430 Data on Variation in the Comb of the Domestic Fowl 
(2) Number of points. While, as is evident from an inspection of the 
figures, it is impossible accurately to count the number of points in each comb, 
owing to the difficulty in defining how great the projection of the margin must 
be in order to be designated as a point, yet it is obvious that there is a great 
deal of variation in regard to this character. Such combs as are shown in Figs. 7, 
17, 26, 64, 73, 76 and 88 obviously have more points than do such combs as are 
shown in Figs. 3, 12, 18, 31, 44, 50, 63, 89 and 94. There is further no doubt 
that there is continuous variation between the extremes in respect to the number 
of points. 
(3) The extent of the serrated region. The region of large and distinct 
points may extend over nearly the whole of the comb (Figs. 7, 22, 38, 46, 88 
and 93), or it may be confined to a restricted region of the comb (Figs. 29, 33 
and 58). 
(4) The direction of the points. The angle which the points make with 
the base line of the comb varies in a continuous manner from the condition in 
which they form approximately a right angle with the comb base (Figs. 7, 62, 64, 
66 and 96), to the condition where they slope in a posterior direction at a pro- 
nounced angle (Figs. 2, 13, 15, 22, 28 and 65) or to the condition where they point 
forward (Figs. 48 and 77). 
(5) Intercalated points. It happens rather frequently in the single comb 
that a small point or serration will be set between two larger ones in the series. 
Examples of such intercalation are shown in Figs. 8, 14 and 17. 
(6) Branched or split points, and points with spurs. The combs studied , 
rather frequently have one or more of the points either branched or split at 
the tip, or bearing on either the anterior or the posterior side a small spur or 
secondary point. Examples of this sort of point variation are seen in Figs. 37, 46, 
62, 66, 78, 79, 80, 82, 86, 88, 90, 91 and 94. 
The blade of the comb (d) varies in respect to : 
(1) The condition of the dorsal free margin or boi'der. This margin of the 
blade may be smooth (Figs. 4, 5, 10, 30, 49, 50, 82 and 94) or it may be serrated 
(Figs. 7, 12, 21, 22, 26, 33, 56, 69, 75 and 76). 
(2) The contour of the posterior and ventral free borders. These borders 
of the blade may be either smooth (condition shown in the majority of the figures) 
or they may be to a greater or less extent indented and of irregular contour 
(Figs. 12, 23, 31, 39, 48, 51 and 61). 
(3) The degree of extension behind the posterior end of the base of the comb. 
The blade may lie nearly or wholly behind the posterior end of the comb base 
as in the normal case (shown in the majority of the figures), or, on the other 
hand, little or none of the blade may lie behind this point (Figs. 11, 15, 37, 
77, 83, 84, 85 and 95). There are all intei-grades between these extreme 
conditions. 
