The presence of acquired antibodies is shown by a hyperactivity which serves to eliminate or neutralise the foreign substance. Beyond certain limits allergies arise in the form of genuine illnesses like bronchial asthma, hay fever, allergic rhinitis and conjunctivitis, nettle rash, erythema nodosum and eczemas. In animals, too, contact with antigens causes, as in man, the development of antibodies. However, it is not possible, even with the most ingenious methods, to reproduce in animals allergies similar to those which afflict so many people. It is even suspected that, in humans, allergies to certain drugs may in some cases be due to eating the meat of animals treated with those drugs.
Collagenous tissue exists virtually everywhere in the organism.
It is like, in a cloth, the weft, without which it would be impossible to weave the warp. When it changes, the functional capacity of all the organs and all the tissues is impaired. So experimental models have to be found. Those who believe they can understand arteriosclerosis in humans through animal experiments will feel rather annoyed, if not downright indignant, when they examine the bio-chemical characteristics of arteriosclerosis. They look for those dietary factors which cause or favour the development of the disease.