404 
Study of Blood Corimseles of Tadpole 
TABLE I. 
Mean Cell Length for each Body Length. 
Mean Cell Length 
Millimetres 
Working units 
Millimetr 
5-35_ 6-35 
8-15 
•0218 
6-35— 7-35 
8-22 
-0220 
7-35— 8-35 
7-81 
•0209 
8'35— 9-35 
7-91 
■0212 
9-35— 10-35 
7-73 
•0207 
10-35—11-35 
7-67 
■0206 
11-35—12-35 
7-64 
-0205 
12-35—13-35 
7-48 
■0200 
13-35_14-35 
7-25 
-0194 
All body Lengths 
7-86 
-0211 
Diagram I. Regression Line of Length of Blood Corpuscle on Body Length. R. temporaria. 
71 
5-85 6-85 7-85 8-85 9-85 10-85 11-85 t2-85 13-85 14-85 
Body Length in mm. 
the tadpole diminishes as it develops. It appears to me that this point wants 
testing in other species ; it may well be that we are here dealing with a peculiar 
cellular change consequent on the development of the tadpoles, the larger of which 
were beginning to develop hind- and in a few cases fore-limbs. At the same time 
the decrease in size of blood corpuscles appears to have started with tadpoles so 
small that they showed no sign of limb development. The correlation — '25 is 
in excellent agreement for the result obtained for tadpoles of B. vulgaris, namely 
— '28 ; see Table IV. below. It will be obvious that if absolute lengths of the 
