Badania nad sztucznem przeobrazeniem aksolotla . — 
Researches on the artificial Metamorphosis of Axolotls . 
Mémoire 
de M> le LAURA KAUFMAN, 
présenté, dans la séance da 4 Février 1918, par M. E. Godlewski fils m. c. 
(Planches 1 et 2) 
CONTENTS. 
1. Introduction.p. 32 
2. Specimens and methods. p. 39 
3. Observations on living animals.p. 40 
4. Anatomical and histological investigations . p. 49 
5. Discussion of results; conclusions.p. 63 
6. Summary. p. 70 
References.p. 72 
Explanation of tables.p. 74 
1. Introduction. 
The metamorphosis of amphibians has not as yet been fully 
investigated. It is true that certain factors are known which are 
favourable to metamorphosis and certain others which retard the 
process; we also know some of the morphological and physiological 
changes which occur during the period of transformation. All these 
informations, however, are scanty and do not permit any conclu¬ 
sion as to the transformation of larval into perfect forms. 
Authors have chiefly studied the metamorphosis of Anura , prob¬ 
ably in view of the morphological changes (more striking than 
the corresponding changes in Urodela) which take place during 
transformation: loss of the tail, transformation of the horn-jaws 
into bone, shortening of the intestine. In Anura the period of meta¬ 
morphosis begins simultaneously with that of the appearance of the 
limbs, which in Urodela precedes considerably transformation; but 
