NOTE ON THE DEVELOPMENT OP AMPHIBIANS. 295 
Note on the Development of Amphibians, chiefly- 
concerning the Central Nervous System; 
with Additional Observations on the Hypo- 
physis, Mouth, and the Appendages and 
Skeleton of the Head. 
By 
Henry Orr, Pli.D., 
Princeton, New Jersey. 
With Plates XXVII, XXVIII, and XXIX. 
The material for the investigations which are described in 
this article was collected at Princeton, N.J., except a few 
specimens of Triton alpinus kindly given me by Professor 
H. F. Osborn. Through a failure to obtain adult specimens 
at the time when I obtained the embryos, there remains room 
for doubt as to the exact species of the embryos. The Ambly- 
stoma embryos correspond exactly to Clarke’s 1 description of 
the embryos of Amblystoma punctatum, but there is one 
difference in the appearance of the egg-membranes which leads 
me to think that this may be a different species from that 
described by Clarke. It is, perhaps, A. bicolor, for which 
Jordan 2 gives only the habitat New Jersey. The Frog em- 
bryos are either Ran a halecina or R. palustris. I judge 
them to be the former. In the stages of development with 
1 S. F. Clarke, “Development of Amblystoma punctatum. Part I, 
External,” ‘ Studies from the Biological Laboratory of the John Hopkins 
University,” No. ii, 1880. 
2 D. S. Jordan, ‘Manual of the Vertebrates of the Northern United 
States, &c.,’ 187G. 
