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HANS-PETER HAFELI 



whereas most of the remaining eggs remain naked, though some of them 

 may receive a thin jelly layer. 



6. At the completion of egg descendence fertilization takes place in the caudal 

 section of the utérus, during which a jelly plug formed by pressing the egg 

 membrane into the utérine orifice serves as the ascending path of the sperm 

 from the séminal réceptacle into the utérus. 



7. Normally only one egg, the embryonic egg, in each utérus is fertilized, 

 whereas those eggs having no jelly membrane remain unfertilized. 



8. The development of the egg is dépendent on the degree of membrane formation. 

 Eggs with a thin jelly membrane, if they were fertilized, stop development 

 at very early stages (two to four cells) and disintegrate to a yolk mass like 

 the eggs without jelly membrane. 



9. The development of embryotrophic eggs without jelly membrane does not 

 take place. An excessive number of embryos or larvae in each utérus is thus 

 always due to an excessive number of embryonic eggs. 



10. The gestation period of Salamandra atra is strictly limited. It lasts, at 650 m 

 altitude, from the middle of May until the end of June; at 1000, 1400 and 

 1700 m over the whole month of June. After thèse dates females of the 

 corresponding altitude will be no more pregnant. 



11. For females at an altitude of 650-1000 m, birth of the young animais occurs 

 in the summer of the third pregnant year after a gestation period of two 

 years, for those at altitudes of 1400 and 1700 m in the summer of the fourth 

 pregnant year after a gestation period of three years. 



12. From the middle III stage onward there is no more change in the position 

 of the larvae in the utérus. Head- or rumpposition are equally fréquent. 



13. The youg animais are born according to the head- or rumpposition and take 

 an active part in the paturition process. 



14. Females which bear will not be pregnant again the same year, but only in 

 the following year. This means that the rising génération of the alpine sala- 

 mander in the subalpine région amounts to two individuals every three 

 years, and in the alpine région even only every four years. 



15. Beside abnormalities of the ovaries and the derived génital tract, numerous 

 and manifold abnormalities of the utérine content were described; thèse 

 include: d) start of gestation in both uteri at différent reproductive periods, 

 i.e. in différent years, b) significant différence in the size of larvae of the 

 same âge in the adult female and the birth of young animais of the same âge 

 at différent times, c) one-side and double-side abnormalities in the form of 

 dead or malformed larvae and arrested development, d) more than one 

 larva in one or both uteri. 



