INTRODUCTION. 
By R. M. Srrona. 
Durine the autumn of 1913, with the aid of Mrs. Whitman, a search was 
made in the Whitman house, and some fish-embryology records were found. 
Among them were the descriptions of the accompanying plates. The original 
drawings for all of the plates except Plate XX XIII were also discovered. 
Pencil marks on the original drawings assisted greatly in locating explana- 
tory material, which was found for all of the figures in the eleven plates. It is 
evident that these are the plates which were mentioned in the footnote (Mem. 
M. C. Z., 1889, 14, p. 7). No other manuscript was located but the material 
available appears clear enough. ~The pictures are to some extent self explanatory 
to the embryologist who is familiar with the first paper, and a fairly complete 
story is told by the records published in this paper. The plates published in the 
earlier paper contained figures illustrating early cleavage stages but almost no 
text on cleavage beyond that contained in the ‘‘explanations”’ of plates. Ap- 
parently the entire history of the cleavage was planned for the later paper. 
The material found appeared in the form of descriptions of drawings (very 
likely first draft), which were fortunately grouped systematically. The records 
were not numbered as on the published plates but bore a number which I have 
placed in parenthesis after the number of the plate as it appears in this publica- 
tion. The number in parenthesis occurred on the original drawings, in pencil, 
in almost every case. Thus the description of Fig. 1 in Plate XXXII was 
numbered 12 in the records left by Professor Whitman, and this number also 
appears on the original drawing. 
It has seemed wise to do little editing, and this little has been done very con- 
servatively. The records are consequently published largely verbatim. Signi- 
ficant changes or additions have been placed in brackets, especially when they 
have involved the use of considerable discretion. For many valuable sugges- 
tions I am indebted to Prof. E. L. Mark. 
