HIS OM THE VASCULAR SYSTEM. 353 



"like the four comers of a letter." Yet this wonderful 

 " envelope theory " of the vertebrate limbs is surpassed by 

 the " waste-rag theory " (Hollen-lappen Theorie) which His 

 gives of the origin of the rudimentary organs : " Organs 

 (like the hypophysis and the thyroid gland) to which no 

 physiological part has yet been assigned, are embryonic 

 remnants, comparable to the clippings, which in the cutting 

 of a dress cannot be entirely avoided, even by the most 

 economical use of the material " (!). Nature, therefore, in 

 cutting out, throws the superfluous rags of tissue into the 

 waste heap. Had our skull-less ancestors of the Silurian 

 age had any presentiment of such aberrations of intellect 

 of their too speculative human descendants, they would 

 certainly have preferred relinquishing possession of the 

 hypobranchial groove on the gill-body, instead of trans- 

 mitting it to the extant Amphioxus, and of leaving a 

 remnant of it to us, in the equally unsightly as useless 

 thyroid gland. (Of p. 836). 



It will probably be thought that the ontogenetic " dis- 

 coveries " of His, which appear in a doubly comical light in 

 consequence of the accompanying display of mathematical 

 calculations, can only have occasioned momentary amuse- 

 ment in critical scientific circles. Far from it ! Immedi- 

 ately after their appearance, they were not only much 

 praised as the beginning of a new " mechanical " era in 

 Ontogeny, but they have even yet numerous admirers and 

 adherents, who ^eek to spread the scientific errors of His as 

 far as possible. On this account, I have felt myself obliged 

 to point out emphatically the complete falsity of these 

 views. The vascular system afibrds especial occasion for 

 this ; for among the most important advances which Hit 



