412 
theory that the secondary calcaneus, having become fused with the os 
calcis, has entered into abnormally close relations with the scaphoid. 
Now this specimen shows all this; but it shows also that the greater 
part of the bridge is made neither by the secondary calcaneus nor 
secondary cuboid, which latter forms with the os calcis the plantar 
part of the union. 
Incidentally it may be remarked that there is a peculiar twist 
in the os calcis which seems to be factor in producing some degree 
of flat foot. The anterior calcaneo-astragaloid articulation is reduced 
to its posterior portion on the sustentaculum. Seen from the dorsum 
the scaphoid passes less than is usual in such cases behind the cuboid. 
It shows anteriorly four articular facets, the fourth at the outer end 
being for a part of the cuboid. This last is decidedly oblique. 
I have expressed the opinion that there is no described case of 
a free calcaneus secundarius under these circumstances. The 
only possible exception that I know of is Prirzner’s foot no. 75. 
There were two small bones between the os calcis and scaphoid. One 
formed a small part of the joint for the head of the talus, the other 
had an articular surface to meet a corresponding one on the scaphoid. 
This therefore was not a case of coalescence, but only an approach 
to similar relations. 
Harvard Medical School, Boston, 
Nov. 4, 1901. 
Nachdruck verboten. 
Sulle cellule germinative del tubo midollare embrionale 
dell’ uomo. 
Pel Dr. Ermanno Giexi0-Tos in Torino. 
Con 6 figure. 
Dopo che His nel suo importante lavoro sui neuroblasti!) ebbe 
esposto in qual modo traggono origine e le cellule nervose e le cellule 
di sostegno dell’asse cerebro-spinale, le sue idee furono tosto favore- 
volmente accolte dai pitt dei biologi e vennero diffuse nei principali 
trattati di istologia e di embriologia. 
1) W. His, Die Neuroblasten und deren Entstehung im embryo- 
nalen Mark. Abhandl. d. mathem.-phys. Kl. d. K. sachs. Gesellsch. d. 
Wissensch., Bd. 15, 1890, No. IV, p. 313—372. 
