238 NATURAL SCIENCE [April 



which common comparisons might be estimated, is, 1 think, essen- 

 tial to a better understanding of the subject. 



Macalister ^ divides the varieties of human organism into nine 

 classes, as follows: (1) Hetero-meral or anomalies of quantity; (2) 

 Metaplastic or anomalies of material ; (3) Didymal, anomalies of 

 repetition ; (4) Diastematic, anomalies of cohesion ; (5) Antithetic or 

 anomalies of alternation; (6) Metathetic, anomalies of position; (7) 

 Homoiotic, anomalies of series ; (8) Atavistic, anomalies of inherit- 

 ance ; (9) Neoplastic, anomalies of new formation. Such a classi- 

 fication, perhaps with slight alterations, might be universally applic- 

 able. It has an advantage over most others on account of each 

 term having a clearly defined meaning. But whether this or some 

 other classification be adopted, such as Osborn's, it should at least be 

 universal in its adoption, and should cover all the chief divergences 

 from any common average taken as standard. 



In conclusion, I fail to see the use of continuing this discussion 

 as it now stands. No case has been yet adduced by one side which 

 has in any sense been regarded by the other as final. If I am right, 

 the cause is to be sought in the loose way in which variations have 

 been classed. If it is urged that to make such a close study would 

 require almost a lifetime, and exceptional capabilities besides, it 

 should be recollected that it would at least settle a question of 

 extreme difficulty, and one which, until answered, will greatly 

 interfere with the progress of biology, while its solution would in 

 addition probably help to solve many problems in modern medicine 

 and kindred sciences which must otherwise remain more or less 

 incomprehensible. J. Lionel Tayler. 



^ Third Boyle Lecture, Oxford. 



