Neck Extensions in Folliculinids — Matthews 
233 
were observed the counter clockwise movements 
so characteristic of normal neck formation. This 
was understandable because, although it resem- 
bled a proboscis, it already possessed peristomal 
lobes {d). 
Believing the process completed, I made a 
small aperture (h) in the lorica (g) in order 
to determine if the entrapped folliculinid would 
attempt to free itself. Rather more quickly than 
expected, it metamorphosed into a small but 
otherwise normal folliculinid which almost im- 
mediately gained access to the outside by means 
of this aperture (h). There was no "feeling 
around" inside the sac for the location of this 
opening: rather, the animal went directly to 
and through it. 
These two folliculinids shared the same lorica 
from March 22 to March 24. During this time 
the folliculinid attached to the sac continued to 
use the aperture made for it. It would relax and 
extend its body and peristomal lobes (/) high 
above the dorsal surface of the old sac but made 
no effort to secrete a new neck. The folliculinid 
attached near the old lip ( c ) was at no time 
a 
i — — i 
200 jj 
Fig. 4. Lagotia viridis as viewed from the right side 
showing: a, hemispherical, caplike neck extension; 
b, body attachment point; c, lip; d, peristomal lobes of 
new occupant; e, neck; f, peristomal lobes of original 
occupant; g, sac; and h, aperture cut in sac. 
as active as the one in the old sac. Its peristomal 
lobes (d) were never held aloft and the beating 
of their pectinellae was never observed. The 
following morning (March 25) both folliculinids 
had vacated the old lorica. Whether or not they 
metamorphosed into swimmers was not ob- 
served. However, the swimmer that had attached 
itself near the old lip had secreted a strange 
type of neck extension (a). This consisted of a 
hemispherical cap whose opening was placed 
at right angles to the main or longitudinal axis 
of the original neck. 
Although it is difficult to distinguish one 
species of swimmer from another, the fact that 
this swimmer was at first a deep violet and 
that Parafolliculina violaceae were present on 
the original plate suggests that in this instance 
the neck extension may possibly have been the 
result of another species! 
Because under laboratory conditions organ- 
isms frequently respond abnormally, modified 
experiments were performed in the organism’s 
natural habitat. Empty loricae of M. andrewsi 
without extensions were stained with acidulated 
borax-carmine, washed thoroughly, and the glass 
plates were returned to the anchorage lagoon at 
Coconut Island. At the same time, other empty 
unstained lorica without extensions were marked 
and these glass plates were returned to the or- 
ganisms’ natural habitat. Although both stained 
and unstained loricae were observed over a 
period of 2 months, neither possessed new 
occupants nor extensions. And although the dis- 
couraging results of these experiments throw 
some doubt on the possibility that neck exten- 
sions are formed by new swimmers entering old 
loricae, other naturally occurring examples point 
very strongly to this possibility. 
In M. andrewsi the condition illustrated in 
Figure 5 is frequently encountered. Two body 
attachment points {d, e) are clearly discernible. 
Although Penard (1919:317) incorrectly as- 
sumes that longitudinal fission occurs in Follicu- 
lina holtoni (see his Fig. 17), he correctly points 
out that only a single body attachment point 
persists, that of the original occupant. If, as 
suggested by Andrews, neck extensions are the 
result of the original occupant of the lorica, 
then only a single attachment point should be 
present. It is absurd to assign two attachment 
