xlvill CHARLES OTIS WHITMAN 
lution and heredity, an extraordinary breadth of field for a modern 
zoologist. But whatever subject he touched he illuminated. 
He was slow to publish, not because of lack of industry or results, 
but because he was determined to examine the subject to the 
bottom, and to be sure of his view-point. He rarely had occa- 
sion to correct any published statement, and even less rarely, 
perhaps, to change in any radical way a point of view to which 
he had once committed himself. Work of such classical distine- 
tion could not be very abundant. He has left a large amount of 
unpublished material, especially bearing on pigeons, though there 
is much that dates from an earlier period. The statements that 
follow concerning unpublished material are on Dr. Riddle’s 
authority. 
Embryology 
In his first scientific publication, ‘‘The Embryology of Clep- 
sine,’ Professor Whitman at once took rank as a great zoologist. 
Although this paper was his doctor’s dissertation, it was unusually 
mature, and showed in striking manner the qualities which char- 
acterized all of his later work, viz., patience and accuracy in 
observation, great power of logical analysis, and a firm hold on 
large problems. Indeed so fundamental and comprehensive was 
this work that almost all of Professor Whitman’s later embryo- 
logical work is foreshadowed in it, while it furnished the stimulus 
for a large amount of work on the organization of the egg and its 
cell lineage, which was done later by his associates and students 
at Woods Hole. 
Even at this early date (1878) his conclusions as to the organi- 
zation of the egg and the formation of the embryo were fundamen- 
tally the same as his later views. He observed the bilateral 
symmetry of the egg of Clepsine before cleavage; he studied 
carefully the cleavage of the egg and observed the formation and 
subsequent history of the ectoblasts, mesoblasts, neuroblasts, 
and entoblasts; he described the growth and concrescence of the 
germ bands of Clepsine, and compared them with the growth and 
concrescence of the germ ring of fishes. His conception of the 
fundamental problem of all development is expressed in these 
words: ‘‘In the fecundated egg slumbers potentially the future 
