Can these be wired in series?

Yes, you can wire these ceiling lights to operate on the same switch as a series. Wiring more than one of the lights to a single switch is similar to wiring any other series of lights together on one switch. The lights should be wired parallel to each other. This means connecting the corresponding wires (neutral, hot, ground) from each fixture to each other. If you are not familiar with electrical work or feel uncomfortable performing the installation, it is always a good idea to contact a local licensed electrician for professional assistance