(a) the "Rochers du Reposoir", so called because the Whymper team who first climbed GJ made a stop here after 10 hours of continous march from Coumayeur!; (b) the Whymper couloir; (c) the "Rochers Whymper"; (d) the Tour Des Jorasses (3813m.), a GJ satellite where several difficult rock climb have been opened, deserving a separate entry on SP;
(e) the towers of the Tronchey ridge; (f) Col Des Grandes Jorasses (3818m); (g) Pointe Young (3996m); (h) Punta Margherita (4066m); (i) Punta Elena (4045m); (j) Pointe Croz (4110m); (k) Pointe Whymper (4184m); (l) Pointe Walker (4208m); (m) The "great serac"; (n)the upper Jorasses plateau; (o) the Planpincieux glacier
(1) and (3) Normal route (Whymper/Croz/Almer/Biner, 1865, AD, III, 1400m) opened just 20 days before of Whymper's conquest of Matterhorn, and reportedly just as a reconaissance for the first climb of the Aig. Verte, it was an incredible exploit for the time - the climber left Courmayeur at 1,35am, summited at 13:00pm and was back at Courmayeur at 20:45pm! Neglected for some time because of the bigger appeal of the direct route to the Pt. Walker, it's now far more frequented.
(1) and (2) Direct route to Pt. Croz (Hasenclever, Klemm, Konig, Weitsenbuck, 1909, AD, 1200m). Almost never used in ascent, it's now becoming quite popular in descent for parties doing the Croz spur on the north face, or as escape route from the west ridge, because it does avoid the Whymper couloir gauntlet.
(1) and (4) Direct route to Pt. Walker (Walker/Anderegg/Yaun/Grange, 1868, AD, 1200m) The line of the second ascent, was for almost a century the most popular way to climb the Grandes Jorasses, because it was faster and slightly easier than the Whymper route. It's now rarely ascended because of the instability of the Great Serac, threatening the upper plateau of Jorasses. May be still a feasible descent alternative in cold wather for parties reaching the Pt. Walker from north, east or the Tronchey ridge.
(background picture courtesy of Gilles Perrin from www.flying-doctor.org, visit his site )