Basic Guidelines: In the strictest sense, nature photography should not include "hand of man elements". Please refrain from images with buildings or human made structures like roads, fences, walls. Pets are not permitted. Captive subjects in zoos, arboretums, or aquariums are permitted, but must be declared, and must focus on the subject, not the captivity. Images with obvious human made elements will likely be deleted from the thread, with an explanation to the photographer. Guidelines are based on PSA rules governing Nature photography which also cover the Nature Forum. Keep your image at/under 1000 pixels on the long axis for in-line viewing. Note that this includes photos hosted off-site at Flicker, Photobucket, your own site, etc. Are you new to this thread? We post one image per week. Inner workings of nature. My wife found the shed exoskeleton of what I think was a giant water bug, Lethocerus species. Inside were these tree-like tubes which, I believe, are part of the breathing apparatus: spiracles at the base of the "trees" and the tracheae forming the "trees" themselves. Looking forward to other images of nature this week!