i) The American Naturalist. RA 
As the sperm stains very darkly it may be easily recognized in sec- 
tions. Itis found in the sperm ducts of both worms as well as in the 
sperm receptacles, where some of it is not even now ripe. Tt is also seen 
issuing out of the openings of the sperm ducts onto the outside of the 
body in both animals. There it may be traced for some distance as it 
is held beneath the pseudo-cuticle of mucous that envelopes the worms. 
Especially abundant along lateral lines it rises up onto the dorsal side 
of the worm enclosed by the girdle and may there be seen collected 
about the openings of the seminal receptacles and traced into the short 
ducts of these organs to the mass that more or less fills up these four 
bags in all the conjugating brandlings as yet studied. 
The anatomical evidence thus shows that in the conjugation of 
brandlings the girdles form grasping organs that envelope the part of 
the other worm containing the seminal receptacles and that a secretion, 
probably from the girdles, binds the two worms firmly together at these 
two regions. It also demonstrates that both worms pour out sperm 
onto the outside of the body and that this passes some distance back- 
wards and not forwards along the sides of the worms and is finally 
taken into the seminal receptacles. We cannot, however, decide from 
these sections whether none of the sperm of one animal enters its own 
receptacles, but there is nothing to militate against the facts observed 
on the live Lumbricus, by Hering, that is the passing of two currents 
of sperm, each backward from its orifice to the girdle and so into the 
other animal and the sections indicate that no sperm passes forward to 
the animals own receptacles. 
In the main the process of conjugation in the brandling as deduced 
from the anatomical relations of preserved pairs harmonizes exactly 
with the observations made upon the live Lumbricus and as we have 
seen by sectioning conjugating Lumbricus that the anatomical relations 
are almost the same as in the brandling we have little doubt that direct 
observation upon the brandling when they are made, will be pt et a 
confirmation of Hering’s account. 
Yet the action of the girdle may be somewhat different since the 
dorsal opening of the seminal receptacles in the brandling as compared 
with the ventral opening in Lumbricus makes it difficult to understand 
how such movements of the girdle as described above by Hering can 
collect the sperm about the openings of the receptacles though they 
might bring it to the lateral positions shown in fig. 5. In the brand- 
ling even more than in the large Lumbricus we may suppose with Her- 
ing that same sucking action of the receptacles may be concerned in 
taking in the sperm. 
