126 
ANIMAL ACTIVITIES. 
terata. For our purpose it seems best to regard the 
Porifera as a separate sub-kingdom. 
Questions, i. What force propels the water through 
the canals in a sponge ? 
2. Write the functions of the sponge in columns as 
we have previously written the functions of other 
animals. 
3. In what respects does the sponge resemble the 
Paramecium ? 
4. How does a sponge differ from an Amoeba ? 
5. Where are sponges found ? 
6. Why are sponges called animals rather than 
plants ? 
Topics for Reports. Chalk. Tripolite. The Dis¬ 
covery of the Microscope. How to use a Microscope. 
Sponge-fisheries. 
VOCABULARY. 
An i mal'cule (Lat. dim. of ani¬ 
mal , from anima , breath), a 
very small animal. 
As sim i la'tion (Lat. ad, to, and 
similis, like), the process of 
making digested food into living 
tissue. 
Cal ca're ous (Lat. calx , lime), 
made of carbonate of calcium. 
Cell (Lat. cella, a small room), a 
bit of living protoplasm contain¬ 
ing a nucleus. 
Cil'i a (Lat. pi. of cilium , a hair), 
hair-like bodies capable of rapid 
movement. 
Ec'to derm (Gr. ektos , outside, and 
derma , skin), the outer layer of 
cells in a sponge. 
Ec'to sarc (Gr. ektos , and sarx, 
flesh), the outer film surround¬ 
ing one of the Protozoa. 
En'do derm (Gr. endon, within, 
and derma), the inner layer of 
cells in a sponge, the layer 
which forms the lining of the 
digestive channels. 
Fis'sion (Lat. fissus, a cleft), the 
process of reproducing by cell- 
division. 
Fo ram i nif'e ra (Lat. foramen , a 
hole, and fero, to carry), Proto¬ 
zoa having shells punctured with 
many small holes. 
In fu so'ri a (Lat. pi. of infusori¬ 
um, an infusion), Protozoa mov¬ 
ing by means of cilia. 
Ker'a tose (Gr. keras , a horn), 
horn-like. 
Mesoderm (Gr. mesos, middle, 
and derma), the part between 
ectoderm and endoderm. 
Nu'cle us (Lat. dim. of nux, nut), 
a denser bit of protoplasm in a 
cell. 
Os'cu lum (Lat. dim. of os, mouth), 
a minute pore or mouth. 
Pseu do po dium (Gr. pseudos, 
false, and fous, foot), a project¬ 
ing portion of an Amoeba’s cell, 
a false foot. 
Pro'to plasm (Gr. protos, first, and 
| plastna , form), the substance of 
