2 Herr Max Weber on the Origin of Hair 



As regards hair this hypothesis is not without opponents, 

 who, however, have attacked it only in so far as it deals with 

 the development of the three structures. 



A second hypothesis as to the origin of hair has recently 

 been advanced by ]\laurer*. This author finds it quite 

 impossible to emphasize sufficiently the difference that exists 

 between scales, feathers, and hair as regards the manner of 

 their earliest development. He states, however, that a great 

 agreement is found between the earliest rudiments of reptilian 

 scales and feathers, since in both cases the rudiment consists 

 of a papilla of the corium, above which the epidermis at first 

 extends unaltered. A hair, on the other hand, arises, 

 according to Maurer, as an epithelial bud, wherein the corium 

 in the first instance takes no share whatever f, though it soon 

 afterwards does so. Nevertheless he admits that the epithelial 

 rudiment of the hair frequently originates upon the summit of 

 a previously-formed papilla of the corium. He regards, 

 however, " the relation of the hair-rudiment to the corium- 

 papilla as a purely topographical one." Maurer then proceeds 

 to explain why a large cutis-papilla of this kind has nothing 

 to do with the hair-rudiment as such. He states that it 

 never becomes the hair-papilla; the permanent hair-paj^illa 

 is always a subsequent formation. Since Maurer then goes 

 on to assert that he " ascribes great importance to the primi- 

 tive cutis-papilla," and that " it is undoubtedly homologous 

 with the primitive feather-papilla and with the primitive 



* ' Morphologisches Jalirbucli/ Ed. xviii. p. 717. 



t Maurer, liowever, even in his earliest stages already figures a co- 

 existent first rudiment of the subsequent connective-tissue hair-follicle. 

 According to this, therefore, the cutis would participate in the formation 

 of the hair just as soon as the epidermis. The folio-wing consideration 

 might perhaps have been worthy of mention. The high degree of 

 specialization which hair has attained indicates a long pi-evious histoiy. 

 The specialization was directed towards longitudinal growth, conse- 

 quently to the production of corneous matter, and therefore to advanced 

 functional capacity of the epithelial portion of the hair. That this finally 

 made itself apparent in the individual development also of the hair by 

 means of precocious participation of the epithelial portion as soon as the 

 first rudiment of the hair was formed, while the connective-tissue portion, 

 on the contrary, underwent a regressive process, appears to me to be a 

 point that at least deserves to be mentioned. It would be conceivable 

 that the recession in point of time also on the part of the papilla, which 

 subsequently becomes the hair-papilla, did not take place until the class 

 of hair-bearing animals (" Haartiere ") was reached. It would not be the 

 first instance of the gi-adual acquisition by a composite organ of an onto- 

 genetic development which no longer harmonizes with its phylogenetic 

 evolution. Since in considering the very important question of the 

 phylogeny of hair it certainly behoves us to be cautious, this point should 

 at least be touched upon. 



