text: Figure 4. Here is a rope cluster of several dangling, distorted SWNTs. Two SWNTs at appear slighted curved and displaced with respect to the other SWNTs of the bundel, suggesting that were possibly growing faster than the others in the cluster. These curved SWNTs appear to be coated with a more electron dense layer, suggesting that possible metal catalyst labeling is present on these SWNTs. This adds to the suggestion that they may have been growing faster. Perhaps they may grow in "spurts" as entire end regions are generated, then these straighten out, and then the other SWNTs in the rope will follow with similar additions. Unlike most clusters or bundles, this case appears to have been a fortunate example revealing the true ends of the SWNTs. Note also several linear electron-dense structures which are interpreted as chains of linear acetylenic carbon coated with metal catalyst (see fig 5 below).