Science-Teaching in the Schools. 913 
Compare this animal with the oyster and the clam. Note that the 
former has only one adductor muscle; while the latter has the 
mantle lobes united, forming a sack which is continued posteriorly 
in the breathing-tubes, or siphons. Examine some pond-snails. 
These will be found to resemble the preceding in their flabby, 
unjointed bodies, destitute of internal skeleton; but will be seen to 
differ in having a distinct head with feelers, and a spiral univalve 
shell. Examine shells of some of the sea-snails. Lead the pupils 
to recognize characters of Lamellibranchiata and Gastropoda, as 
classes of the sub-kingdom Mollusca. Contrast the Mollusca with 
the Vertebrata and Articulata. Give some talks on corals, sponges, 
and other animals lower in the scale than mollusks. Do not let the 
pupil suppose that the classes he has studied comprise the whole 
animal kingdom. Talks on geographical distribution of animals. 
Give a little idea of geological succession of animals. 
Botany.—Geographical distribution of plants. Uses of plants. 
Relation of plants to animals. 
Geology.—Gravel, sand, clay. Show that these result from the 
disintegration of pre-existent rocks. Erosion, transportation, and 
deposition by watér. Study gutters and puddles for illustration of 
action of aqueous agencies. Conglomerate, sandstone, shale. Show 
that these result from consolidation of gravel, sand, clay. Visit 
Portland quarries. Other rocks are sediments not merely consoli- 
dated, but crystallized by action of internal heat. Study specimens 
of gneiss and mica schist. Contrast their texture with that of 
sandstone and other sedimentary rocks. Still other rocks have 
come up in molten condition from interior of globe—eg., lava, 
trap. Talks on volcanoes. 
GRADE VIII. 
Physiology. —Review nutritive functions, using elementary text- 
k. Illustrate subject with a few dissections. 
Physics.—Elementary text-book. Illustrate with experiments, 
as much as practicable. 
GRADE IX. 
Physiology.—Review functions of relation, using elementary 
text-book, 
Chemistry.—Elementary text-book. Illustrate with experiments, 
as much as practicable. 
