Strange green organ I've never heard or read from

[Vilo512]

Hello, this is my first post. My name is Vinny, I'm from Spain, and I have 17 years old. I'm doing a research project to confirm the Laws of Mendel, kind of a kids game. Well, I'll try on september/october to expose the flies to chemical agents, so I'll see how they afect the flies or if they mutate in any form.

Well, my question is about a green organ in the pupal form of the Ebony variety of Drosophila that appears when the fly is not pigmented yet. I've seen 5 of them, and here I'll put photos (not so good, I had to take the photo with a camera pointing at the ocular thing... -.- but the organ is very visible) and my question is if anybody had heard about this organ, or whatever it is. Also, I've seen the formation itself of the abdomen of the fly "eats" this organ, so it dissapears...
Anybody knows about it?

The photos are here (remove the "(dot)" thing, and place a dot instead):

1st: The Organ:
imageshack.us/photo/my-images/807/dscf1572.jpg/

2nd: Better image of the Organ:
imageshack.us/photo/my-images/851/dscf1573x.jpg/

3rd: It's disappearing:
imageshack.us/photo/my-images/225/dscf1574g.jpg/
4th: Less visible:
imageshack.us/photo/my-images/832/dscf1575ga.jpg/

5th: Another pupal form, developed better, and bigger. Notice the "C I" shape of the green thing:
imageshack.us/photo/my-images/832/dscf1575ga.jpg/

6th: The same the last time, but another one not so well taken:
imageshack.us/photo/my-images/204/dscf1578e.jpg/

Well, I hope somebody could help me. Thank you everybody.

[Fredrik]

This is the meconium

[Vilo512]

Thank you very much! I really didn't know what it was and I was so lost. Thank you again!