Hi, everybody. I am currently working on a project in Blender…I am making a woodland path scene. To do this, I am watching a tutorial. In the tutorial, he changes the number of particles (trees) from 1000 to 100, and changes the end keyframe from 250 to 1. After he does this, particles become visible on the plane. My particles are there until I change the number of particles, and then they disappear. Does anybody know how to fix this, so that I can have my trees again?
So, going back and messing with the numbers of particles, I may have found something that can help…For some reason, the number of particles start to disappear around 375. Also, there are particles at the bottom of the plane. I do not know if this has something to do with it. Sorry, but no, I am not able to provide a link to my Blend file, as I am working on a separate computer. I am able to provide a picture if somebody thinks that this will help. To anybody that is going to answer this, thanks in advance. 
Here is the link to the tutorial that I am using, if you want to check it out: https://www.youtube.com/watch?v=uAvG2E7p_W8 It is around 21:10 where I am having a problem.