Auto Add
Off:
Often:
Sparse:
After Grab:

From anywhere:
From outside:
From top:
Speed
Slow
Medium
Fast
Lightning
Particle Size
Pixel
Small
Medium
Large
Aggregation threshold
1.0 * size
1.5 * size
2.0 * size
3.0 * size
Aggregate on
Any particle
Only fixed particles
Mouse click creates
fixed seed particle.