428 BICKFORD. [Vou. IX 
CONCLUSION. 
The chief results of this paper, briefly stated, are as follows : — 
1. The regeneration of the hydranths of these Tubularians, 
is due, zo¢ to simple processes of budding or an entirely new 
formation, but largely to the transformation of the tissues of 
the stem, into the body portion of the hydranth. 
2. That where the portions of stem are sufficiently short, 
the whole coenosarc may be transformed into the two hydranths, 
with no stem portion intervening ; OY, in some cases, it may be 
transformed into one hydranth; while in other cases, where 
the portion of the stem is still shorter, it may be transformed 
into a partial hydranth, whzch zs not completed by any process 
of growth. 
Since completing these experiments at Woods Holl, I have 
had the opportunity, while doing some work in the Johns 
Hopkins Laboratory, of repeating some of them upon the 
Cordylophora, which was easily obtained in Baltimore. I 
found this form possesses similar regenerative power ; stems 
often being obtained which showed the heteromorphic forma- 
tion of hydranths on both ends of stems. 
The regenerative processes appeared to differ in some 
points from those found in Tubularia tenella. I hope to 
determine more fully these regenerative processes for both 
forms (the Cordylophora and Tubularia) in a future work, as 
the results of a careful investigation of the histological changes 
which take place during the transformation and growth of 
stem portions into hydranths cannot fail to be of much interest 
when compared with the processes of budding and embryonic 
development. 
MARINE BIOLOGICAL LABORATORY, 
Woops HOo.Lg, MAss., 1892. 
