134 
J. D. SIDDALL. 
dopodia, that it was necessary to use a camel-hair pencil to 
transfer it to a cell. In so doing I twisted it twice in the 
course of its length, thus causing stoppages of the sarcode- 
current. Before long, by a series of spasmodic movements 
of its body, the creature succeeded in stretching itself out 
quite straight upon the glass, when the jerking movement 
at once ceased. As the internal rotation resumed its course, 
slowly at first, and then more quickly, pseudopodia were 
emitted plentifully. Since then I have observed the same 
irritability in several other specimens, and believe that the 
source of such movements is the nucleus, which furnishes 
the impetus required to produce them. I have never 
before seen any Bhizopod exhibit the same sort of irrita- 
bility, or make such manifest attempts to rectify itself when 
placed in an abnormal position. The power of curving 
laterally, combined with that of crawling by the aid of its 
pseudopodia, enables Sliephear della to move from place to 
place with considerable rapidity ; but its habit is, when once 
fixed, to remain for many days in the same spot with its 
pseudopodia fully extended. 
Abnormal forms . — Several specimens observed during the 
months of October to December differed considerably from 
the normal form and also from each other. Two of these 
are represented in PI. XV, figs. 5 anfi 6. For some time I 
looked upon them as distinct species, but having since 
traced other specimens of Shephear della through similar con- 
ditions during their breaking up,^’ I am disposed to con- 
sider them as representing an early stage in that process. 
One of them (fig. 6) was found on Nov. 29th. Its body 
was continually changing in form, pseudopodia being ex- 
tended from no less than thirteen distinct orifices in its 
integument ; some of the main branches of pseudopodia 
reaching to the extraordinary length of three-fourths of an 
inch (20 millim.), and capturing infusoria in all directions. 
Most of the food so captured was digested outside the body, 
in temporary masses formed by the accumulation of sarcode 
from the pseudopodia. The bodies of the abnormal forms 
were also full of dark- coloured food particles, diatoms being 
occasionally noticeable among them, but the sarcode of the nor- 
mal Shephear della seldom seemed to contain any alimentary 
or other foreign matter. On one occasion I detected a typical 
specimen in the act of conveying towards an aperture a 
relatively large mass of apparently faecal matter, so large 
that it choked the orifice for a considerable time and was 
eventually ejected suddenly and passed away by an excurrent 
pseudopodium, and finally thrown off at some distance from 
