Newly hatched chick: what is this?

[Larrickchick]

I hatched chicks for my students at school. Came in today and one that hatched last night has something black coming from it's lower abdomen, around it's foot, back into it's abdomen. Tried to get pictures, they are not the best. From my limited understanding of embryology their abdomens are open until the last couple of days, then they close up. Could it be a vein or something that was around the foot and things closed up with it still out?? It wasn't getting up and around at all, now they hobble around. Do I cut it, leave it??? Any thoughts?

 

[casportpony]

I hatched chicks for my students at school. Came in today and one that hatched last night has something black coming from it's lower abdomen, around it's foot, back into it's abdomen. Tried to get pictures, they are not the best. From my limited understanding of embryology their abdomens are open until the last couple of days, then they close up. Could it be a vein or something that was around the foot and things closed up with it still out?? It wasn't getting up and around at all, now they hobble around. Do I cut it, leave it??? Any thoughts?

Picture would be helpful.

-Kathy