41 
Metamorphosis of Axolotls 
On October 18 almost completely transformed (fragments of gills remaining); it 
weighed 84 7 gr. The loss of weight was here only about 20°/ 0 . During observation 
the animal was abundantly fed on meat. 
In order to ascertain whether a connection exists between loss of 
weight and the beginning and course of metamorphotic processes 
in specimens fed on thyroidine, the animals were weighed every 
two or three days; at the same time their behaviour was observed 
and recorded. The results are given in tables 1, 2 and 3. These 
TABLE 1. 
White axolotl. 
Day of obser¬ 
vation 
Fed on 
Weight 
j Behaviour of the animal 
November 
28 
meat 
and thyroidine 
30-5 
gr. 
W 
26 
. » 
%. » 
n 
28 
n 
r> r> 
rt 
29 
„ 
n n 
30-5 
n 
December 
2 
31-5 
n 
n 
4 
287 
n 
11 
6 
n * 
27-5 
ii 
r. 
8 
meat without thyroidine 
273 
V 
The tail-fin is smaller; the 
11 
9 
n 
» n 
265 
w 
gills are shorter. Circul¬ 
ation normal. 
11 
10 
n 
n v 
n 
11 
ll 
ll » 
26 5 
n 
Rapid resorption of fin and 
V 
12 
V 
n » 
264 
gills. 
* n 
13 
ll 
n n 
26 
» 
il 
15 
11 
n « 
25 
» 
n 
16 
* 
n n 
24 
ii 
Small fragments of gills. 
n 
19 
T. 
r> n 
217 
n 
The animal transferred 
to a terrarium. 
data show that, before the beginning of their sexual function, axolotls 
are easily induced to undergo transformation; but if we use animals 
which have been already sexually active, we meet with difficulties. 
For it is impossible to consider it an accident that the two animals 
which died whilst feeding on thyroidine were females which had 
laid eggs. It may be supposed that we have here to do with the- 
antagonistic influence of the hormons of the sexual glands. 
