Volume 1
A system of medicine by eminent authorities in Great Britain, the United States and the Continent / edited by William Osler, assisted by Thomas McCrae.
- Date:
- 1907-10
Licence: In copyright
Credit: A system of medicine by eminent authorities in Great Britain, the United States and the Continent / edited by William Osler, assisted by Thomas McCrae. Source: Wellcome Collection.
Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.
67/986 (page 43)
![Whether such a specialized cell under any conditions multiplies and gives rise to the complete individual—as ha])pens, to c|Uotc trite examples, in the case of certain cells of the hydra and with the cells of the begonia-leaf —depends upon the extent of the departure of the biophores from their primordial constitution in the germ-cell; or, perhaps more correctly, upon the tenacity with which they retain that original constitution. We may imagine that in such cases the central ring remains unaltered, the cell differentiation being the result purely of modification in the side- chains; the newly formed bio])horcs, res])onsive to the change in envi- ronment, develop side-chains of the jjrimordial type, and so are capable of developing the whole individual. The relationship of what are to be the germ-cells in a multicellular organism are such that in the process of their development the contained biophores depart least in constitution from the biophores of the ovum from which they have developed. Thus the properties of any individual cell are to be regarded as the outcome of (a) the constitution of the biophoric molecules passing into the cell at its formation as a separate unit; and (b) the alteration in those molecules and their derivatives induced by the forces acting upon the cell. 11. The biophores contained in the germ-cells of an individual are not those contained in the germ-cells of the parents; they are the outcome of the ovum by growth, and as in general they have been subjected to a like environment, so in general they have (with certain reservations to be discussed later) the same constitution. But just as with growth the bi- ophores of the body-cells are capable of alteration in constitution, so in their growth the biophores of the germ-cells may be modified, and that by like causes; namely, by diffusible substances circulating in the nutritive fluids, as also by purely physical influences telling upon the organism as a whole. The difficulty in determining that influences of this nature, telling upon the body generally, affect also the germ-cells, lies in this, that in man and mammals the growing embryo is nourished by the maternal tissues, and so where the mother is subjected to deleterious conditions it is difficult, not to say impossible, to distinguish surely between conditions due to pre- conceptional disturbance of the ovum and those due to placental absorp- tions after fertilization; and considering man more particularly, it is difficult to collect a sufficient number of cases in which the evidence is positive that the mother has been normal, the father alone the subject of one or other form of intoxication—alcoholic, tuberculous, etc. It is, for example, a matter of common belief that j)aternal alcoholism is frequently associated with the development of offspring of a lower vi- tality, and more })articularly exhibiting mental instability. I am inclined to hold that this belief is well founded. At the same time 1 must admit that sound statistical evidence in its favor is lamentably lacking. Simi- larly the influence of paternal tuberculosis alone, not as inducing active tuberculosis in the offsi)ring, but in producing what may be termed para- tuberculous lesions, has not been adequately worked out. Too many other factors have to be taken into consideration: ])o.ssible tuberculous diathe- sis already inherited by the parent, the environment of the young child, etc. Nevertheless we have a certain amount of evidence showing that this is actually the case—that j)aternal intoxication does influence the semen and leads to the production of vitiated progeny. More than one](https://iiif.wellcomecollection.org/image/b24907212_0001_0067.jp2/full/800%2C/0/default.jpg)
