215HOW CHARACTERISTICS ARE TRANSMITTED

doctor has been sent for privately by the patient orher friends, a midwife may retire or may remain asa maternity nurse. In reply to another inquirythe Board states that to give ergot at the end of thefirst stage of labour, save in emergency, is bad

practice and such treatment is regarded as definitelyoutside the midwife’s province. The Board sees no

objection whatever to the taking by midwives of

any steps which may result in the resuscitation ofapparently stillborn children. Finally a nurse-midwifeemployed by a district nursing association is boundto report to the local supervising authority shouldshe be attending septic wounds or any othercondition which may raise suspicion of infection.

HOW CHARACTERISTICS ARE TRANSMITTED

To enable us to distinguish between the inheritedtendencies and the environmental influences whichtogether mould a developing organism is properlyconsidered one of the most important tasks of

biology in its relation to human welfare. In anaddress delivered on Tuesday last Dr. David Forsythendeavoured to persuade the Eugenics Society thatit is " a false issue " to regard heredity and environ-ment as separable entities ; we are wasting our

time, he thinks, in analysing living organisms on thisassumption. Dr. Forsyth argued that the environ-ment of a mammalian germ cell is the parent’s bodywhich begins to exert its effect immediately thegerm cell is formed. The parent is however as muchthe product of inherited as of environmental influences.The surroundings of the germ cell are therefore an" inherited environment," and hence we cannot reallydistinguish between heredity and environment. But

surely Dr. Forsyth lays himself open to the retortthat he is using the word heredity in two differentsenses ? To the biologist the inherited constitutionof an egg is that which is contained within it at itsformation and which, as experiment shows, never

deviates from a certain mean in its ultimate expres-sion in spite of environmental changes. An environ-ment is not inherited in a biological sense but onlyin the sense in which property and traditions, whichare external to the organism, can be inherited. Forthis biologists have unfortunately no separate word.Though organisms certainly inherit (biologically) a

tendency to produce a particular type of environ-ment for their germ cells, so far as the latter areconcerned it is still purely an environment, in whicheggs of different hereditary constitutions can developwithout losing their individual characteristics. Dr.

Forsyth sought to reinforce his argument by pointingout that soon after development has started the

embryo is mainly, and probably entirely, composedof substances derived from the environment, so thatthere is nothing left of the originally inheritedmaterials. The biologist would reply that theessential things that are inherited are not certainsubstances but configurations of substances-patternswhich persist as inherited characteristics though theoriginal molecules which compose them are com-

pletely replaced by others from the environment.These patterns require a certain range of environ-mental conditions in which they can express them-selves and by which they can within limits bemodified. Dr. Forsyth extended his desire forunification to the organism itself and its environment.He showed that spatially no hard and fast line can bedrawn between an organism and its environment ;the two imperceptibly merge into each other and arecontinually interacting. No doubt this is true, butit cannot prevent us from regarding an organism as

a kind of focus around which certain configurationsof matter are performing characteristic reactions.This conception is not invalidated by the fact thatthe reaction system is not sharply demarcated fromsurrounding matter. It is again these patterns andreactions which are the essence of the thing calledorganism ; the materials taking part in them are

derived from the surroundings where these samesubstances are not behaving in this manner. Wehave reasonable grounds for differentiating betweena single organism and its environment, although, asDr. Forsyth quite logically concluded, each may beconsidered in a sense as part of a larger organismcomprising all living things and their environments.But while unable to follow Dr. Forsyth in his con-clusions, or to find convincing evidence of theirpractical or theoretical value, we admit that the

question of heredity and environment is not as easyto define as many biologists and even medical menare apt to assume, and welcome the stimulus he hasgiven to consider clearly what we mean by theseterms.

GASTRIC ACIDITY

ACIDITY of the gastric juice is sometimes confusedwith its volume, so that the terms hyperacidity andhypersecretion have even been thought synonymous.Such confusion has arisen partly through difficultiesin measuring the amount of juice secreted (unmixedwith saliva, food, or the contents of the duodenum)and perhaps partly because a highly acid juice isusually found in large, and an achylic juice in verysmall, quantities. Gradually, however, it has becomeclear that the hydrochloric acid of the stomach issecreted by the acid cells at a constant fixed con-centration and that these cells cannot appreciablyvary its strength. The variable factors are thenumber of cells actually secreting-and thereforethe volume of acid put out-and the diluting agents,of which in recent years the alkaline duodenalcontents and the neutral or alkaline gastric mucinhave been especially studied. Welin and Frisk i

have lately recorded their estimations of the volumeof gastric juice secreted in man, obtained by a

technique which excluded saliva and duodenalsecretions. Using as their stimulus to gastric secretionan intravenous injection of 20 units of insulin, theyfound that an increase in acidity and an increasedvolume of juice followed in about 30-45 minutes ;but there was no correlation between the degree ofacidity and the rate of secretion-in other words,the rate of secretion might drop while the total

acidity remained almost unchanged. In all the casesof duodenal ulcer investigated the rate of secretionwas high, the amounts varying between 200 and500 c.cm. of juice in an hour as compared with100 to 200 c.cm. an hour in normal subjects. The

acidity was found in these experiments to be ininverse relation to the amount of mucus, and theconclusion is drawn that hyper- and hypo-acidityare merely terms representing varying rates ofsecretion of a juice of fixed (maximal) acid con-

centration altered by the diluting effect of gastricmucus. This conclusion agrees with views of thosewho hold that the only means the stomach possessesof reducing its acidity is the secretion of mucus ;duodenal regurgitation, they say, plays little or

no part in this regulation. Such investigationsemphasise the significance of the volume of gastricjuice secreted: they suggest that hypersecretionand not hyperacidity is the essential consideration

1 Welin, G. and Frisk, A. R. (1936) Acta med. Scand. 90,543.

216 EXAMINE YOUR METHODS

in conditions like duodenal ulcer, and that the

gastric mucin is very important as adsorbentand acid-regulator.

EXAMINE YOUR METHODS

METHOD is a good servant but a bad master, andit is useful to appraise from time to time the valueof all routine procedures. This has been attemptedfor the methods used to control tuberculosis byDr. Jean Downes in the Milbank Memorial Fund

Quarterly Bulletin for October, 1936. Dr. Downesbelieves that to ascertain the effectiveness of our

procedures it is necessary precisely to define the

objectives of any procedure and to test accomplish-ment by comparison with other methods or withcontrols. Ten per cent. of 1386 cases referred bypractitioners to the clinic were found to have tuber-culosis, but among 1437 children surveyed in theschools no definite case of tuberculosis was discovered,and under 2 per cent. from among 969 referred by thepublic health nurse. In this country it is only prac-titioners or school medical officers who refer cases tothe local dispensary ; the other sources are negligible.Considering the work from another angle, Dr. Downesnotes that 2 per cent. of 265 examined because ofcontact with an infectious case were found to betuberculous ; 14 per cent. of 266 seen because of

suggestive symptoms-cough, lassitude, or wasting-were tuberculous, but no cases were found among177 persons seen because of other complaints, suchas back-ache, indigestion, or giddiness. Most instancesof infection were found during the investigation offamilies including a primary focus of infection, nextcame the results from families where tuberculous

meningitis had occurred ; no cases were found bythe investigation of families in which a child gave apositive tuberculin reaction. To test the value ofthe increasingly efficient control two series of familieswere considered, one group of 51 families comingunder observation from 1923-30, a later group of41 families first seen from 1931-35. Of those from0-19 years tested with tuberculin 74’2 of the earliergroup showed infection, but only 51’6 of the later ;70 per cent. of the patients of the earlier group hadsanatorium treatment as against 80 per cent. of thoseseen more recently. Moreover, 44 per cent. of thefirst group were admitted to institutions within amonth and 76 per cent. of the second. Contactexamination has also become more comprehensive: o33 per cent. examined as against 51 per cent. Thisshort paper introduces no new therapeutic methods,nor does it suggest new modes of control, but it doessuggest to all of us the advisability of adopting fromtime to time a similar survey.

INDICATIONS FOR OPERATION IN PYLORIC

STENOSIS OF INFANTS

THE introduction of eumydrin as an antispasmodicdrug may alter the whole outlook of psediatricianson operation for hypertrophic pyloric stenosis. Mean-while, however, some observations by Paschlau 1may be of value. His opinion is that the resultswould be better than they are in many centres ifthe indications for operation were more exact, andhe recommends preliminary X ray examination aftera barium meal. The child is given a small feed towhich a teaspoonful of barium emulsion has beenadded and the stomach is examined immediatelyafter the feed and again at four and eight hours’intervals. Paschlau says that if both the four- and

1 Paschlau, G. (1936) Münch. med. Wschr. 83, 2007.

eight-hour examinations show that none of theopaque meal has entered the bowel this is an absoluteindication for operation. More usually the stomachhas emptied a little ; but if after eight hours lessthan half its contents seem to be in the bowel, thenoperation is probably the treatment of choice. Inanother group there appears to be relatively goodemptying during the first four hours, but almost nofurther progress in the next four hours. This,according to Paschlau, means atony of the stomach,and for such cases operation is also strongly recom-mended. These are the main indications to begained from the study of the opaque meal. Thedegree of peristalsis as shown by careful screen

examination is said to have prognostic significance ;strong peristaltic movements are held to be a goodpoint. Paschlau’s other observations on the generalstate of the child cover ground familiar to Britishpaediatricians and he is also expressing an opinioncurrent in this country when he writes of the riskof making the infant’s condition worse by washingout the stomach with an alkaline solution. Salineonly should be used for this purpose. He claims thatby a careful study of the indications for operationthe mortality-rate from pyloric obstruction in twochildren’s hospitals in Berlin has been reduced tojust under 4 per cent.

PERFORATED GASTRIC ULCER

AT a recent discussion in Brussels on the treatmentof perforated gastric ulcer, Dr. Robert Leclercqdescribed 1 a case that came under his care at theHopital Saint-Pierre in which a large perforatedulcer, situated on the lesser curvature, was so rigidand friable that all attempts at suture failed. Primarygastrectomy was considered to be out of the questionas the perforation had taken place twenty hoursbefore operation. Leclercq decided to close thehole by insertion of a hollow sound. The manoeuvrewas successful. The sound used was a soft Nelatonof number 16 gauge, which was kept closed exceptfor a short time in the morning and evening whenit was used to evacuate the gastric contents. Theamounts of fluid obtained from the stomach on fivesuccessive days directly following operation were

(in c.cm.) 600, 600, 500, 800, and 1200. On the sixthday the sound was definitely closed, and on the tenthday it was withdrawn. A gastric fistula did not formand the wound rapidly healed. Three months laterthe patient was readmitted to hospital. Althoughhis general condition was good he still had symptomsand the radiological examination showed considerabledeformity of the stomach. A partial gastrectomywas successfully performed.The main points raised in discussing Leclercq’s

case were the certainty with which perforation of thestomach could be diagnosed, and the indications forand against primary gastrectomy in acute perforation.Dr. Leclercq was criticised by Dr. Appelmans becausehe had made his first incision over the appendixto rule out the possibility of appendicitis. Dr.

Appelmans said that a simple radiogram would haveshown the presence or absence of air under the

diaphragm. If air were present, operation was

urgent and the diagnosis of perforation was proved.The absence of air did not rule out the possibilityof perforation, but it did mean that immediateoperation was not called for, as the perforation wasclosed off. Dr. Demuylder considered that a smalldiagnostic incision over the appendix was permissibleas it could be used, in case of perforation, for the

1 J. Chir., Brux., November, 1936, p. 379.