The daily morning journal and courier., 1898-11-01

germ-cells of plants has brldSed the gap between isolated living cells ani complete organisms, and has enabed the study of the former to be employed in calculating the life of the latter. In medical school where the teaching is almost exclusively concerned with hu- man beings this sentence should be writ | large: The organism is not an indi- vidual, but social mechanism" Two corollaries must also be stated-CD that | every living organism, like every or gan and tissue contains cells: CD that the cells are composed of organic chem ical substances, which are not them selves alive. The progress of truth in these matters was much retarded by that portion of Schwann's cell theory which sought to establish the existence of free cell formation which really inn piled the revival of the old doctrine of spontaneous generation. This belief was gradually driven out of the domain of zoology, but in connection with the formation of plastic exudates found sanctuary in that of pathology I my self was taught the discontinuity of pathological growths-a view which would logically lead back to the origin of living from non-living matter, But enlightenment in this matter came to me. At the end of my academical ca reer l was acting as clinical assistant in the eye department of the Berlin hos pital, and l was struck by the fact that keratitis and corneal wounds healed without the appearance of plastic eXu- dation and was thus led to study the process of inflammation in other non- vascular structures such as artlcular cartridges and the intima of the larger vessels. In no one of these cases was plastic eXudation found, but in all of | them were changes in the tissue cells. ! Turning next to vascular organs, and in particular those which are the com mon seats of emulation processes, I succeeded in demonstrating that the ! presence of cells in inflammatory exu- dates was not the result of emulation, but of multiplication of pre-eX sting cells. Extending this to the growth in 1 thickness of the long bones-which was 1 ascribed by Dunhamel to organization ! of a nutritious juice exuded by the ! periosteal vessels-I was thus eventu- ally able to extend the biological doc Urine of omins cellula cellula to path ological processes as well; every new formation presupposing a matrix or tis- sue from which it's cells arise and the i stamp of which they bear
 Herein also lies the key to the mys- ! tery of heredity. The Immoral theory attributed this to the blood and based the most fantastic ideas upon this hy- pothesis; we know now that the cells are the factors of the inherited proper ties, the sources of the germs of new tissues and the motive power of vital action. It must not, however, be sup posed that all the problems of heredity have thus been solved. Thus, for in- stance, general explanation of thero- morphism. or the appearance of varia- tions recalling the lower animals, is still to be found. Each case must be studied on it's merits and an endeavor made to discover whether it arose by atavism or by hereditary transmission of an acquired condition. As to the oc- currence of the latter mode of origin, I can express myself positively. Equally difficult is the question of hereditary diseases; this is now generally assumed to depend on the transmission of predisposition which is present though not recognizable, in the earliest cells, being derived from the paternal or maternal tissues. But the most elabo- rately constructed doctrines as to the hereditariness of given disorder may break down before the discovery of an actual causa viva. A notable example of this is found in the case of leprosy, the transmission of which by inheri- tance was at one time so firmly believed in that thirty years ago law was nearly passed in Norway forbidding the marriage of members of leprous fami- lies I myself, however, found that a certain number of cases at any rate did not arise in this way, and my results were confirmed by the discovery of the leprosy bacillus by Armauer Hansen
 In a moment the hereditary theory of the disease was overthrown and the old view of it's requirement by contagion restored. Precisely the same happened few decades earlier with regard to favus and scabies. Another instructive condition is that known as heterotopia, in which fragments of tissues or or gans are found dwelling in situation other than that which is normal to them. This is particularly the case l with certain glands, such as the thy 1 roid and supraenal, but is also known with cartilage, teeth and the various constituents of dermoids It is no doubt occurs by process of transplanta- tion, the misplaced tissues developing no new properties, but merely preserv- ing their normal powers of growth. The attempt to generalize from this fact and to attribute all tumor.-forma- tion to this cause carries the idea be- yond it's proper scientific limits.
 With regard to the subject of para sitism, the progress of scientific obser- vation was retarded for centuries by the prevalence of the assumption made by Paracesus that disease in general was to be regarded as a parasite. Pushed to its logical conclusion, this view would imply that each indepen- dent living part of the organism would act as a parasite relatively to the oth- CTS The true conception of a parasite 1 implies it's harmfulness to it's host. 1 The larger animal parasites have been 1 longest known, but it Is not so many years since their life history has been | completely ascertained and the nature of their cysts explained, while an alter nation of generations has been discov- cred in those which are apparently sexless. Very much more recent is the detection of the parasitic protozoa by