In most of the best schools I believe this plan is adopted.

I will mention some of the subjects which would come up at such a time.
1.

There are some studies which can be advantageously attended to by the whole school together, such as Punctuation, and, to some extent, Spelling.
2.

Cases of discipline which it is necessary to bring before the whole school ought to come up at a regularly-appointed time.

By attending to them here, there will be a greater importance attached to them.