CILIATION OF ECTODERM OF AMPHIBIAN EMBRYO. 465 
Notes on the Ciliation of the Ectoderm of the 
Amphibian Embryo. 
By 
Richard Assheton, M.A. 
With Plate 35. 
Tue fact that the embryo and larva of Amphibia possess a 
ciliated ectoderm has been frequently noticed, but since, as far 
as I know, a description of the distribution of the cilia, and of 
the currents of water over the surface of the body, which 
result from the action of the cilia, has not been hitherto 
published, my notes upon the ciliation of the tadpoles of 
Rana temporaria and Triton cristatus may perhaps be 
of interest. 
Quite recently the fact of the existence of a ciliated embryo 
among craniate Vertebrates seems to have been doubted or 
overlooked. Osborne (10), in his preface to Willey’s ‘‘ Am- 
phioxus and the Ancestry of the Vertebrates,” with respect to 
the ‘‘ real invertebrate and vertebrate affinities” of Amphioxus, 
writes thus :—“ For example, among the real invertebrate ties 
of the Protochordates are the ciliated embryos of Balano- 
glossus and Amphioxus, the Tornaria larva and ciliated ecto- 
derm of Balanoglossus.” 
Willey (17), in the text of the book, page 113, says, ‘The 
fact that Amphioxus has a free-swimming, ciliated embryo is 
important as providing a general connecting link between the 
Vertebrates and the Invertebrates, since the possession of a 
ciliated ectoderm is very common among invertebrate embryos, 
but entirely unknown among the craniate Vertebrates.” 
