266 Dynamic Theory. 



be communicated. And it 'is rendered pretty certain that it is conveyed by means o* 

 clothing, &c. (Flint.) 



Dysentery usually begins as a plain diarrhea. Vigorous remedies of the proper sort, if 

 applied in time may arrest the disease in that stage, so that the subsequent stages are 

 omitted. It has even been arrested in the stage of dysentery which follows. 



Goitre or Bronchoctle is a disease which is rare in any other than a 

 mountainous region. It is most frequent at the base of high mountains in every part of 

 the world. It consists of an enlargement of the thyroid yland, which sometimes becomes 

 very large. After a long time it becomes hardened into a cartilaginous condition, in 

 which state it is incurable. 



Leprosy or Lepra exists in three species. In one of these the skin is 

 covered with scales, in another it is covered with crusts or scabs, in the third witli tuber- 

 cles. These forms of Lepra are said to be endemic in Egypt, in Java, and certain parts of 

 Norway and Sweden. Elephantiasis, a disease similar to Lepra, generally attacks the 

 feet and legs, which swell to a large size. There are several varieties of this disease, 

 some of which are hereditary and contagious and incurable. In one variety the disease 

 affects the lymphatic glands and the areolar tissue under the skin. The disease exists 

 in Barbadoes Island, and others of tiie Antilles, in Arabia, in Cayenne ( S. A.), in India 

 and in Java. There are a few lepers in Louisiana and Colonies in the Sandwich Islands 

 and Mexico. In each locality the disease appears to have taken on habits due to peculiar- 

 ities of the place. 



It is evident that there is an evolution in many diseases, as in other 

 organic existences. Take any of the contagious or infectious diseases enumerated 

 above, except splenic fever, pebrine and some others, and we see a development in the 

 exciting cause. The " exciting cause " of a disease lurking about some swamp, or other 

 locality, having the proper breeding conditions, develops sporadic or scattered cases; a 

 greater intensity of the exciting cause produces a greater number of cases, and then it is 

 an endemic ; another addition to the intensity of the exciting cause and the disease be- 

 comes epidemic and infectious. In passing through these experiences the exciting 

 cause evidently undergoes modification. There can be little doubt that in many cases 

 this exciting cause is at the beginning some sort of an organic cell capable of expansion 

 and multiplication by the budding process, or fission, when under the stimulus of heat 

 and in the presence of an abundance of nutritive organic matters. As before observed, 

 it is well known that many varieties of parasites have taken the liberty to make their 

 homes in various quarters of the human and other mammal bodies. Some of these have 

 been mentioned. Some of them give us no trouble, and we are often not aware of their 

 presence. Others annoy us but not dangerously; while still others are more or less in- 

 jurious, and some fatal. Of these parasites some are of a considerable degree of organ- 

 ization and of large size, often inhabiting the larger cavities of the body. Others are 

 microscopical in size, extremely elementary in organization, and live upon the blood or 

 some special secretion. To this last class belong some that are quite harmless, and of 

 whose existence we are generally unconscious. But a great many also belong to this 

 class whose presence is a cause of disease more or less serious. Of the harmless kind 

 may be mentioned the Leptolhrix buccalis, which consists of a thread-like process or 

 mycelium, and is almost always present in the mouth. The cells and spores of the mi- 

 croscopical Algoid plant, called Palmella, are sometimes found in the secretions and 

 mucous expectorations of healthy persons, in places not malarial. ( Flint.) 



The nature of the cells which constitute the miasm from which endemic diseases 

 originate, is largely a matter of analogical inference from their effects. They may be 

 surviving cells of tissues of plants that have become dissolved and disintegrated by 

 water soaking. Or they may be diverted cell growths, in which cells, composed of the 

 normal protoplasm of some tissue, are formed outside of the walls of the tissue in some 

 such manner as we have found fruit cells formed outside of the skins of fruits. Or, 

 finally, they may constitute new modes of organic growth originating from a recom- 

 bination of protoplasm disengaged from disintegrating plant or animal tissues. 



In any event when taken into the system these cells find in the fluids of the body suit- 

 able conditions for their multiplication, and their mischievous action on the human 

 body will produce a certain type of disease. But they themselves receive modifications 

 in the process of their development, because the conditions under which they are placed 

 in the animal body are different from the conditions under which they are supposed to 

 have been originally produced. Now if the cell, as changed by a generation of existence 

 in the human body, is taken into another body, it will be found to live in a somewhat 

 different manner and produce a modified type of the disease. And so on during several 

 generations or transmigrations of cell life. 



