only found in the intestine, while its products are 
rapidly absorbed and lead to the well-known 8yin|itoHis. It is 
therefore clear that the effects of the action of organisms in the 

Fi(i. 117. 




u ■■- , ■ 

"■JOw't lan«— vcHsU p1iik8»<I with baclUt antlirnctii : n, alvenlus: v, rein tul\ of iMClllI : 
'•'^PtlUrj', iil*<i ftill ; fcr, lirDiu'hiui. X .VX», slUfhlly reduced. (Bonley.) 

iioiiy a|.^ ypry varied. Sometimes they are str'retly locaf, A small 
•"i"** of organisms by means of its chemical jiroducts excites an in- 
"ininiatory focus anti exerts n po])torii/,ing, caustic, or other action 
on the tissues in which it lies (Figs. 107. 108). The action is 



litiiited to invasion of the tissues ueiir the }>oint of entrT. 
times the action is less strictly locul. Such inflauimntiun w 
diffuse. Occasionally the mere mechanical plugging of tht* rrm*it 
may be of importance. The accom|ianying figure (Fig. 11"). »li 
iug the bacillus of splenic fever in the vessels of a mou»c's lui 
gives an iilca of the extent to which this process may be rsmnl 

Sometimes, when the orgunisms uniltiply in thv blcMtU or Ji»ch«r)^ 
into it the products of their action, the most marke<l fffects arc//f«- 
eral. These consist mainly of fever, wasting, and coma frum tU 
action of substances circulating in the blood, the coaguUbihij iif 
which is sometimes le.xsencd. lu others, again, in achlition In iht 
strictly local and general effects, the circulating producLt an«rk 
special parts; as in diphtheria, in which the albumosc* nnf 
marked dcgcnenitinn of certain nerves and eon.«r(|Ui'nt local |>i 
ysis. I'ossibly p»ru:<itic fungi also produce >i)imi' ■■fTi-ct li\ 
abstraction of nourishment from their host. 

Reference must here be made t<» the conditions whidi iiiHurt 
these two factors, increasing or diminishing the power of thei 
isms or the resisting capability of the tissues. 

(1) Arreet of an orgranism is absolutely necessary before it ( 
by its metabolism produce /wvi/ irritation and intlammatiou, forifl 
products are poured into the circulating blood, they become 
dilute to effect any local injury. Tbun, pyogenic oocci have 
Uncntly been found in the bloorl of persons having no >b 
Again, lym]ihadenitts is much commoner than lymjiluiiigiut. 
because the glands are more accessible toorgani«mJi than there 
but because the organisms are more likely to be arrested in 
narrower and more sinuous channels of the former. Kut *uch i 
is not neces.«ary for organisms which, like those of septic infn 
of mice, act by pouring into the blood fsiisons which fercfi 
other symptoms, infill, though n-nt is only mxt'ittial to the innltif 
cation of tome organisms, it is itdvantittjeon* to the growth of '"t| 

Organism* circulating in the blood may be arresttfii iu one | 
many ways. Of these the conunonest are rmtii>(i*m, f/ma 
estrai'titiitioii of blood from injury, anti the miifratiou and »o 
i|uent death of a leucocyte bearing in its interior onr nr more li» 
germs; which will occur most easily in part-s in which the vt 
are distended and the circulation slow (venous congestion). 1*1 
conceivable that a germ might escape uuaide<l from a vessel uo 
tbeae oircumstaucen, just as a red corpuscle ilocs. Xt 



itthods httve been devised to cause tiie detention of organisms iu 
ipillnries (hruiigh which they could ordinarily pass, such ivs mixing 
\m with sterilized cinnabar or potato-starch. The result was the 
jpaction of the cocci and the development of intlammatinn, thus 
imon-strating the effect of simple arrest of the germs. 
(2) Predisposition. — Unless there is pn'disposition to suffer from 
8 products of the organisms thus arretted, their impactinii in ves- 
li may not be sufficient to enable them to excite inHammation. 
lus, in rabbits Rildiert fouud numerous masses of pyogenic cocci 
the capillaries of the lung and other organs twenty-four hours 
er their injection, but all disajipeared in forty-eight to seventy- 
it boiirs. except in the kidney.s, where alone abscesses formed, 
ibits are less prone than man to suffer from these organisms, and 
them, at all events — and very likely in man also — tlte predhposi- 
i of the ti$tiut'» mti»t br imreaged before these particular organ- 
w (pyogenic cocci) can excite inflammation. The predisposition 
mlTcr from the attack of organisms is increased by general de- 
Msion of vitality. This may arise from privation and faulty 
gicnic surroundings. Dcfircssed vitality is also seen after severe 
Itc fevers, and in alcoholic, albuminuric, and diabetic patients, 
long these trival wounds often prove serious, and operations 
fuld. if po.ssible, be avoided. Pyogenic cocci easily gain access, 
Icellulitis, boils, and carbuncles result. Among savage races and 
mals serious wounds frecpiently heal by first intention. Local 
TTeseion of vitality may be brought about by any kind of injury, 
] it is here that the ■■• simple " causes of inflammation chiefly come 
M pretlisponents. rendering the tissues more open to the attack 
micro-organisms. It ha^ been experimentally demonstrated that 
tmia or mechanical hypenemia of a part for some hours enables 
tic cocci to .settle and excite a progressive iiitbimmation. Thus, 
terbouse injected staphylocoeci subcutaticously into his own 
Unni with a negative residt. He then constricted a portion of it 
11 it was purple and swollen, and made a similar injection. An 
iena resulted. The effect of ordinary mechanical injury {iisunlh/ 
\i) in leading to simple abscess, osteomyelitis, and tubercular 
*wc of joints has been known, and it has been proved that such 
>nfl act cither by simply depressing the tissues or by causing ex- 
'watiou of blood, and thus allowing germs which cannot grow in 
circulating blotxl to pass out into the connective tissue, there to 
and excite inflammation. Drdinurv chemical irritants 



i k 


$<itnilarly (lo|)re8K the ti^i«lU'8 and excite RiiDpie itiflaininstioa 
Clicync point.'* out that Ktronj: injoctinns into noptic cavitiee pM 
!il)ly fac'ilitatf tlio untn into tlie general circulation of auyorj 
which the injections fail to lU'stroy. The injurious effect ny 
tissues of strong coM or lieut applied directly to a part nc 
comnient. arnl liadsar's exj)erinieT)ts (p. 309) dhow tin- effect 
inteniul organs of cold applied to the surface : ami. tliough it itw* 
yet known how the cold acts, we may conclude that it would &oili 
tnte the passiige of organisms into the tissues of the |«rt» 
become intcrstitially inflanu'd. These agencies, if they cbu)«' 
nizable changes at all. excite simple inflammation, and the vie 
an infective inflammation may. so to speak, be grafted <tn t<> n i 
inflammation has met with wide acceptance. It would siTni.J 
ever, that pyogenic cocci and other organisms circulating 
Mood do not enter the inflanied area and {lass out into the ill 
tissues iluritxj nil ulnr/rii of the inflammatory process: they 
freely until the stage in which leucocytes escape in numli 
reached, when, according to Rinne's experiments, they are no] 
to be found in the vessels of the inflamed area. Tocci in 
•luring the formation of scar-ti.osue are said to enter the vcf 
the damaged part in excessive numbers. Thence they may | 
into the tissues, but when the scar is fully formed no such dil 
is noticeable. The explanation given of these observations 
in the early stage of inflammation the tissuen are weakeuiMi 1 
injury and unable to co|>e with invading organisms, which 
ijuently multiply in them: but in a more advanced stage, nhc 
escape of leucocytes is occurring, the damaged ti.ssues are inii 
and fK>rhaps replaced by a swarm of healthy active cells, and] 
Idy by an antagonistic fluid, both capable of dealing with py4 
eiKici. Sear-ti.ssue, again, in its early vascular stage seem* t#ij 
feeble resisting power. It sounds some what strange that l)i< 
stage of inflaiuMiatinti should give to u liicu» minnriM rr 
— as regards puigenic cocci — whilst a later stage i|oe» not 4*l| 
but Cheyne thinks that it fits in well with the fact that acQiaj 
iiivclitis and tubercular disease are often indnc<'d by slight il 
— rarely by severe, whieli ."eeiu to excite tno miieh renctioti. 

(8) The seat of inoculation and the anatomical ar 
of a part are of importance in enalding organisms to obtain i 
hold in the body in two ways: 1. I'frtnin wiVtuAc* can only. i 
in crrtain ti»»uc» ; thev are harmless unless thev reach and 


these tissues. 2. The physical characters of a part have much to 
do in determining whether an organism will live in it, and what 
form of inflammation will result from its growth. The bacillus of 
malignant cedema illustrates both these points. It can grow only 
in connective tissue : when introduced into the blood it sooner or 
liter dies, leaving the animal protected against the disease ; but if, 
vhilst it is circulating, a bruise is produced, the bacilli pass out 
with the extravasated blood into the tissues, commence to grow, and 
thus cause the lesions of the malady. Again, inoculation with this 
organism at the tip of the tail in cattle has little effect, on account 
of the density and coldness of the part: the intensity of the inflam- 
mation increases as the point of inoculation approaches the body, 
and the reaction may also be increased by raising the temperature 
of the more distal parts. Sheep, which have loose tissue in their 
tails, react strongly when inoculated even at the very tip of this 
»ppendage : the reaction is diminished by cooling the part. Cheyne 
showed that the injection of a certain quantity of a cultivation of 
the Proteus vulgaris into the subcutaneous tissue of the back of a 
rabbit caused an abscess, but the same quantity in the muscles of 
the back produced death ; and, further, an amount of the cultivation 
too small to have any appreciable effect in the subcutaneous tissue 
cansed an abscess when placed among the muscles. No explanation 
is as yet forthcoming. The limitation of acute infective osteo- 
mjelitis to growing bones is another example of the influence of 
structure upon disease. A last illustration of this point may be 
fonnd in the difference between the behavior of the peritoneum and 
the cellular tissue to pyogenic cocci. The success of a surgeon who, 
*fler an operation, washed out the peritoneum with ordinary un- 
imrified tap-water has been greater than that of any one practising 
the most rigid antiseptics ; but the result of washing out wounds of 
sofl parts or of bones has been, on the other hand, extremely 
unfavorable, acute inflammation often supervening. The explana- 
tion given is that the peritoneum has great powers of rapid absorp- 
tion, so that considerable quantities of putrescible fluids may be 
•njected, together with septic organisms, into its cavity, and they 
*ill be completely absorbed before putrefaction has time to advance 
*'^' » jwisonous extent ; but, if injected in still larger quantity putre- 
•ftction occurs with great rapidity in the unabsorbed fluid, and death 
•tim septic intoxication results. showed that if a given 
'*ose of pyogenic cocci were suspended in normal saline solution 


and then injected into the peritoneum, uo |H*ritonitis followed: W 
that if a tvnth part of the dose were injected n'ilh hh»MM>it ■•■ 
peritonitis resulted. It is easy to understand that the gr • 
such organisms may fre(|uently depend upon the irauicdiate .< <" 
ihility of suiliihle noiirishnient (p. ii.'UJ). It is notoriou.'i, ni" 
that a chronically inHanied peritoneum with a j5iK>d ninny >< i 
ndhesiouH staniLt itgury bettor thau a normal membrane, iiKi w 
jiroof exists that the lymph-flow frrmi the former is more fr 
from the latter. Possibly there are more availabh- i.lii.'i' 
this case. 

(4) The niunber of orsanisms which gain entry to the Uxi* «i 
any one time is a matter of j-reat importance. At first si?)" "■■ 
might think that tiie only difference in the results after tli 
tion of 1 and of 1.000.000 pathogenic microbes would br thr »oni*- 
what slower development of the disease in tiie former ease. It «u, 
however, stwn found e.xpennientally that this was not so. except* 
cases of animals strongly predisfKised to suflcr from the orpaniim 
in ({uestion : and it was then understood that small niiml)<T> •>( 
organisms would be destroyed by the tissues before they omM 
produce their products in any iiuantity, whilst a rery large number 
could not he got riil of with sufficient speed to prevent thcni fn'iu 
producing more or less poison, and thus gaining a greater »x\v» 
ailvnntage over the tissues, ('[(on this jioint Cheync's own re- 
searches enable him to enunciate the ftdlowing laws: 1. Tin* ji»t!i"- 
genie dose of a virus varies inversely with llie |ire<lts|>o»itiou of il"' 
animal to the disease in ijue^tion. '2. In animals nut very lutc'f' 
tible to a germ-disease the severity of the disease varies dirwtlj, 
within certain limits, with the dose: a small dose produce* d" 
effect, the germs being rapidly destroyed ; a larger cue c»u»» » 
local inflammation, the organisms being hemmed in and drstro^ 
more or less speedily by leucocytes; whilst a very large dow "' 
comes all local limitations, the organisms [lenetrating into the ' 
culation, producing poisons freely, and causing death from wp 
(loisouiug. We cannot with certainty predict the <lo»e nec«ri«>aryj 
pro<lucc any om* nf the above results, because predisposition ''I 
greatly even amniig animals of the same species. 

(6) The viruleDce of orsranisms may usually be it 
(**exaltetl ") or diminished ("attenuated") by suitable cxtr 
conditions; thus, attfiiinition may result from cultivating an 'irij 
ism and allowiug long intervals to elapse between the mect^' 


loculations, or from cultivating it at a temperature at which 
rowth is very slow, or upon media containing antiseptics in 
uantity not sufficient to inhibit growth. Exaltation of virulence 
I less readily produced. In the case of the spirilla of cholera it 
an be effected by procedures described on p. 363. As these proce- 
urc8 can effect such important modifications in these organisms, it 
I evident that the body may have to deal with them in states of 
arying virulence; the weaker the virus, the more of it will be 
equired to produce a given effect, and vice versd. The absence of 
ttflammation from a wound treated carelessly or left to nature may 
ometimes be due to the attenuation of any organisms which may 
are fallen upon it. 

(6) Concurrent errowth with other bacteria may either increase 
r diminish pathogenic action, and many facts make it probable 
bit the presence of putrefactive with pyogenic cocci in a wound 
onsiderably increases the danger to the patient ; for the putrefac- 
ive organisms by their irritant products destroy the granulation 
ssae and open up a way of entry for the pyogenic germs. A 
irresponding fact, vouched for by Cheyne, is that general tuber- 
ilosis is much commoner in cases of joint disease complicated with 
ptic sinuses than in cases which are kept aseptic. The presence 

pyogenic cocci does not seem to increase the spread of tuber- 
ilar cavities in the lung, but the cocci certainly intensify the 
ects of the B. diphtherise (p. 386). Again, it is said that an 
teomyelitis due to a mi.xed infection of the staphylococcus aureus 
d albus is of greater severity and of worse prognosis than a case 
which only one of these species is present. On the other hand, 
«nt experiments have shown that two microbes growing in the 
ly may successfully oppose each other. Thus, if erysipelas cocci 
injected both under the skin and into the blood, and if a large 
le of anthrax bacilli be introduced twenty-four hours afterward, 
that a large numbr of cocci are present at the time of the infec- 
a, the anthrax bacilli will all die out in seventeen to twenty-four 
irs without causing even local oedema. Now, these two organ- 
la will grow together readily outside the body, so it is not clear 
*■ their opposition in the body is brought about. 
,7) Lastly, it is probable that local and seasonal conditions may 

upon pathogenic organisms, and thus account for such peculiari- 
* of disease as endemicity, or greater prevalence at certain times 
i under certain atmospheric conditions. 


organisms in Fluids. — .Sim/>Ir mirrnornpic rrainiiuttiim may he «uf- 
fieii'iit to rt'vcal oririiiiisin.s of ilistiiictive form or possessing markwl 
])owc'rs of locomotion. No preparation will be necessary bvyotii 
niountiiijr u thin lnyer of blood nr titlitT fliiifl. 

Stiiiiiiii;/ is In- far tla- nio.^^t iiiiportiuit mctliod, ami it is to Wi-ijtrrt 
that we owe tltc introfliiction of the most Hiiitable rejigenl-*— 4lii' 
aiiiliiH" dye.''. Logwuoil stiu'iix iiiiiny fiui<ri well. Imt it has no prcfrr- 
eiHX' for them over imiDiiii tissues, uinl tloes not therefore make tiio^ 
siifliciently prominent. The aniline dye? most often used are fl^H 
sine, methyl violet, methylene hliie. iind, for photo;»raph» espeoi-illf. 
Bisraarek brown : watery solutions are employed, from J to 5 f<r 
cent. ( ' anil slides should be eleaned in dilute niinc 
aeid and kept in aleohol ; before use they should be heated in a »pirit 
flame whilst held in forceps. The followiiii; is the niefho<l of |iw- 
cedure: Take two enver-glasses whiuh ha\e just cooled : place i» '""i" 
drop of the fluid on one, put the other glass on the top of it. wjuiti* 
the glasses getitlv together, ami then glide one off the other. «'** 
to leave a reri/ thin layer of the fluid on i^aeh. Ne.xt set alio* 
both cover-glasses to dry in "air." and then pass them three tinw* 
through a spirit flame. A ti-mperature of li!()° C. should be re.ti 'hiHi 
for a few seconds to precipitate and fix any albuminous matenilw 
the glass. If a weak staining solution is used, the cover-gl«-«** 
must he flouted on it, prepared side downward, for some minntf*"*' 
hours. A strong solution ('2 to 5 per cent.) is sometiini's as px)**- 
and stains deeply in less than a minute. Pour a little on to ih* 
dried cover-glass, leave it for a few seconds, wash with distille<l w»'^ 
frr)ni a wash-bottle, and dry over a flame. Next warm a slide, »***! 
just melt III! it a little solid Canatla balsam: drop the slight'* 
warmed cover-glass mi to this and press it down very carefully, ] 

Certain organisms arc distinguished by retaining basic niiili*^ 
dyes, such as I'uehsine, gentian violet, and methyl violet. rrvM »U 
they are acted on by a solution of nitric acid (1 : 3), which ilecol 
izes everything else, including other kinds of bacteria. After t 
acid has been washed oft' the clec«doi 
some contrast color — c. //. fuehsine ( 
fungi known to stain in this way are 

leprosy. H. tuhereulosis is now constantly sought for in pu^ 
sputum, and in urine, either for pur|K)ses of diagnosis or to I 
the result of treatment. 

■r kinds of bacteria. After t ^ 
irized parts may be stained *• ] 
or methylene blue. The ehi4 
ire the bacilli of tubercle «iiil ] 



For the examination of fluids for B. tuberculosis, Gibbess double 
stain is the quickest. It consists of two parts of fucbsine to one 
part of methylene blue dissolved in an alcoholic solution of aniline 

A method of very general use in the search for bacteria, both in 
cover-glass specimens and in sections, has been introduced by Gram 
of Copenhagen. Prepared cover-glasses are soaked for some min- 
utes, and sections for some hours, in Ehrlich's solution of gentian 
violet,' until they are deeply stained. They are then placed on or 
in a solution of iodine* until they turn brown (i. e. two or three 
minutes). The specimens are next washed in alcohol, dried, and 
finally mounted in Canada balsam. Some organisms remain deeply 
stained, but some — such as the gonococcus and Friedlander's pneu- 
mococcus — are decolorized. Eosine or Bismarck brown may be 
ased as a contrast stain. This method of staining often helps to 
distinguish allied forms of bacteria. 

n. Presence of Mioro-orsranisms in Tissues. — Thin slices of 
the tissues to be examined should be placed as soon as possible after 
death in strong methylated spirit or in absolute alcohol. When 
thoroughly hardened, sections may be cut : these must be very thin. 
If a freezing-machine is used, a thinnish slice of the tissue must be 
soaked in plenty of water for two or three hours to remove all trace 
of alcohol, and then put into mucilage for a similar time. The sec- 
tions are washed, and then placed for twelve hours or longer in a 1 
per cent, watery solution of the dye selected, which must always be 
filtered before use: warmth facilitates staining. Some workers 
transfer the stained section to a 1 per cent, solution of glacial acetic 
•O'd, then to absolute alcohol, and finally to whatever clarifying 
'gent is employed (cedar oil, xylol, coal-tar naphtha) : others omit 
"■0 acetic acid. Each of these fluids dissolves the dye out of the 
tissiie and the difficulty is to carry the sections through them rapidly 
enough. It is best, therefore, at first to take only one section at a 
'■iDe out of the staining fluid. One or two trials will show how 
""S the section must be left in each fluid in order that it may still 
'*'*iii a rather pale color when it is spread out on the slide. Excess 
^' tte clarifying reagent is removed with a piece of clean filter- 
P*F>«T pressed firmly on it. A drop of Canada balsam dissolved in 
^^ol is put on the cover-glass, and this is applied : chloroform and 

Stunted alcoholic (olution of gentian violet, 5 c. c. ; aniline- water, 100 c. o. 
Iodine, 1 grm. ; potassium iodide, 2 grm. ; water, 300 c. c 



benzol li.'ilsiiin slowly dissolve out the stain, and pure bulsani ii 
nitbur (litliuult to work with. 

If a blue or violet 8tain has been used, the sections, after wMbiniJ 
in nlcohivl, niav be dipped in water for ii moment, and then pl»c<J 
in eosine or carmine solution for an hour; the tissue-eirati 
acijuire a red tint, whilst tliu orjjanisins remain blue or viol 
The sections must now be placed in alcohol. The gabsctint-nt 
stages are the same as before. 

To examine lisHiies for B. tuberculosis or B. leprte. Ziehl's sttio- 
inj5 fluid ' J8 the best. A satnrated alcoholic solution of tnethylfiif 
blue will also be rei|uired, as well as a mixture of nitric aeid (B. I'-) 
with two or three ]iarts of water. I'lace the sections in the fuchsi 
solution, and leave them in a warm place for at least two hoi 
then transfer them to the nitric-acid solution, iind leave them nntl 
the color is almost gone; then them in water, and put them 
into methylene blue for an hour. Now i)ass them through aWulf 
alcohol and whatever clearing reagent is used, and then mount « 
before. B. tuberculosis and B. Icprre will appear iw rod ro<lii »n 
a blue ground ; all other organisms present will be blue. 

With large and delicate sections it is a good plan to use the 
slide as a section -lifter, ))ushing it obIii|uely into the xylol <irc« 
the alcohol, and there spreading the section out upon it. 
vessels ami plenty of the fluid must be used for this purpos<k< 

With large organisms or with sucrcssfiil contrast-stainiii| 
power of 500 diameters and ordinary illumination will be suffici 
for most purposes; but for the smaller fungi an oil-immersion 
and a sub-stage condenser of very wide angular aperture 

Cultivation of Micro-orgranisms. — Having determined the pr<* 
ence of organisms in :i lliiid or tissue, it may be necessary toci 
vate them, in order cither to study their life-conilitions or to n 
rate tlu-m IVmu all otiicr species mid other matter. Cuitimtii 
may be uiade in fluids or in scdids, 

In Fluids. — Klebs iutnuluccd a method which consisted inadililf 
to a sterile Huid a small ([Uantity of the substance containing <'"* 
fungus. Under suitable conditions the latter will grow. A 
quantity of the culture-fluid may then be added to another Hi 
and so on until all vestiges of anything introduced into tie 

DiHsnlTe one )j:rainnic of fiiclmiiie in 10 c. c. of alcohol, and add 100 (■(• 
■mtiKTj «olution of carbolic acid \ 1 : *20). 





h the original organisms must have practically disappeared, 
than one kind of fungus is inoculated, or if in the inocula- 
successive flasks contamination from the air or apparatus 
it ma}' be impossible to obtain a pure cultivation of one 

lids. — Koch therefore introduced solid, transparent culture- 
. Clear meat-broths and other fluids are peptonized, and 
lened by the addition of sufficient gelatin (5 to 10 per cent.) 
;r them solid at 65° to 80° F., at which temperature most 
ill grow fairly. Agar-agar, obtained from dried seavreed, 
ased (1 to 2 per cent.) to stiffen fluids required to remain 
temperatures above that of the melting-point of gelatin, in 
at the life-conditions of organisms at any temperature pos- 
the body may be determined. Solidified blood-serum and 
edia are also employed. In all cases the culture-ground 

sterilized by heating to 60° C. (140° F.) for short periods 
ecutive days. Transparent culture-grounds are generally 
d in one of two ways. 

be-cultures. — Fill the lower third of a test-tube with the 
culture-ground ; insert a plug of cotton-wool into the orifice 
tube ; sterilize according p^ , ,„ 

lethod just described, and 
t the tube aside to cool, 
a a vertical or an oblique 

according to whether 
or surface is required, 
id the following details 
wn in Fig. 118. To 
cultivation on the ground 
jpared, invert one of the 
>move its plug, then with 
ized platinum wire take 
the suspected liquid and 

it to the culture-ground, 
ing this with the wire as 
in the figure. Re-insert 
;, and put the tube — the 
ly up — in an incubating cliamber under such conditions of 
ture as may be desired, 
ies of organisms will gradually appear (1) on the surface 

Culture -tubt's: n, tube prepared for 
" stick " • culture ; 6, tube preiiarcd for 
"streak "-or " rub "-culture ; f, method of 
making " stick "-culture. 



only if oxygen is essential (aerobic); (2) in the lower part of thrtnd 

Fio. 119. 





'" — ' 6 c fl r 

DiaKrammattc ruprcucntatinn of vartnun fornw of iitlrk-<'nltare : a, an aftoMr ot«Mil«- 
RrowH lliureforc only on stirfaco: It, an HnaiTiilito orKaiiUm— Krowa tht-rffon> oiil; brMtt 
the KurfHce; r, an omnlam IndifTerent to the preaencfl of air— tcmwa thcnfure (• ■■' 
lnMU-ath Hurfacc : ><, an ai'mlilc ormntnni whirh Ilc|urfiv« Ki'laOn : r, an af-rnbic. bal <t^'^ 
anacroblir orKanlxm, « liloh also lli|uvflc8 Kclatin, but In a diflcrvnt manuvr to d. 

only if oxygen is fatal (anaerobic); or (3) on the surface an>l along tbr 
track if the j)re8ence of oxygen is a matter of comparative indilTrt- 

ence. In some cases the form <>f 
■■""' '-"• the growth is chara<'teri>tif {T\p \ 

120); in others the metlii )« 
li(|ncfied in some peculiar ax> 
therefore diagnostic manner (Fig- 

II. Plate • culturee.—Inori' 
late a tube as before, warm tl* 
medium until it is jnst fla>^ 
jiently agitate the contcDt*. •»■ 
ociilate a second tube from tl" 
first, and then a third fmm tl" 
second. Pour the contentii •« 
each on to separate glass plat^ 
and keep these in glass-cove*^ 
chambers under the <lesirtil c«^' 
ditions. Isolated colonies will gradually develop in different p*' 
|><irti<nis on each plate, and, if very numerous, may run togctb*^ 
DiflVreiit orfianisnis will produce colonies differing in api)ear»B*^ 
Tiil)es can he siihsoijuently inoculated from whichever of th*^ 
colonies a cultivation is desired. Thu.s, for each organism ne c^ 


a ft 

TuU-iiilturri-. "huwlnc |p<'<ullnritloi. nf 
Kriiwtli ulonK thv limii of punctiiri-. (.\fti'r 



[•sccrtain tbe influence of different temperatures, media, and gases, 
well ns separate one organism fi-om any others that may have 

simultaneously introduced. 
To examine air. a glass plate covered with gelatin-peptone may 
[be exposed for a given time, and then kept undor a uioist bell-jar: 
[colonies will grow wherever germ.s have fallen, and any of theui cau 
[be »ubse(|uently cultivated in tubes. Again, a jiortion of earth or 
' ti.<<siie may be broken up in sterilized water, and a little of this may 
be slutken with sterilized gelatiu-[)eptone ; the latter is then poured 
on a plate and allowed to set. Host fref|uent]y sni'li ruUivations 
»re carried on in test-tubes inoculated with a platinum wire heated 
to reiliu'ss just before it is dip))od in the substunee to lie exiimiiii'il. 
A puncture with it is then made into the gelatin. A very liandy 
methwl of cultivation is the inoculation of slices of recently-boiled 
]i*itiitn, made with a pure knife and kept under a bell-jar in moist air. 
Ill all experiments the Hp])aratiis must be carefully sterilized, and 
wch procedure carried on in as still and pure an atmosphere as pos- 

pointed out that all organisms are by no means of the same shape. 
Are tLere sufficient grounds for assuming that because organisms 
differ in shape they also difl'er in species, and that each shape means 
tdifferent species ? or do tbe nuiny different shapes merely represent 
different stages in the life-history of a companitively few species? 
Ni) classification is possible until this matter is set at rest. The 
Uuwer is. that /orm alone is not sufficient to establish or to disprove 
iilontity of species. To obtain satisfactory evidence on this point it 
U kbsolutely necessary to Match a given organism pass through its 
vh)l« dn'elopinenial cycle irwn beginning to end: to note carefully 
Reform, size, structure, staining affinities, ami method of reproduc- 
lioii of the individual ceils in each stage ; and to observ f their group- 
'fg and effects — macroscojiic and microscoj)ic — both in the tissues 
Mill on various culture-grounds. It is necessary also to discover and 
^panjte their chemical proiiucts, and to ascertain the effects of inncii- 
'»li'in. All these observations must be carried out nut only under 
•^nditions us natural as can be devised, but also under such as are 
'"'St calculated to induce variations. In this way. and in this way 
"loiip, can the specific individmility of any organisms be made out 
*iiil a useful classification of the different sjiecies be devised. 




WluTCvtT this laborious investigation Ims bf^fn carried oot 
reason hu* been found to ilonbt the exislenrc of ili^itinct »]« ' 
bucteriii. And. just a» anioii^ hij;her fornis 9|>e<;ie» nnd evi-ii 
Lavo been confounded with one another until the difTcrcntuitmi; 
point* were discovered, so iloiibtless \^ it with bncteria. sml ti» 
number of recognixcd speeies uiuy therefore be cx{>ected to incrpwr 
continuously. Two coceus-fornis may apfiear to be exactly the wbt 
until inoculated upon some particular anininl. when marked diff(T- 
ences between them will become apparent. Cohu points nut si 
analogy to this in the close naked-eye and microscopic resemblinrr 
between the sweet and bitter almond, the chemical constituent* aixi 
conseipient physiological actions of which are so very difTeront: wl 
Virchow allu<les to the impossibility of distinguishing l»etw«?en tb» 
cells of the early embryo, thongh their potentialiti4'» are wi ranai. 
In ftome of the cases in which bacteria resemble one another ii 
microscopic appearances, in staining affinities, an<l in culture-effrciv 
differing only in pathogenic results, it is i|uite possible that tlir ii>* 
nocuous organism is not a distinct species, but only an atteaiufJ 
variety (p. 84G). 

Difficulty naturally arose in early times from imperfertion ia ti» 
culture-methods, from inappreciation of the absolute uccewitY (^ 
seeing the development of any given form throughout it« ■b"l« 
cycle, and lastly from the polymorphism of certain forms »Lichb»» 
before been alluded to. The introduction by Koch of solid cultiirr 
grounds enabled observers to fix the organisms under examinatio>i 
and added enormously to the ease an<l certainty with which p*" 
cultures were obtaine*! ; and when it was found tliat the vtmio* 
developmental stages of polymorphous bacteria were constant h"*" 
in appearance and in order of sticeession, it became clear that tb*'' 
wore no more disipialified by their polymorphiMn from •pwi* 
classification than was the frog on account of its tad|Mde ktage- 

In sup]M>rt of the view advanced by IJillroth and Niigeli, that ^ 
organisms are variation.s of one or, at most, of a very few «li«lii^ 
species, the following are the chief arguments: 

1. That in auccessh'v culfhuitionii, et/teritilly in dijfrreut mm<Jm, 
fonnn developed vary i/ri-atli/ from the orlijiiuil : that ihrte itMMM 
tucceution the thapea e/iaracten'itir of Cohn't orden ; ' and thtit, 
the tiiiiiir time, their phi/»i"lot/irit! artiriti/ ehtingea e^fHaJlg. Tbi» 
of course, a direct contradiction of Koch's experience mnd may 
'1. Coed; 2. Microbacteria; S. Denaobacteria; 4. SpirotecMria. 



uae; but it must be renK^mberod that these results were obtained 
Willi fluiil ciilturf-niedia ; that thi- difficulty of obtaiuiiij,' pure ciilti- 
mions Id fluid media is gi't;iit ; and that the iiiethoil i')i)plo_ved(MUC- 
ccMive cultivation) ia one in which the accidental iiitroduotiun of 
either organisms renders error easy. In fact, it is far easier to fail 
than to succeed ; so the suspicion arises that the cultivations were 
never pure or that they became contaminated by other organisms. 

2. That di(f'rri'nt f'irrmg of hnetitia art- found taking ptirt in the 
tamt ihe<imi>oni(ioii (»•. 7. putrefaction). This shows simply that 
!H;ver»l difTerent organisms are capable of living in the same fluid. 
The process is a complex one, and the products arc the result of the 
lifc-aetions of different forms : it does not show that different forms 
<li;velop from one species. 

S. That the. name form may he fnund associated with the very 
Jifffrrnt rhi'niifdl fhtintjcK. Thus microencci in<Ustinguishal>le from 
each other by form or size occur in relation with pneumonia, ery- 
iipelas. small-jM)x, pyamia, infective osteomyelitis, and many other 
<li»ea8es. This argument can oidy be met by tracing the life-histnry 
»a(l e.vamining the products of each organism as described on p. 

4. That the virtilence of orffanismg can he modified in either direc- 
^. Davaine produced an artificial septicsemia hy injecting putrid 
fluids, contaitiitig many forms of bacteria, into rabbits, and found 
•hat the virulence of the poi.son increa.<e(l as the disease was trans- 
tuitttrd from animal to animnl, but that no increase of virulence 
wiirred after the second or third generation : and Koch sliowed 
'h»t this increase was due to the preponderating growth of one of 
the organisms inoculated and the simultiineous disap|)earance of all 
oihrr forms, so that the a])parent in(rrease of virulence was really 
«ae to the injection of a larger ((uantity of the specific organisms, 
"itiiilar increase in physiological activity produced by cultivation 
oaa been alleged to occur in other organisms, and have been simi- 
'■'"ly explained. 

Moreover, it has already been shown that the virulence of some 
*l5"'''*n>8 '■'"' '"-^ modified by cultivation and inoculation. 

The whole argument, however, is beside the mark : for variation 

I '*> intcuAity of virulence, in whichever direction, accompanied by 

^ morphological or other change, is no evidence against the indi- 

^'lunliti/ of organisms. A.* Baumgarten ))uts it, mitigation of 

Virulence is no better ground for depriving a bacterium of its 



specific character than would the extrttcliori of the t«th of i 
[H>i8<>tiou8 snaicc be a reosou for rcgariiibg it n!< a noD-puijOttMW 

5. That une onfanitm can be erpcrinu-ntalh/ cimvrried itUv imMkir. 
Buclirier !»t:ite«l that by ctiliivittin^ the iioii-iiatli<ij;oiii(' h«v ' 
in uioHt-iufusioD8 and in utiiiterilizeil hluod he nitnlv it " wi! : 
converted it into B. anthracis, and that by » convorse pp" > ■ 
converted B. itnthraciH into B. Hubtilis. The oxperinicnt* h«<f 
been repeated by Koch and others with a negative result. Ihert 
ure distinct morphological diflerencen between the two bacilli »! 
which Buchuer does not seem to have been aware, and ioabilit; to 
distinguish between the two clearly invalidates the rmult uf tb« 

This is the experimental evidence as to the mutability of btiO- 
teria. At present the liahince is most decidedly agauiiit it, M 
Koch himself recognizes that his experiments do not |>rovf i« 
impotigiliilitff. Like all other organisniB. these unicellular Wwf* 
must have more or less power of adapting themselves to «ltiT«"l 
surroundings, and be liable to modification by their envir^muicnl* 
They may grow more or less rapidly, may be larger or smaller, ami 
may separate early or remain united in strings, tbread.<i. or hft^ 
On poor substrata the developmental cycle of a jKilyinorphon* forw 
may be incomplete, or the cell.-* of a monomorphous form mar I* 
stunted and irregular, or abnormal ("involution" Niigeli) fotv* 
may appear: an<l tliey may be rendered more or less viruleal. B"* 
Koch's observations of various bacteria, often extending fiver ye***- 
suffice to show that all he dealt with preserved unaltere«l, throvgk * 
long series of cultivations, their inherileil charucterii«tic«. Wli*** 
ever the life-history of a species (muiiuimirphous or jMilyniorpfco^' 
has been made out, no important departure from its various »ia^^. 
has ever been recorded : the coccus of erysipelas has never heat 
to grow into a bacillus or a spirillum. 

Looked at from the clinical point of view, every one feels 
the best-marked group of infective diseases — the specific h' 
must have an unvarying, speciBc cause. Most observer* beli^'^ 
that tbcMe diseases never arise except by infection from a previ^j 
case. Assuming the virus to be a fungus, tbey admit that it bc^I 
at souie time have accjuired the physiological action which enab^^ 
it to produce a certain disease; but they hold that there i* no '"^^ 
dcnce that harmless fungi do at the present time ever aci{uire sv^^ 


poirere. Isolated communities remain free from such diseases for 
centuries until a case is introduced among tlieiu ; then it spreads 
»ith the utmost rapidity. In li>2(> a negro covered with stnall-pox 
|iuatule8 was landed on the Mexican coast, where the disease was 
D<il then known: three and a half millions are said to have died of 
it. In 184»» measles was introduced from Copenhagen into the 
Faroe Islands, and almost every one suffered. Similar facts con- 
cerning other acute specifics are given by Sir T. Watson in the 
first volume of the Xineteenth Cfluturi/. Murchison and others 
believed that typhus and typhoid might originate </»' novo, being 
filth-begotten ; but the conditions of life in slave-ships and Arctic 
winter-houses arc as insiinitary as ever they were in our jails when 
tyjihiis was endemic in them, yet no typhus occurs. As to the 
origin of typhoid fever from sewer-gjis, many towns and hotels show 
th»t I'xliiilations of it may be intense and prolonged without ever 
gvneniting typhoid fever. 

The poison of the most infectious diseases sj)read8 so easily by 
»ir. fund, and clothing that it is exceedingly difficult to find a case 
io which the possibility of infection from a previous case cannot be 
shown. The less infectious kinds have, therefore, been turned to 
br the advocates of the dc novo origin. Many cases of diphtheria 
believed to have arisen spontaneously have heen recorded, ami an 
urethral di.scharge like gouon-liu'a in symptoius ami roniiininicability 
luay, it is said, be contracted from a woman suffering from any foul 
discharge not gouorrhital. It is of course ijuite possible that ure- 
thral discharges may be excited by infective irritants other tlmn the 
irrhueal poison. With regard to the so-called " liosjiital clis- 
•wes" — pysemia, sejjticaMuia, and hospital gangrene — there is per- 
hapa evidence of some change from non-pathogenic to pathogenic 
organisms. How otherwise is it to be explained that when a new 
building, which has never before contained wounded, is used in time 
of war as a hospital, these diseases bresik out as soon as the crowding 
"f the wounded reaches a certain point, whilst they do not attack 
P»tieut8 in tents close by ? Is it likely that the specific causes 
•ere present in the building? Do not the facts tem|it to the belief 
that ordinary bacteria acijuire patliogenic ])ro]»erties. or at any rate 
•oeh a degree of virulence as enables them to become pathogenic, 
"J cultivation under the cuiiditions brought about by overcrowding 
of the wounded ? The state of atmosphere produced in tiie building 
•ould seem to be analogous to the " epidemic iniluence " — that 



influence wliicli cunscs infective diseases everv now and «gsinw 
became widclv epidemic. From the clinical standpoint, therefore, 
it would seem that but little evidence is forthcoming in favor of tLf 
uiutubility of bacteria, but the ([uestion must be regarded as »till 
suit juiiice. 

It will be seen that by origin de novo is meant, uot the sponlwiMiii 
development nf uii organism, but the acquisition in an organinmof 
siicli ]iiitliogeiiir iuid ntlier properties as may fairly entitle it to be 
regarded as a diHliiK-t >(jiecio.s. 

DISEASES. — The acute s]ieeifie diseases, to which allusion lias •" 
often been made, are now regarded as forming only a class in ibe 
much larger group of Infective Diseases. An infective ilis*** 
iiuiy be defined as a iliie to the action of a poison or vini» 
wiiieh has the power of invading and multiplying in or on liviiijt 
tissues. Infective diseases may be locfd or erenersl, just m tin* 
effect.s of organi.sms may be local or general (p. 841). 

There i.s at present no satisfactory da.ssification of infectivt dis- 
eases. They are generally grouped according to the acutonesj"' 
their course, the n.'iture and distribution of their lesions, and ?ucb 
prdiiriuoit cliiiiciii <'liaracter.s a.s they may possess. The seat of ll>'^ 
micro-organisms has been suggested as a basis for clsssificatiou- 
Three groups might in this way be made — (T) those due to organisu'^ 
which do not penetrate beneath the surfaces, but discharge tlie'*' 
products into" the blood; (2) organisms which thrive in the tissn«T* 
anil produce local effects: (3) organisms which enter the circulttio** 
and thrive iu the blood. (See " Pyicmia anil Septicemia.") In tl>* 
majority of cases, however, it is still impossible to say into whicri* 
of these groups a given instance should be placed. 

Tlicre is, on the strength of the analogy which exists between ff «*' 
mentation and infective diseases (p. ;]1T), a prinid fiicie case in fav*^** 
of the germ-theory jis applie<l to the infective diseases. And it «i ■' 
be found. u{)on exauiiuatiou of the evidence yielded by actual ubst^*'' 
vation of these diseases and by exjieririieiits upon aniiuals, lliut tt»^ 
deiuonstration of the casual relationship of organisms to tlicm i» ••• 
some cases as cotiiplete as it is iu the case of fermentation, altlmn^'" 
in the great majority the proof is still more or less doubtful. 

To prove that a micro-organwm i» thv catise of a diteate it is m 
sary — 



1. That the organism in question, as recognized by its form, mode 
of v'mwtli, or products, be found constantly associated with the 
ilisciisi', at least in its earlier stages, and in sufficient numbers to 
KcDnnt for the symptoms. 

2. That "pure" cultivations of this orjianisrii tlirough several 
lenerutions he made, until it may reasonably be su))[)osed that every- 
iin^ which could possibly have been taken from the animul that 
ieliicd the virus has disappeared. 

3. That other susceptible animals be innculated with the culti- 
llcd organism, and that the di.^ease be thus reproiluccd. 

4. That the same organism be fitimd in the tissues of the success- 
lly inoculated aninuils, in such nuiul)crs and with such a distri- 
Ition as to account for the disease. 

The demonstration of a well-fharacterized organism in ronstant 
Sociation with a disease is now by many taken as almost eijuivalent 
proof that it is the cause of the morbid process. For it is. in 
tat cases, impossible to experiment on man, and frei|uently no 
Jmal can be found which siifTors from the ilisease under investi- 
tion. Consequently, the proof cannot be carried beyond the first 
Ige. This, however, is no proof at ail to those who believe that 
ider certain circumstances a certain form of organism will develop 
Dntaneously, nor is it satisfactory to others who think that, when 
uidus favorable to a certain organism exists, that organism is sure 
drop into it. Sidney Martin has suggested that an attempt should 
made to discover and separate the cbeiiiical prmlucts (»f the organ- 
D. both in the tissues of the animal or person dead of the ilisease 
d in the subsequent culture-ground. If suitable media are selected, 
ese protlucts shoulil clearly be identical. 

The amount of patience and skill necessary to carry on an in- 
■tigation of the above kind can be appreciated only by those who 
|ve worked at the subject. T/iej/ are not surprisetl that so few 
leases have been thoroughly investigated. In the case of man tho 
fficulty of obtaining material in the early stages of diseases au<l 
toediately after death must also be taken into account. Until 
'te recently, too, the methods employed were wholly iuadoijmite 
'he discovery of many kinds <if fungi. At first tliere was uiiaidi-d 
Ctoscopic examination otdy, and with inferior objectives. The 
Section of all fungi under these circumstances was very difficult, 
d often impossible. A considerable step was made when von 
tcklinghaitsen iri 1871 pointed out that the uniform sixe of micro- 



cocci and their resisting power n^ainst dilute acids and alkt 
glycerin iiiiglit be employed as a meuns of diagnosis between' 
and fatty atid albiimiiioid ]»artit'les. But progress lias been macli 
more rapid since the introduction by Abbe of a powerful 8ub-'Ugc 
condenser, by Weigert of the aniline dyes as stains for orgauiso)', 
and by Koch of many improvements in the mode of ex&miiiJiij 
specimens and of car'-ying on pure cultivations. 

eases tend to recur again and again in the same individual. Of 
these bronchitis ainl facial erysipelas are prominent examplw. 
Other diseases show a preci.scly opposite tendency. To have dif- 
fered once from one of them is to have secured almost certain frw- 
dom from a second invasion. Freedom thus ensured is knowni 
(ict^uiri-il hnntuvlt}/. Persons, for example, who have had small-] 
arc said to be iinmiine against a second attack. The same is pn 
tically tnic of typhoid fever, measles, and other speciBc diseases, 
is by no moiitis ccrtjitn how long such iiiimnnity lasts, and in 
there arc no tiifatis of definitely usccrlaitiing its duration. Ag 
certain diseases which arc coinmon in some species of auiniabi 
]iractio;illy unknown in others very closely allied to them. Thus. 
tubercle is common in pigs and cows, but excessively rare in slici'p. 
goats, horses, nn<l asses. Mice fall a ready prey to anthrax, while 
rats escape unharined. Acconlingly, |)igs and cows are said tn Iw 
gugrrpfililt' to tubercle, while sheep, goats, horses, and asses arci" 
like manner said to be liiimiiiir against it. The exact condition* 'in 
which this susceptibility or immunity depend are unknown. Toiiis- 
tinguisli it fnnu the stcipiired form it is known as tKifiinil or inhfriteJ 
iiiuintiiiti/. When iiti animal is only slightly susceptible, an<'tiw' 
absolutely immune, it is often termed refractory. 

In Ininntu patliolngy there are also many examples of th'"'*' 
peculiarities. Negroes are immune against yellow fever; w'''"" 
races are susceptible. A nurse in a fever hospital may never b*"* 
had scarlet fever, and yet may continue to resist all exiiosurp to tli* 
infection. It may be that inheritdl immunity is due to flu' Iw"'' 
ing down to offspring of that aci|uircd by ancestors. Thus, r»«* 
among which certain acute fevers (like measles) are common c""'''' 
much less severely than those among whom the disease appears ni'l' 
at very long intervals. Tlio ronipletc immunity of the nt'pni t" 
yellow fever is generally accounted for by supposing that thow*'"' 



W could resist the disease best would, by living longest luid Laving 

■ mint children, be most likely to hand on their peculiarities to the 
I succeeding generation ; and, furtiier, that the degree of iminiinity 
I thuii gained would be strengthened by the intermarriage of those 

■ alreaiiy partly immune. But this ex[ilanatioii ofterj* no ad('(|i!ate 
H reason for the peculiar sporadic immunity enjoyed by some iudi- 
I viJuals, as in the case of a fever-nurse just cited. Occasionally this 
I sort of immunity is more apparent than real. Two medical students 
I pail! almost daily visits to scarlet-fever wards for several months, 

■ Mil failed to contract the disease, but late one afternoon, on entcr- 

■ ing ihti wards much exhausted by severe e.xercise and a fast of five 
^ hours, h()tli took the disease in a severe form, and one ilied. 

M Artiflcially-acquired Immunity. — Three forms of preventive 
H inoculation have been employed to secure immunity from disease or 
H t)i arrest the development of contagia that have already reached the 
I ti.itiues : 

■ 1. Inoculation with the attenuated virus of the original disease. 

■ -. Inoculation with the chemical products of the organisms of the 

■ '•figinnl disease. 

I -i. Inoculation with serum obtained from an animal that has been 
I '•'I'ated by one of the two preceding methods. 

I I. If has been well known siiice the sixth century that the arti- 
I ^fial inoeulation of small-pox ])roduce8, on the one hand, a mild 
I y*ttB of the disease, and, on the other, confers upon its subject 
"Dftiunity against a second attack. In one ci>nutry after another 
" has for a time been the custom to practise inoculation to ensure 
I **>i« resnlt. It has also long been recognized that epidemics vary in 

■ ■eTCTity. and that mild attacks and severe attacks are eijually effica- 
t *^ioii» in securing immunity. 

I Pasteur was the first to place preventive inoculation on a scientific 
*HmU . He demonstrated that the virulence of some contagia can be 
l**Hed by experimental procedures. In the case of chicken cholera 
P** showed that by exposing ciiltiires of the virus for long jjeriods 
P*** virulence became so reduceil that inoculation of the weakened or 
¥**f*rftuatril organisms gave rise to a coinjuirutively mild disorder, 
[^'*ich, however, sufficed to secure innnunity against subseijtient 
l^ltacks, Other observers have since shown that the virulence of 
|'*^>»liy other organisms can also be modified, and that the organisms 
I *^*H be kept in their attenuate<l condition through .several cultiva- 
*'<Jii», though there seems to be a general tendency for them to 


return to their previous degree of virulence. The atteniutioD ii 
generally eflfected by one of two methods : 

(1) A series of animals is experimentally selected, genenllr od 
account of their slight susceptibility to the disease in question. Sk* 
cessire inoculations are then made from one to another, until it ii 
found that the desired degree of attenuation has been reacheil. {i) 
Cultures of ordinary virulence are exposed to the air. or to u in- 
creased temperature only slightly below the fatal limit, or to tlw 
action of small doses of various antiseptics. Pasteur's treaimeu 
of persons bitten by rabid animals is the best-known illustration «( 
this method, though no hydrophobia-organism has yet been di«cov- 
ered. By a series of successive inoculations a special virus is pre- 
pared which is known to have, when injected into rabbits, a coD^tut 
incubation-period of six days. Rabbits are inoculate<i with tbit 
virus, and their spinal cords are subsequently drie<l very giwl- 
ually in tlie presence of caustic potash. The longer the drying ii 
continued, the weaker the virus becomes. If an emulsion of a cord 
that has been dried for six days be made an<l inoculated uponnb- 
bits, it entirely fails to produce the disease. Pasteur's method i» 
to give ten injections, extending over four days, according to the 
following table: 

FirHt injection, first (lay, KmuUion of cord dried ten davs. 
ScH-ond " "' " " " nine •*' 

Thirtl " " " " " eight" 

" « « aeven" 

" « « five " 

" " four " 

a u „„ .. 

Tenth " fourth " " " " one d«T. 

After three <lays a few more injections are given daily, and tbe 
process is complete. Statistics are strongly in favor of the effit*'.^ 
of the method. There is generally plenty of time to carry it ">iA 
as the iiictibation-period in man is never less than twelve day**"" 
is usually about six weeks. 

This nietlio<l of securing immunity is not applicable to the »»" 
majority of specific On the one hand, certain orgaoi*"''" 


" second " 


(( (( 11 


i( (1 (• 


•' thin! " 


tt 11 *l 


I. tt ii 


inch as the tubercle bacillus, have hitherto defied all efforts made 
to attenuate them, and, on the other, there is some risk, even after 
attenastion, that the disease may be produced in a virulent form. 

2. To avoid this latter danger the chemical products have been 
freed from the living organisms and injected alone. The organisms 
CM be removed by filtering fluid cultures through porcelain, or 
they may be killed by the action of heat or of some volatile anti- 
septic, such as oil of mustard, which can be subsequently removed. 
Sometimes the full degree of immunity attainable is reached after 
two or three injections, but in other diseases and other animals the 
injections have to be repeated every two or three days for several 
weeks or even months. Immunity thus conferred is not always 
very certain nor of long duration, and the method is not attended 
with favorable results in those cases in which exposure to infection 
precedes its application. 

Haffkine's vaccination against cholera illustrates both this and 
the precetling method. He employs two vaccines. One is made 
from an attenuated virus, the other from an exalted virus. The 
attenuated virus is prepared by cultivating the cholera spirilla in 
aerated media at a temperature of 39° C. (102.2° F.). The exalted 
virus is prepared in the following manner : A pure culture of the 
organism is introduced into the peritoneal cavity of a guinea-pig. 
Death follows in twenty-four hours. The peritoneal fluid is im- 
mediately removed, and another guinea-pig similarly inoculated. 
This process is continued through a series of animals until the 
interval between inoculation and death falls to its lowest limit. 
Persons to be protected are vaccinated twice. On the first occasion 
the attenuated virus is used; on the second, three to five days 
afterward, the exalted virus. The vaccination is supposed to pro- 
'hce a sufficient tolerance to the cholera-poison to enable the body 
*«" react" more vigorously when attacked in the ordinary way. 
Sometimes the living cultures are used, but more often the vaccine 
" fterilized by the addition of carbolic acid. Prepared thus, the 
"lid can be more easily preserved and can be introduced with less 
"m. but, as in other cases, the results are neither so certain nor so 
prolonged. The sterilized products of bacteria, irrespective of 
Weir exact nature, are often termed toxines. 

3- These results led Behring in 1890 to examine the serum of 
'Dirnals thus immunized, and since that time many observers have 
ioOowed in his footsteps. In the case of tetanus the serum of 


immunized rabbitM vi&s used, and three rerj remarkable 
were established. It was found that — 

(1) Ke|)eated injections of this serum will render mice, which ut 
particularly susceptible to the disease, absolutely immune. 

(i2) The addition of the serum to living or t« steriliz<<<l niiturs 
of the bacillus will completely destroy the pathog<''nic jmiwit 4 

(3) The injection of the serum into animnls nlrrady unSmtit 
from tetanus will not iufreiiuently lead to nbs<jlutv reco\i-n. 

Furthermore it was found that while the ordinary scnimnfi 
naturally immune animal possessc<l none of these propertiet, litn 
could be developed by a series of similar inoculations. 

This method, when aj)plic<l to the treatment of disease *\n»it 
contracte<l, is known as »erum'therapeulir$, or treatment by «•*>• 
toxin. It has been employed in tetanus with not very satisfid^T 
results, but is more extensively used ' in diphtheria. The nrio* 
stages, comprising the whole process as given by Roax it ik 
Budapest Congress in 1894, will serve as an admirable illnstnMfc 
They are as follows : 

(1) A pure culture of the bacillus diphtherii« (Locffler) i» aiit- 
This takes about three weeks. 

(2) The organisms are removetl by filtration through porCfl»i« 

(3) The toxine thus obtained is injected into the liorw in n"*" 
quantities two or three times a week, until no reaction foUn"' 
This periiiil extends over from one to three months. 

(4) Some of the blood is then withdrawn, and the seram 
arated, sterilized, and stored for subsequent use. 

(o) When rec|uired for the treatment of diphtheria a 
about 20 c. c. is injected under the skin. A second do8« if 
sionally required. Improvement follows in the coarse of tantt* 
four hours. 

The active principle contained in the serum is unknown. ^ 
this Cfiuntry it is generally referred to as •• anti-toxin." 

Attempts have been made to ileal with tuberculous disease is V* 
same manner. The tubercle bacillus has, however, sucoeMWv 
resisted all attempts made to attenuate it, and to inje<'t the orgssil* 
in its ordinary degree of virulence is simply to inoculate tke iiio* 
from which immunity or relief is sought. The next 
by Koch, who prejjared a sterilized extract of itji pi 

' Novumbor, 1894. 





WM known as "tuberculin." This, wbeii injected, produces an 
iDflammBfory reaction at tlie sites of tuberculous infection. At the 
present time experiments are being made to discover an anti-toxin 
analogous to that just described in connection with diphtheria. 

It may hero be mentioned that ordinary healthy blood-serum is 
foiinJ experimentally to be in many cases a distinct germicide. If 
anthrax organisms be suspended in it, most of them will die. Evi- 
dence has been adduce<l to show that this germicidal action is due, 
It anv rate in part, to the action of nuclcin. It was found that 
digestion of the serum did not remove this influence, but that a 
temperature of 55° C. (131° F.) did. It was accordingly assumed 
that while the action was clearly not due t<> albutuin. it was still 
mont likely due to some form of protcid. The proteiiis were there- 
fore precipitated with alcohol and ether, and the precipitate digested 
with iiopsin and hydrochloric acid. The undigested residue was 
then washed and sterilized. The compound thus (drtained gave the 
n-actious of nuclein, and was fonnd to possess a germicidal |)ower 
over cholera spirilla, staphylococcus j)yogenes aureus, and a-sporo- 
genc anthrax. 

Theories of Immunity. — Much controversy has taken place 
during the last few years concerning the real nature of the immunity 
*liich has been discussed in the proceiling pages. 

It is well known that immunity against some chemical substances 
tan be obtained by certain persons. Opium-eating an<l arsenic- 
fating are illustrations of this. Furthermore, it has liitoly been 
»h«»n that if minute but gradually increasing doses of ricin, the 
•ctive principle of the castor-oil bean, he given by the mouth to 
guinea-pigs, they can be renilered so far immune against the action 
"fthe poison when injected subciitaneously. that they will survive 
•dose four hundred times that ordinarily sufficient to produce death. 
In other words, the tissues of the higher organism possess a certain 
power of ailapting themselves to a new environment if only a suffi- 
"ifnt time be allowed. But as soon as we attempt a detailed ex- 
planation of these results, as well as of those previously mentioned, 
•c find that they appear in many cases to be absolutely contra- 
dictory. The serum of some iuuiiune animals is fatal to cultures 
of the virus in question ; in other cases it is not. Again, while 
'«0 Serum may be fatal to cultures, the blood itself may have little 
"r no resisting power against the organisms when introduced into 
tlie body. Possibly the term " immunity " covers several dissimilar 


and complex processes. It is suflicient to mention that then art 
two views current. According to one, immunity is simply a t\m' 
tion of chemical reactions ; according to the other, it is due to vital 
forces which arc called forth by the action of the virus. Mrttk- 
nikoflf in his " phagocytosis " theory considers that it depends nuiiniT 
upon the specific action of certain of the leucocytes (p. 315). 

Pathoobnic Bactbhia. 
A more detailed reference must now be made to certain mirni- 
organisms which, on more or less satisfactory evidence, are belieT»J 
to be the exciting causes of certain infective diseases. For vaal 
of a better classification we shall follow Cohn's (p. 3{>4). 

or oval cells, generally .5 fi to 2 ft in diameter They are arranjwJ 

Fio. 121. 



I. mlrnKMMTl from «ii iwiilr iiliw'fw— Mrt'iitiK'iH-H trvv, hta|>li>'I<>nK-rt in* |i«i»<*l'' - 
Mrt'iiUx'iHil friim wcoiiilnry su|i|>iirHlli>ii In the cHhiw, tKiMirrlnn In iMH-riwrnl Mi* '"''*■ 
l<'j I : :t, nilir'M'iw'i'l In iv\\» ftnni K<>niirrli<i'al jmH : 4, Hnrt-ina' vi-nlricull : .'•. wM-mlW tarW" 
t<'rni<i: A. luiiilli anilirni'is fniin IiIihhI of iniiusf iHorKlcyi: 7, i-hainn fhim i'nltir*tl>« "< ^ 
Hnllirni'U. xomi' N'Mrini: siHin-H innt-r IMiclanx): K, ImHIII iirtyphotil frvcr, ftom • mrKUl'''' 
(.'Iniiil (i;HitK-i; 1".'-lUn of n-la|MinK fi'ViT. and iv<l tHirpuM-lc* (afWr Vaniljkr rut"- 

singly ; in |)airs (iliplororci) ; in chains (gfreptococci) of fonr «'*' 
to three hundred, which may be straight or wavy ; in grouf* 1'** 
bunches of grapes {ntdphifloi'orci); or in colonies and loogl"'*' 
Miiis.««'s. The organisms belonging to this order differ among tb**" 
.srlves in form, size, mo<le of grouping, and physiological action. 

The absence of <listinctive form makes it very difficult to v^' 
tiiiii ulu'tluT a culture is '• pure," and whether a coccus under ob«f* 
\atii>n is the caii.««e of a di.«»ease in <|uestion. Of all forms of fung"*- 
cocci are the frequently associated with disease. 


1. Farmentation of Urine. — The Micrococcus urece is one of 
causes of the ammoniacal fermentation of urine, which it enters 
n the air. Urine obtained pure and exposed only to pure air 
I keep acid for years. The transformation of urea into ammo- 
m carbonate is said to be usually due to the action of an " un- 
ned " ferment secreted by this micrococcus. The ferment, how- 
r, must be indiifusible, for the urine in an excised bladder does 
putrefy even if placed in putrid urine. The change often 
irs in urine contained in the living bladder, and may extend 
» the pelvis of the kidneys with the most fatal results. (See 

Fio. 122. Fio. 123. 

■pbylococcua pyogenes aureus (from a Streptococcus pyogenes (from pus found 
culture). in a pysemic abscess). 

appurative Nephritis.") The M. ureae is rather large (2 /<), and 
in singly or in chains. 

enbe has demonstrated the existence of four other distinct 
«ria producing the same effect on urea. These and the M. 
e are capably anaerobic, and may therefore be the causes of 
efaction of urine in the bladder. Miquel has discovered 
ilicate bacillus which has a similar action, and is anaerobic. 
Sappuration, or Pyosia, whether in the form of acute abscess, 
DOyelitis, or metastatic pyaemia, is usually associated with the 
ence of cocci. Many varieties of cocci are described as occa- 
illy present. By far the most common of these are the Staphy. 
■cut pyogenes aureus, the Staphylococcus pyogenes albus, and 
^reptococcus pyogenes. They all grow readily at the body- 
lerature. The Staphylococcus pyogenes aureus and the Staphy- 
cut pyogenes albus differ from one another in only one import- 



ant particular — namelv. that the former, when cultivated on p-litit.' 
agar-agar, or potato iu the presence of oxygen, produces » i4^ 
orange pigment, while the latter does not. (Sue Frontwpif««.| 
They resemble one another in forming clusters, in liquefying gtlatiit, 
and in being able to exist for weeks in the dry state. M 
when ititroduced into the tissues under favorable eircumsi^i 
both form a peptonizing ferment; albumoses and peptones cinilnn 
be obtained from pus. The Streptococcu* pi/oiffnes ronsixta «>f oxri 
rather larger than the preceding, and grows in chains. Ii liM 
not Ii<|uefy gelatin, and does not form pigment. When introdiwrJ 
into the tissues it peptonizes even more vigorously than the sUiJij- 
lococeus. The staphylococcus is principally found in circum.vrM 
abscesses, while the streptococcus is especially ««»<ici»trtl »i]4 
spreading and diffuse suppuration. H 

All these organisms exist in considerable numbers on inr mt 
especially where they can "obtain cover." 'i'hey reach w(>uDd«bj 
growing under the dressings, and not, ns a rule, by failing fma Al 
air. Minute i|uantitios of boric acid (1: 300. applied tu cultara) 
and other antiseptics suffice to flop th'ir tfrutcth. Obsorvew »rr W 
no means agreed as to the length of time which a 1 : 1000 tolnDsa 
of mercuric chloride takes to hill them, tin- times given varyin|{6«* 
eight seconds to thirty minutes. Possibly some of thi* diffntsrt 
ilcpends on the different virulences of the 8(>eciuieu» loueA, •» 
may be said to be consistent with the results obtained by 

In the case of these organisms the chain of prwif 
(p. 3.*)H) is complete. Ogston inoculated eggs with cocci fnxn ' 
acute abscess. By a series of cultivations he obtained the «<« 
" pure," and with these he successfully inoculated ftnim*!* 
Although abscesses were the usual results, well-marked septi**** 
occurred in some ca.<»es. Cocci were then found in tht Uw* 
though never in very large numbers. 

Further proof that these organisms can cause suppuration W 
been given. Similar operations were performed with •ntii'f*'' 
precautions on both eyes of each of a series of rabbitji, and 
in each animal was inoculated with [lyogenic cocci, chi* 
staphylococcus pyog«!nes aureus : all the aseptic eye* healMi 
out suppuration, while all those infected suppurated and 
destrovc<l, except some in which the operation was ijuite supeffr'* 
(Knapp), Upon man numerous experiments bave bMii v**' 




cultivations of staphylococci have been inoculated upon the cutis 
ind have leil to the foriiifition of small iiliscesses. Similar cultiva- 
tions have beob rubbt-iJ into the normal skin of the arm, and have 
indncxMl the formation of numerous impetiginous pustules. Boils — 
ud in one case a large carbuncle — have been pnjdiiced in a similar 
manner. Lastly, the subcutaneous injection of these organisms 
has resulted in the formation of abscesses (p. 343). 

Under ordinary circumstances pyogenic cocci can enter the 
skin by the orifices of ducts or tlirotirrh small abrasions. Impetigo 
results if they gain entrance to the ducts and mnltiply there with- 
"iit penetrating the true skin. If the cocci reach the de[)ths of a 
li«ir-fi>llicle or sweat-gland, their action is more vi<dcnt. mid tliey 
prixlnce a slough — a boil results. When the cocci actually pene- 
trate the cutis vera they cause an abscess of the skin. 

Ill metastatic pysemia the proof is not ijuite so complete. 
Large numbers of micrococci are found in the secondary foci. It 
ha*, moreover, been shown that the unhealthiness of the wound is 
in proportion to the number of zooglnea-masses on its surface, and 
tbe severity of the disease to the number of cocci in the blood; 
"bilst the cocci have been traced from the wound into conuective- 
tiaue interspaces, and even into a vein. They are present in all 
clotii undergoing infective softening. On the other hand, large 
tiumbers of cocci have been forind in the blood of healthy persons. 

Concerning the special organism present, it may be noted that 
iMtnbach examined six cases of metastatic jiyfemia and found the 
mtftococcux pyogenes in five, in two of which it was accompanied 
by aainaller number of the ntaphylococcug pyogenet aureus. In one 

K— the only one which recovered — the latter coccus occurred 
In acute osteomyelitis Kosciibach demonstrated that the »ta- 
piyfocoetru* pyogenes aureus was present in the great majority of 
■ssw; and he was further able to support Lccffler in his statement 
'liat the same organism, when injected into the veins of aniiuals 
*no8e bones had been bruised or fractured, caused acute osteo- 
li.vclitis; and this whether the source of the organism employed 
*w a case of osteomyelitis or a boil. 

Spreadingr traumatic eran&rene often seems to be due to the 

'^^fptoeorcu* pyoge-nes. Ogston found that injections of »tuphyln- 

fix-d might cause similar gangrene of tbe skin in animals. Koch 

mdaced a spreading gangrene in rabbits by injections of a little 




putrid blood, and in bis cases only ttreptoeoeei developed. In I 
cases of stircadinjx traumatic eanei'cne in wbich aubcutaneoi 

ompbyscma was u iiiiirkeil featiiif Rosenbacii found a b<ii-illu$. vprr 
few cocci being present. 

Lastly, the above cocci may give rise to inflammation ttopyiM 
thort of suppuration, the streptococcus being associated with ihe 
more dtffute varieties. Cocci are frequently associated with inliani- 
niations about tlie fauces, even without the presence of pus. The 
evidence we have of tlie infective nature of papillary and ulcerstiie 
endocarditis is given in Chapter XXVI. 

Ill the large majority of cases in which pyogenic cocci are inlro- 
duced into the tissues only local results follow. In the presence* 
conditions favorable to the growth of the organisms they tend | 
spread. With especial ease they are carried to the lymphatic gl» 
There they becouie arrested luiil give rise to glanilulnr iihscea 
Thence, once tii<tre. their progeny and their products are distrilmM 
to more distant parts — it may be throughout the body. SL«lt< 
has drawn a jiaciillcl between this process and that wliiidi 
"tubercular" infection. As the latter is called '■ tubercidmsis,"! 
suggests that the process we are now considering should be n«nitHl 
" pyosis." 

Tfie circumstances under which these very different results fiill 
are unknown. The probable factors have been already discuwi^ 
(p. 340). 

Bryeipelas. — Micrococci have often been described in eryjip 
tous skin. es|it'cially at the spreading cdgi-. They occupy the Ij 
phatic channels and spread along thetn. hence the name — inf«t4 
cujiilliiry lynij)!iiiiigitis. Ortli pmdiict'd ty))ical erysij>elas in » I 
lilt by subcutaut'utis iiijection of the tliiiti ivum an erysi|K.'l«* 
bulla: with ccdema-fliiid from this aniuiul li«' successfully inociil*'" 
a secontl: the fluid and affci-tcd skin cnntained cocci in large oo 
bers. He next cultivated the fungus, and proiluceil erysipelas 1 
injecting it. In ISSl, Fehleisen fouml chains of cocci con.'tJ'i" ''.''' 
j)resent in pieces of skin excised from the /</>rcrt<//w</ <•</</(• of «" 
erysipelas rash. The cocci filled the h/m/ifiatirfi of the ftiprrifi^' 
part of the corium, like an injection-mass, and occasionally extondi'^ 
to the subcutaneous fatty tissue, but were tifver found in tbr hi""* 
vessels. R(Mind-celleil infiltration and dilated blood-vessel."* niar 
their presence, and in jiarls where the inflammatory zone liad '>'''■ 
ajipeared the cocci had vanished also. The organisms wrr* c'' 


sted upon gelatin through fourteen generations in two months : eight 
ut of nine rabbits, subsequently inoculated, suflFered from the dis- 
ise, and six out of seven inoculations upon man were equally suc- 
essful. The incubation was fifteen to sixty hours ; then followed 
igors, fever, and typical rash. The evidence assigning a causal 
sintionship to the streptococcus is therefore complete. Immunity, 
' conferred at all, did not last two months. Three per cent, solu- 
OD of carbolic acid or one per thousand of mercuric chloride suf- 
ced to destroy the vitality of the fungus. 

Fchleisen stated that the gtreptofovauis ciyHipelath presented dis- 
ncf, though slight, difiFerences from the streptococcus pyogenes, 
Q(l that it never caused suppuration ; if ab.scess occurred with 
rysipelas, it was due to a mixed infection. The majority of recent 
riters upon the (juestion have failed to detect either morphological 
r phygiological differences, and many are therefore inclined to think 
lat the two organisms are identical, and that the point of inocula- 
on, attenuation of the virus, and similar conditions must determine 
hether erysipelas or diffuse subcutaneous suppuration shall occur 
I any given case. The clinical differences between the two diseases 
nuld seem to warrant hesitation in accepting this view until it has 
■en proved that the streptococcus erysipelatis, taken from a case of 
I'loubted erysipelas, can cause diffuse suppuration, and, on the other 
md, that the streptococcus pyogenes from an acute abscess can 
verise to erysipelas. No case of erysipelas from inoculation of a 
'und with pus containing streptococci seems to have been recorded. 
Oonorrhoea. — Neisser in 1878 discovered in the urethral pus a 
ge micrococcus (gonocoecug. Fig. 124) peculiar to this disease. 
- recognized it by " facets " or flattenings on the surface in con- 
■t, such a-s are now known to occur in other rapidly-multiplying 
-ci. It is distinguished from ordinary cocci by its size; by the 
istant interval, about equal to the diameter of the coccus, between 
'individuals in the groups; and by the frequency of its occurrence 
n and in the pus-cells. Neisser considered its presence a means 
diagnosing gonorrhoeal from other discharges. It was subse- 
mtly shown that the separation of the cocci is due to swelling 
their capsules. It multiplies by fission in two planes alternately, 
the first stage it is a diplococcus, each coccus having a bean-shaped 
line. In the next stage each " bean " subdivides and a tetra- 
CU8 is formed. The number of cells affected is always relatively 
dl, and varies in different cases. The coccus is cultivated with 



luiK'li difficulty. Cultures were first carried out succeMfuIW bv 
Bockiiunlt. Tliix iiivt'stif^iitor injcotfil u "•' fourth " cultivatiou iuto 
the urt'tlini <ii' a <;fiifral [)itrnl_vlic and produced ii purulent di:^ 
charge. The uiuu died of piieunioiiiu teii days later, and an exuni- 
natioii of the iirctiira led Bockliiirdt in believe that the cocci |irob»- 
bly pass throiigh the epithelium into the lymphaticii of the fossa 
navicularis. wlierc they excite acute inflammation. They enter into 
white corjjuscles, and either pass with them into hlood-vessel.H. where 
they die, or they come iiway in the pus. 

Since then Bumiii has succeeded in cultivating the gonococcu* 
upon solidified blood-serum : he inoculated a second and a twcutietb 
culture upon the fcnuile urethra, ciiusing tyj)ical gonnrrhira in each 
of the two cases. The proof of causation, thus placed beyond dftiiljt, 
was diflicult to obtain, as no animal is snsceptible to the diBea'f. 

With regard to complications: the occurrence of suppuniti'* 
lymphadenitis (bubo), which is unusual in gonorrhcca. is s«i<l i" '•<? 
due to infection of the gland by ordinary pyogenic orgnnisim, the 
urethra in these caaes being the seat of a mixed infection. Th( 

Flo. 124. 

GonococcI from urolhinl jnia : the I'm-cl arr 111 the pii»-ofll». There »rs Iw" ' 
two (Ingle uoccl; the rent are UipUiroori. The three ceUii ahown are kll of Ui* I 
cleated variety. 

gonococcus, injected into subcutaneous tissue, does not c»nae 0**"" 
ration, but disa|)[pears in twenty-four to thirty-si.K hours. 

The evidence as to the presence of the gonococcus in joints 
are the seats of gonorrhoea! arthritis is contradictory : perbaj'-"' 



r tbritis also is the result of a mixed infection, but we may note that 

I it is quite unusual for goiinrrlia'iil joiut.s to suppurate. 

1 The gonococcus is infapiiljlf of multiplying external to the body, 

I except under the very special conditions of a culture. Its resisting 

I |iu«er is feeble, and it soon perishes. If thi.s wore not so, consider- 

L^ ijigtbe great frequency of the disease, infection otherwise than by 

HI tontaot would almost certainly occur. 

W Pneumonia (see Chapter XXXI.). — The production of acute 

m pneumonia has been attributed to two distinct organisms. (1) The 

I first — known as Friedliiuder's pneumococcus, though, strictly speak- 

■ ing. it is a microbacteriuin — was discovered by that observer in 
^■l168'2. lie found groat numbers of these organisms in the early 
^BStage<i of pneumonia, not only in the e.xudation. but also in the 
V lymphatics of the lung and in the tluid of any pleurisy or pericar- 
^Lditis tthich was present. These cocci are oval or rod-shaped; they 
^■irc contained in oval or elliptical capsules with rouniled enils. 
I Two, four, or even more cocci may be found in these capsules. The 
I capsiilt' is ili.s.solved by alkalies and by water ; is contracted by acetic 
I aciij (liku mucin); is present only in the lung; is scarcely or not at 
I "11 (levelope<l in cultures; and is best stained in prep- 
I stations by immersion for two to three minutes in a solution of 
I ?<"itian violet in aniline-water, followed by treatment with alcohol 
I "'f lialf a minute. 

I Friedlander subsequently stated that he had cultivated the coccus 

I '^ blood-serum and gehitinized meat-iiifusinn and on potato. Intro- 

' **"eed by needle-puncture into tiie two foraier siib.strata, the growth 

'*»kes the very characteristic form of a round-headed nail ; on the 

L «att«.r ground it forms grayish drops. Diffused in distilled water 

' '"1 injected into the lung and pleura of rabbits, the organisms pro- 

^'^cod no eftects, but of thirty-two mice inocidated all died in less 

"*ii twenty-four hours. The lungs were very red and almost uni- 

'**^allv stdid, and the spleen was en larked; both orgiitis contained 

■ '*■ characteristic cocci, whicii were also present in cnnsiderable 
'•ttibers in the blood and in enormous numbers in some Huid which 
*^*-»ipied the pleura. Guinea-pigs were more ri'fraetory to the poi- 
"**». ami out of five dogs only one suffered. 

^ianmgarten is strongly of opinion that tliis parasite lins no 

VTitMiiiionia-exciting action in num. but tliat it enters the pneumonic 

V^tcli from the upper air-tubes or pharynx and multiplies in the 

^t^flamed tissue. For it seems that apparently identical " capsule- 



Flfi. 125. 

cocci " are not uncommonly to be uict with in pus, in the epitLelmm 
of the mouth, in sputum, or in the secretion of" uasal catnrrh m 
Otherwise healthy men. A still more serious objection lies in tbr 
fact that other ob-scrvers have not been able to demonstriitc tlii- 
organism with the constancy of which Friedliinder spoke The 
stroniffgt objection, however, seems to be that the cocci found »iiil 
the cncci cultivated are not identical; for Friedliinder considfird 
that his coccus retained the aniline stain when treated with Oruin'* 
iodine solution, whereas the coccus which he cidtivated is ilecoliir- 
ized by this treatment. The cocci which remained staine<l in *k- 
tions of pneinnnnie lung prepared aecordinj; to Gram's methoii wi'W 
therefore not the cocci Friuilliiiider cultivated, but were prolmlilt 
those subsei]uentl3' demonstrated by A. Frnnkel and Weichseibttniiu 
to the description of which we now pass. 

(2) Friinkel and Weichselbauni independently demonstrateii ihf 
presence in pneumonic lungs of another organism — the pneumo- 

COCCU8 (or diplococcusj pneamo- 
nisB. This consists in cultiirf.'> I'f 
round or oval cells, usually in p»i'*< 
but often in chains of four to ten. 
or even twenty to thirty. Thw*^ 
longer chains are much straiplitf' 
than those of ordinary streptococci 
(Weichselbauni). In the tissu<?* 
the microbes often become lanf*' 
shaped, and their pointed ends a»*3 
be tfiw ard or away from each oth*'' 
usually the latter. These cO*** 
have capsules just like Fri^*^' 
liinder's, and they may be si*** 
larly stained. They retain ^^ 
avilhie »tam when treated ^^ 
Grnmn method. Kruse and I*^^*^ 
sini insist on the variability •^ 
form. They describe no less than thirty varieties. Wherciw Fri*'^ 
lander's coccus can be reaflily cultivated on gelatin at 70" *''^ 
Frankcl's is best grown on agar at a temperature of 95° F. to 9^-** 
F.. and tin- .Mnutb is scanty and not nail-shaped, but of charac*^'* 
istic *'de> form. "When the organism is grown on gel»**** 

tiii.s medii"" c6eil. In many of its character* it tb"** 

niplnooopl r>Mciiiui>iilii'. (■ntnuKli-il In 
the* iiieRhfH of Ihf hliriiiouH exudation 
ffW>ni a wrtinn of liinji in tlu* red hofi«- 
tlKHtion BtsKi' of iiriito iint'iimonln). In 
the iipptT pMii iif the (ieid 1r a cell er>n- 
lalnlng several cocci — pueHllily a [itiagu- 
cyte. X icon. 


obles the streptococcus pyogenes. The substratum must be 

slightly alkaline or growth ceases. Even when transferred 
• from tube to tube, the diplococcus rapidly loses its virulence 
assumes the streptococcus form : to preserve or to restore its 
jgenic power an occasional inoculation upon a , susceptible 
al must be resorted to. Cultivation for one to two days at 

F. destroys the virulence ; it is weakened by longer culture 
ightly lower temperatures. 

ibcufaneous injections of virus of full intensity into rabbits, 
, and guinea-pigs cause an acute, generally fatal, illness, like 
csemia, with characteristic post-mortem appearances ; but there 

sign of pneumonia. An attenuated culture introduced beneath 
ikin does sometimes give rise to pleurisy or pneumonia, or both, 
these results are usually after injection of such a culture into 
lungs. Then the appearances usually very closely resemble 
J in pneumonia and pleurisy in man, and the exudation con- 
i large numbers of encapsuled cocci. Pericarditis also may 

le inoculation either of filtered cultures of the organism or of 
lerum of animals vaccinated with them is in each case said to 
;r a temporary immunity. Issaeff asserts that the cocci thrive 
Itures treated with the "immunized serum " — a result altogether 
rary to that obtained under similar conditions in tetanus (p. 
Sputum before the "crisis" is virulent, but sputum after 
' crisis " is said to confer immunity. 

lumgarten believes that this coccus may be regarded as con- 
ly present, for, though Weichselbaum found it in only 92 per 

of a large number of cases, his method of examination ren- 
l it possible to miss the coccus ; and if it really waa absent in 
cases, it might have been dead at the time the cases were 
lined, for, as in cultures, so probably in the body, the diplo- 
18 pneumoniae has but a short life. These cocci occur in suf- 
it numbers to account for the symptoms, 
sides being present in pneumonic lung, it is occasionally foond 
le blood (sparingly) and spleen and in inflammations arising 
pendently or during the course of pneumonia — plenrisy, 
ircma, meningitis, endocarditis, peritonitis, and otitiB media. 

it appears to be an oeeasional denizen of the month, also 
rring in the saliva and in the middle ear of bealthy people, 
t suggests that it is only an accidental parasite in pnenmonia. 



Against this view the following points seem to tell : Ita incon 
in the mouth ; its constant occurrence in fineumonic lung, som? 
times as the ro/c lifnioiintni/iff iirijnnisiH ; its distributiou not 
uniform in the inflamed area, but chiefly at the Hpreadiug «lge 
and in tlio »iirrouii<ling (eilenui. rneomonia does not follow inwy 
ulation unless the parasite is loejilizeil in the lung. Salvioli !*» 
that he succeeded in inducing lobar ])neumonia in guinea-j)ip br 
intratracheal injection of pneumonic exudation containing tliwe 
cocci ; but Fatichi I'ailed with rabbits. Further e.xpfrimontJ of 
this kind arc required, for there is every reason to believe tbil n 
man infection occurs through the long, though in some ciwi-s ihc 
disease in thi.s organ may be .secondary, or. at any rate. merclv»n« 
of several morbid changes. 

When pneumonia runs on to suppuration and gangrene, lb«f 
complications are possibly due to a secondary infection by the 
staphylncDcctis pyogenes aureus or streptococcus jtyogenes. fLougt 
pyogenic effects have been attributed to the unaiiled pneuniococcuj- 

Micrococci have been described in meatleg, vaccinia, rariola^^li^- 
demic cerehro-apinal mcniiujitiit, typhun fever, acutr yellow atrofhji 
of the /(Vcr (early stage), whoopini/ cnnqlt, di/xniteni, fat-vn'rntiit.iw 
many other diseases, but the evidence in favor of their wi 
relationship to the respective diseases is not sufficient to jiisti^ 
description of them here. 

A micrococcus which divides in tijree diameters at right snglw' 
each other — Sarcina — is often fijiind in vomit from stomachs ililatf"! 
from pyloric obstruction and in cases of dyspepsia from chr 
catarrh {Surclna reiitricitH) ; in the bronchi and deeper parts oft 
lungs in phthisis (Sarrina pii/iHi)niiiii); and in the urine (>'<»''" 
urina) : it has been seen also in abscesses and in blood. Sin 
cocci may be seen, but the majority form cubical groups of four ( 
some multiple of fViur (Fig. 121). S. ventriculi (2.5 /i) i.« Urj 
than S. urinw, or than the fungus of this shape occurring in 
lungs (1 ft to 1..') fi). iSarcinse may occur in the stomach wid" 
appearing in the urine or elsewhere. It is extremely difficult to j 
rid of the fungus when it is once establisheil. The nature of I 
decomposition to which it gives rise is unknowo. 

MICROBACTERIA. — This group contains no organism pa<* 
genie in man, 



DESMOBACTERIA. — The members of this group are sleudcr 
frxb, of which the leugth is generally much uinri:' tli:>n tAvice tlio 
ireadtb. Thi-y multiply by tninsverse division, anil oftcQ grow into 
^ng, jointed, but nnbrttnehe<i filameuts, without constrictions at tho 
lointii. Formation of spores bus been detected in some species. 
Ill the pathogenic organisms in this group) arc straiglvt: they are 
Down as bacilli. 

The Bacilli of Tubercle, Leprosy, Syphilis, Glanders, and 
liinoecleroina are described iu the chapter on the " Infective 

Splenic Fever. — The B, anthraci», found in tins tiisease. is the 
let known of all parasitic fungi. Its life-history was worked out 

Kli. In blood from the s|ileen of nniniiils. deail of splenic 
e found enormous numbers of rods ;V-2il // long by aljouf 1 
. They have slightly concave ends, are straight and niotton- 
Bs (Fig. 121). In a suitable culture-material, such as the blood 
I the ilcad animal, with a plentiful supply of oxygen and a temper- 
iure between 60° and 10"'^ F. (77° to S7° F. being most favorable), 
I* rods grow into very long interlacing filaments often groujied into 
WiTolutcd bundles. (See Frontispiece.) In these filaments round, 
Ighly refracting spores form at short and regular distances; the 
icilli now break up and the spores are set free. Under favorable 
fcumstances these grow into bacilli. In living animals long iila- 
^Vand spores are never found, the rods multiplying solely by 
Pmon. The rods exist in enormous numbers in the cn))illarics, 
>p«cially those of the spleen, lungs, liver, kidneys, and mucous 
*nibraue of the intestine (Fig. 117). Numbers leave the body in 
w urine, fjecos, and blood flowing from the nose anti mouth of the 
Mnjal before it dies ; thus the ground in its neighborfiood is 
■Vered with the fungi. In bodies buried at the depth of one metre, 
l*re there is neither oxygen nor a suitable temperature, no de- 
lopment of spores occurs and the bacilli soon die. As to the mode 
'octioii : I'asteur says that the mouths of unimals :ire wounded 
sous grasses, and believes that the cuts thus made ore inoeu- 
with bacilli or spores. This view is supported by the fre(|uent 

Rof the cervical glamls in sheep, Init both these animals and 
frcf^uently infected by insects which bite men on the face, 
inks the intestine is the commonest seat of infection. Klein. 
i*cver, records a case in which one mouse ate, without any ill 
t8, most of another that had died of splenic fever. Iu warm, 


iiiarsh V districts the bacilli form sjiorett plentifully ; thcw; are ( 
by floods to meadows where iiiithrax Duiy not bttve prcT 


[n uiuii uHlignant pustule is due to inoculation with (kt & 
authnicis; and peiienilly. in England, from wwjI or liiilee linmrit 
from countries where the discnise Ik endemic. Some time after ihf 
a|)pearance of the pustule generol symptnnis a[i()«nr, bronehitimr 
diarrhoea being common. Duvies-Colley found numcrou* bacilli lo 
serum pressed from sm excised pustule and in the spntuni. aniir. 
f«ccs. and sweat. Tlie patient recovered, but. though free frm 
symptoms, he was still eliminating in his urine a few bacilli a noDtk 
after excision of the pustule. In some cases there is no <>u|>fHii'i>l 
lesion, and the symptoms may be those of acute septic iKUsouin^ nr 
be chiefly |>ulmonary or intestinal (woolsorter'a disease). I'rrfaif* 
the predominant symptoms indicate the mucous membrane tbroof^ 
which infection has taken place (p. ;{.'{;)). 'f he pn>ducts of tie 
anthrax bacillus are shown in the table on p. 889. Other £wi* 
regarding the R. anthracis are given in the early part of the pmrtt 

B. anthracis is constantly present in splenic fever, and nltim«i'l; 
in enormous numbers. The blood of a ftetus in an animal "ii^ 
splenic fever contains no organisms, and iloes not produce ib« 'U*- 
ease, whilst blood containing spores or bacilli capable of d«?»rl'i|>' 
ment always does so in suitable animals. The bacilli may beM{*- 
rated by filtration, washed with distilled wiiter, alcohol, iil^ 
then ilried, but, notwithstanding all this, they can still caii" ■; 
fever. Pure cultivations may be niaile through fifty geiieratwi* 
with the same result. They never give rise to any other dl"***'- 
If this is not proof that B. anthracis is the ritutt of splenic ferttj 
the belief that itch is due to the acarns scabiei or that trichii 
line to frichiuie must also be regarded as ill-founded. 

By cultivating B. anthracis for twenty days ut 107° to V 
and using the vaccine for rcpeatcil inoculations upon sbwp' 
cattle. I'asteur rentlere<l these immune to the spontane«>it> 
and to the action of the virulent virus, .\fter much contni' 
the possibility of this " attenuation " has been fully e»tabl 
there is, however, still some doubt as to the valne of vorcti 
against splenic fever; Koch, for instance, maintaining that 
of any use the vaccine must be so strong that «»me anim; 
perlitt|ta very many, will die of the induced. The all 


tion of anthrax bacilli has been brought about in other ways — by 
cultivation in air under a pressure of eight atmospheres, by the 
iddition of small quantities of antiseptics to the substratum, or by 
the passage of the organisms through the bodies of certain animals. 
Klein failed with Pasteur's vaccine to protect rodents ; they seemed to 
hare no immunity : if the vaccine acted at all, it caused splenic fever. 

The attenuation is not accompanied by any morphological change ;. 
the virus "breeds true," and its virulence may be restored at any 

Typhoid Fever. — Klebs, Eberth, Koch, and Meyer were the first 
to describe organisms in this disease. These organisms were figured 
u small bacilli with rounded ends. They were found in the intes- 
tinal lesions, mesenteric glands, and spleen. They were most 
Damerous, and therefore easiest to find, during the first and second 
»eek8 of the disease. They stained badly with aniline dyes, and 
for a time these observers worked with unstained specimens clarified 
by an alkali. Eberth was thus able to discover the bacilli in eigh- 
teen out of forty cases. Koch succeeded in staining the organisms 
with Bismarck brown, and demonstrated their presence in half the 
CMes examined by him. 

All these observers made control-observations on other cases, such 
u tubercular ulceration of the intestine, but they never found the 
typhoid bacillus in diseases other than typhoid fever. They some- 
times found cocci in the intestines and glands, but regarded these as 

A very important paper by Gaffky appeared in 1884. He started 
»ith the observation that the bacilli had been found in only half the 
'Mes examined. They must therefore have either disappeared be- 
fore the disease which they caused had run its course, or else they 
'«e present, but not found. The latter alternative seemed prob- 
*We, as they had been demonstrated in late stages in some cases 
•"d missed at early stages in others. He pointed out that in 
typhoid fever the bacilli are not scattered everywhere, but are 
'Iwayg in foci, and therefore more difiicult to find. 

Gaffky himself investigated twenty-eight cases, and in twenty-six 
'eoionstrated the presence of bacilli in parts other than the intes- 
''De, such as the mesenteric glands, spleen, liver, or kidney. In one 
'f the other two cases the bacilli were found in a recently swollen, 
"^'itary follicle, and in the second the intestines showed only healing 


Ill one cs8e, which Gaffkj doeH not inclinU' in his Htit. althuu^iit 
had bcoQ diagnosed -ah typhoid fever buth during life and at tti« 
post-mortem examination, immense niimhers of cocei «rcr« fbikl 
in the organs, and it wan impottAiblc t«i disitingiiiith the tTj 
bacilli. Gaffky tiirows mit the suggestion that thrn- m»\ 
disease clinically like typhoid fever due tn in\nsii>ii of tlir 
tine by cocci. 

The earlier the ease the more numerous are the haeilli. If 
aw found in old eases, it is j>ndjalde that a relap.^e ha« occum* 

Since that time many other observations have been pabli 
The following is a summary of the results arrived at : The li 
can, with some diffieulty, be found during life in the fjpccd. »] 
(obtained by {>uneture), and urine. After death, if the part* 
removed without any delay, the organisms can bo cAsily diiw 
in the intestines, spleen, liver, mesenteric glands, and kiili 
They occur in groups, but do not give rise to "tubercles." Tbai 
presence can be more readily ascertained by inornlating a ci 
ground with a piece of the suspected organ than by cxaminliw 
atained sections under the microscope. They stain slowU w^ 
part with the color easily. The best stains are probably Ii<ill0' 
methyhme blue (p. 384) and Ziehl's fachsine stain (p. 3.10). Tk* 
bacilli will not retain the color when treated by (iraw'.'i mrlfc*' 
(p. .-UO). 

In ap|>earanee typhoid bacilli are not unlike tubercle bacilli. Tbrif 
breadth is abnut a third of their length, which varii-s betwefii i " 
and 3 ft. Thns they are a trifle thicker than tubercle bacilli. »l"i«' 
tlieir ends are distinctly rounded. Clear spacea often <»ccnjij ih* 
centre of the rods. There is some doubt as to the exii«ten( 
spores. Those who believe in their existence describe lb 
rounded bodies, reaching right across the breadth of the ro<l» 
lying at their ends. The chief microscopic feature!* nhirh 
tinguish tyj>hoi<l from tubercle bacilli are the possession «»f flap'l'*' 
the power of active movement, and some of the staining reartio"*- 
A typhoid bacillns when stained by Locfller's method afp*'* 
enveloped by a thick capsule. In intimate connection wiili •*•** 
capsule, ap|>arently composed of the same substance, and '»'*'' 
triboted over its whole surface, arc the llagella, eight to t*eb« '* 
number, varying mu<'li in li-ngfli and thickness. Sometime* ^f 
are considerably longer than the parasite itself. Some ci '■' 
bacilli are said to have only a single flagellum at one rktl 


Caltares can be readily obtained. The organism thrives in milk, 
and can even multiply for a time in sterilized drinking-water — 
points of practical importance. It does not liquefy peptonized 
gelatin, but produces in it roundish, slightly granular, yellow-brown 
colonies. It is mainly aerobic. Potato-cultures of this bacillus are 
almost invisible : this fact is utilized in the recognition of this 
organism. Thus, if a fresh potato-culture be incubated for forty- 
eight hours, no visible change occurs, but if surface-scrapings be 
then taken, stained, and examined, threads of the bacilli will be 
easily found. Other methods, none of which are absolutely cha- 
racteristic, have been devised to meet the same diflficulty. Singly, 
each is of little value ; taken together, they are practically sufficient 
for the purpose of identification. Thus, acid products, but no 
indol, are formed in bouillon-cultures, while most bacilli, occurring 
nnder the same conditions, form indol. Another suggested test 
depends on the tendency which this organism possesses of absorbing 
the color when cultivated on a gelatin medium stained with gentian 
violet, thus leaving the gelatin colorless. Still another is founded 
on a slight indifference which some organisms show to the action of 
carbolic acid. Thus, if a minute quantity of carbolic acid (2.5 per 
1000) be added to a culture of mixed organisms, the growth of 
most Till be arrested, but that of typhoid and a few others will con- 

According to Sternberg, ten minutes' exposure to moist heat at 
140° F. destroys typhoid bacilli : others give the boiling-point as 
the fetal limit, and state that " spores " will survive a temperature 
of 194° F. Brieger has separated from cultures some fatty acids 
»nd a poisonous basic substance which he names " typhotoxin." 

Inoculation has hitherto been only partially successful. It is 
<loubtfnl if any animal is susceptible to typhoid fever as we know 
It in man. Rabbits, dogs, and mice have been inoculated, and have 
died in thirty-six hours with symptoms of general septicaemia ; but, 
•hoogh enlarged spleens and swollen Peyer's patches have been very 
gonerally found, the disease never runs a longer course, nor is there 
ever any characteristic ulceration. Furthermore, almost precisely 
"ailar results have been obtained by injecting either the filtered 
products of the organism or the typhotoxin itself In spite of this 
8*P in the chain of evidence, all the observers quoted believe that 
this bacillus is the cause of typhoid, and we may, at any rate, affirm 
that it is constantly present in typhoid, is recognizable from all 



known bacilli by tbo various cLarnctcristics given above, ana 
not found in any otliiT tiisease. Uaffky believes that infw 
always occurs through the mucous lueuibranc of the intestine : 
when the poison seems to have been inhaled as dost, be thiuk»ittf 
caUjLrlit on the mucous membrane of the pharynx, swallow. ' 
rie<l through the stomach, anil thus brought into contact "m' 

Bacillus Coli Communis (Hnctcriuni c<ili comn 
bacillus is a coiiinion lU-nizeti nfilic uiiinciitiirv tract, aii 
of the neighborhood of the ciecuin. It is nltw found in the DiootlL 
and occa:<ionally in other parts. It very rarely occurn alone. Insw. 
in shape, in the po».se»sion of flagella, and in staining reacti-'f^* '' • 
organism very closely' resembles flint of typhoid fever. Ai 
to some observers, the B. coli communis has fewer flagella, hut iJi» 
supposed peculiarity is certainly not constant. There is a lemlrDn 
for the bacilli to occur in pairs, and. when cultivated, in tlwrt 
threads. This organism probably doea not form Hporen. It i* 
mainly aerobic, and seems to have a slight power of activr mort- 
nieiit. Like the tyjihoid bacillus it grows best in acid media. It 
is easily cultivated, but the results are not sufficiently distinctir 
be of much diagnostic value. In gelatin tube-cullun-s it 
the form of an irregularly encrusted stick, with small oatgrov 
here and there, but without tapering in either direction. 

There can be no doubt, on the niu- hand, that this organi^n I'l 
in perfectly healthy intestine, nor any iloubt, on the other, tbrtj 
many disca«!r<l conditions it is by far the most prevalent of I 
organisms present, and occasionally, perhaps, the only one that i 
be fouml. Hence it seems probable either that other barilli i 
present confounded with this one, or that this is subject »•> 
great variations in virnlvnce. There is a very general Wlwf i 
at any rate, the latter alternative is true, though the cau»e »f I 
variation is i|uitc unknown. In .some states the orgBDi^m 
able to produce a condition similar to scptiiwmta : in otb(t«. i 
to give rise to local irritatictn and sup[)unition. Maraignr is| 
opinion that this organism is the chief causative agent in the 
lowing comprehensive group of con<litions. The cviiiencc on ' 
be ba.Hcs this opinion will be found in his very interesting 
graph.' In no case does the evidence amount to absolute prouf* 

Qmerai J}i»f(iiifg. — Clmlcra nostras, cludera infantum, 
' " Ixi Raclcrium Coli IV.minuiie," I'aria, 1892. 


obscare infective febrile disorders, and chronic enteritis with marked 

Local Di»ease». — Dysentery, ulceration of the vermiform appen- 
dix, pylephlebitis, abscess in the liver or gall-bladder, and peri- 

It has been suggested that the bacillus coli communis and the 
rphoid bacillus are identical. Besides the points of similarity 
Iready mentioned, it is found that when injected into the veins of 
ibbits and guinea-pigs it produces a fatal disease identical with 
at already described as occurring when cultures of the typhoid 
cillus are similarly introduced. 

Diphtheria. — In 1888, Klebs drew attention to a bacillus which 
had found constantly present in diphtheritic membrane. In the 
lowing year Loeffler published a full account of its morphology 
d cultivation, together with results obtained by inoculation, 
nee that time many workers have traversed the same ground, 
d the main facts concerning the organism have thus been fully 

The bacillus is to be found in all cases both of diphtheria and of 
;mbranous croup. It is limited to the false membrane and its 
ighborhood, and grows most abundantly in the more superficial 
rts of the membrane. It is never found in any internal organ, 
ough its presence in the membrane can be made out during all 
Jges of the disease, while the examination of scrapings from the 
ucoas surface of the mouth shows that it may continue to live a 
ecarions existence for three weeks after the fever has disappeared. 
is not found in any other disease ; at least such is the conclusion 
the vast majority of competent observers. Bacilli having a close 
Mphological resemblance to it seem to be occasionally present in 
e mouths of healthy individuals, as well as organisms giving even 
esame culture-results as the diphtheria bacillus, but not possess- 
g any pathogenic power. These may be attenuated forms of the 
Jginal bacillus. Bacilli taken from diphtheritic membrane can be 
'hivated through many generations, and after an interval of some 
onths are still capable, when inoculated, of giving rise to the 
•ginal disease — not merely the local inflammation and membrane, 
'• also the subsequent paralysis. 

The diphtheria bacillus is generally rather shorter and thicker 
»n the tubercle bacillus. It is usually from 1.6 fi to 2.5 [x long, 
id about a third as broad. Some observers have accredited it 



Via. 126. 

Bacilluii of diphtheria 
(Ijt-IIUt.) (From a iipcd- 
mcn by Dr. Arklt.) 

witli .1 U'li^rtli iif <! // to S ji, hut tliev Liive probalily inclnJeil nwre 
thun one iiidiviilual in tlieir measurement. Its shape is not bUih 
regular : sometimes tlie ends are thicker than the centre, ami M)nl^ 
times the cen^e than the end-*. The l«iw 
are roiiniled. The bacilli not infrecjiiciitlf 
contain a row of two or three highly refraiiioj! 
areas, the nature of which is unknown. In 
all ))rol)ability they are not spores. The w- 
ganisni i.s believed to multiply bv fission oiik. 
It never forms long threads : it is motionW 
LicHler's iilkiiliiie mefliylene-blue soiutinn' 
gives the best .staining resiilt.s. but (inmit^ 
method cau also be employed. ^| 

The can be cultivated in msiif 
media. It <Ioes not liquefy gelatin. It grows well in milk, bm lit 
mo!»t fre<(uently employed culture-ground is Ltcffler's sernm.* A 
minute i)ortinn of membrane, transferred to this, will develop in tli» of twenty-four hours small gray elevated disks with paiecif- 
eumferences. In secondary cultures these show a tendency tolHtoiM 
arranged in lines. (See Frontispiece.) Growth can take pli 
any temperature between 70° F. and 108° F., but is most Inxii 
when it remains between !)2° and 99° F. Moist heat of 140*, 
is fatal to its life. A free supply of oxygen encourages, btit it 
essential to, its growth. There is no difficulty in maintaining t' 
virulence of the organi-sm during cultivation : but if a culimvlii' 
left undisturbed for some months, its virulence diminishes, nnJ 'I"* 
result follows much more rapidly if it be allowed to bccoiui; wi"!- 
In either ease replantation into a fresh culture-ground rapi 
restores the virulence. The organism resists drying lo a 
greater extent than is usual in non-spore-bearing bacilli, 
specimen be dried and kept dry for six months, it will grow «s 
as it is placed under favorable conditions. This pt)iut is of 
practical importance, and em|diasizes the necessity for thoi 

In 189(1, by means of filtration through porcelain and sub«e<[ 
precipitation with absolute alcohol, Houx and Yersin succowW 

' Saturated alcoholic solution of methylene hi ue. 30 c. c. : solution of aiaill>' f*** 
of 1 : 10,0(10, 100 c.c. Ivctffler's rnfthwj of slaining fliigcHa is altogwW diftw*' 

' I'eplonc, 1.(1; ^rape-«UK:>r, 1.0; chloridv uf suUiuni, .5; DeutnU geUUniOu^ 
broth, 100.0 ; blood-serum, 300.0. 


isolating, from cultiircs of tlic organism, a poison which if injected 
iiiiii auimals in large (loses ciiiiscd prostration and death, L tit if in 
yiunli (luses only paralysis and alljiiiniiiiiria (iu rahbits on the tifth 
tisy). In no case v/as any moubranu formed. It was also noted 

Fio. 127. 


Birdluj of (llphtherl*. Colony on iMjar twcnty-Ciur houni «Rer Inocalation. x 100. 

I«« Fninktil.l 

•li«t the addition of acid to the poison rendered it harmless. They 
Wi«ved this poison to be an ■' unformed ferment." 

Two years later, by very similar procedures, Sidney Martin sepu- 
"itftl identical series of substances (1) from the tissues of persons 
lieadof diphtheria, and (2) from cidtures of the organism on media 
tlosely resembling those of the tissues (p. 359). This series cou- 
"iflwlof hetero-albumose, j), deutero-albiimoso, and an 
Ofpmic acid. Of these, the first was only to be obtained from the 
ttifuilirane and the last from the tissues ; the proto- and deiitero- 
>ll)muoses were present in both membrane and tissues. Martin 
woweJ that the factory of the albumoscs was the tissues, anil espe- 
ei»liy the spleen, and that but little was formed at the site of the 
"■finbrune. He regartled all tlie products as the result of a ferment 
produced at the seat of llie local disease, and thence entering the 
"STcqlation. He showed that the paralytic effecte were due to the 
*«tii)ri of the ulbumoses on the periphcvnl nerves, which caused 
breiilting up of the myelin sheath, and move or less thinning anrl 
•**n ilisappearance of the a.xis-cylinder: fatty degeneration of the 
'''^rt nnd voluntary muscles were also found (p. 340). 

Prom the foregoing account it will be seen that the requirements 
*' the organism aa regards air, temperature, and moisture are ad- 




mirably provided for iu the mouth and upper air-pasMges. Mor^ 
over, they arc .sup|ileincnteil by the co-operation of varion« own. 
especially the j)yogenic varieties, whicli are always ready to haml. 
The spread of the membrane inward is probably due partly to lie 
mure suitable temperature and partly to the force of inspirati. i. 

Auutlier step in advance was iiuide in the same yearll^'. 
Behring, who drew attention to the acijuired immunity wbicb coald 
be obtained iijiainst these diplillieria liiicilli. He ilesii-ribed four 
ways b_^ which animals co(dd be rendered immune. He injected (1| 
cultures of the bacillus attenuateil by heat; (2) cultures attcuuat«<l 
by the addition nf trichloride of iodine ; (3) the pleural exuiiation 
of animals dea<l of experimental diphtheria: or (4) a dose of viru- 
lent diphtheria bacilli, folbivved by one of trichloride of iodine Hf 
next showed that the addition of some serum from an auimnl tbii' 
iuimunized to an ordinary culture of the organism not only kilW 
the bacilli, but neutrali/ed the jioisun as well, so that when injrcifi 
it was found to be innocuous. The iinal stage was reached when hf 
showed that if a fatal dose of diphtheria poison hail been 
it could be neutralized by a subsequent injection of this " imi 
serum." A good deal was found to depend upon the method fin- 
ployed for rendering; immiine the animal from which the scrum »*• 
taken. Within certain limits the injection of small amount*. s|iri*l 
over a long period, was found to give the best results. The princi- 
ples determining the dose of •' imnuini/.cd serum" or •• antitoxin 
are not yet understood. Does the " antitoxin " simply neutrali« 
the chemical poison, or does it induce action on the jmrt of tlif tis- 
sues ? In eases iu which only the filtered culture, and not ti* 
actual bacilli, is employed the dose of serum reijuired is fopml l*" 
vary not only with that of the (Toison, but also with the body-weig"' 
and possibly with the species of animal employed. Again, thclw* 
rc(|uisitc depernl upon the interval between the two injections. •' 
was smallest when that of the serum immediately followed the pobon- 
These results have led to the extensive use of the jmmuni«e<l s«i»* 
for therapeutic purjwses : these have been more fully referred U> •■ 
the section on Immunity (p. 3()8). 

Influenza. — In 1S!*2. Pfeiffer, Kitasato, and Canon aucct'eded id 
finding a minute bacillus which they believe to be the cauM.- of ih" 
disease. If is extremely minute, measuring .0 fx by .2 ft ; that \i, it " 
about half the size of the bacillus of " mouse-septicarmia." It st«iD* 
with Ziehl's and Loefller's fluids : the ends take the stain best, aoil 


tius the organism often looks like a diplococcus. It occurs singly, 
in pairs, and in short chains. Large numbers have been found in 
the bronchial secretion : they disappear with the catarrh. The 
orgaoism has also been demonstrated in the blood. In that fluid 
it is either less frequently present or more difficult to stain. It 
ius been found in the peribronchial tissue. 

Pare cultures are not easily obtained. On sugar-agar these 
tppear as small, discrete, transparent globules visible only with a 
lens. The bacillus is aerobic, grows best at the body-temperature, 
and is easily destroyed by drying. 

Local inunction of pure cultures into the respiratory mucous mem- 
brane of monkeys and rabbits is followed by the disease. 

The Plaerue (Bubonic Fever). — In a preliminary communication ' 
Kitasato has described bis researches during a recent epidemic at 
Hong Kong. 

(1) He succeeded in finding bacilli in the blood, buboes, and 
internal organs of the plague-stricken patients. The organisms 
stained readily with the usual reagents; they had rounded ends, 
vhich appeared darker than the central parts ; they possessed 
•light power of movement. No spores were discovered. The 
organisms were easily destroyed by sunlight, heat, carbolic acid, 
»nd quick-lime. Similar organisms were never found in healthy 
persons or in those suffering from any other disease. 

(2) Cultures were obtained on blood-serum, glycerin-agar, and 
other media. The colonies were whitish-gray, rounded patches 
»ith uneven edges. In the cultures the bacilli often formed long 

(3) Mice, rats, guinea-pigs, and rabbits, if inoculated with pure 
cultures or with blood from patients, succumbed with a constant 
*iaenee of symptoms. Roughly speaking, these appear to have 
^"Tesponded to those in man, though the enlargement of the glands 
••oes not seem to have been so marked. The bacilli were found in 
">« blood, glands, and organs of these animals. Pigeons are im- 
""De. Animals fed with the organism or blood died in the same 
•*J as those inoculated. 

Septicseznia of Mice. — Koch injected putrid fluids beneath the 

'•in of mice in quantities too small septic intoxication. A 

Peculiar disease, without abscess-formation, occurred in some cases, 

*nd was transmissible with certainty to others by inoculation of a 

• The Praetitiotwr, October, 1894. 


Fio. i2tl. 

very small tjiiaDtity of blood. Extroindy »niall bacilli, cliiefly 
leucocytes, were mIiumii to hv tlio cansi- of the (lijiiease, <*no atUi 
confer« iiiitutiiiity. It is not iiioctilulili* ujK)n ticlil-iuice, gi 
pigs, or chickeus. (Sec "Scpticnjmia,") 

Tetanus. — Iti 1SR4 it was shown tlnit trtanus W8;< an in< 
disease. In the same year a special bacillus was described 

was not isolated and cultivai 
til IS^n. KitaiMito ac<Htni|ilisfc< 
these results by koatiug the inipo 
cultures of pus. obtained from d 
original wound, to a tempenlv 
of 80° C. (ITfi" F.). and then r 
cubating the residue in an mm 
sphere of hydrogen. ■ 

The bacillus thus obtnineil in ♦»! 
small. It is generally armng<[^ 

lUeUliu of tcun.... ,r«r U«criptloD, p„|,^. ^^^^ ^^j „,- ,,,p {,„,.in„^ 


longer rods (8 // to 5 /t X 
Spores are often found. TIipt~ 

being two to four times the tiial^ 
of the organism, give it the appearance of a miniature dmiiiltii 
(Fig. 128). One or two flagella at the oj)posite end arif draeribi 
by some observers. The bacillus can be staineii by the ttfa 
methods. Its habitat seems to be the superficial s«iil, frun 
it can often be obtained. 

It can be readily cultivated if great care be ukcD to 
oxygen : this bacillus and that of malignant a*demB arc 
most prominent examples of anaerobic organisms. The tt4/St 
bacillus lii|uefies gelatin slowly and grows only beneath the si 
The most suitable temperature is l»7° F. to 100° F. The ci 
have a characteristic odor. The spores are noted for the p«> 
resisting power they show to the ordinary methods of dcst 
Thus, they have been known to resist successfully /»«»i7i»«y 
minutes. Jn/in;/ for five months, and immersion in rnrh«\H 
(1 : 20) for ten hours and in mfrmric vhloride (1 : 10«MH for 
hours. Fifteen minutes' boiling is invariably fatal. For a 1^ 
time all attempts at attenuation failed, but it has lately b««n 
by Tix/.oni and Oattani that attenuation results froin < 
sure to the air of s[>orp» on threads, and (2) the pi' 
cultures in various gases for long periods — generally or*r a y* 


The constant presence of the bacillus in cases of tetanus, and the 
possibility of purifying it by cultivation, having been established, 
it renuiiiieil for Kitasato to couijilcte the proof by successfully in- 
ociiluting these cultures on animals. lie showed not only that iu- 
ui'nlation of the bacillus proiluces the disease, hut nlso tlmt in such 
ciwoi the organism remains confined to the wound, mid thstt the 
imptonis arc due to the absorption and (.irculation of their prod- 
ncld. Thus, he found (1) that irmcultition of a utrrilizftl culture 
produced a fatal form of the diseuse, but that no bacillus could be 
found in. and uo cultures obtained from, the organs of an animal 
iillcd in this way; (2) that inociil.itioii of an unMfrlUzi'd culture 
/iroducetl a similar disease, and. similarly again, that no bacilli 
wtild be found in. and no cultures obtained from, the dixtuiit 
•Tgans; and (3) that in the latter ca,«e the symptoms were first 
wliserved in the locality of the itioenhited part. He concludeil, 
'herefore. that the bacilli in tlie wound ])rodiiced their effect by 
taanufacturing poi-sons which are gradually disseminated. 

The first of the products se))iiratcd was a crystallizable substance 
»Oown as tcfariiiii', while the second was called ti'tnnotorinc. The 
third, in order of discovery, though the moat poisonous of the three, 
«L«« been named ti-tnrius tuj-nlbinnnae. 

tlvitiksato conferred a two-months' imuiutiity on riibbits by inject- 
"> tj II small portion of a sterilized (filtcruJ) culture, followed by five 
da».ily injections of trichloride of iodine (3 c. c. of 1 ))er cent. 
**>lution). Subsequent observers have obtained results precisely 
*-Ta»lr)gous to those already described in di]ihtheria. Small but 
■f^^ularly increasing (3 c. c. to 120 c. c.) and repeated doses of the 
I ■It'orcd cultures gradually confer imnuinity. and the serum obtaiiieil 
™~«Jiii animals thus protected is found to prevent llie develojinieiit of 
^.y mptoms if injected bt'foir, or with, a fntal dose of the toxines. 
■V some observers the same result is claimed when the injection 
L'*'-»//o«'» the development of the 8ym]>toms of the disease. The 
^*^^cacy of the " antitoxin " serum, when kept in tubes, lasts little 
**»«tre than a week. 

Maliernant CBdema. — A spreading tedema. ending fatally, may 

'*<? [iroduccd by inoculation of mic<'. guiiifa-|jigs, or rabbits with 

^rden mould. One form of bacillus develo|is. and the tedema-tluid 

**>ntainiug it is easily inocMilahlc (ji. 34.">t. The bacillus is 3 ft to 

3.0 ;/ in length, but gro«s iiiln longer threads which much reseudjle 

Mtkrax bacilli. They diflcr in showing no segmentation, in having 



roiinilod cmis, amJ in being iibsoliitoly anaertibic. In culmre*J 
cLnractcristic air-bubbles occur at the fhlan nf the tube. (Sc« , 

8PIROBACTERIA. — Two ilisoases, Ki'la|i8iug Fevt-r nntl f'hol. 
era, arc assuciatfil with curved organisms behmging tu thix ordi*r. 

Relapsixifir Fever. — The Spirocha-la Ohermeirri (Fig. 121). nftcn 
called spirillum, i^ fouml in the blood in this dixeuxc. It «v lii*- 
covcrcd by Uberiueier in 1873. It is ii /.ignag, !«har|dv cnr»«L 
uniform thread, 16 to 40 ft long, with quick nnduUting roorcmi'iiU. 
No 8]M)rc.»i arc known. The organism takes the ordinary »uui» 
feebly, and does not retain the stain when treated hv <tnJn« 
method. The organisms appear in the blood soon nfWr the mn* 
mencement of an attack, and disappear with remarknhle »pi>rd »ft«r 
the crisis. Metchnikoff states that during the afebrile intrrv*^ 
they accumulate in the spleen, and Soudakewitch has shown lt»*^ 
the previous removal <if this organ enormously incrcamw the 
tality. Nothing is seen of thorn till the relapse, when they n-tuTt*^ 
All attenijits to cultivate them have hitherto failed. The di»t**** 
hiM hern inoculatc<l from man on man and from man on Ap*^ 
(Carter. Koch), It is said that blood taken io the fever-free prt^***^ 
is not infective. 

Cholera. — The infective nature of cholera has long been m^**' 
tained by many observers, but nothing ilelinite was known in If***-** 
when Koch began his work in Egyjit an<l India. He was at <»«**^ 
struck by the discrepancy between the accounts of the poM-\ 
appearanri-t as given in text-hooka and the con<litions which 
actually found. He observed that it was (|uite rare to find 
intestinal mucosa simply opaipie with slightly swollen folIicl<« 
the intestinal contents like gruel, as had been described, 
found that this happened only in the most acute cases, and that 
gruel-like content.-* then consisted of un almost pure cultivation 
the jmrasite presently to be described. Koch only vcnr cxcepltt^^ 
allv found in the intestines any fluid so thin as to be <-om|uiraE^ 
with rice-water. In cases of somewhat longer duration he foo^* 
the follicles and Peyer's patches surrounded by «ones of by 
mia. running together into red areas; and idtimately, in the I-'Tiu' 
est cases, the small intestine became int«'n»ely cougeste*!, the cun- 
ge«tion being most marke<l above the ileo-cwcnl valve and djinf! 
away in the upward direction. With these chungcs the totMtioal 




Dlents became increasingly bloody, and finally exhaled a dis- 
JCtly putrefactive odor, whilst the parasite above referred to was 
»re or less replaced by other bacterial forms. 
Li the stage of patchy redness .sections of the mucosa parallel to 

surface showed that in the most acute cases the redness corre- 
Joded to an invai<ion of the e[iitheli(iiii of the tubular glands by 
^parasite found in the intestine : the organisms were found lying 
*ecn the epithelium and the basement-membrane. This bacte- 
m, therefore, soon attracted attention by its definite form and by 
apparent constancy. 
Koch'it i'holtrn Spirilfum or Vibrio is about one-half to two-thirds 

length of a tubercle bacillus, but thicker {aliout .;') //). It is 
md. usnally to a degree ei|uul to that of a comma (hence the first 
^p>comma-baci)liis). bnt sometimes to that of a semicircle. It 
lipfies by transverse division, and wlien the organism is grown 
^I'lutinnus media or the intestinal mucosa tiie segments sepa- 
^om each other at once: if two remain united, they form an 
^g. 12f'), their curves being in opposite directions. When cui- 
ted for any length of time in nutritive fluids, the spirilla may 
ttiu united until they form <k'liciitc sjurals of seuiie lengtli, very 

tB spirillum of relapsing fever: these are probably degenera- 
rms. A single flagelluui is usually attuciied to one end of 
I organii^m. Occasiiuially two or more tiagella may be sinn'larly 
ched. More rarely still, flngella may be connected with both 
I. Botli single cells and sjiirals are actively mobile. When 
*nt in the intestines in large numbers, thcv form, according to 
h. little heaps in wliich the single cells have all tlie same <lirec- 

tthat it looks as if a little swarm of them were making their 
e behind the other, like fish in shnvly-moving water (Fig. 
I. The organisms stain with tlie ordinary solutions before men- 
ed. but do not retain the color when treated by Gram's method. 
he vibrio grows well upon nil the onliiiary media ami its rapid 
tiplication can be watched in a droji of meat-infusinn u(ion the 
IT surface of a cover-glass. If linen stained with cholera dejecta 
;ept moist and e.xjxiscd to rlie air, growth is also very free for 
jg three days. The colonies upon nutrient gelatin or agar 
^k very pale tiny spots, which, as they get larger, present a 
nljr irregular outline ami a finely granular surface: Koch com- 
M them to heaps of fine bits of glass, On the second day the 
ilia liquefies in the immediate neighborhood of each point, an<l 


the colony sinks into a bell-shaped depression with a white apical 
point. The appearance of a long narrow funnel is very typicai 
when a tube is inoculated by puncture. (See Frontispiece.) In the 
case of allied organisms liquefaction generally takes place Bort 
rapidly. For diagnosis Koch relies on the combined eridenc* 

Fig. 129. 

Cholera uptrilla. Klagella not nhown. (From it upvcimeD by I)r. ArUe, prepMcd in Korh'k 

afforded by (1) the microscopic appearances : (2) the result? of culti- 
vation on gelatin and on agar ; (8) the indol reaction with peptone- 
cultures: and (4) the effect.s of inoculation on animals. 

The growth of this spirillum is unusually rapid ; it roacbeff its 
limit in u few days, remains a short time stationary, and then dimin- 
ishes, the bacilli either shrivelling or swelling, and staining more 
or le.«s imperfectly. Many strange " involution-forms " appear : these 
have been thought to belong to different species. Clear spots failing 
to stain have often been taken for spores, but Koch showed that 
spirilla containing these spots were obviously dying, for they failed 
to grow and did not po.isess the resisting jmwer of spore-bearing 
organisms. He does not believe that s|)ores are formed, but Hiippe 
and others have described the splitting up of vegetative cells into 
small fragments, which become rounded, like spores: these when 
transplante<l grow into spirilla (iirthrosporet). 

Growth is most rapid at 8t>° F. to 104° F. (30° to 40° C), anJ ^ 
stops below (10.8° F. (H»° ('.). Death results from exposure ti>^m. 
a moist temjjeratiire of l^il" F. (.").'>° C.). Oxygen is essential tci».^ 


grotith, but neither its absence nor an atmosphere of carbon dioxide 
causes death. An alkaline reaction is most favorable to growth, 
while distinct acidity often arrests it ; but all acids have not this 
effect, for, though the surface of a potato is acid, yet growth occurs 
freely upon it. Koch added many antiseptics to cultivations to dis- 
cover those which most powerfully hindered development. Quinine 
(1 : 5000) and mercuric chloride (1 : 100,000) head the list, but it 
is obvious that the constitution of the material to which they are 
luhlei will greatly affect the result. Koch's most important obser- 
'ation on this point was that complete desiccation killed the vege- 
tating cells of these bacteria in three hours. It must be remem- 
bfred that in pappy substances many hours may be recpiired to 
<^oniplete de.«iccation, but even in such twenty-four hours suffice to 
Jcstroy cholera-germs. On the other baud, Hlij)i»e obtained fresh 
^''Jltures from arthrosporous spirilla after four weeks' desiccation, 
and vigorous growths have been obtained from desiccated cultures 
•fter ten months. It is not yet certain, but Hiippe believes that 
**"throspores were contained in the latter, and that new growths 
*fter long intervals always arise from these structures. Lastly, it 
is very probable, if not certain, that this spirillum soon dies in 
pKtrid fluid, cesspools, and the like, and that, consequently, the 
**J<lition of antiseptics to such collections of matter may possibly 
P^'eserve rather than destroy the cholera-germ. 

Koch was strongly of opinion when he wrote his early papers on 
*»*>8 subject that the form of the "comma-bacillus" was quite cha- 
racteristic, but Finkler and Prior discovered a spirillum very like 
** in "English cholera;" Denecke found another in cheese; 
*«8clierich obtained one from the alfine discharges of infants with 
**'»namer diarrhoea; and Metchnikoif, one from fowls suffering from 
*• special form of enteritis. Koch found a bacterium like it, but 
thicker, in the water of the Hooghly. Careful study of the plate- 
*'*«l tube-cultivations of these very similar organisms and of their 
T**thogenic effects has shown that they can be readily dii^tinguished 
**.y thoroaghly competent observers. 

It would seem from the above morphological and physiological 
"stalls that Koch's cholera germ is a perfectly distinct organism, 
*^d that it is invariably present in the early stages of the disease. 
* ®t all of Koch's statements are not fully accepted. Some observ- 
^''s affirm that the spirilla do not necessarily invade the intestinal 
Epithelium. Gruber maintains that variations in the size, curve. 



Hharpncss of ends, and number of flugdiii ar<> (!(>iiini«ti, nt 
on the special epidemic in i|iiegti<>n, on the eonditioni* n 
and on the stage of cultivation. 

Koch's theory as to its action is that, being eonfineti tci th<- inti*- 
tine, it produces a virulent general puiiwn, which is alxwirW Mii 
at the same time nets as :in intense irritant to the niiicoiis men ' ^• 
Early death in coilapwe. perhaps liefore the passajre 'd' «i«in;:l- 
may result from general {tui.soning, and it is in thitie raoitfi that tb» 
intestine is found pule — simple hypertemia having <lied a» ■ 
longer cases the loeiil eflects iteeome more markc<I. and ini : 
extravasation of re<l eorpuseles remains to indicate the existenwf 
the liyper:rmia. Then tlie eholeru germ having rearhe<l itJ" ■ ' 
development, hindered perhaps from further growth by the | : 
of its own action, is more and more replaced by putrefaetiT«' j^^i' 
the proflucts of which are both extremely irritant and pt>i»oiK'i»- 
Various toxic bodies have been obtained from culturei of tk» 
cholera spirillum. These when injected give rise to cram|i«). otrdiv 
failure, and lowered temperature, respectively. The exact n»turr 
of these is at present unknown. 

Koch examined the intestinal contents and stoids of a \*t^ 
number of — dysentery, intestinal catarrh, nlceration. t\pb«i'l 
iiikI tvphns. diurrhieu nf iidtilts and children : the stools of aoiiDil*- 
normal and after arsenical {>oisoning: the contents of the ('il<"ii"» 
drains; and water from the most varied sources. iUxcv odIt. in* 
tank in a cludera district, was the spirillum found externn' 
body, and here it .seemed to have a dear relation to the tj..u- 
around it. Koch therefore cotieludes that thi» HyiriUiim ocrun**rl 
tn catfii itf cbolfra. It« di.icovery. therefore, in tlie stools of dis'- 
rhira would be most imjwirtant. 

Metehnikoff has |M)iiited out that during a neighboring epiJ"** 
of cholera the drinking-water of Versailles containe^i the cb'ilf* 
vibrios, yet that those who drank the water remained unaff'*''''- 
He has further shown that the organism persistiil in the »»"■' 
for months after the epidemic had ceased, and therefore ih«l "* 
appearance of the microbe in water did not neecs.sarily invoh 
appearance of an epidemic. He believes that cholera or/j 
may exist for some time in the intestines of animals without 
ducing cholera. This result he attribute*! to the action of < 
tiguous and contemporary organisms. Some of these aid. 
otht^rs hinder, the action of the cholera vibrios. 


In the proof of causation we have now shown — 

(1) That Koch's cholera spirillum is a specific organism to be 
and in all cases of cholera, and rarely, if ever, in persons not 
iSering from the disease. 

(2) That pure cultures of the spirilla can be obtained, but that 
ccessive cultivations tend to cause their degeneration. 

The possibility of inoculating the disease must now be considered. 
' an accident cholera dejecta became mixed with water : this was 
mk by seventeen persons ; of these, five had cholera (Macnamara). 
;ain, at Berlin, during a course of demonstrations upon the bac- 
ia of cholera, one of the members of the class was attacked by a 
tinct though mild form of the disease, his stools containing num- 
ra of spirilla. No other source of infection seemed possible. 
Meanwhile, Nicati and Rietsch at Marseilles succeeded in infect- 
; dogs and guinea-pigs with a disease like cholera by injecting 
Itivations of the spirilla into the duodenum, and their results 
!re repeated and confirmed by Koch and others. This method 
i« adopted to avoid the stomach, in the acid secretion of which 
e cholera germs ordinarily perished. Of eighteen guinea-pigs 
08 treated, thirteen died of " cholera," whilst of " control " ani- 
ils injected with other bacteria, none died. 
Koch next neutralized the gastric juice for about three hours by a 
itable injection of carbonate of sodium, and later injected spirilla 

meat-infusion, but with a negative result. He next delayed 
iristalsis by means of opium, with the result that of thirty-five 
'inea-pigs infected through the stomach, thirty died of 
Infection through the stomach would apparently be much easier 

man than in guinea-pigs. Ewald finds that water introduced 
to an empty stomach remains neutral, or even becomes slightly 
Wine : its quantity decreases slowly for an hour or more ; then 
'^Teases suddenly — evidently from opening of the pylorus — before 
' reaction has become acid. Cholera spirilla introduced shortly 
'fore this juncture might reach the duodenum alive. If arthro- 
Ofes exist, this is even more likely. It would therefore seem 
•ssible that the cholera spirillum might occasionally pass through 
* stomach of man without predisposition. As with other acute 
*cific diseases, of those exposed few take the disease ; and, accord- 
gto Koch, almost all these had digestive troubles, gastro-intestinal 
tarrh, or an overloaded stomach, the latter condition diminishing 


the general aciclity of the stomach and enabling the »pi 
\niss with undigosfed ntn-sses. 

The I'imtiiijion of cholera frUt$ in the rtrjecta and finite < 
ally in vomit (when this has regurgitated from thu int«Httn( 
uprfdd to oeciir. tiioistnre n* essentini, lu* de!<icration »)• a 
above) means death ; cholera, therelure. does Dot, like 
spread by the shaking of dust from linen; it is not e^rrioi 
nor by inerchnn<, but by man. As a rule, it is sprau 
infection of water ; this occurs very easily in India, vrhor 
tank i.< employed to collect water for nmny [icople. and the 
is used indifferently as a public bath, a w.ish-tub, a cosap< 
reservoir of drinking-water. Koch (|Uote.s convincing i-j 
show thill the su|iplY of pure water will preveni thr nn-w 
the ilisease where previously it has been rife. Most prov 
be infect^-d by contaniiniitoi han<|?i or perhaps by Hies. 

It has already been shown liiat ifiin para»itr ran tuMit 
from the body — e. g. on moist linen, on }>otato. or in nettl 
As it requires rather concentrated nourishment, it prnli 
not multiply in ordinary running water : but many of t 
of India are extremely foul, and organic matter incrcasi 
where the waters stagnate, drains and gutters enter, and 
and animal refuse collects: round about such ma.sses wati 
muddy froui germs. Stnguant surface-water. ibiMvfore. *^ 
the great culture-ground for cholera germs external to tlie 

.Ml cviilence g(»es to show that thf hurin' of thr rholrrA 
the delta of the Ganges — a region so peculiarly a'Upt 
growth of micro-organisms, by the <|uantity of dend aa 
vegetable matter and by the heat and the moisture, that 
expect to meet with i|uite special forms of bacteria. To ij 
careful incjuiry has always been able to trace epidemic* of 

For an account of fireventivc vaccination against rb 
p. 363. 

The Buastomycbtes, ob Yeasts 
These are small round or oval cells which multipl 
(gemmation). Sometimes the cells cohere au<l f« 
chains. When food is not abundant, oa in the 
cultivation.*, one to four sjiores may form in the intei 
yeast-i-ell.>» ; these develop when placed in fermeuial 
Under these same conditions unjointed mycelium may W 



Fio. 130. 

Furthenaore, when it is remembered that the growth of some higher 
fungi (e. g. Mucor Mucedo) under exceptional circumstances is the 
«»me as that of yeasts under ordinary circumstances — i. e. by gem- 
nation — it seems possible that yeasts may really be vegetative 
forms of higher fungi. 
Yeasts are of importance only as causes of fermentation. They 

nerer invade living tissues. They are common in the stomach, 

either alone or in company with 

MTcinse. They are frequently 

foand in diabetic urine, but not at 

the time it is passed. 

Thrash. — In this disease toler- 
ably adherent gray or milky patches 

form in the mouth, pharynx, and 

gullet, either of children at the 

breast or of adults exhausted by 

wasting diseases (typhoid, phthisis). 

These patches are due to the growth 

of the oidium albicans, a parasite 

which was regarded as a mould; 

bnt Grawitz states that when cnlti- 

nted this fungus shows itself to be 

» yeast, and probably the Myco- 

flerma vini, which he has proved capable of growing on mucous 

■netnbranes. The patches consist of tortuous, often-branched fila- 

"•ents, formed of long cells united end to end and distinctly con- 

"ricted where they join. The filaments end in roundish cells which 

P>x>dnce one or more spores : these form heaps in the epithelium 

(^ig. 180). 

Thb Htphomycbtbs, OB Moulds. 

These consist of filaments {Myphce) formed by a single row of 

''^lls placed end to end, growing by means of an apical cell which 

'•ongates and divides transversely. Lateral offshoots are common, 

"**t dichotomous' branching is rare. The thallus may consist of a 

*'Ogle hypha, but usually the hyphae are numerous and intercross 

'^sely or closely. All spring from an axis or germinal tube which 

pt)wg directly from a germinating spore. Compared with that of 

oacteria (p. 326), their growth is extremely slow. 

In the adult plant the hyphse are of two kinds : (1) the nutritive, 

Oldlam albicans. Cells and spores 
seen on the surface of epithelium, 
scraped from an "aphthous" patch on 
an Iniiint's tongue. 



which grow intn iiml extriict iiourifihim'nt from the ciilttir?«i 
roniiiiig ill it. Iiv their iiiti-rlacfuicnt, tlie mt/ri-lium ; aud (2) (be 
reproductive, which s|>riiig from tlic mycelium ami stand up frnni 
the substance in which the mycelium lies: these are called friiil- 
hyphtc. They are simple or branched, and bear at their ends 
spores or sexual organs. Reproduction is either asexual or oexual: 
the two methods may occur together on the same plant or nn; 
alternate regularly nr irregularly. Spores are fornietl by {-ach— 
round, oval, or cylindricul, f»uiootL or irregular, colored or color- 
less; most are motiouless, but some '"swarm." Each consiM of « 
little mus.s of protojibism. surrouinlpd by an envelope, which is m»il( 
U|i of an outer {ijuxjinfiuii)) and an inner {I'UihitjMjrtuin) lavir: iL* 
exo8])orium is often pigmenteil. All spores have great power of 
resisting the action of physical ami chemical agencies, and roiiin 
life for long periods; those lnrmed asexinilly are ready at nm-etd 
germinate, but those due in a sexual process almost always ret|iuit 
a rest. The latter are the true refitinij-i>porrit ; but this name is 
often apjdicd to all spores capable of retaining life for long periodi 
in spite of adverse conditions. 

To unilerstand the above and what follows the student sliouU 
examine a few moulds from the surface of thin jam. paste, dceaviB^ 
fruit, or the surface of a slice of potato which has been exjiosed f"r 
an hour nr two in a dwelling-nmiu. In all the aerial jwrtion tf 
easily studied, and tlie mycelium is readily shown by crushing » kit 
of the cultiire-grnuiid under a cover-glass. 

Asexual spore-formation occurs in three ways: 

(1) Ilyidiie spring frnin the mycelium, and perhaps bninoh. Thi 
terminal cells divide transversely into .spores (^coiiiih'n). whirii ciibcr 
fall away singly or form chains. 

(2) A hyjdia (Mfiiiniiii/iitp/inrc) stands up from the mycelium, ai"! 
its end swells into a ball full of jinUoplasiu, which .segment* »i" 
forms ronidia {uporauffiuii)). 

( -i) Fr()ni the surface of a knob on the eml of a hypha {ronidiifhpr'] 
peg-like jirocesses (Wcrf(/w(»^7) sprout, each sterigma, by growth •"fti 
tninsverse ilivisinn, forming a chain of s|iore8. 

Sexual reproduction occurs in three ways : 

(1) Coiyugration. — The a|dcal cells of two hyphae meet cinl 
end and blend into one cell {zi/fpmpori'). From this, after a Ion 
or shorter rest, a sporangiophore 8j)rout8, and from its sjiorcs 
plants grow, as in Mucor. 




(2) Fertilization. — («) The end of a hvpha becomes twisted like 
» ciprliKcrrw. niore iind more closely, until the turns form a contiii- 
miuii tulie — the 'tuiw/oiiitim. From the lower turns spring fine 
linmciies. one of which (antheridium) conjugates by its apex with 
llic ancogoninm ; and others siinjily cover the ascogoniinn oontin- 
imusly, and are converted by division into polygonal cells which 
(«m a capsule {peritJiecium) around it. Many transverse septa 
fonu iij the tube of the aiicogonium, and from tlie cells thus pro- 
duced fla.-'ked-shaped lateral jirojot-tions (*»»(•/) develop ; in each of 
these eight spores generally appear. The perithecium thins as the 
Mci enlarge, the walls of the asci disajipear, and an easily-ruptured 
sphere of spores remains. When these germinate the ciidospore 
swells, splits the exosjtore, and throws out the germinal tube, 
whence springs the mycelium. This again gives origin first to 
conidiophores, then to perithecia. Eurotinm repens and Asper- 
gillus glauciis, found especially on preserved fruit, show these 
ch»ngcs (Sachs). 

(A) In some species certain cells form an organ (oo;jonium) in 
*hich one or more female reproductive bodies (ooHphi-rm) are 
formed, whilst other cells form a male organ [iin/ln'ridiinn) in 
*hich *permatozouln are produced. The oosphere, which is hun- 
dreds of times larger than the spermatozoids. remains in the 
*'g>iniiim, and is there fertilized by the mobile spermatozoids. It 
•» now called an oospore, and may, after a rest, directly develop 
into a new plant or form cells, each of which develii])s in like 

Conditions of Life. — Food. — Possessed of no chlorophyll, moulds 

"* niiitble to build up carbon-compounds. They a,ssimilate those 

'"'•It up by other plants or animals. They are therefore always 

titlier saprophytes or parasites; in the latter ciise they may kill 

['"fir Lost. They reijuire a free supply of oxygen, but some can 

ifotain it, at least for a time, by decom]iosition of organic com- 

iTwund.s like sugar. Thus. Mucor racemosus, cultivated on the sur- 

»<•& of a saccharine liipiirl. absorbs oxygen, oxidizes completely 

"*>neof the sugar, exhales carbon dioxide, and grows rapidly. If 

''^'lirivrd of oxygen, as by immersion, ojdy the mycelium grows, 

••xl this becomes broken u]) into shoi^ cells, which multiply by 

("idding and much resemble yeast-cells. Their growth is much 

''"wer, carbon dioxide escapes in bubbles, and alc(d)ol appears in 

tile li({uid. But all these changes soon cease, and the process can 



bo started again only bv a frcsli supply of oxygt-n ( l)uclaus 
luuulds. as Pfni'.Mlliiini gluucntn, Aspergillus uiger, iinvc no 
of thus obtaining oxygen, and die if cat off from the (re*l 
The change in the cliaracter of growth above nieutione»L ttrtm-* 
panying changes in conditions of life, is often pointed to «» e»ji 
in favor of the mutability of bacteria. 

Light. — Many moulds can develop completely without light; 
reijiiiru it for the discharge of spores and other proce!«m». 

Temperature. — Ziegler states that moulds flourish Initt it Ira- 
poratures hfihw that of the body, and that s«»we will not gr««tiiD 
at so high a temperature. .\ few species* of Aspfrgillu.'* and Miiror 
grow well between 9.0° and 10;"»° F. The 8[>ores are a* rrsiMai^* 
external agencies as are those of bacteria. 

Water is essential, but mere dampness is sufficient. 

Action, — Moulds are associated with processes of rottiHjf 
The peculiar smell and taste which they impart is known to alL Tb* 
products of their life-action have not been closely invontipitcil. V«l 
they are neither very |M)isonou8 nor very irritating, so far a* hum** 
tissues are eimcerned. 

DiBtribution. — The spores of moulds are much more numeroa*" 
the air than are other organisms. They therefore conxt 
upon tlie skin and enter the air-passages with air ami li 
passages with food. As a rule, they find no nidus suitable fur 
development : the supply of free oxygen is <»fkcn in.^uffieienl 
temperature too high. Certain of them, however, when bnn 
contact with accumulated inflammatory discharges or with 
take root and fructify. This i.i most likely to occur in the 
mouth, and pharynx. They are here saprophytes, but tbr 
to which they give rise may irritate the living tissues lying l 
the soil in which they grow. Species of Mucor and Asper^gilli 
those commonlv fouml. 

Patboerenic Moulds. — Owing to the ]»eculiarities mentioiKvl 
their life-history, these fungi have but little |>ower of inradio ^ liri 
tissues. Certain skin diseases are. however, due to the gro 
speciej* of this cla.ns in epiilermic structures: they are (!)/< 
(2) tint^a tonturaut, t. kfrion, t. ttirrinata, t. ai/cona, and I. un^ 
and ('i) tlnfii rrrtifolor. Two disen-ses. ai-tinumtie«»i» an' 
J'ltot of India, have been aliribuled to penetration of i;. 
sacs by byphomycetoug fungi, and true mycoses may a]M> c 
ally be due to growtbs of the AtperyllUui fumigatut or A. 

..I.. f.;i 


Favus. — The Achorion SchSnleinii forms almost the whole of the 
light, yellow, mouldy-smelling crusts characteristic of Favus. 
When in hairy parts, which are the usual seats, the hairs are always 
invaded, especially the roots. Here the parasite grows luxuriantly, 
but it does not extend far up the shaft : its primary seat is the epi- 
thelium of the hair-follicle. On non-hairy parts the mycelium 
invades the deeper layers of the epidermis, and may ev«n penetrate 
to the corium : in this case the local irritation will be more marked. 
The mycelium consists of unjointed, branching, confusedly inter- 
crossing tubes ; in certain of them, which become divided into joints, 
oval spores form. 

The nails are very rarely invaded, and then only by mycelium. 

Tinea Tonsurans. — The Trichophyton tonsurans is generally 
assumed to be the one parasite common to tinea tonsurans, tinea 
kerion, tinea circinata, tinea sycosis, and tinea unguium. Different 
varieties have lately been described. These are distinguished by 
die size of the spores (t. megalosporon, t. microsporon), their pyo- 
genic effects {t. megalosporon), and their culture-results (Sabouraud). 
These forms are not found growing together. 

Wben the hair is affected the root and the lower part of the shaft 
we crammed with spores lying in rows between the fibrils of the 
degenerate hairs, which are opaque and brittle. It is doubtful how 
fiff the fungus makes its way down between the shaft and the wall 
of the follicle before it penetrates the former. The hair breaks just 
beyond the scalp, leaving a stubbly line of split or twisted ends. 
Epidermic scales from the surface of the scalp may contain the fun- 
gns, but the deeper living cells of the root-sheaths are always free 
from it (Thin and Taylor). Spores are abundant and oval in shape ; 
■"jcelial threads are rare. Points worth remembering in connection 
"•A the undoubted fungoid origin of the disease are — (1) its usual 
'imitation to children ; (2) its tendency to fasten upon the weakly ; 
(3) its great contagiousness when acute, diminishing as it becomes 
*hronic; and (4) its greater severity when contracted from animals, 
** tbe horse (Tinea megalosporon). It may excite severe irritation, 
*id even suppuration — T. kerion. 

Tinea Circinata. — Here the parasite infests epidermic cells, 
'^vayg causing desquamation, sometimes vesiculation, or even more 
SSTere inflammation. It spreads uniformly from the point at which 
•t first takes root, and consequently assumes the form of a gradually 




enlarging circle. The central partM of the funguit die. ami tlir I 
cuinlVrential give rise to hyjicrseniiii in tlifir ni-ighlMirhood. 
celiiim is present chiefly in the fonu of very long jointni 
branched threads; the sjwres are scanty, single, or in »h«rt cht 
The fungus altogether is often sciinty, and is especially tlifficnlt u 
detect if it haw excited intlaiumation. 

Tinea Sycosis ( ?'/«<■(» invtfahiitfioroti). — When attacking the \mv>\ 
the fungus is found chiefly in the hair, but also in the follicle ; Imtii 
mycelium and spores are seen, the latter in exccM. bat not » 
markedly a»* in T. tonsurans. The mycelium generally lie* roirod 
the root of the hair, and is pulled out of the sheath with it. Sevat 
inflammation is generally excito<l. 

Tinea Unfiruium. — Mycelial threads of trichophyton may oca- 
sionnlly invade a finger-nail, rendering it opaque, thick, ami brittlr. 
I'nlike a general condition, the fungus produces these chanjjw in 
two or three nails only, and the toe-nails are scarcely ever affwtrJ- 
In this situation it is extremely diflicult to destroy. 

Chloasma, Pityriasis Versicolor. — Micronporon furfur inr»il« 
the horny layer of flic epidermis of covered parts of the trunk, 
growing more superficially than any of the above, rarely ctuio; 
irritation and not attacking nails or hair. It consists of ymxti 
mycelial threads, which are always almndaiit. and spores, »liifk 
vary in form, lie in groups, and grow at the ends of ihc nivc«li»l 
threads. It can be easily cultivated. 

Actinomycosis. — The ray fungus (actinomjfcet) is believe<i tol 
the cause of this disease. Its de.scription will be found in the 
ter on " Infective tirnniilomata." Its botanical pt>sition is douUfl 

Madura Foot. — Mtjiilninn. — In certain parta of India thr 
of the natives lire linlile to ii [leculinr swelling : "tubercles" 
beneath the skin, burst, and leave Minus«»s froJU which IsHlirt 
those constituting the roe <»f a fish are dischargeil, or, more rmrrly. 
bodies like grains of gunpowder. In the latter fungous eleincB'* 
have been recogniied, and called i'liioni/fthf i'urirri. The»» »'* 
believed by some to be the cau«e of both classes of the dise««e. '*' 
section masses of the above bodie.n are seen, especially in the fr**,^ 
layer; the masses may have no obvitms communication with <*^ 
other or with the surface. The botanical position of the f"^ 


I doubtful. Kanthack considers the disease a form of actino- 
Boyce and Surveyor acknowledge the similarity, but not 
itity, of the two. 



term infective granulomata is applied to a group of diseases 
g tubercle, lupus, syphilis, glanders and farcy, leprosy, 
yeosis, and rhinoscleroma. It was originally used by Vir- 

emphasize the points of resemblance which the lesions of 
ve diseases show to some forms of tumor. These lesions 
3f cells varying between lymphoid and giant-cells in size, 
ig in a scanty matrix, while the mass thus formed presents 
aked eye a more or less defined outline. The lesions there- 
;mble sarcomata in structure. Many of them develop with- 

obvious cause, and are not accompanied by any distinct 
inflammation ; they often pertist for long periods, and, 
e exception of gummata, rarely undergo absorption ; they 
^generate early, and show little tendency to develop into a 
!nt tissue ; and lastly, most of the lesions have an infective 
•eproducing themselves in neighboring or distinct parts by 
od- and lymphatic vessels. In all these respects the above- 
ed new formations resemble malignant tumors, but they 
om them etiologically. In the case of some it is certain, 
he cSse of all it is probable, that the tumor-like nodules are 
i of chronic inflammation, excited by the growth of organ- 
certain points in the tissues. Irritation is maintained as 

the fungi grow, and, as their growth is often slow, the 
s are often chronic. The development of vessels is im- 
and so degeneration is the rule. Secondary growths in 
rts are due to infection from the primary focus, but organ- 
d not tissue-cells, are the active agents, 
bove diseases are as specific as the "acute specifics." Their 

lesions have a general resemblance, but the primary seats, 
if generalization, varieties, and times of degeneration, as 

the clinical symptoms, establish them as distinct diseases, 
ismissibility from person to person of syphilis and glanders 



is well knnwn: tubercle can be transmitted experimentally, and the 
clinical evidence of its ordinary communicability from man to uua 
is Vi'Ty strong. Leprosy lias been ac<iiiired through a po9t-raorl«ii 
wound, and exjifriiiu'iital inoculation has been successfully per- 
foi!))i'd upon a criminal. Actinomycosis baa been transmittoil fniis 
man to animals. The term infective granulomata. though .iilnpifil 
at a time wlieu their real nature was little understood, seems ticltcr 
fitted than any other to express the nature of the lesionfl — tnnior- 
like bodies consisting of granulation tissue and locally or genenllj 


Tuberculosis is an infective disease which is cbaracteriiwl «»»- 
tomicully by the formation of those small nodular lesions known >► 
tubercles. The distribution of these lesions may be more or l« 
general — acute general tuberculosis ; or they may be liinitc*! to 
small areas — c. 7. a pleura or the synovial membrane of a jnint— 
local tuberculosis. The latter, as a rule, runs a much more cIiphib 
course than the former, and perhaps its chief danger is that it wtf 
serve as a focus for general infection. 

The virus of tubercle does not always produce nodules. Lairniw* 
divided tiilicMTuhir lesions into the nodular and the infiltrating, l** 
tlie hitter case a diffuse inflammatiuu is found, and micr<i.>>i'Opic f*' 
auiiuation shows the presence of numerous non-vascular collection* 
of cells, not aggregutcd into visible nodules, but separated by »* 
ordinary nmnd-cellcd infiltration. The presence of the orJini»'fi 
tubercles in a tissue is always accompanied by more or less i: 
mation, as is best seen in serous membranes. 


NAKED-EYE APPEARANCES. — Tubercles are divided i«»' 
two varieties, gray and yellow, the latter being later stages of ** 
former. Gray nr miliary tubereles (gray grrunulataonsi an 
semi-translucent, rounded bodies, varying froui just visibi' , 
to nodules the si/,e of a ]iin's head or larger. They art firm 
shot-like, distinctly circumscriiicd and prominent above the snrfi 
of the section. Yellow tubercles are generally larger, less regu' 
less closely defined, and softer than the gray. They may even (at^ 
masses the size of a cherry or small walnut. In some caim* id9^ 
of the tubercles present are gray, whilst in others all arcycll(»^i 
but it is fre(jueutly po.ssible in the same case to trace every htagt H 




tlie formation of a yellow from a gray notliile. Fatty (lo<:^encration. 
connivncing centrally, is the main cim.ic of tlio clifl'erence between 
them. A large mass of yellow tubercle is formed, not by the growth 
of uny single tiibercle. but by the blemiing of several arising close 
liigethcr. It is often jKissible lo recognize, round a yellow cheesy 
Dmss, a narrow gelatinous zone consisting of gray tubercles. Gray 
tuljorcles may be also seen radiating frnni the eheesy focus into the 
ailing tismics, thus indicating that infection from the central 
to the formation of fresh tubercles in itx immediate 
neighborhood, and these, as they enlarge and degenerate, become 
part of the central mass. A yellow uniss thus formed is called con- 
glomerate tubercle. 

SEATS. — The skin and subcutaneous tissue, the inucons mem- 
branes — res|iiratory, aliuientiiry, and geiiito-urinary — ami the serous 
Mil synovial membranes are very commonly affected ; so also is the 
pia mater. The dura mater, the e|(eiiilyrn!i, and the endoeardium 
rarely suffer. Tubercles are frenuent in the lyiu|iiiHtic glands, lungs, 
liver, spleen, kidneys, and testes; less common in the brain and 
spinal cord, adrenals, and ju-ostate ; rare in the heart, salivary 
gland-s, and pancresis ; and very rare in the mamra.T, ovaries, thyroid, 
»n(l Voluntary muscles. They are common in bone, es|)ecially in the 
cancellous part. They are particularly comuuiu in childhood and 
wiflv adult life, but no age is cxenijit. 

HISTOLOGY. — On examining microscopically even the funnlh-Ht 
tiiheri-h- fim'fi/r tn tlif nnki'il i'i/i\ it is found to be made up of a col- 
lection of still smaller tubercles, eiicli of ir/iif/i. as a rule, contains 
'iiK following elements: (1) centrally, either one or more multi- 
"iideatcd eriant-cells (Figs, l^^l and 1:^2) or some granular iltM)ris 
"urroimJeil by giant-cells ; (2) outside the giant-cells usually, but by 
""means invariably, large cells with big nuclei and granular proto- 
l''»sm, often called epithelioid cells; and {•1} imtside these, again, a 
*ine of lymphoid eleiueiits which has no definite external or inter- 
"*' limit. The giant-cell or cells in many cases .send off processes 
»luch ana-stomose and form an open network (Fig. 133), in which 
"ic other cells, especially the epithelioid, lie. The lymphoid cells 
•fp commonly containe<l in the meshes of a homogeneous or more or 
leii« fihrillated reticulum, which in some eases, especially in slowly- 
Jfvclopcd lesions, is well marked |Fig. 1;^4). In others it is less 



Kui. i;J4. 


A portion of « tiTRV mili- 
ar}' tulRTi'lc of ttic luni;, 
tilir>\vlii|< the rctiiulBtud 
Ktnu'tiiro ofti'ii mi't with in 
tbeae iiodulen. :< 20U. 

I'ng fine hairs into it. Laulauit'- states that in t)ie lung disease 

>d in dogs by the gtnmr/i/lug vnaoriim the ova ami cnihryof* may 

)en in giant-cells, suri-ounded by zones of ejiithelioiil and lym- 

I cells. In actinomycosis in animals uu 

:lv similar arrangement of cells is found 

^^Ktnt the central iwHnoinyvcs or fungus 


T can the .ibovc structure be said to be 

ant. For, especiall}' in acute cases end- 

'atally. some of the tubercles seem to 

St entirely of small round-cells, no epi- 

»id or giant-cells being visible. In the 

the alveolar epithelium often enters 
■unto the constitution of the lesions. 
Ries visible to the nakeil eye will, however, generally consist 
;gregations of nodules of tlie above structure (Fig. 102). 
urce of the Cells in Tubercle. — Baumgarten's explanation is 
>ne generally aefe]tteil. According to liiui. the cells are 
ed from the local tissue-cells, including both epithelial and 
Bctive tissue (fixed and endothelial). This observer, experi- 
ing with albino rabbits, introduced pure cultures of tubercle 
h into the anterior chiuuber of the eye. In a few days there 
»red i»uclear changes in the connective tissue and endothelial 
of the iris, such as are characteristic of cell-division (p. 27). 
e changes were limited to the cells in which bacilli were pres- 

They were followed by pndifenition of the cells themselves, 
h then gradually assuiucd au e])ithelioid type. No nuclear 
ges iiulicative of ])rolift'ration of any fiu'ui of leucocytes were 
"ved, but the jiroliferating [mtuli was gnidiiiilly invaded by leu- 
■nutil they ijuite obscured the epithelioid cells. Giftnt-cells 
oocasionally present, but only in the Inter stages; when pres- 
hey showed no sign of division, but only of degeneration. 
^tchuikofT maintains that the cells believed by Baumgarten to 
H|)rogcny of connective ti.ssue are niononticlenr leucocytes. 
[Rase of the lung he admits the endothelial cells of the blood- 
Is to a share in the jirocess, and also attributes to them a 
ocytic function. In his opinion, the tubercle is formed by the 
mulntion, not by the prolitVrtitimi, of phagocytes. Giant-cells, 
rdiog to him, are phagocytes that have eoud)ine<l for the common 
) to Baumgarten and Koch they are solitary individuals 



tlisit have tried to niultiply. but, tlioiiph their nuclei bave diri<l«4 
utitl iLfir size has increased, have failed at the final stage nf e^U- 
division. In parts in which epithelium is present, *s in the loEmi:. 
liver (Fig. IS.")), kidney, or testicle, there can be no qnestioo hmvt 
that the ei)ithclial cells multiply freely. In a lun;: affected by acv^tt 

Fro. l:«. 


A »liii;le tubercle, Invlalble to the iwk«d cj*. tnm the IlTer nf k rhilil, a«n| flv*. vke^ 
from ncutc tiilirrculcpilf. .iiiUiit.rcll with (wo i,T<iii|* uf iiu> \mrtOihi 

tii-iir DuM'L'filn*. Surrtitifidiiijc it Ih All iire4» <if L'oinnieiictnK ' i.llieeKUa 

InwoiuIiik IniliKllncl. KiivoIujiIhk thU U n «>iic of crlU con- •(• i 

cjrtM, The leueiioytc* lire 1111141 niiini'rvii<< mi llir >liU- Mlurt <<all 

Tba wbok' lUttM !• liiilwiliU'il itmiiiiu KnifiiiUr IIvitivIIk III III irra. Xt 

miliary tubercuhisis we find that many, even the majority, of i 
nodules do not { the lymphoid structure above de«rrititfd. 1 
are collections of epithelial cells in the alveoli, (iiant and t>|»itb« 
oid cells may be present, formeil apparently from alveolar epithdii 
as Klein and Cheyne a.><sert. Koch regard.s certain pi^ 
containing giant-colls as originating in alveolar epithelium, 
ijuotes Cheync's observation of giantH'ells in the alveoli in Mf 
of his view. 

SECONDARY CHANGES.— Tubercle invariably nnrl 
more or less fiilty metiimorpliosis and caeeation with its iiltii 
changes (p. B9). In some cases the nodules may become devdi^ 
into an imperfect fibroid structure. 

Caseation. — The occiirreiice of fatty changm and 
before the vessels have developed is probably due to the actkMii 
the surrounding tissues of some substance secreted by the barilli. 



Fii,. \m;. 

— - -i^^io --■ 

One of the irrey ntxl- 
uli'S from tb(? tuni; In a 
I'm!!' tif acute tutjcn'iilo- 
si*. wliirh ly booominn 
i>|)U(liiir niid Hon ill thv 
"i.'iilri-. (lUnKrammatlc.) 

Thifl uittj also account for the obliteration of pre-existing blood- 
vessels which accompanies the sprcu.d of the lesintyy. The change 
commences in the centre of the nodule, this being the part first 
«lcveloped. and consequently that which is the 
[farthest removed from vascular sup|)ly : it is also 
the jinrt nt which the bacilli are at first most 
niinierous. arnl it is therefore most expose<l to 
■their deadly influence. The noddle breaks 
■down into a granular fatty d^-bris, so that its 
Kcentral portions soon become opuijui' and yel- 
lowish (Fig. 130). In some cases the process 
of di?inte;:ration is rapid, whilst ig others it is 
more gradual. It is usually most marked in 
the larger and more diffused lesions, and hence 
is these lesions which are most commonly 
>f a yellow color and soft consistence ("yellow tubercle"). 

Fibroid Chang's. — In other the retrograde change is less 
larked. The central portion undergoes fatty degeneration and is 
n>re or less completely absorbed, whilst the ring of leucocytes 
ibicb intervenes between the baccilli and the liealtby tissues is 
dually replaced by a dense, contracting, fibrous capsule. Ulti- 
mately, a mere sear may remain, but points of fatty degeneration 
lire fretpient and may undergo further changes. 

It will be noted that this " fibroid change" is simply the eneap- 
sulntmn of a slightly irritant foreign body, iiTid might take place in 
e.xiictly the same wiiy if a bullet or piece of wire lay in the ti.s.sues 
instead of tubercular organisms in fatty detritus. This replace- 
Bient of the tubercular tissue by scar-tissue occurs in the smaller 
lesiiins and in many of Inrger size which o|ien upon the inner or 
'>ut*r surface of the body, and from which the infective material 
tan be thus discharged. The change obviously tends to protect the 
•"■ against generalization from the focus in which it occurs. 
""'l indicates that the tissues have gained the upper band — they 
''*^»' imprisoned the bacilli. There is the same antagonism between 
tuc organisms and the tissues in tubercle as in other diseases, and 
""■' rwisting power of the ti.ssues may also be sutlicient to enable 
'■'fni in the long run to overcome the invaders — a fact for some 
tinie overlooked. But fretpiently the predisposition of the tissues 
•o suffer from tubercle is so great, or the <lose of the organisms is 
W large — as when most of the contents of a small cavity which had 



just burst into a broncbus i.s sucketl hy inspiration into othwl 
tubes — that a wiilespreiid, diffuse intiaiumiilion results; and llici 
extended the lesion, the more rapidly and freely the inflauimsU 
products caseate. 

Sometimes, es]>ecia!ly in cases which have run u chronic cni 
and in which the diagnosis may have been "chronic brontliitis, 
hard, glassy bodies, often specked with black pigment, are foun 
the lun^-tissue. There is no caseation, and tlie microscope sll 
tlie masses to consist of almost hyaline fibrous tissue. Tbi«i 
plete fibroid transformation is said by Birch-Hirschfeld to 
occasionally in lyui))liiitic glands, and is often thought to iti'li 
that the bacilli are dead. On the other hand, while the oa« 
material persists the focus remains infective, and the organian 
tlu'ir spores, tiiough ([iiiescent, are alive. 

Calcification fro(juently ensues upon caseation, when the ch« 
])roiiuuts bec<mic encajisuled and ahuost all fluid is ubsorM: 
deposit of earthy salts in this truly cheese-like material eoiivf 
either into a gritty mass or into a more or leas irregular *l 
body. Caseous mesenteric glands are especially prone tu 

Sections of these calcareous nodules when decalcified ntid 
amiued under the microscope are seen to consist chiefly of n ( 
of concentric layers. These layers are composed of a substi 
which, according to Metciiiiikoff, gives the same reactions iw t^ 
forming the envelopes of the tubercle bacilli. Arguing from ^» 
experiments on Algerian rats, he maintains that these laycn^^ 
formed by successive secretions of the bacilli, and that they sow*' 
• piently become infiltrated with phosphate' of calcium. Accord^j 
to his view, the concentric layers would seem to be the hned^l 
defence which the bacilli tlirow up against the advancing pL«^*^ 
cytes, while the calcification is the investing earthwork by 
the attacking phagocytes seek to enclose and to reduce by »t) 
tion the organisms they cannot reach, or, reaching, cannot destl 

Softening and Chronic Abscess. — Caseous«'s do 
always dry u|) and become encapsuled. but often soften and bl] 
down into the pus of a chronic abscess; and even when they 1 
become encapsuled and calcified, softening may occur mund 
them : a chronic abscess is then furmed and the dead muteril 
discharged. It is the smaller encapsuled foci, and especially ' 
which lie deep in the substance of organs, that become dry • 


alcified ; whilst the extensive, diffuse lesions and those lying near 
I skin or macous surface tend to soften. In other words, the less 
he resistance of the tissues to the infective process, or the greater 
:heir proneness to be irritated by the tubercular organism, the 
^eater is the tendency to softening. It seems likely that this irri- 
tation of the tissues is the cause of the exudation of fluid into the 
ciieesy mass, and that this exudation changes the latter into a 
:hronic abscess; for an examination of the "pus" of a chronic 
ibsces-s shows that it consists chiefly of fatty granules suspended in 
finid, with here and there a fattily-degenerated, granular leucocyte. 
The fluid, therefore, is quite different microscopically from that of an 
icute abscess (p. -301). It differs also to the naked eye, being gen- 
erally whiter and thinner than true pus, while it often contains 
curdy masses, which may be either gritty or stony from calcification. 
The " pus " of chronic abscess, being thus formed by the suspen- 
sion in albuminous fluid of fatty particles derived from the fatty 
degeneration of cells, has received the name of " pathological milk." 
The enormous majority of chronic abscesses are of tubercular 
origin: a tubercle forms, spreads, and softens as above described, 
the originally firm swelling becoming more and more fluctuating as 
the softening proceeds. So chronic is the process that there is 
often no sign of inflammation until just before the " abscess " 
bursts, when the tense skin where it is pointing becomes red, shiny, 
>nd progressively thinner. Ultimately, the epidermis bursts and 
the cavity discharges its contents. The wall of such a cavity is 
lined by a thick layer of pale purplish granulation tissue in which 
••■e yellow foci. This lining is so loosely adherent to the surround- 
">g tissues that scraping with a sharp spoon easily detaches it, and 
brings it away either entire or in large pieces. The tissues beyond 
" are not infiltnited. It is very important that the wall should be 
■^njoved from such abscesses, as well as the base from any ulcers 
f^sulting from their bursting ; for the granulation tissue is infected 
V the tubercle bacilli, and will continue to caseate and soften in 
'P<its, and perhaps slowly to invade surrounding parts. Healing 
* 'mpossible until the diseased layer has been cast off and replaced 
'y healthy granulation tissue. 

This account of the formation of a chronic abscess holds good 
*herever it may appear : in the subcutaneous tissue {subcutaneous 
^f^mout nodule, so common in children) ; in a lymphatic gland (the 
^'^moua abtceas, par excellence); in the lung, where sooner or later 



it bursts into n bronchus, dischurgfs its contents, nnd forms «< 
or vomirn ; in the tLickcued synovial meuibrnuo of a scrofulous] 
{white atpeUing) ; or iu a bone, as is seen in cnries of the 
The chronic abscesses which arise in connection with deep 
especially those of the spine, are freipiently eallefl gra 
af>»ff»ni'K, because the pus often runs long distances among i 
partM before it reaches the surface, and usually in a di< 
toward the feet. But extension by no means always occurs ial 
direction, and when it tioes occur is not iirrestc<l by placing 
|)aticnt in the horizontal |)08ition. We may thecefore cno 
that in these, as in all other cases, tlie pus spreads in the ilirfl 
of least resistance, and that gravity has couiparatively little I 
with it. Instances have been recorded of alwcess starting from d 
low«'r dorsal or luiiiliiir spine, entering the sheath of the pooas, OMI 
ing gradual absorptirm of its muscular fibres, working il« V" 
beneath Poupnrt's ligament, taking the counw of the profan 
artery, passing thmugli the adductor magniis into the p<i| 
space, penetnvting between the su|ierficial and deep posterioi 
muscles, and finally pointing by the inner malleolus. Sot 
abscess is contained in a dense fibrous sheath formed by infta 
torv thickening of the natural connective tissue. This *b« 
Sometimes strong enough to be dissected out and dried. The ari 
is crossed by stoutish bands, many of which contain voweU, M 
care must be taken lest a finger introduced during life irar ihri 
The inner surface of the cavity is but slightly vascular, the coi 
between the chronic and acute abscess in this respect bvinj 
marked. It is usually coated with a cheesy deposit of ir 
thickness, beneath which lies a very thin layer of granQUiiti 
sue. At the upper extremity is the diseased bone — tbe/oM 

In the pus of these abaces.se8 no organisms can be discover 
the means at present iu use, yet the pus is infective ami 
general tuberculosis when injected into animals. 

RESULTS. — Recovery may occur after the tiischi 
pletc removal of all tubercular tissue. I'nder tbc«« ciirm 
healthy granulation tissue springs up and develi>ps into ai 
ing up and drawing together the cavity of the alMceta ur 
There is alwa^'s loss of substance. 

In the condition known as obeolesoenoe the caaeoM 



jiiirrounded by a dense fibrous capsule, often with radiating bands 
liwing from it into the siirroundini; tissues. It is often seen at the 
apices of lungs, and may serve as a practical cure; but, theoreti- 
cally, it is not one unless the tubercular organisms are dead, for 
tliev may at any time be carried from the focus into the system at 


Lantly, death frecjuently results from tubercular processes, both 
general and local. The acute general tuberctiloses, afiectiug chiefly 
meninges, lung.i. and peritoneum, kill by their general to.\ic effect, 
by fever, and by interference with the functions of vital parts; c. ;/. 
the functions of essential cerebral centres may be arrested by the 
compression of the effusion. Chronic local tuberculoses kill either 
by leading to a general outbreak or by e.xhuu.stion from fever, pain, 
•nd profuse and prolonged discharge, especially when septic pro- 
cectes are supera<lded (p. 347). Indirectly, a tubercular process 
may open the door to some infective wound disease, such a.s erysip- 
elas or pyiemia. 

commenting on the very frequent presence of caseous foci in general 
tulierculosis, anil on the local infection which often occurs round 
socb foci, promulgated the view that a jroisnn capable of giving 
•o tuberculosis was generated during the caseation of infiauiiuatory 
products. CdSfation was the one essential feature. Virchow, how- 
ever, pointe<l out that caseation occurred in new growths and under 
•^'•MUmstances in which all connection with tubercle could be nega- 

III I860, Villemin made numeroiis experiments which seemed to 
•***ttionstrate the infective nature of tuberculosis. He placed tuber- 
*^»*lttr material beneath the skin of rodents, and general tubercle 
'^ovolopeil. Villemin believed, therefore, that tuberculosis was a 
''oasc due to a sj)ecific poison contained in the foci of the diseiuse. 



•s experiments were repeated by Cohnheim and Friinkel, Wilson 

•^X, Sanderson, and others, who found that tuberculosis followed 

"G inoculation of cheesy material which was jtresutiiuldy mit tuber- 

*^^lur. and even such simple inrtammatiou as resulteil from the inser- 

''»li of setons, of vaccine virus, and bits of cork or paper. Sander- 

^*», however, condutled that nothing induced tuberculosis m'th such 

^'^taititt/ as material taken fnuii iin iiudiitibtcdiy tubercular source. 

Klebs pointed out that possibly the non-tubercular material might 



Lave become contaminated by the tubercular virus, as at that date 
])recnntions were not vcrv strinppnt. It wiis probable, too. that in 
many cases where septic materials were used the process iinlun 
was pyflemic. 

It tlien occurred to Cohnhcim and Salomonsen to select tlif 
anterior chamber of the rabliit's eye as the point of inoculutio 
Here the results of the inoculation could be watched from dav 
day, and, as primary spontaneous tuberculosis of the iris had ik 
been seen in rsibbits, the possibility of this couhl be excluded, 
was thus pntvcd that wliilst inoculation of >um-tuberrular miitera 
into tlie anterior chamber of the eye invariably failed to indi 
tubercuhisis, the inoculatiiui of fulifi-culnr material jiroduced tnl 
ck'S in the iris and, a little later, in the body at large. The ji 
of the infective nature of the tubercular process was thus complet 
and it was further shown (hat tubercular materials from wiiiclj 
different sources containeil the same virus. Tappeiner caused liugt, 
to inhale daily for fourteen days si.x grammes of tubercular s|H 
delivered during six hours from a s[)ray into a narrow box contail 
ing the ajiiniul : all beeatne tuberculou.s, the twenty-third day bi'il 
the earliest upon wliieh tubercles were found. Thus tubercle cat 
to be regar<led as a »penji<- iiifectiniiK di»ra»e. 

Many of those who held this belief suspected that the virii.s «ra»i 
vegetable parasite, and seiirclied for it. Between 1877 anil 1^^ 
several premature announcements were made. 

The next publication was Koch's paper.' By a special pi 
of staining he first demonstrated the constant presence of pecnlil 
bacilli in eleven cases of acute tuberculosis, twelve cases of chwsy 
bronclio-pneurtmnia. one of tubercular nodule in the brain, and t*" 
of intestinal tuberculosis in man. Ten cases of perlsucht and ra«* 
of spuntuiieivus tubercle in monkeys and other animals were invc#- 
tigated with a like result, and finally the bacilli were found in 
large number of rodents and five cats artificially infected, 
proving that the tuberculosis resulted from the inoculation and 
not accidental, there was (1) the invariable coincidence; (2) 
more rapid development of the artificial than of the spontaneoi 
tulierculosis ; (3) tlic early infection of the glands nearest the seat 

' " D. JEtioloRJe d. Tubercnloae," Btrl. klin. WoehrnDfir^ Nn. 15, 1R«)2. Hin papw 
on the 8anie subject in the Mitihril. niui lUm Grtundhrilmmle, vol. ii., 1884, lnu»- 
lateJ ill the New Sydeiihaui Society's Microixtrantet in Diatoie, is fuller, and < 
be read liv nil. 



of iDoculntioD, whereas the bronchiul glands usuuUy enlarge first in 
>|wiiit:iut'iiiis riiscase ; an<i (4) roiitriil-cxjR'riim'iitt' in whivh animals 
wiw treiitfd exactly as the iiioctiJMted iininials were, witii the single 
pxce|)tion that no living bacilli were introduced: in these no tuber- 
niliwis occurred. 

Finftlly. the bacilli were cultivated at 'J8° F. to 10<l.4° F. (;J7° to 

•'<'*'('.) in sterilized blood-serum. After thus passing through many 

Xeserationa. these bacilli were su.sfiended in distilled water and in- 

j«ti>(l; thcv then jirodiu'eii tuberculosis as surely as did the original 


These results have since been fully confirmed, and their truth is 

FiQ. 137 

Fto. 138. 




[••Iwrclc tiaclUi In triinitH-fU ift-um tiilier- 
>i>iir horwi. • WKI. ((.'hejrne.* 


Tubercle bitrilU (fniin a rolnny on 
hlood-«eruni),«hiiwln(f the wavjr paral- 
lel lines. X 'VIO. (.ifter Koch.) 

►^"^ nnqnestioned. We are therefore jiistifieil in believing that the 
illus tuberculosis is tlie cause of nil tubercular [ircicesses. Its 
*ence. rather than any anatomica) stnicture, is, at least in the 
***"ly stages, the essentia! characteristic of tubercle. 

Characteristics of the Bacillus. — The bacillus i« 2 to 6 /i long, 
^i^o or three, placed end for end, making n]> the disinieter of a red 
^BlcKkl-corpuscle. It is very thin (i to J^ of lengtli). niottonleiis. and 
H^'ihded at the ends. It can be stained with Zielil's fluid (ji. :150) 
"■*r W (iraiii's method (p. 349). It has genenilly ii bciuled appcar- 
tiice — clear spots (four to eight) alternating with stained parts. 
'^i bacilli are usually straight, but may be curved ; they occur 
*"ig|y. but sometimes in pairs. Mu!ti]>lic!ition is very slow, and 
•>ke!» place by fission, and poissibly by spore-fornintion. though this 
: i» uncertain. As a rule, the bacilli are found in the cells of the 

41 r, 


tubercle, especially in giant-cells opposite to the nuclei. The? u» 
we!) shown in the accompiinying dnnving (Fig. 137). 

The organisms can be ciiiiivali'il on nieilia containing glycerin or 
litoinl-serura. They are aerobii-, but as they grow only at higb !«»• 
peratures (82° to 108° F.), they probably do not multiply oat*vit 
the body, but live a wholly parasitic life. To the nakc<l eye !*«■ 
Frontispiece) the colonies have a hcapod-up, scaly appoiramr. 
AVlieii cxiimiiu'd under the micro.scope the margins of the colouiw 
show a peculiar wavy form due to parallel chains of organism* fol- 
lowing the same curve (Fig. 138). Although the bacilli do art 
)«/(/^/i/// outside the body, they can Iht' for a long time, having l»tn 
found to retain their virulence after existence for forty -three ilaj»m 
putrid sputtini and for one hundred and eighty-six in the dry sutf. 
In putrid fluids they do not long hold their own against the rapiiiW- 
multi])lyiiig sejitic organisms, which are specially adapiwl for thf 
ordinary conditions external to the body. It is in the sutr 'if 
" dust " that we are most likely to meet with tubercle bacilli in m 
surroundings, and obviously this is the state in which thoy »renii»* 
fit to cause a fresh infection. 

With regard to the origrin of the tubercle bacUluB from wne 
non-pathogenic fomi. no other bacterium, even under such favowMf 
conditions as the bodies of rabbits and guinea-pigs present, ImstHfn 
found to develop any of the peculiarities of the tuherculnr orpu'- 
ism. Nor are there at present any facts known as to circiiiii!*tati(»» 
under which its virulence can be modified — increased or attt-nuaic'l. 
Nearly two years" cultivation external to the body caused no chan|.'f i" 
the latter direction (Koch). We must conclude, therefore, that tlirn- 
tubercle bacilli lutiltiply only in the body of man or some other aiiira^'- 
and that, cousei|Uently, the bacilli which cause a fresh infection Ci'D" 
either directly or indirectly from some tubercular individual. 

Obviously, all cases of tubercular disease in man are not «iu»ll.'^ 
prone to disseminate the bacilli. These may be eliminated wil" 
the .sputum, the fieces, the urine (in tuberculosis of the genito-orintff 
tract), and discharges from tubercular ulcers and abscesses, hut tbf 
first is the only common source of infection. When we conwilrt 
that about one-seventh of mankind die of phthisis, and that in all 
cases in which cavities form the patients for weeks or mouths vn 
expectorating large quantities of bacilli, we see that this one soon* 
'b capable of keeping u(t an ample supply. The bacilli expelled by 
ah with small particles of mucus may be directly inhaled bv tlit 


healthy; but »putum, which dries upon handkerchiefs, bed-clothes, 
«n(l woollen garments, thence to be detached as dust, appears to be 
tie most fertile source of infection. Bacilli found in the air are 
iiraally adherent to some bit of vegetable fibre, hair, or epidermis. 
Tnbercular disease in animals is also a frequent source of infec- 
tion to man. It is true that they produce no sputum, that few or 
no bacilli are expelled from their lungs, and that bacilli are not fre- 
quent in their excreta ; but the milk of tubercular animah may give 
rise to infection. As it contains bacilli only when the mammae are 
tnbercular, this cause, is easily preventible if dairies are efficiently 
inspected. Lastly, there is ianother possibility of infection — through 
the ingestion of tubercular meat. This can undoubtedly occur, as 
has been proved by feeding animals on tubercular flesh, but many 
things militate against its occurrence in adults, in whom primary 
intestinal tuberculosis is not at all common. The flpsh, if visibly 
diseaised, is usually rejected ; it is generally raised above 100° C. 
before being eaten ; the disease in animals used for food, and 
especially in cattle, is usually localized, and infection could follow 
only upon eating the tubercular parts, such as the lungs or glands. 
'Vhile, therefore, the domestic animals are possible sources of infec- 
>ion, in the majority of cases the disease is conveyed from man to 

The bacilli are readily destroyed by boiling, by sunlight, by 
'erchloride-of-mercury solution, and by carbolic acid; but they 
esist the action of a 1 per 1000 solution of the perchloride for 
t>ine minutes. A five per cent, solution of carbolic acid acts more 
apidly. Desiccation without sunlight does not destroy them. 

Modes of Entry of the Bacillus into the Body. — The sound 
tan would seem to be impossible, and but a few cases have been 
ecorded in which infection through toound« has occurred. One of 
ue most conclusive is the following : A perfectly healthy woman, 
»ith no tubercular history, cut her finger with a broken vessel con- 
fining sputum swarming with bacilli. Acute inflammatory symp- 
toms followed, but subsided under carbolic fomentation. In the 
mean while a small subcutaneous nodule of granulation tissue 
developed, and was removed at the end of a month, the wound 
healing by first intention. Then came pain in bending the finger, 
» swelling extending along the tendon into the palm, and swollen 
glands — two above the elbow and two in the axilla. All these 
parts were completely removed, the wounds healing at once, and 



no further spread took place. Tlie tendon-sheath was full of inn- 
uhition tissue containing numerous tubercles; the glamU «e 
simply hypcrpliustic. Bacilli were fairly common in both. 
eral observers have stated that dissecting warts arc tuberciil 
because they have constantly found tubercle bacilli in ginnt-p 
taken from degenerating UDtiiiles in the aflccted skin. MorwiT. 
these warts have commonly arisen after contact with tnbercnUr 
subjects. Riehl ami F'altauf regard the warty, inflamed papill.T.i« 
resulting from a mixed infection, cocci having been inociil.ii"l 
with the bacilli. Volkmann examined one case of scrofiilnn* 
eczema, and discovered tlie bacillus of tubercle in the epithcli*! 
and other cells. lie therefore believes that these catarrhs of ibf 
skin and the more frequent catarrhs of mucous membranro »rf 
due to the irritation of this organisiu. Certainly, lesions of lli* 
kind lead to the development of utrumous glands; and in onlcrt" 
account for the np]iiirently firimary enlargement of suporficul 
glands Koch |iut furward the now generally accepted view, thit 
the swelling bus really been preceded by some scratch or !tli|ili< 
sore (on the skin, whence lyuipbatics pass to the gland), iipo« 
which tubercular bacilli have fallen, and whence they have 
conveyed into the lyni|diafics too siK'e<lily to interfere much 
healing. Lastly, tuberculosis is said to have been c"oiiveve<l by 
tmecination. The evidence is of the usual pout hoc kind, and ik* 
statement has probability against it, for the hhod of tubrrciil»r 
animals is only infective in the most acute cases of general tutifrcu- 
losis, and the children from whom the " lymph " was taken wfw 
probably, to all appearances, healthy. 

Lupus is possibly another illustration of tubercular infection I 
the skin (p, 4:J8). 

The mucx>UB membranes — pulmonary and digestive — Bi<| 
therefore ordiiuinty Jiflurd passage to the bacilli : the possibility! 
this has been demonstriited by the success of inhalation erprriti 
with tubercular sputa and cultivations, nai o{ feeJinff f^rpfrin 
with tuberculiir tissues. Pulmonary tuberculosis being much m"" 
frecpient than intestinal, wo may assume that bacilli more ofirt 
pass into the tissues through the pulmonary than through tbcftlin 
tary mucosa. The difliciilties in both cases are considerable, 
regards the thora.x. tlie bacilli are drawn most deeply into 
lungs by deep inspirations through the open mouth. Evidently- 
they cannot be carried beyond the regions of the tidal and coid|iI*- 



menial air. ami will therefore be <leposited in the smaller l»n>nchi ; 
tint they nuiltijdv m shiwly tlint tliev iire usiiiilly exjielU'il by fiiiiiry 
Mlioii and i-oiighing before they can sorioiisiy injure any spot jinil 
vfTect an entranee. To enable them to do this 8)ieeially favarftl)le 
tirfumstances are necessary, such as the removal of much of the 
kniiirhial epithelium (after measles); the presence of broncliitis, 
»illi tenacious, ami therefore retHine<l, secretion : ami the exist- 
wiff of pleural adhesions or of a badly-formed thorax, preventing 
fiill expansion of the lunfr, and therefore lemliiiji to local retention 
<if secretions. Primary intestinal tuberculosis (which would occur 
fri>m tubercular food) is rare, except in children ; but ulceration of 
till' iinwels occurs in every three cases of plithisis, beiuvj sipfmrent- 
Iv line to infection by the bacilli in swallowed sputum. Koch says 
tbal the intestinal mucosa offers n less favorable point of attack 
•li»n the pulmonary — that the a<lult buciJii, like anthrax bacilli, 
•re usually destroyed in the stomach, whilst the spores escape: so 
"Illy spore-bearing bacilli can infect the bowel, and these only on 
I' •"omlition that they are not hurried throurrh the canal. Lastly, it 
•*eeins that just as a superficial gland niuy be infected from some 
^lesion of tlio skin so sliglit as to escape notice and t<i leave no 
H^i^ce, 80 the bronchial and mesenteric glands may be infected by 
^Hnpili which pass through their respective mucosa; without leaving 
^Mi^' permanent trace of their passage. Instead of settling in the 
F^ultuonary or intestinal tissue, they are evidently curried on by the 
iijph-stream. and in the majority of cases arrested in the tit'drcgt 
•ind, though the arrangement of lymphatics is such that they 
aj be at once conveyed to more <listant parts. The affected 
inds enlarire, caseate, and often infect others. Such caseous 
ands act as reservoirs of bacilli and their spores, and too often 
'*"ovc sources of more or less wides|ireu(l infection. 
It is well known that in young children t!ie liin(/» are not affect- 
in the same proportion as they are in hiter life, that the disease 
not so locali/efl, ami that the lyu)|)hatic gluiids especially are 
ore universally aflTected. The intestine seems in a large number 
f cnsw to be the part primarily attacked (jt. 42H), ev<'n, as Wood- 
"««d insists, in those cases iu wliicli patients ultimately succumb 
from disease of the lung. Thus we can often trace the infection 
from an old calcified gland in the mesentery to the retroperitoneal, 
[ulterior mediastinal, and bronchial glands, and thence to the 
'uags; in which organs the disease radiates from the root. 


Having no power of locomotion, tbe tuborcle bacilli iuu«t hf 
carrit'd tbrou;!;ii tlie puimonary mucosa by leucocytes like carbno 
particles. The leucocytes, wandering short distances t'roni llrf 
Iyin|)lioid tissue, may easily reach the surface, and thcrr mttt, 
enclose, and carry back bacilli. If the cells sicken while i\ut 
bacilli survive, the latter may find theui-selves in some plncc wh«rr 
they can thrive and multiply, and thus tubercles may iirisr. In 
catarrhal states nmre [ihagocytes will reach the inflanied siirfaw, 
and more bai'itli are therefore likely to be introduced into ilw 

A somewhat straineil analogy may be drawn between the ciillct^ 
tious of iyni])hoid tissue distributed along the mucous t-urfncc* aiiJ 
the fortified towns which guard a fnmticr. The lymphoid iirnwrt 
serve as garrisons from which leucocytes issue out and deal «iili 
any organisms they may chance to meet. I'nfortunaiely, tlic iIb- 
criuiinating [lower of the phagocytes is not eiiual to the iiofssi'iti, 
and they sometimes C4irry back bacilli whose subsequent lirvfloft- 
nient rcminils one of the oltl story of the Trojan Horse. 

Predisposition. — Nothing is more certain than ihaf iii(liviiln«Ii! 
vary in their liability to tubercular diseases, for these an? f'f 
coninmnt'i' in the young thnii in the old, and run mnrkcilv "' 
families. ^Ve have no knowledge of what constitutes this prf*'"" 
position, which may be inherited or acquired, local or general. ^ 
small flat chest and a tendency to catarrh are ot^en prtwni "> 
people who ultimately develop phthisis, and the absence of fr** 
respiratory n»ovement8 is often hehi to favor the entry of '■'' 
bacilli. Often, too, members of tubercular families are spcciiH/ 
exposed to infectiot» in nursing a sick relative. But. even all<i«ii'? 
for these facts, it seems impossible to believe that there is no Jiffcf' 
ence between the predis|(osed and the immune, save that in lb' 
latter the bacilli do not gain ontr.ince ; for it is so much more pr'l'- 
able that in many cases they enter, but fail to grow, being >l«- 
stroyed by the tissues. How can we e.x)dain acute meniugcal tabtr- 
ciilosis or tuberculosis limited to the peritoneum, in both of «hic\» 
multitudes of bacilli must have been thrown into tbe cirouUtios 
from some bronchia! gland or other focus, unless we assume thtt 
the bacilli could not develop elsewhere than in the tneuinget (if 
peritoneum respectively ? ' How, loo, should we otherwise expUil 

' It is powiible (Iml n mingle infoction of the pleiirn, pericardiiini, nr (irrila 
might liv Hpn.-!ul more or lees nt]iiilly over the whole uiembmne tbniiurtt it* 



fhi' recovery of some people from plithisis, except by assuming that 
tb« noil, which was at mic tiiiio favorable to lliv growth nf the 
tiacJIlus, became later ou iinfavoriiblf ' The precljsipositiori seems 
to vjrr from time to time in the life of the same individual. 

Development in the Tissues. — liiiving found a spot at which it 

cmi grow, the baeillu.s proceeds to multiply : most bacilli are taken 

lip b_v cells which enlarge into giant-cells and become the centres 

rtf typical "tubercles " (p. 404). The presence of these in a tissue 

Mcites more or less inflamnintion. often so much that we find the 

tiwoeg diftusely infiltrated, distinct niiditles being scarce or absent 

tuijHtratint/ varieti/). Caseation at the non-vascular centres soou 

follows, being preceded by coiigtilativf iiccrosi.s of the cells, due, 

(10 doubt, to the liirect action id' the prodiicts of the bacilli. The 

nearest lymjihatic glands often become affected. The primary lesion 

may become localized, as before explained (p. 408), or it may act as 

a starting-point for fresh infection. 

Modes of Spread. — (1) By Continuity of Tissue and by Lym- 
phatics. — This is the way in which the masses of conglomerate 
yellow tubercle are formed, and in which jmtches of infiltrating 
tubercle — such as of the skin. HrrnModrrmn — s])rcad. It is sup- 
posed that leucocytes enter the primary focus, take up a bacillus or 
* Kpore, and wander out again along fine lym))hatics into the sur- 
rounding tissues, there to sicken auil swell into a giant-cell not far 
frwm Uie parent mass. A fresh tubercle thus forms an<l caseates, 
audits margin coalesces with that of the [isircnt mass, which in this 
w«v gradually enlarges. The young tubercles form the grayish 
trnnslucent ring round the conglomerate (|). 40r)), with here 
*>»d there an offshoot of slight length. But occasionally a leuco- 
cyte containing a bacillus finds its way into a lymphatic, and is 
<'arricd by the lymph-streatn to the nearest gland. The situation 
lieing a favorable one for observation, the process of infection of 
•nesenteric glan<ls from an intestinal ulcer may sinnctimes be traced 
".V tubercles along the track. I'oiifiek lias described tiilKTcles in 
'Iw* thoracic duct in cases of acute tuberculosis: this he regards as 
""dence that the bacilli had pas.sed by this channel to the blood.' 

PMlio) and liv means of the iiiovi>iiient.< of tin- orfpin. It ist iliffienll to (M)nceive an 
"iffctinn of lx)th Sylvian srlerics ;nid s|>reiid agiiioft the lymph-nlrcain from the 
"* I'J the convexity of the brain. 

' TliF Irmphoid tiiwneisnotnnly the medium l>y which thedisen«e!<]>read.s; it isaliio 
I'lf pl»(v where Ihe tubercle bacilli are ino-»t actively attaeked, and where, therefore, 



mA TA. 

(2) By Infection of One Part from Another. — Examplo' of tlri* 
are eusily f'ouiul. I'erliajis the bi-st is Been when a Fiiddoo iiwpirt- 
tioii follows the Itiirsting of a tubercular focus into a bronchnit. *oi 
draws the infective runterial into many other bronchi, with the n->iilr 
that a ca.seoiis pncutuuiiia devdops, beginning in numerooB p»ida 
of •" racemose tubercle " — /. t. the tubercular tinnue is moulded 
racemose forms by the alveoli in which it grows. Otkrr rxaai| 
are the infection of the j>alnte from the tongue, of the '■ 
swallowed .^[Mituiii, and of the lower urinary tract frniii :.. ... .... __ 

(3) By Veins. — Miigge described tubercidar infiltration of -»:V 
walls of pulmonary vei«»el». especially veins, in pulmonary tnber-'^''' 
losi.s, and Wcigert believe* that this actual growth of the bacil 
into the circulation is frequently the source of general infection. 

(4) By Arteries. — In two cases of death from acute tabernili 
examined respectively by Koch and Cheyne there were pi 
cnseuted bronchial glands. In each case a perviuim mtriy wn fiw 
with it* wall infiltrated inth tubercle. This was the assigned 
of the general infection. 

In one or more id' these different ways the virus reaches the 
and is carried all over the body, developing when and where 
conditions are suitable — in the lungs. nieuinge«, joint*, or u<l 
parts. If the supply of virus is plentiful, the cose is likely U» 
acute. Laeunec used to teach that the tubercles appeared in 
distinguished by the amount of degeneration they hail nnd< 
This would indicate un intermittent supply. 

Oeneralization. — An acute miliary tuberculosis of the niei 
lungs, peritoneum, and various abdominal viscera plainly tnj 
that a large number of bacilli have found their way »ilb 
space of time into the blmul : the result is just such ii."i {<•: "■ 

intravenous injection, in rodents, of a gyringeful of a pure ealtiva ' 
tioii of the bacilli. .\s it is ineonceiviiblc that ba<-illi in xnrh onoi-^ 
bers coubl be ab.s(irbed so rapidly through a mucous membrane int<r 
the blood, it is necessary to assume the existence of some primart 
focus, where bacilli have multiplied and whence they can be ftoarnl 
into the bloo<|. stream, 'i'he pulmoniiry mucous tnembninr b«Df( 
that through which bacilli commonly enter the system, it follov* 
that the focus in which this multiplication uccure. and vIwimf 
generalization usually takes place, is a caseous bronchial gland, 

ihry nri' iiiimi likvlv lo lie ilcxtroyeil. If tb« orpuiimiu pa* \him l}rm}>hnU !{•«> ia 
the luuvoua UHin)l)nnv, l\wy have iilill to ileal wilh the l/niiihsllc gland* 



tliougb generally there is evidence of tubercular disease of one or 
Wh lungs as well. But acute miliary tuberculosis may spread 
from any localized focus containing living bacilli. Extension by 
moans of any lymphatic vessel leads to the formation of tubercles 
»loDg this ve.«sel or in glands through which tin- lymph pas.^es. If 
the thoracic or right lymphatic duct be affected, the orgaui.sms may 
ilw) find their way into the systemic veins. They would ne.xt reach 
file lungs, and the bacilli are so small that they would easily pass 
through the pulmonary capillaries into those of the systemic circu- 

Limited Infection. — We have spoken of acute (jeneral miliary 

tuWrculosis, using the term in Cdutradistinction to a /onilizrd 

tuberculosis — e. //. a mass of cungluiiicnite tubercle in tlie brain or a 

caseous gland. But even a " general " tuberculosis, due apparently 

to the rapid entrance of numbers of orgjiiiisms into tlie blood, is far 

from being really general ; for while the lungs, spleen, and liver 

»r« ftrry frequently affected, the voluntary muscles and mammiB 

(}*. 40.')) nearly alwriys escape. 'I'lius wo have ;i series of regular 

/gradations, commencing with the most widespread miliary tiibereii- 

'oai», and including successively ciuses of miliary tuberculosis 

''niitcd to the meninges or peritoneum ; eases of multiple infiltrated 

tuberculosis — /. >■. tubercle limited to glands, skin, or bones and 

J*>»nts; and. linally, cases in which ii single spot of skin, a single 

J«int, or a single gland seems to be affected. 

As we have before said (p. 422), the selection of speeinl organs 

*** '"general " tuberculosis seems to indicate special predisposition 

**** the part of these organs. There is no reason for assuming that 

bacilli are arrested in tlu^m rather thiin in r)ther parts. The 

e explanation would appear applicable to cases of limited 

"'iliary tuberculosis, and may possibly be the reason why tnher- 

•^lUr meningitis affects the base rather than the conve.vity of the 

Irain. Again, there seems no other explanation to offer of what 

teems to be a well-established clinical fact — viz. that cliildren who 

taSer from multiple lesions of skin, glands, bones, and joints do not 

develop visceral tuberculosis ueiirly so often as those in wIikiu ;i 

single joint is affected. 

Xext with regard to the dose of organisms: this may be largo 
or .small. It may be single or it may be repeated at longer or 
shorter intervals. The different may come from the same or 
frooi different foci, giving rise to the successive " crops " of 



tubercIcB to ivhich Lnenucc drew attention — the more recent b«iiK 
sniiill !iii<l pray, and the older large nn<l yellow. When niil 
bacilli enter the eircuhition at one time the infiltrations whi'. 
excite reaeh a far larger size than tber could pumiMT attain id tlw 
speedily fatal general eases. Many of the ciwie» in which «injlf 
gland.1 are aflfeeted are doubtles.s due to infection from Kmall wounil* 
or tubercular sores, either of the skin or of the mucous nn'mbrn" 
from which they obtain their lyn)|di-sup|)ly. But many i-aMo >i 
localized tuberculosis, especially of bone and joint, admit of b" 
such exjdanatiou : these Koch believes to be due to the entrv nS» 
the circulation, and lodgement in the affected part, of a hd|J* 
bacillus: and he thinks that in these eases — a» in those of wi*^*" 
ttpread infection — the organism is o)>tained from some prin**'! 
foeua, usually a bronchial gland, whence it haj<. as it were mC*^ 
dentiilly. slipped by the lyni|ilt-path into the bbrnd. lie think*" 
biglily improbable that even a single organism could pa.-** ini** ' 
cnpillary of the lung from an alveolus without cauning a inberci^ •■ 
focus in tlie lung itself. 

The seat of infection may not be without effect in explain^' 
some peculiarities of the, and should be borne in mind. A 
to heredity, tubercle, unlike syphilis, very rarely extend* in nt^^ 
from the ])arent Ut the f<etus : Koch found that guinea-pip> pr"^H 
nant at the time of infection or becoming pregnant soon after t--^ 
not transmit the disease to their young. 

It is impossible to explain why some tidierculnr prorcwe* rrm 
local, whil-st others generalize. Blocking of lymphatics, uon-in 
sion of the walls of blood'Veasel.s. feeble local growth of the bai 
ius. healthy resistance on the part of the tissues in geaend, a 
afford hypothetieal explanations. 

.Mthoiigii ill the great majority of caseH of acute tubercaloaii 
primary chee.iy focus is fouml, it mui>t be remembered that riu 
llitii, pi-r if. has nothing whatever to do with the produetiom of t^ 
tubercular virus. 

Tubercular Meningitis. — In the pia maler the tnbernilutu 
MM is aiw>ciated with inflammatiim of the meninges* and mtf 
parti' of the brain, constituting the <-onditioii known a> tul 

meningitis (really nieniugo-eneephaliti.i^. 'I'Mi !■> uli t lrivari»b" 

a part of u general!*. 


The process is almost exclusively confined to the pia inater at the 

base of the brain, anil the graif tiihcri'les — wliidi may easily escape 

observation — are seen in connection with tlie small arteries in the 

Sylvian fissures and are deeply seated between the convolutions. A 

fv* scattered granulations are fre'|neiit!y visible on tlie upper sur- 

fai-c of the hemispheres. (To see the tubercles, strip off ti ))iece of 

mc-mlirane with a Sylvian artery and its branches, float it in water, 

and sjtread it out on a glass jilute : examitie over a dark baek- 

grriimd.) The inflauiruatory growth originates in the perivascular 

Iriophatic sheaths which enclo-se the small arteries of the pia mater 

(Fig. 139), and by a double process of |»roliferation and (j). 407) 

Fio. 139. 




, **'Hnr)- tubercle In the pl« m«tcr. Tht- drifted Hne indlfiites the nrii^nal size of the 
"^'i-'uUr uodule: j1, the Ij-mphHtic sheath: V, the bloodvessel; /', elements within tlie 
*"**U». > 100. (Comll and Knnvlcr.) 

'^filtration, commencing at several centres, numerous small gray 

'*Oilules are produced around the vessel. These, which are di.s- 

'iictly visible to the naked eye, cause an external bulging of the 

"Death, and a diminution in the calibre, or even couijdete oWitera- 

^"^^i of the enclosed vessel. 

The localized obstructinns to the circulation which result from 

^"•^ pressure of the perivascular luidiiles increase the by|ier;eiMiu at 

^■'P la*e f>f the brain, which thus becomes exceedingly vascular, 

there being in some cases rupture of the vessels and extravasation 

'i blood. A tifiritioitx frinisiiffiitio}! takes place from the hy|ter;emic 

Mil iujured vessels; blood-corpuscles escape; and thus the meshes 


rnr. infective giianulomata. 

of the pia mater become infiltrated with u sero-fibrinouji or puri- 


form li<mid, wliicfi tends to eolloft in tlie 

betweon tiiecun- 

volutions, 'i'hf siibnriu:hnot(l fluitl is turbid an<l ini-n 


n (jiiii 

tity: pressure within the dura mater rises steaiiily. 

These ehanges in the pia mater at the base of tiie iiraiu irt 
attended by iiypeneniiu, infiitrution with leucocytes and tluid. sail 
softening of the subjacent cortical substance, accounting fortbcturh 
delirium and of the special senses. The rjifii- 
dyma and choroid jilexus also become exceedingly vascidar. »hile 
the waU» of the t'cnfrirlex, tho /ornix, and the iiot't cittninUmirt luijif*. 
The lateral ventrieh-» become progressively dwtemh'il witli fluiJ 
{ai'uti' Iii/<lr<>ci'ft/iiiluii). so fhut the roin'olutirnis on the surface of thf 
hemisj)heres are found presseil against tlie skull aiu\ jlnttrned. U 
is uncertuin huw f;ir this fluid is ilue to local inflammatory cxv 
tiou and how far to drnjisy. The exudation generally niiw* 
marked pressure upon the veins of Galen near their entry mto tlif 
straight sinus. All trace of fluid is driven from the subdural »pKt 
and the arachnoid is dry niid nfirkj/. 

The insensibility, dee|)er)iiig into coma which precedes doatli, i» 
accounted for by the rise in intracriiniul pressure, and Ity the injurv 
to the cells of the cerebral centres which results from the inflanii 
tory process atid the prolonged high pressure to which they arc 

Tuberculovis Masses in the Brain. — Large musses of 
glomerate tubercle (p. 40;")) arc occusionally met with in the brnifir 
unassociated with any general tuberculous process, yet, ciiriowij. 
in spite of their considerable size, they rarely give rise to svinptontf 
indicative of pressure. The explanation is that their growtli i» 
verv slow, and other cells assume the functions of those dcKtroyi'"- 
whilst fresh conducting paths are opened up, compensation li*'"? 
thus effected. The masses, which vary in si/e from a hajtleiiiit W 
hens egg, commonly occur in the cerebral sub.stance, especially 
the of the brain, 'i'hey are of a pale-yellow color auil ni 
consistence, and usually fitrni round ghibular tumors. Their """ 
face is often seen to Ite covereil with minute gray nodides. wl"' 
extend into the surrounding tissue; and on section similar noJi 
are sometimes visible scattered through the substance of the tutnor 
In most cases only one or two such ma.sses are found, but occvi''"' 
ally they are more numerous. They occur especially in chilill'**"'' 
Near the edge, where the structure of the tubercles is recogniu'''' 



Kio. HO. 

•ml typical (p. 4U5), coiujjresseJ or obliterated blood-vessels may be 
iHccD. Attention has already been drnuu to the infective nature 

I (p. 422) of" these masses. 

Tuberculosis of Lymphatic Glands. 

Ill the lymphatic glands tuberculous processes give rise, in the 

first place, to changes in the cortical portions of the gland, inas- 

mnrh as it is with these that the iiif'octivo material which is brought 

liy the lymphatic vessels first couies into contact (Fig. 140). In 

the earlier stage of the process siuall pale gray nodules are often 

risible. These are scattered through the warmer-colored vascular 

cortex. They grndually increase in size and become caseous. The 

Igiaud menu while enlarges from 

the addition to its substance of 

lhe!«c "tubercles," which gra<lnjilly 

Ipread in along the lymph-sinuses 

tint medullary portion. 

By this tinie the distinction 

►etween the medullary ami cortical 

►Ttions is lost in consequence of 

he infiltration and filling up of the 

niph-sinus. <(n section at this 

tn-ge the gland presents a gray- 

»h homogeneous surface on which 

IT"*? blotches of caseous material. 

ibroid changes frequently follow, and the capsule thickens, so that 

^ut' caseous masses become surrounded by dense fibroid tis.sue. The 

^liole glaml may be ultimuicly converted into a cnseoiis mass. 

•be caseous portions niav .>iitbse(|uentiy soften, dry up. or calcify 

(p. 409). 

Sometimes no "tubercles" are visible, and a section in the early 
'••ge has a pulpy, swollen appearance, and may be ilistinctly more 
Wcular than normal : micnisc<)])icully, a round-celled infiltration, 
«ith a few large cells. \k found. Tlie result of the infection has 
ieen a more acute and diflusi- infiainmation tiian tluit above de- 
ncribed. Caseous jiatchcs iiinl fibro'ul cliiinges ultimiUely appear. 
As before stated, the affection of lymphatic glands is in most 
indary to a tubercular inllanuiiation in the area whence 
their lymph ; but soinetiiiics it n/)/n'(irg to be jirimary, 
bacilli having entered through mucous membrane or skin without 



TiilwroulosU of * lymphKtii' iilmid. 
The eMrlfiwt tftafff of the procetui, show- 
ing till' Klmit-ci'U. :■ ■JM. 


exciting any marked inflammation. The glands most couinionlr 
affected are the bronchial, mesenteric, anil cervical. 

Tuberculosis of Mucous Membranes. 

The alinieiitavy, gciiito-iiriiiary, arrd respinitory mncouc me 
branes way all be .'<eat8 of tubercular infiltrutioii and ulceration: it 
IB extremely probable that some catarrhal affectioDH of the tnR»ib 
and |)harvnx. of tlic Eiis*tat'liiaii tube ami middle ear, as well a» ff 
the intestine, are due to the irritutiou of the tubercular orgaiiifm. 

Tubercular ulceration or fissure of the lip, ueually with iuarli«i 
thickening, is not uncommon in children and young adult*, 'hi 
the tongue and pharynx tubercular ulceration is rare, and i* 
usually secondary, at in point of time, to phtbi^s. The 
occurrence of tubercles in the nesophagus and stomach is very nn, 
but cases have been described. The course and the microwipif 
and naked-eye iiniituniy nf all these ulcers is the same. Thov «ill 
therefore be describfd under the heading of "Intestine," in vM 
part td' the aliun'iii;iry tract they arc most fre(|uently found. 

Intestine. — Priniitry tuberculo.^is of the intestine is rair m 
adults. It is probably caused by infection from tubercular milk w 
meat. Secondary infection of the intestine occurs in from oni4»lf 
to two-thiriLs of the fatal cases of phthisis, and is caused by i'»'»l- 
lowed tubercular 8])Utum. The small ami the large intestine »w 
said to be affected with about efjual fretpiency. and t>ot?i are gener- 
ally involved. The morbid begins in the sohlarv m" 
agminated follicles, and is most marked where these arc niOf«t 
numerous — namely, at the lower end of the ileum and in the cfff"" 
— but any part may be affected (p. 419). 

The tirst stage of the |»rocess eonsist.s in the appeamncf "' 
tubercles in some solitary glands and in certain follicles {not all) "' 
some Peyer's patches. The affected lymphoid tissue swelb. *" 
therefore projects too much above the surface of the nicnitr*"'" 
The new elements, consisting largely of leucocyte.s, then nnJci'?* 
fatty changes and soften. The degeneration in Peyer's imKb* 
commencing at a number of separate centres, is foUowwl I'J * 
patchy ulceration of the mucous membrane, and the procc** <'' 
tends by the appearance and subsequent breaking down of ff'' 
tubercles at the margin until a consiilerable part of the r' ' " 
<lcstroyed. As the result of these changes an ulcerated m. 
produced, the floor and edges of which are more or letw thickcneti. 


jwing to the production of tubercles and tubercular infiltration in 
the surrounding tissues. In the floor of the ulcer — formed usually 
by the submucous, sometimes by the muscular, and rarely by the 
peritoneal coat — small tubercles are developed, principally in con- 
nection with the blood-vessels and lymphatics, and, as these are 
arranged transversely around the intestine: the new growth pro- 
ceeds in the same direction. These nodules also soften and become 
caseous, and thus the process of ulceration gradually extends trans- 
versely until a complete ring of the mucous membrane may be de- 
stroyed (annular ulcer). These appearances, together with the dila- 
tation of the neighboring vessels, may reveal the position of the 
ulcers before the bowel is opened. By the blending of adjacent 
ulcers most irregular figures are formed, and in extensive cases 
mere islets and bands of mucous membrane only are left in wide 
Keas of the bowel. The ulcers thus produced (Fig. 141) present a 

Fig. 141. 


A tDbercular nicer of the Intestine (diagrammatic) : a, epithelial lining ; b, aubmucoua 
Oaae ; c, moBCUlar coat ; d, peritoneum. 

Strong contrast to those of typhoid fever. Bacilli are usually 
nnnaerous, and may be recognized in the stools by suitable staining. 

The tubercular ulcer rarely, if ever, heals, but an ulcer may heal 
«t one place, while it spreads at another, and the contraction of any 
■^^r-tissue that forms will lead to marked narrowing of the gut. 
O^ing to the thickening of the tissues at its base, perforation is an 
*^ceptional occurrence. This takes place more commonly into a 
neighboring viscus, to which the ulcer has become adherent, than 
•i»to the peritoneal cavity. 

The lymphatic glands in connection with tubercular ulcers are 
generally affected. The lacteals leading from the ulcers, and even 
toe thoracic duct itself, may be irregularly swollen by tubercles, 


The larynx and, to a less extent, the trachea both suffer from 
tubercle in its miliary and infiltrating forms. 

Tubercle of the Larynx (Laryngeal Phthisis) may be primary, 
but is often secondary to disease of the lungs. It is said to com- 
mence as subepithelial tubercles situate chiefly in the ary-epiglottic 



foldn, on the cords, ami on the under surface of tbo epiglottic 
These may he few or numerous, and may ulcerate early — eapecul/f 
on the cords — or may multiply and form a diffuse iDfiltr&tioD, wbici 
in the ary-epiglottic fold pri>diice8 a pear-shaped awellinie nitii ia 
lar^e end toward it8 fellow in the miii-line. ^^preadiug ulci-ntKW 
ultimately occurs, perhaps leading to the formation of abi««M«iLto 
necrosis of cartilage, and hence to hectic fever. exhauAtion, vtA 
death. Tubercular ulcers are distinguished from thow dtte tn 
syphilis or to new growths by the small amount of new tiMue i> 
their floor an<l margins and by the absence of cicatricial iitsw- 

Tracheal Ulcers are usually superficial. Occaisionally tbrr •>* 
very extiMuiive. 

TuberctiloBia of the Lungs (Acute Miliary). — Tnbcrcnioiw f"* 
cesses occur in the lungs as part of a general tuberculosis, and *"' 

Fio. 142. 

>y - 

A tmoll x-n icray tii>i«rcle fKim thr luiif In « cur of •riilx IntixrruUail*. Tb* •* 
(lir tiiU-n-ln l> kIiiiuil III llu' >lniwiiiK, >ii>l U l«n|iil)r roiutltiiU-d "f lolmaHvatef | 
X IW. rv<liu-c<t tn i. 

in pulmonary phthisis. The nature of the resulting iuilamiuni.* *Tl 
lesions i.< similar in both. It will be well, however, in the pit^-**( 
place more particularly to describe these lesions as they oorar *• 
the general infective disease. The more limited proceaaea wbiC* 
take place in phthisis will be again refern <l to in u miImmiM 
chapter. (Sec " Pulmonary Phthisis.") 

The pulmonary lesions met with in general tuberculo-^ . 



the Tnost part, of tbosc dissctuinatc<t iioilular growths which 
c been already described as gray and yellow tubercles (p. 404). 
loth the f/rai^ and the iffVow nodules are often fuuud associated 
tlie same lung ; in other eases the gray nodules only arc met 
1. whilst less frenuently nearly all the growths are of the yellow 
ety. The condition of the pulmonary tUsdU' which is situated 
•un the nodules varies considerably. It may be (1) perfectly 
nal: (2) more or less congested and (edematous ; or (-i} it may 
ent varying sized tracts of grayisii, grunuhir, friable coiisolida- 
. A perfectly normal condition of the intervening pulmonary 
le is found in many <>f those cases in which all the growths 
of the firm, gray variety ; but when there are numerous yellow 
loft gray nodules the lungs are nearly always more or less con- 
ed or consolidated. Although the virus is ilistributcd by the 
Illation, the tubercles are usually present in greatest number at 
loar the apex — like the lesions in ordinary phthisis, 
"hen these nodules are examined microscopically they are seen 
xhibit ilifferent kinds of structure. 8ome consist mainly of 
mt-cell systems'" as already described (p. 4^5), while others are 
acteristed by accumulations of epithelial cells within the pul- 
iry alveoli. There is, however, this marked diference between 
'arious kinds of nodules — that whereas the mnnlJ Jinn (/raif ones 
3on.<)tituted almost entirely of the first-named structure, the 

r toft qrmi and most of the 

' -^ " . . , . ,, Fio. 143. 

'«• ones consist mainly ot the 

-alveolar accumulations. 

rst, with regard to the soft 

and tffllow noiluleg: most of 

' when examined with a low 

lifying power present the ap- 

ince represcnte<l in Fig. 142, 

nodules evidently consisting 

iy of accumulations within 

alveolar cavities. When 

> highly magnified their con- 

tion becomes more apjiarent. 

I then .seen that the nlevo!,ir 

lies are filled with epithelial 

0Dt« and small cells resembling leucocytes, whilst the alveolar 

^ are more or less cxtensivelv infiltrated and thickened with 

A portion of a uninll sotl gray tubercle 
ft-iiin tilt' liiiii;. Tlil!^ i> fWirii ii nuso nfucute 
ItilH'nMiIoyiH, f>rohttMy In un ejtrller slu^e 
Umii that rriiiu whli'h Fi^ir. 11'^ was druwn. 
The Niirnrv show* one nf the alveoli filled 
with e|»ilheiiiil eleinentH un<i a few xinaU 
felln. with miino oellular Inflltration of the 
iiiveoittr Willi. >: 3)0. 



lymphoid cells (Fig. 143). In many casc3 tlio central ponioiis of 
the nodules have undergone extensive degenerative cbangc». aiul 
consist merely of a structureless granular debris, so that the sau- 
mulutiuns within the alveoli and the cellular infiltration of liie 

Fig. 144. 

A portion of a jrellnw tii)irrr|p (toin the lung In a «im of srute lubemilosti, iboitM <^ 
dcgunuratiun of llic n-ntrnl iKirtiiiiis iif the nixlulv r, ami the celliiUr ihlcki-nliK nf *** 
alveolar walls and uc-cumuhiUinui within the alveolar caritU-s at the pi-rlpticrj. p. ' •'" 

tlieir periphe 


Fia. 145. 

alveolar wsli.s are only visible 

the case in the distinctly yellow tubercles (Fig. 144). 

The histological characters of the firmer grut/ nodulen differ -"i"- ' 

what from the preceding. In the'?* 
the cellular infiltration and coi)*** 
iiHcnt thickening of the nhec\*^ 
wall are much more markeil, lU** 
many of the alveolar cavities **^ 
occupied by giant-cells. The i'"^' 
gin of these is still uncertain. •^*^ 
cording to some, they are furm*^ 
from the alveolar epithflium eito*^*' 
by fusion of contiguous cells or •*, 
partial necrosis of the cell Brrest»**» 
its attempted proliferation (p. 4"* ^ 
Others regard them as due *'•' 
degenerative change of a gio*'*^ 
nature in the epithelioid cell*. - 

cording to Metchnikoff, they are due to the fusion of mOHonu^''**^ 

f- '■ ■• -~kC ■ 

A portion of the mon.- rxtvmal part of 
ftgray tulK'rcle trtnn the lunt: In a ease 
of acute tulx-rculosifi. BhowlnR the ex- 
tensive Inflllmtion and thlckenluK of 
the alveolar waUa, and the ^anl-eolU 
within the alveidur oavillci. X lUU. 


[(ucocyft^d. In otli