198 THE AMERICAN NATURALIST. [VoL. XXXVI. 
later a nutritive head (7/.) had regenerated on the end of the 
reproductive component and, at the same time, stolons (s7.) 
had pushed out from the nutritive polyp, fastening it to the 
bottom of the dish.. As this was the only instance in which 
a reproductive polyp produced a nutritive head, it was prob- 
able that a new condition had appeared and. affected the 
regeneration. What this condition may have been was not 
satisfactorily determined, but a possible explanation was sug- 
gested by comparison with the results of another series of 
experiments carried on at the same time. These will be 
described. below. 
Peebles showed that pieces of the stalk of nutritive polyps 
cut free from the colony and allowed to remain undisturbed at 
the bottom of a shallow dish of water sometimes sent out long 
branching stolons, the original stalk becoming absorbed and 
indistinguishable from the newer growth. * After several days 
new individuals began to appear, growing up at right angles 
to the stolons, just as the different individuals of a colony 
grow from the hydrorhiza. The formation of new polyps con- 
tinued for several weeks when the experiments were brought 
to an end. As many as ten to fifteen new polyps were pro- 
duced by one piece of the stalk. These polyps were inva- 


Fic. 5. — Represents a small portion of a colony which had. developed from a nutritive polyp, 
showing a new nutritive polyp (s), a reproductive polyp (+), and stolons (sż.). The original 
pelyp had been abserlied., colony was started July 24. The drawing was made August 3. 
The disintegration of the colony began August 8. 
riably nutritive individuals, characterized by their long slender 
tentacles.” I repeated this experiment and also used pieces 
of nutritive polyps as well as pieces of the stalk. The 
growth of a large number of colonies followed. New nutri- 
tive polyps were always the first to appear on the stolons, 
