n8 Phenomena Refuting Simple Epigenesis 



Thus for example a larva of Rana esculenta from 

 which there had been cut off the most anterior part of 

 the head including the eye anlagen, the anterior part 

 of the brain, the nasal groove, and the primitive mouth, 

 was so grafted upon the caudal half of the abdomen of 

 a complete larva, as to form an acute angle between the 

 back of the former and the abdomen of the latter, the 

 abdomen of the former being turned toward the head 

 of the latter. After allowing the double larva twelve 

 days of development, it was killed and it showed that 

 "all the organs of the partial larva up to the surface of 

 amputation and union had developed quite as com- 

 pletely as though there was no part of them lacking 

 and as though their normal environment and their or- 

 dinary relations were quite undisturbed." 80 



The anterior portion of a larva so short that it 

 scarcely extended beyond the commencement of the elon- 

 gated spinal cord, was grafted upon the abdomen of a 

 complete larva, and continued to develop normally. 

 "All parts developed completely up to the surface of 

 amputation: the cartilaginous trabeculae, the quadrates 

 with the chewing muscles covering them, behind the 

 mouth cavity the cartilages of Meckel, the cartilages of 

 the lower jaw and behind these again the hyoids." 81 



Upon these and other similar examples, Born bases 

 the following conclusions : "Although up to the moment 

 of grafting there had been no trace (of primordial cra- 

 nium) present, and the mesoderm from which it develops 

 remained in a quite indifferent and almost primitive con- 



80 Born : Ubcr Verwachsungsversuche mit Amphibienlarven. 

 P. 97. 



81 Born: Uber Verwachsungsversuche mit Amphibienlarven. 

 P. 108109. 



