34 MATHILDE M. LANGE 
affinity to staining agents. Later the neuropil becomes vacu- 
olized and the neuroglia nuclei increase in numbers. Blood- 
corpuscles penetrate the degenerated portions of the myelin 
cords, but disappear again. The differentiated nerve cells do 
not multiply by division, but by means of neuroblasts, which 
originate in the central mass of nerve fibers as well as in the 
layer of ganglia. Probably both neuroglia tissue and ganglia 
contribute to the formation of the neuroblasts. The myelin 
cords do not pass through a blastema stage. They grow as a 
well differentiated tissue, and are easily discerned in the regen- 
erated piece. Together with the epithelium and the blood- 
vessels, they are the first tissues which can be distinguished, 
all the remaining tissues still being in a blastematous stage. 
4. The connective tissue. The first elements which later on 
go to construct the new connective tissue are probably evolved 
from the primary blastema, a product of the agglutinated blood- 
corpuscles. 
The general results of this study may easily be expressed in 
the following two sentences: 
1. All new tissues with the exception of the dermal connective 
tissue are produced by the preexisting tissues of the same kind. 
2. Sepia occasionally replaces a lost arm by means of com- 
pensatory regulation (development of the correlated buccal arm 
to replace a lost one). 
