1. A male guinea-pig which has received a single injection of a mixture of diphtheria toxin-antitoxin causing severe constitutional disturbance, may beget offspring of slightly lower resistance than normal to diphtheria toxin

2. This effect is generally restricted to young born within twelve months after the injection of the father, being rarely noticed in the young of later litters.

3. An increased susceptibility to diphtheria toxin is likewise observed in the offspring of male or female guinea-pigs which have received a large dose of horse serum. The greater susceptibility to diphtheria toxin of the young of male guinea-pigs which have been treated with toxin-antitoxin may therefore be non-specific in character.

4. The injection of diphtheria toxin-antitoxin mixtures into guinea-pigs whether male or female reduces their rate of breeding and lowers the vitality of their young.

5. These effects are most pronounced when the toxin-antitoxin mixture produces severe constitutional disturbance or contains excess of horse serum

(1) There are two methods of examining industrial material for anthrax spores, viz. agar plate cultures and the inoculation of guinea-pigs.

(2) Though no worker has yet made a large series of examinations of equal portions of the same material by both methods simultaneously, yet the available evidence indicates that animal inoculation is superior, provided that guinea-pigs, not mice, are employed.

(3) It is better to inoculate two guinea-pigs than one, and to use the centrifuged deposit of the watery extract, though this practice may also increase the mortality from pathogenic anaerobes.

(4) The inoculation of guinea-pigs is more successful than plate cultures mainly on account of the larger quantity of watery extract usually tested, which more than counterbalances the disadvantage that some of the animals died from anaerobes before they develop anthrax.

(5) If plate cultures are employed it is essential to examine the superficial colonies after a short incubation, probably 12 to 16 hours is the most suitable.

(6) Anthrax spores have been demonstrated by the inoculation method in 21·3 % of 141 samples of industrial material, supposed to have produced anthrax in Liverpool amongst those who handled them. Of these samples 28·6 % were from hides, 22·2 % from wool, 20·6 % from hair and 7·1 % from bones. The largest proportion of infected samples came from Singapore.

(7) Anthrax spores have been demonstrated in one sample of hair “ disinfected ” with 5 % fluid of high coefficient at 100° C. and in two out of six samples of hair disinfected in Germany probably by steam at 105° C. It is practically impossible to completely sterilise certain industrial materials without seriously damaging them; yet partial disinfection should on no account be abandoned, because the perfect method has not yet been discovered.

(8) Anthrax appears to be steadily increasing among domestic animals, and consequently a larger number of agriculturalists are becoming infected. The reason for this dissemination amongst animals is still obscure.

(9) We have found B. anthracis in a sample of pea meal used for feeding cattle confined to a shippon, one of which died of anthrax. The meal was probably infected from the sack.

(10) Anthrax is preventible among men and domestic animals, and its ultimate suppression depends largely upon the certainty with which bacteriologists can demonstrate the presence or absence of bacilli in suspected industrial food, or other materials.

The variously coloured patches appearing on the surface of chilled beef are caused by fungi. Amongst these, Cladosporium herbarum, producing black spots, is the only fungus that has become specially adapted for flourishing on such an unusual substratum, and may in consequence be expected to continue and even increase in quantity on its new matrix, unless stringent measures are adopted. This fungus is not pathogenic, and the only effect caused by its presence is the unsightly appearance of the meat and consequent deterioration in value. If extensive, the meat may be rendered unsaleable.

The beef is infected with the “black spot” fungus before, it is shipped, and to arrest the continuance of this infection special measures should be taken, with the object of exterminating the fungus, which in its specialised form can only occur in the vicinity of the establishment where meat is prepared for shipment.

The great reduction of the number of cases of Mediterranean or Undulant fever in the Naval and Military forces has been frequently noted since the year 1906, when the prophylactic measures recommended by the Commission of the Royal Society were put into force. Very few cases have been notified since, and in all, the means of infection has generally been easily explained.

Following the subcutaneous injection of typhoid vaccine into rabbits the average antibody response was estimated from day to day, and found to vary for agglutination, bactericidal action, phagocytosis (including tropins), “precipitation” and probably for complement-fixation according to the dose of vaccine.

As estimated by the maximal value reached by the serum the response increases with increasing dose in nearly all cases. This increase becomes relatively less and less as the dose increases, and its progress suggests that with a sufficiently large dose a limiting-value might be reached, which if not actually a true limit would be practically one.

The observed relationship between dose and effect is such as to suggest that the combination of antigen and reacting-cell takes place in accordance with the rules governing adsorption processes; but this does not hold for the response in bactericidal power.

With increasing vaccine-dose the date at which the maximal value is reached gets later for the various antibodies, with again exception of the bactericidal power.

The precipitation observed differs from the usual precipitation reaction and is perhaps really an agglutination-phenomenon.

Phagocytosis was observed in three ways, and the bearing of the results on the mechanism of the action of the antibody concerned is considered; and the relationship between the bactericidal and other antibodies is also discussed.

Everyone who has been occupied with the weekly production of diphtheria toxin in quantity has been struck with the great variations which may and usually do occur in the strength of the toxin from week to week. It is indeed extraordinary as Madsen remarks (1908, p. 83) that a bacillus should for a long time give good and fairly constant results when grown in one laboratory and yet fail to do so when grown in another laboratory in a medium prepared with the greatest care according to the formula used in the first laboratory. That it is notmerely a question of medium is shown by the following experiment.A batch of bouillon was made up and inoculated in the usual way. Then half the flasks were placed in one of the two hot rooms we have here, and the other half in the other hot room. After nine days' incubation the cultures were treated as usual. Both lots were tested on the same day and it was found that while the M.L.D. of the one half was 1/150 c.cm., that of the other was 1/50 c.cm. Many and varied have been the procedures suggested for growing the diphtheria bacillus so as to obtain a highly potent filtrate and most of them have been tried in this laboratory but none can be depended upon to give a constant result. When discussing this point Dean (1907, pp. 467–468) gives the M.L.D. of a large number of toxins prepared under his direction, but they are notgiven in order as they were prepared and so one cannot get an idea as to how one batch differed from the next. I have not come across any such series in the literature of this subject and so it seemed that it would be of interest to put on record a two years' series of results in theorder in which they were obtained—more especially as a study of thisseries gave more food for thought than was anticipated.

Numerouspapers have been published on the effect of heat on diphtheria antitoxin, but there appears to be no record of a series of observations carried out at a temperature nearly that of the human body. The object of this note is to fill in this slight gap in our knowledge.

(1) Pathogenic organisms such as B. dysenteriae (type “Y”) cannot be recovered from pupae or imagines reared from larvae to which these organisms have been administered.

(2) When the larvae have been bred from disinfected ova and are subsequently fed on B. dysenteriae (type “Y”), this organism may be successfully recovered from the pupae and imagines in a small proportion of cases.

(3) Under similar conditions B. typhosus was not recovered in a single case from pupae or imagines.

(4) In those cases in which B. dysenteriae (Y) was successfully recovered from pupae, the colonies on the plate were invariably fewer than those obtained from pupae and imagines after administration to the larvae of more adaptable organisms such as “Bac. A”(Ledingham).

(5) When organisms such as “Bac. A” were administered to larvae bred from disinfected ova, or non-disinfected ova contaminated with this organism, it was in many cases possible to recover the organism from pupae and imagines.

(6) In no series of pupae examined after administration to the larvae of either B. dysenteriae or “Bac. A” was it possible to recover the organisms in every instance. A certain proportion of pupae in both cases proved sterile, so that the process of metamorphosis is undoubtedly accompanied by a considerable destruction of the bacteria present in the larval stage.

(7) The temperature at which the larvae develop (19°–25°C.) has probably an important bearing on the survival of pathogenic organisms such as “Bac. Y” of dysentery, administered in association with organisms such as “Bac. A,” in view of the fact that the latter grows far more luxuriantly at this temperature. Even when grown in broth at 37°C. (the optimum temperature for Bac. Y) together with “Bac. A,” the “Bac. Y” was found to form after two days only one quarter of the total number of bacteria present in the mixed growth.

(8) There was no evidence that the larval juices contained substances bactericidal for Bac. Y. The bacilli died more rapidly in normal saline solution.

(9) The possibility of flies becoming infected from the presence of pathogenic organisms in the breeding ground of the larvae may be considered as very remote.

1. The generation-time of B. typhosus in 1% peptone at 37°C. is 40 minutes.

2. The rate of growth of B. typhosus is greatly influenced by the concentration of peptone in nutrient medium when the peptone is below 0·4%.

3. Below 0·2% the generation-time is inversely proportional to the concentration of peptone used.

4. The addition of 0·175% of glucose to a medium containing only 0·1% of peptone lowers the generation-time by about 50% With 1·0% peptone this effect is less marked.