C. L. Edwards 
255 
These warts are much more prominent in the young for 97^ of this class 
show warts or their traces, as against 63 7o of the adult. Of those with warts, 
80 % of the young have them in the prominent right and left lateral rows, while 
this is true in only 27 "/^ of the adult. 
TABLE XV. 
2. Number of Wart.s on Sides of Bivium. 
Adult 
YoDNCi 
Right 
Left 
Right 
Left 
Mean 
Range of Variation ... 
9-25 
5—15 
8-65 
5—19 
7-90 
1—14 
7-68 
3—12 
d. Papillae around the Anus. 
Selenka, 1867, p. 325, mentioned a crown of papillae surrounding the anus, 
and Theel, 1886, p. 216, described a specimen of H. mexicmia Ludwig, as having 
the " anus with five minute groups of papillae." 
TABLE XVI. 
Distribution of Papillae around the Anus. 
In Groups 
Age 
Number of Groups 
In a 
Circle 
Indefinite 
Destroyed 
Totals 
2 
3 
5 
6 
Adult ... 
Young ... 
1 
1 
0 
0 
1 
0 
1 
1 
8 
4 
44 
31 
1 
1 
4 
7 
12 
1 
73 
45 
From Table XVI. it is seen that in 60-4 7„ of the adult and 68-8 7^ of the 
young there are 5 groups of papillae around the anus. These groups may run 
into one another but their centres are always clearly marked. The anal papillae 
vary in length from '1 to 1'5 mm. and have the supporting rods characteristic of 
papillae in general. 
F. Thickness of Body-walL 
The much larger mean and range of the adult show, as one would naturally 
expect, that the body-wall (skin) becomes thicker with age. Not only is the adult 
body-wall nearly three times as thick as the young, but at the same time the 
standard deviation is nearly three times as much. 
