100 years ago: Session 1905-06; Presidential Address

Dr Stockman began his address with a few remarks on the probable primitive views of man on the Creation, and then went on to state the theory of evolution of Lamarck viz:– that evolution was due to the influences of external agencies.

After discussing this theory and stating some objections to it he dwelt for a time on Darwin's views on the origin of species and on natural selection and contrasted these with the views of Lamarck. Then after discussing the phenomena of fertilization he defined and explained the continuity of the Germ Plasm and proceeded to discuss variation as exhibited by individuals in a species. He explained the two views as to variation viz:– that it might be inborn or contained & transmitted by the continuity of the Germ Plasm or that in the second place it might be acquired or impressed on the Germ Plasm. In this connection Dr. Stockman described Darwin's theory of Pan Genesis and alluded to his belief in the heredity of acquired variations. Weismann's theory, that tho' variation & natural selection were the main forces concerned in the survival of the fittest, yet no acquired variation could be transmitted from parent to offspring, was mentioned and then Dr Stockman proceeded to sum up these theories as follows.

1st. If Darwin & Lamarck are right, then the offspring must inherit the acquired variations of the parent e.g. disease
2nd. If on the other hand all variations are inborn then disease cannot be hereditary.

The distinction between the terms Congenital and Hereditary was strongly insisted on and views as to the heredity of immunity were then discussed.

Proceeding to the more practical aspects of his subject Dr Stockman pointed out that most diseases were the direct or indirect sequelae of infections and that selection was going on continuously in relation to disease i.e. those with the greatest resistance to disease survive. He mentioned that there were 3 main ways in which resistance to disease was strengthened viz:– by

1. Destruction of Germs
2. Avoidance of Germs
These two are due to Climatic, Geographical, Sanitary or Quarantine conditions.
3. Undergoing evolution against them.

Of these three the third seems to him to be the strongest and it has been going on unceasingly throughout the ages.
Then three possible fates under infection were mentioned viz:–

1. Entire escape
2. Recovery – almost unhurt – or more or less damaged
3. Death

After this certain diseases were discussed in detail as to their behaviour in regard to immunity; Scarlet fever was taken as a type of a disease producing immunity in the individual attacked and Tuberculosis as a type of one which conferred no immunity. At the same time Dr Stockman insisted that in his opinion immunity was inborn i.e. that the Germ Plasm is resistant to disease in certain people and they survive and beget offspring with a like resistance while the weaker variations die off; and further that as almost all our pathological conditions are consequences of infection, therefore they are not transmissible and that it is only the tendency of the Germplasm to resist or succumb to infection that is transmitted.

With regard to Tuberculosis, Dr Stockman stated that our attitude should be 1st to stamp out the bacilli as far as possible & 2nd to prevent people from marrying if in both male & female the Germplasm seems weak in its resistance to the disease.

Then the gradual immunization produced in a species by the dying out (without reproduction) of the weaker individuals was pointed out and Malarial, Syphilitic and the Tse-Tse fly infections were cited.

Finally Dr Stockman referred shortly to the recent Commission on Physical Degeneration which answered NO to the question "Do Alcoholism & disease in individuals give rise to degenerate offspring"; and then after some remarks to the effect that anatomical malformations are inborn and therefore truly hereditary he brought his most interesting address to a close.
Ralph Stockman

Archive: Royal College of Physicians and Surgeons of Glasgow
Reference: GB 250 RCPSG 73/1/11 Minute Book No. 6

Further reading
Jean-Baptiste Lamarck
Charles Darwin
Germplasm
Pangenesis
August Weismann