  We describe near-IR imaging data for a sample of 23 class I sources in the
Taurus-Auriga dark clouds. Combining our data with previous photometry, we
detect brightness variations of 0.1-0.5 mag in many sources. The near-IR
morphologies are consistent with mm continuum measurements. Most (60%) of the
sample are true protostars; the rest may be objects in transition between class
I and class II, T Tauri stars with edge-on disks, or heavily reddened T Tauri
stars.
