116 Phenomena Refuting Simple Epigenesis 
locking of the two organisms which would give a most 
asymmetrical and irregular dividing surface. 
The continuation of development in the tail frag- 
ment of the tadpole seems to speak likewise against both 
epigenesis and preformation. For in his experiments 
upon tadpoles, Born has proven the accuracy of Vulpian’s 
statement that the amputated tails not only continue to 
live for sometime (some even thirteen days), but con- 
tinue to grow and to differentiate into their various 
tissues. He has further observed the following processes 
of new formation. 
“A few days after the amputation, the margins of 
the fin of the amputated tail commence to grow over the 
cut surface of the axis; they unite in front of it to form 
a high semicircular tail fin. The axis is not entirely 
without participation in this process, for prolongations 
of the notochord as well as of the spinal cord grow 
into the newly formed fin, but the metameric muscu- 
lature shows nothing like this and terminates sharply at 
the original surface of amputation. But this prolonga- 
tion of the notochord, like that of the spinal cord, even 
in the most favorable instances, scarcely extends half as 
far forward in front of the cut end of the original axis 
as does the newly formed marginal fin. This latter is 
formed of typical embryonic mucous connective tissue 
with a few pigment cells scattered through it. I have 
not been able to discover in it any rudiments of vessels.” 
“This observation teaches then,” continues Born. 
“that the provision of yolk in the tail end cut off from 
a tadpole does not serve merely, as Vulpian has already 
shown, for further growth, and further differentiation 
of the tissues, and for the formation of a new structure 
growing out from the cut surface, but it shows that 
