PROTOZOA OR SIMPLEST ANIMALS. 
7 
Joblot, who, in 1754, first discovered it pirouetting about in an High Wall 
infusion of celery, speak of it as “ the most extraordinary fish one ^, as ® nd of 
could imagine.” A continual streaming of the protoplasm rendered Gallery, 
visible by the granules in its substance is continually proceeding up 
and down the pseudopods. The little organism reproduces itself by 
dividing into two (Model 4). 
Actinosphceriurn eichornii (see Plate V. in the Case) has a spherical 
body with a well-defined outer zone of large vacuoles ; this form, 
which is also abundant in ponds, somewhat resembles a giant Sun 
Animalcule, being about five times the size of Actinophrys. 
Rhaphidiophrys elegans may be either solitary (Model 5), or may 
form colonies in which several of the spheres are joined by bands 
(Model 6) ; numerous slender curved spicules of silex abound in 
the surface layer of the body and pseudopods. 
Clathrulina elegans (Fig. 3), which lives in ponds and ditches, 
may be compared to a Common Sun Animalcule enclosed in a 
latticed sphere of silex supported on a slender stalk ; the diameter 
of the shell is about -g-^-g- inch, and the length of the stalk about 
inch. See Model 7 in the Case. 
Foraminifera or Eeticularia. 
The majority of the Foraminifera form a shell of carbonate of 
lime ; in some, the shell is composed of cemented sand, mud, or 
sponge spicules, and, in a few species, of membrane or silex. The 
series of Foraminifera mounted on slides is arranged in ten families 
according to Mr. H. B. Brady’s classification, an enlarged figure 
being placed below each slide. The classified series is preceded by 
an introductory account of the group. The small plaster models on 
steps and on the floor-shelf represent selected types, both living 
and fossil. 
When the skeletons of Foraminifera were first discovered, they 
were supposed to be the shells of tiny Cephalopods or other Molluscs. 
G-reat was the sensation in the scientific world when, in 1835, 
Dujardin found, from observation of the living animals, that the 
builders of these complicated shells consisted simply of apparently 
structureless protoplasm, which extruded root-like trunks of branch- 
ing and anastomosing threads whereby the creatures crept along 
(Figs. 4, 5). Accordingly he removed these organisms from the 
Mollusca and placed them in a new group, Bhizopoda ( rhiza , root ; 
pons, foot). 
Foraminiferal shells either have only one or a few main apertures 
