Batrachia

“ This name, signifying the Thick-jawed Labyrinthodon, was given by its discoverer to a species of these singular Batrachia, found in the new red sandstone of Warwickshire, and which bears to the largest species the proportion exhibited by the head and fore-part of the body, as emerging from the water, for which parts alone the fossils hitherto discovered justify the restoration. ”

“ CRYPTOBRANCHUS, a genus of thoroughly aquatic, but lung-breathing tailed Batrachia, of the family Amphiumidae, characterized by a heavy, flattened build, a very porous tubercular skin, with a frilled fold along each side, short stout limbs with four very short fingers and five very short toes, and minute eyes without lids. The vertebrae are biconcave, and although the gills are lost in the adult, ossified gill-arches, two to four in number, persist. A strong series of vomerine teeth extends across the palate. ”

“ Radiate development is probably typical of the radiate structural type. (4) In the massive type, the development seems to be a spiral one.
Common to most modes is a separation of the germ into animal and plastic layers, a separation which seems to be conditioned largely by the presence of yolk. A classification based upon embryological characters ought to be applied even to the lesser groups and would here prove itself of service. Embryology, for instance, fully supports de Blainville's separation of Batrachia from true reptiles, [176] for reptiles develop an amnion and Batrachia do not. ”

“ The Batrachia, which are at present (in a restricted sense) called Amphibious animals, comprise Frogs, 196 Salamanders, gilled Salamanders, Cæcilia, and the extinct Labyrinthodonta. Their entire organization is closely allied to that of Fishes. The Pholidota, or Reptiles, on the other hand, are much more closely allied to Birds. They comprise lizards, serpents, crocodiles, and tortoises, and the groups of the mesolithic Dragons, Flying reptiles, etc. ”

“ The Balantidium, or Paramæcium coli, has frequently been observed in the evacuations of fever patients, and it has also been found by Dr Treille in patients suffering from the Cochin-China diarrhœa. Monads have also been found in the stomach and intestines of the hog and various other animals. Infusorial parasites are particularly abundant in batrachians, the Bursariæ of frogs and toads being familiar to every helminthologist. ”

“ A great deal has been 527 published on the poisonous secretion of batrachians (34) , which is utilized by the Indians of South America for poisoning their arrows. Some of the poison-secreting glands attain a greater complication of structure and are remarkable for their large size, such as the so-called “parotoid” glands on the back of the head in toads and salamanders. ”

“ The difficulty with which Batrachians are brought to breed in confinement, whether kept indoors or in the open, is well known to all who have attempted to study the habits of this interesting class of animals. It is also generally believed that when once the annual discharge of the genital products has been interrupted by captivity, the individuals are for ever barren. ”

“ Indeed, even after invasion the infectivity of the special disease, whatever it happens to be, will be materially modified by the tissues. When we come to turn to the micro-organisms which are pathogenic parasites we shall further have to keep clear in our minds that their action is double and complex, and not single or simple. In the first place, we have an infection of the body due to the bacteria themselves. It may be a general and widespread infection, as in anthrax, where the bacilli pass, in the blood or lymph current, to each and every part of the body ”

“ We shall never know [319] now, I hope, the history of the plague organism. It was never studied under the microscope—we were too busy—and now we trust that the bacillus—if it were a bacillus—has encompassed its own destruction. What interests you, however, is that this sudden, miraculously sudden, development of its deadly power as regards humanity ran through a determinable cycle of evolution. From what you’ve told us, already, it seems clear, I think, that even in England the bacillus was losing what I may call its effectiveness. ”

“ Contagion may take place both by introduction into wounds, and from the mucous membrane of the intestines or lungs, both by vegetative cells and by spores; in intestinal anthrax, however, only by spores. The Bacillus multiplies as soon as it has entered the blood, and the anthrax disease commences. The Bacilli not only give off poison, [40] but also deprive the blood of its oxygen. Vegetative cells only occur in living animals. This species is a facultative parasite which in the first stage is a saprophyte, and only in this condition forms spores. ”

“ From the under-surface of the oil, if the bacillus be that of plague, stalactite-like growths of bacilli will form. When disturbed, the stalactite growths break off and fall in snow-like flakes to the bottom of the vessel. No other known bacillus behaves in this way. (See p. 325.) In case of doubt, animal inoculation should be had recourse to: a little of the virus from the patient or a culture is rubbed into a shaven area (1 in. square) on the abdomen of a white rat or a guineapig. ”

“ Nothing is more certain than that the disease is due to the introduction into the blood or tissues of the bacillus anthracis or its spores. These microbes are always found in the anthrax lesions and in the blood of the victim in the advanced stages. When grown in bouillon cultures to the hundredth generation they retain their virulence unabridged and determine the same lesions in the animals inoculated. When the infecting culture has been passed through a Pasteur filter the virulence is lost with the removal of the bacilli. ”

“ The anthrax bacillus cannot produce the hardy spore form within the bodies of animals, but it does outside. Now it has been shown that the bacilli of anthrax taken from the blood of an animal dead of anthrax are destroyed rapidly in ordinary River Thames water, for example, but that if the temperature of the water to which they gain access is somewhat higher than usual, such bacilli are able to sporulate or produce spores in the water, and in that hardy form can retain their vitality and virulence for several months. ”

“ Nature has given it no danger signal for us. These germs—these bacilli—are translucent bodies, like glass, like water. To make them visible you must stain them. Well, my dear Paddy, do what you will, some of them wont stain. They wont take cochineal: they wont take methylene blue; they wont take gentian violet: they wont take any coloring matter. Consequently, though we know, as scientific men, that they exist, we cannot see them. But can you disprove their existence? Can you conceive the disease existing without them? Can you, for instance, shew me a case of diphtheria without the bacillus? ”

“ The size of the plague bacillus varies, and bacilli of same character, but of less virulent nature, have been found in the soil of infected places. Some bacteriologists observed some development after death in the bacilli, this, if confirmed by observations at Bombay, will be highly interesting from a bacteriological point of view. If mice, rats, guinea-pigs and rabbits are inoculated with the plague bacillus, they soon become infected and die, and in their internal organs the same bacilli are found. ”

“ It was found that typhoid, cholera, and various other bacilli were most deleteriously affected by insolation. Perhaps an example will best serve to illustrate the nature of the results obtained. Some boiled water contained in a flask was inoculated with an immense number of a bacillus, closely resembling the typhoid organism, normally present in the body and frequently found in water, the bacillus coli communis. So many were introduced that nearly one hundred thousand individuals were present in every twenty drops of the water. ”

“ The fact that plague can be communicated to the lower animals by feeding them on the tissues of plague patients and on cultures of the specific bacillus, suggests that the disease may be conveyed to man in food or drink. The bacillus is sometimes found in the intestinal contents of patients. It is also to be found in the urine. Water or food contaminated with sewage or fæcal matter may therefore be regarded as a possible medium of infection. Food contaminated by infected rats is likely also to be a source of danger. ”

“ The anthrax bacillus may retain its vitality for several years in a desiccated state. Clearly, therefore, desiccation has no administrative value in the prevention of disease, and on the contrary it aids the dissemination of the microbes of tuberculosis, small-pox, scarlet fever, etc.
Direct Sunlight kills a large proportion of the sporeless pathogenic microbes. Diffuse is less energetic in its action than direct sunlight. The bacillus of diphtheria is destroyed by a half to one hour’s exposure to sunlight. As to tubercle bacilli, see page 316. ”

“ In an infusion to which a fragment of cheese had been added, I have seen a pellicle form in three days, which, on microscopical examination, proved to be composed of an aggregation of Bacteria, Vibriones, and Leptothrix filaments. A mixture of albuminous urine and turnip-infusion has also rapidly become turbid in a vessel of this kind owing to the appearance of multitudes of Bacteria, and so has a mixture containing one-third of healthy urine with two-thirds of infusion of turnip. ”

“ According to report among the Chinese, this ‘new plague’ has been spasmodically epidemic in Tibet for more than a century. We have, as yet, no certain facts upon which to base any hypothesis, but is it not credible that during that time some bacterium or bacillus—hitherto harmlessly parasitic, perhaps, in the blood of lower animals—has changed its life habit? In the isolated and sparsely inhabited regions of Tibet, it is possible that for many thousand years the assumed bacterium was never bred in the blood of man ”

“ If fluids in vacuo (in hermetically-sealed flasks) , which were clear at first, have gradually become turbid; and if on microscopical examination this turbidity is found to be almost wholly due to the presence of Bacteria or other organisms, then it would be sheer trifling gravely to discuss whether the organisms were living or dead, on the strength of the mere activity or languor of the movements which they may be seen to display. Can dead organisms multiply in a closed flask to such an extent as to make an originally clear fluid become quite turbid in the course of two or three days? ”

“ All these modes of extension are well shown in tuberculosis. This disease is caused by a small bacillus which does not produce spores, has no power of saphrophytic growth under natural conditions, and is easily destroyed. Moisture and darkness are favorable conditions for its existence, sunlight and dryness the reverse. There are three varieties or strains of the tubercle bacilli which infect respectively man, cattle and birds, and each class of animals shows considerable resistance to the varieties of the bacillus which are most infectious for the others. ”

“ They exist in our food and drink; but the intestine is, one may say, a natural home in which many exist without harm to the body. For surgical purposes their existence is most important, first, in the earth, where, as I have already shown, the bacillus of lockjaw is most frequently found. So, too, the bacillus of wool-sorters’ disease (Anthrax) exists in the earth. If an animal dying of anthrax is buried, worms coming from the carcass up through the ground carry the infection, so that other animals grazing over this surface will become readily infected. ”

“ It was only in 1856 that the method of transmission of the disease was clearly recognized, and in 1880 that the bacillus was discovered and identified by the bacteriologist Eberth, whose name it bears, so that it is only within the last thirty years that real weapons have been put into our hands with which to begin a fight of extermination against the disease.
What is the habitat of our organism, and is it increasing its spread? Its habitat is the entire civilized [Pg 205] world, and it goes wherever civilization goes. ”

“ The men in the West Country you’ve described, probably died from starvation and neglect.”
He paused for a moment and then continued: “Now in America both men and women were attacked. There was certainly a greater percentage of male cases, but I suppose something like half the female population was infected as well. As far as one can judge the bacillus was simply losing power. But for all we know it may have developed, it may be entering on a new stage of evolution, and in some apparently haphazard way now be beneficial to man instead of deadly. ”

“ The medic said patiently, "Remember, the R-rays killed all the microorganisms in your body, including the good ones—the antibodies that protect you against disease, and the small yeasts and bacteria that live in your intestines and help in the digestion of your food. So we have to replace those you need to stay healthy. See?"
The green stuff tasted a little brackish, but Bart got it down all right. He didn't much like the idea of drinking a solution of "germs," but he knew that was silly. There was a big difference between disease germs and helpful bacteria. ”

“ He walked across the room and took up one of several sealed tubes. "Here is the living thing. This is a cultivation of the actual living disease bacteria." He hesitated. "Bottled cholera, so to speak."
A slight gleam of satisfaction appeared momentarily in the face of the pale man. "It's a deadly thing to have in your possession," he said, devouring the little tube with his eyes. The Bacteriologist watched the morbid pleasure in his visitor's expression. ”