276 THE MICROSCOPICAL NEWS. 
with deliberate firmness, that there is not one word of truth in the 
above statement. It is because accounts so fabulous have been 
rendered respectable by the fact that Prof. Owen has thrown over 
them the zgis of his great authority, that they demand a contra- 
diction, which may displease by the strength of the language in 
which it is given.” 
Dr. Williams sums up the life-cycles of these worms thus :— 
“These annelids are annuals; the term of existence is completed 
when the organic cycle is once accomplished. They are born 
during the latter months of one summer, and survive the winter, 
attain to maturity of growth, reproduce the species, and die by the 
spontaneous subdivision of the body into fragments, on the arrival 
of the same season of the succeeding year. . . . . For some time 
before fission of the body occurs, the process of maturation of the 
ova is proceeding. Arrived at the mature phase, they escape into 
the free space of the peritoneal cavity, wherein they sojourn until 
the next phase of their growth has been attained. It is during the 
period marked by the presence of true ova in the chamber of the 
peritoneum, floating in the contained fluid, that the division of the 
body of the parent animal takes place. In each fragment is nestled, 
incubated, a considerable number of ova. Filled still by the fluid of 
the peritoneal cavity, each fragment becomes subservient to the end 
of hatching the young. It resists decomposition only for the period 
required for the accomplishment of this purpose. When the ova 
are committed to the sand, the fragment rapidly disappears by 
putrefaction. ‘The fission of the body, thus interpreted, becomes 
the last act of the parental worm, since the portions into which the 
body is subdivided by fission never take food.” .... “ With the 
fission the necessity for food terminates. If, on the contrary, the 
division of the body were the first step of a real reproductive 
operation, characterised by the superaddition of new fragments of 
the body, the reconstruction of lost heads and the manufacture 
anew of departed tails, a resort to physiological argument were 
little required to prove that each fragment should grow voracious, 
and consume extra supplies of nourishment, in order to provide 
the necessary pabulum for the reparation of the mutilated parts.” 
He also states that artificial sections of these worms do not 
immediately kill them. The two parts of a divided worm writhe 
in involuntary motion for a few days, when mortification attacks 
the wounded segments, and gradually extends to the head in the 
one half and the tail in the other. 
Against this statement I will place the following by Dr. McIn- 
tosh :—“ Besides the ordinary development by ova, it has long 
been known that WVazs and Chetogaster exhibit fissiparous repro- 
duction. In JVais, after a certain degree of growth has been 
reached, budding takes place, so that several tolerably complete 
