x 1907.| Transmission of certain Coat Characters in Rats. 103 
Table I.—Predicted Offspring in a Cross of “Irish” 0 x“ Irish” 6. 
Gametes formed by | i Be ae by aygou ee ae ig Pee cea eee j 
iis,” 6. | ris : of the offspring. offspring. 
CgBSP x CgBSP == CgBSP = Cr 7 
CgBsP x CgBSP = CgBSsP = Cr 6 6 
egBSP x CgBSP = CegBSP = Cr 6 a 
egBsP x CgBSP = CegBSsP = Cr 6b 
CgBSP x CgBsP = CgBSsP = Cr 6b 
CgBsP x CgBsP = CgBsP = Cr 5 
cgBSP x CgBsP = CegBSsP = Cr66 
cgBsP x CgBsP = CegBsP = Cr 5 
CgBSP x cgBSP = CcegBSP = Cr 6a 
CgBsP x cgBSP = CegBSsP == Cr 6 5 
egBSP x egBSP = egBSP = Cr 4 
cgBsP x cgBSP = egBSsP = Cr 4 
CgBSP x ceBsP = CegBSsP = Cr 6 6 
CgBsP x cgBsP = CegBsP = Cr 5 
cgBSP x cgBsP = cegBSsP = Cr 4 
egBsP x egBsP = egBsP = Cr 4 
Total offspring = 4 Cr 44+3 Cr 5+2 Cr6a+6 Cr6 6+1 Cr 7. 
X= gee 
os 
aw 
4 alb. ; 12 pigmented. 
=1 : 3 
Turning now to the actual results of experiments 49, 50, 51, 52, and 53, 
there is produced a total offspring of :— 
OF CrA! 4Or s-423 Cr 6 a-+- 10 Cr 6 644 Cr 7. 
et Ae aeie pdt e's) ay, 
oo alee 
== wheliioy ; 21 pigmented. 
Thus the experimental result departs from prediction in the expected 
proportions only. Dividing the actual result throughout by two, we have 
454+2415+5+2. This is a very close approximation to the prediction. 
The actual result is only one Cr5 and Cr 60 too few, and one Cr 7 too 
many. 
It is instructive to plot out the prediction and the actual result in the 
form of two curves (fig. 1). It can be seen at once how close is the 
resemblance between the two.: It is obvious that the general slope and form 
is the same, and that the difference is not greater than that between a 
theoretical normal curve of error, and one of that form obtained from an 
actual series of measurements. 
It is to be noted that all the types which are predicted have appeared, 
and that none which are not expected have arisen. | 
VOL. LXXX.—B. ’ I 
as 
Ts 
