This data set, previously analysed in 

   Diggle, P.J., Lange, N. and Benes, F.M. (1991). Analysis of variance
   for replicated spatial point patterns in clinical neuroanatomy.
   J. Amer. Statist. Assn. 86, 618-25.

gives the (x,y)-coordinates of pyramidal neurons in area 24, layer 2
of the congulate cortex. The data are taken from a unit square region
(unit of measurement unknown) in each of 31 subjects, grouped as
follows:

1. Controls : 12 subjects, cell numbers 1:43; 44:82; 83:148; 149:209; 
210:274; 275:306; 307:412; 413:475; 476:513; 514:571; 572:617; 618:655

2. Schizoaffectives: 9 subjects, cell numbers 656:691; 692:703;
704:758; 759:770; 771:824; 825:903; 904:964; 965:1040; 1041:1061

3. Schizophrenics: 10 subjects, cell numbers 1062:1108; 1109:1110; 
1111:1167; 1168:1204; 1205:1220; 1221:1264; 1265:1305; 1306:1343; 
1344:1390; 1391:1400