50 
L. Kaufman : 
Bar forth, the last stages of metamorphosis are shortened by 
starvation, and the moult is accelerated. 
The behaviour, in my experiments, of axolotls fed on thyroidine- 
proves that processes analogous to those observed by Rûzicka 
in full-grown newts subjected to starvation take place here. It is 
true that, in my experiments, no starvation sensu stricto occurred, 
as the animals were abundantly fed on meat, but the simultaneous 
feeding on thyroidine subjected them to a state similar to starvation. 
Both in starvation and in thyroidine-feeding, disassimilation prevails 
over assimilation. Metabolism during the period of growth is ex- 
A 
pressed in Physiology by the symbolic formula > 1 (A — as¬ 
similation, D = disassimilation); in full-grown specimens we have 
A 
— 1; in animals subjected to starvation as well as in those fed 
on thyroidine, processes of disassimilation become more important 
A 
than processes of assimilation, so that— <( 1. This may be inferred 
from the loss of weight which is noticeable both in animals deprived 
of food and in axolotls fed on meat with thyroidine. The value of 
A 
the ratio — <( 1, in animals subjected to starvation, follows from* 
the decrease of A, caused by absence of nourishment. Since the 
axolotls experimented upon were abundantly fed on meat, the 
value <1 must be referred to accelerated processes of disassimil¬ 
ation. The effect is the same in both cases; this is evidenced by 
the structure of the skin of axolotls fed on thyroid gland extract,, 
by the appearance of the first moult, as well as histological changes. 
The skin of axolotl larvae (fig. 1) is composed of many-layered 
flat epithelium and of connective tissue, in which blood-vessels and 
large venomous glands may be observed. The breadth of the 
epithelium attains 280 to 300^, it contains 10 to 12 cellular layers. 
The cells of the epithelium (fig. 2) are multi-angular; their nuclei 
are large and easily stained by haematoxyline. Besides the common 
epithelial cells, we find glandular cells, the so-called cells of 
Leydig. Numerous blood-vessels are situated beneath the epithelium. 
The venomous glands lie lower in the connective tissue; they are 
still deprived of ducts. 
A comparison of fig. 2, table 1, representing the epithelium of 
