170 FRANK W. BANCROFT 
is dominant over the absence of red chromatophores at the same 
time (F. majalis condition). 
2. In all of the above characters which concern mainly the 
presence or absence and not the time relations of the pigment 
characters the dominance is very evident, though often to a 
certain extent incomplete. 
3. In the following characters, however, which are mainly 
concerned with the time relations the dominance is much less 
complete, or wanting altogether. 
a. At hatching time F. majalis has a row of 50 or 60 black 
chromatophores along the lateral line, while in F. heteroclitus 
there are usually no chromatophores on the lateral line until 
hatching time when they begin to appear and gradually increase 
in number. The hybrids are intermediate, having at hatching 
time about 15 or 20 black chromatophores on the lateral line, 
and developing additional cells more rapidly than in the pure 
F. heteroclitus. 
b. When the yolk chromatophores in F. heteroclitus first 
appear they are evenly distributed over the whole yolk sac; 
while in F. majalis they are absent from the yolk hemisphere 
farthest from the embryo. The F. heteroclitus egg hybrid is 
like its maternal species, while the F. majalis egg hybrid is inter- 
mediate having, on the side of the yolk sac opposite to the embryo, 
a small area in which the chromatophores are either absent or 
fewer than elsewhere. . 
ec. A more perfect case of blended inheritance exists, as New- 
man has already shown, for the time of appearance of the yolk 
chromatophores. In F. heteroclitus these cells appear much 
earlier (both with respect to time, and with respect to the stage 
of development of the embryo) than in F. majalis. In the hybrids 
the time of appearance of these cells is intermediate, but each 
hybrid resembles its maternal more than its paternal parent. 
4. It appears then that the presence of certain pigment char- 
acters dominates over their absence or lesser development; while 
for the time relations of these pigment characters blended hered- 
ity holds. This difference may be fundamental or due to an 
incomplete analysis of the time relations. 
