INHERITANCE AND MEDICINE 133 



studied with care, if inheritance plays even a debatable part, turn 

 to any of the text-books in our language and what do we find ? 

 A single page, or it may be but a single paragraph, is thought 

 sufficient to introduce and to take leave of the subject. In short, 

 from a concatenation of circumstances the medical study of in- 

 heritance is largely " taboo." Why is this ? 



It depends upon more than one factor. In the first place, 

 while, as I shall point out later, the study of man is singularly 

 well adapted for determining certain points in connexion with 

 inheritance, the fact that the generations of man follow each 

 other at such relatively long intervals is against man being for 

 most purposes a good subject for investigation. In the course of 

 a long life the investigator can but study the characters of three, 

 or it may be four, generations in one family, while influences 

 acting upon the susceptible foetus in utero in man, as in all mam- 

 malia, introduce complications. The basal facts of heredity have 

 to be made out in the lower animals, in which generations succeed 

 each other with fair rapidity, and in which the eggs are fertilized 

 and from the first developed outside the body. 



Unfortunately, too few of us are trained biologists ; the curri- 

 culum of the past, as of the present, lays too little stress upon the 

 value of a broad biological training as an aid in preparing us to 

 discuss those special biological problems which constitute medical 

 study. As a consequence the medical world in general has to 

 depend upon the biologists proper upon the zoologists and 

 botanists for its views upon heredity, and the pure and simple 

 biologists have run riot in their lucubrations upon this subject. 

 Do not think that I mean to belittle them or to indicate that we 

 do not owe much to all the investigations and all the writings of 

 the biologists of the last twenty or thirty years. The facts which 

 they have elicited have been of the highest value. Without 

 these facts we would be nowhere, but the contending theories 

 elaborated by them (perhaps I should be the last to make any 

 such criticism) have been fearful and wonderful, have started 

 from morphological rather than physiological conceptions, and 

 as a result have assumed shapes which would not disgrace the 

 schoolmen of the Middle Ages. While they have appeared to 

 collate and harmonize the facts known at a given moment, new 

 facts have caused them to need modification, and the successive 

 attempts to utilize the old bottles for the new wine, where they 



