78 C. M. Child 
not originally possess or acquire after isolation a certain definite 
reactive capacity. The question as to whether this capacity is an 
original possession of the parts in question or whether it is acquired 
after isolation leads at once to the consideration of the second 
factor, viz: the method of closure, since this is, so far as can be 
determined, the only other regional factor possessing the same 
localization as the heteromorphic reaction. 
The method of closure in the cesophageal region is always the 
same at both oral and aboral ends (Child, ’ogb) and consists in the 
union of the cut surface of the body-wall with that of the cesopha- 
gus, so that the cesophagus does not connect with the enteron but 
opens externally at each end. In the preceding paper attention 
was called to the fact that this method of closure follows necessarily 
from the structural relations of parts in the cesophageal region and 
the character of the wound reaction, which consists in the contrac- 
tion of all parts involved. This method of closure brings the 
various parts at the two ends of the piece intosimilar space relations 
and into similar relations of organic continuity with each other, 
and it seems at least possible that the establishment of these con- 
ditions in two complexes of similar parts may be a factor in deter- 
mining that the two complexes shall react similarly. Under these 
conditions the correlations between the parts in each complex 
must be similar, consequently a similar constitution being postu- 
lated, similar reactions are to be expected. On the other hand, 
the establishment of similar relations of space and organic con- 
tinuity in two complexes can scarcely be expected under similar 
external conditions unless the two complexes consist of similar 
parts. In short, since the two ends of an cesophageal pieceof 
Harenactis are very similar in structure and behave similarly under 
like conditions we are forced to the conclusion that they are essen- 
tially similar physiologically. In restitution their structural and 
physiological similarity determines that closure of the wound shall 
occur in the same manner, this method of closure in turn deter- 
mines that similar relations of space and organic continuity, I. e., 
similar physiological correlations, shall be established, and these 
finally determine the occurrence of similar reactions, 1. e., in the 
present case the restitution of similar structures. 
