537 
JoEST!) has shown that pieces of earthworms could be grafted 
together either in the same direction or in an opposite direction. 
MOoRGAN ?) later described an experiment, in which, after the anterior 
ends of two worms had been united, one was cut off near the point 
of union. In this way, the posterior end of one piece was left exposed 
at the anterior end of the grafted worm. In only a single case was 
a permanent union secured and although the pieces, thus joined, 
lived nearly eleven weeks, they died just as evidence of regeneration 
began to appear. 
My experiment was as follows. The worms (Allolobophora 
foetida) were anaesthetised with chloroform and sewed as described 
by Jorst. I attempted, at first, to unite the worms near the anterior 
ends in opposite directions. Usually the two anterior segments were 
cut from two worms and the exposed ends of the two worms joined. 
One of the worms was then cut off between the sixth and seventh 
segment, thus leaving four segments of one worm attached in a 
reversed direction to the body of another worm. Most of the pieces 
pulled apart within a few days. If, however, the worm which was to 
form the larger component of the grafted worm was cut off posterior 
to the clitellum and the smaller component united with it at that 
point, a larger proportion of pieces remained together for a longer 
time. The pieces were kept in a cold place for three or four weeks 
after the operation as the cold decreases the activity of the worms 
and makes them less liable to pull apart. After the pieces were 
united they were kept at ordinary room-temperature. Occasionally, 
after the pieces seemed to be perfectly joined, they would separate 
by constriction, so that, even with these precautions, I succeeded in 
only a single case, after a very large number of trials. In this in- 
stance, an anterior piece containing the third to the eighth segments 
was sewed in a reversed direction, to the anterior end of a piece of 
a worm cut posterior to the clitellum. 
The experiment was begun Jan. 12, and the pieces were kept 
alive in moist earth in a cold room. One cold night, Febr. 9, four 
weeks after the operation, the posterior end of the larger piece was 
frozen and a few days later, it was constricted off, anterior to the 
injury, leaving twenty one segments of that piece in good condition. 
1) E. Jozst, Transplantationsversuche an Lumbrieiden. Archiv 
fir Entwickelungsmechanik der Organismen, Bd. 5, 1897, Heft 3. 
2) T. H. MorGan, Regeneration in Allolobophora foetida. Archiv 
für Entwickelungsmechanik der Organismen, Bd. 5, 1897, Heft 3. 
