302 THE CASE AGAINST EVOLUTION 



is therefore often associated with the lymphatic glands as the 

 seat of the formation of lymph corpuscles. ... In certain 

 cases of arrested development or of general weakness in young 

 people, the thymus has been found to be persistent." ("Physi- 

 ology," 3rd ed., 1920, p. 1245.) 



In the light of these facts, it is utterly unreasonable to re- 

 gard the thymus as a practically useless rudiment inherited 

 from the lower vertebrates. "That they have an important 

 function in the young animal," says Albert Mathews, "can 

 hardly be doubted." ("Physiological Chemistry," 1916, p. 

 675.) In fact, the peculiar nature of their development in 

 the young and their atrophy in the adult forces such a conclu- 

 sion upon us. The thymus, therefore, is, in all probability, 

 an ontogenetic, and not a phylogenetic, rudiment. It might 

 conceivably be exploited as a biogenetic recapitulation of a 

 reptilian stage in man, just as the so-called fish-kidney of the 

 human embryo is exploited for evolutionary interpretation. 

 The principles by which such a view may be refuted have 

 been given previously. But, in any case, it is folly to interpret 

 the thymus as a rudiment in the racial, rather than embryonic 

 sense. Moreover, the possibility of an ontogenetic interpreta- 

 tion of rudiments must not be restricted to the thymus, but 

 must be accepted as a general and legitimate alternative for 

 the phylogenetic interpretation. 



In the last place, it remains for us to consider the Dar- 

 winian argument, based upon so-called rudimentary organs, 

 from the standpoint of the science of genetics. Darwin, as 

 we have remarked elsewhere, was ignorant of the non-inherit- 

 ability of those inconstant individual variations now known 

 as fluctuations. He was somewhat perplexed, when Professor 

 L. Meyer pointed out the extreme variability in position of the 

 "projecting point" on the margin of the human ear, but he 

 still clung to his original contention that this "blunt point" 

 was a surviving vestige of the apex of the pointed ears found 

 in donkeys and horses, etc. "Nevertheless," he says, "in some 

 cases my original view, that the points are vestiges of the tips 



