476 
DR. E. KLEIN. 
Histological Notes. By E. Klein, M.D., F.R.S. 
I . — Ciliated Epithelium of the (Esophagus, 
E. Neumann (‘ Archiv f. mikr. Anat./ vol. xii, p. 570 ) 
observed on the surface of the mucosa of the oesophagus of 
the human foetus, between the eighteenth and thirty-second 
week, ciliated columnar epithelium. This did not, how- 
ever, form a continuous lining, since in many places the epi- 
thelium was stratified pavement epithelium, such as is found 
in the new born and adult. Kolliker Entwickelungsge- 
schichte, d. Menschen,' &c., 1879 , vol. ii, p. 853 ), found also 
ciliated columnar epithelium in various places in the oeso- 
phagus of the human foetus between fourteen weeks and the 
sixth month. 
Mr. Anderson and Mr. Ricketts, students at St. Bar- 
tholomew’s Medical School, when examining sections of 
the cervical portions of the (hardened) oesophagus of a new- 
born child — full time — found, amongst the stratified pave- 
ment epithelium of the ordinary description, places where 
the superficial cells were not flattened but columnar; 
underneath these were polyhedral cells in two or 
three layers, and finally, a deepest layer of columnar, 
cells. The superficial cells were either without or with 
cilia ; the latter were short and very delicate. The ciliated 
cells were seen, more or less continuous, chiefly in the 
grooves between the folds of the mucosa ; in the neighbour- 
hood of these there were generally only isolated ciliated 
cells. 
II . — Cilia in the Central Ca^ial of the Emhryo Chick, 
Examining with Mr. Anderson the fresh embryo of a 
chick of about the stage figured in Kolliker’s ^Entwickel- 
ungsgeschichte,’ p. 138 , as of the end of the second day, with 
seventeen protovertebra3, in warm saline solution and from 
the surface, I saw in the whole extent of the protovertebra 3 
the central canal of the central nervous system lined with 
very beautiful delicate cilia ; their length was about half that 
of the cells lining the canal, and they were in very active 
movement. It was, in fact, this movement by which their 
presence made itself conspicuous. It could not be seen in 
the caudal part. In a second embryo of about the same 
early stage, observed under similar conditions, the move- 
ment w'as seen distinctly in the commencement of the cer- 
vical region, but was soon lost, owing to the wall of the 
