PACKARD] PARTHENOGENESIS IN AETEMIA. 463 



of tlie iiteras, became darker and darker and surrounded with a hard 

 brown shell, so that the non-fecundated, difi'ered neither in form nor 

 color or structure irom the fecundated ones. The virgin Artemise depos- 

 ited their eggs some time afterwards, dropping them into the mud at 

 the bottom of the jar. The uterus of such unfertilized females appeared 

 to be empty after the eggs were dropped; their shell-glands were pale, 

 but their ovaries again contained new germs, which gradually devel- 

 oped, while the pale shell-glands, after some time, again assumed their 

 brown color, and I surmised that they prepared themselves ouce more for 

 ovipositing non-fecundated eggs. The same ])rocess reoccurred several 

 times in virgins, the latter not differiag therefore in this respect from 

 fecundated ones. In this manner I succeeded in accumulating a large 

 number of non-fecundated eggs in the mud of the jar prepared for the 

 concupiscent, non-fertilized females. I must now draw your attention 

 to the fact that such oviparous virgins were never viviparous before 

 depositing eggs. For the success of my experiment on parthenogenesis 

 this was a bad omen. It is evident, however, that the primiparturition 

 of live young ones is not I'ealized in virgin females of Artemia fertiUs ; 

 but it is, nevertheless, possible that the "Dauer eggs" dropped by the 

 virgins possess the peculiarity of developing themselves without fertili- 

 zation, and do yield females, and therein we would have again a con- 

 tribution to our knowledge on the distribution of parthenogenesis. I 

 shall preserve during the coming winter (lb76-'77) the different kinds 

 of dried mud which are partly impregnated with fertilized, partly with 

 non-fertilized "Dauer eggs" of Artemia fertilise for the purpose of 

 examining next spring whether the mud with fertilized eggs alone, or 

 besides it, also the mud with non-fertilized eggs, will yield Nau|)lii, 

 when it will be of importance to learn from what set the parthenogenetic 

 ISTauplii develop themselves. 



B.— PEOF. GAEL THEODOE VOiT STEBOLD ON PAETHENO- 

 GENESIS IN AETEMIA SALINA.^ 



ABSTRACT. 



By Dr. C. F. Gissler. 



Owing to the remarks expressed two years ago in my paper "Beitrage 

 zur Parthenogenesis der Arthropoden" (Leipzig, 1871, p. 197), I am in- 

 debted to Prof. Carl Vogt, of Geneva (Switzerland), for a lot of live in- 

 dividuals of Artemia salina, which arrived at Miinchen August 27, 1872. 

 I was very pleased to have received seventy live and five dead speci- 

 mens, together with a number of larvae, in ajar of salt water. All the 

 full-grown individuals were females, which was also the case with a num- 

 ber of Artemise Dr. Yogt received from Professor Martins at Cette. I 

 observed that in all the seventy specimens thus obtained the egg-sac was 

 filled with embryos. The various behavior of this brood attracted my 

 special attention. Having dissected the egg-sac of a dead individual, 

 I noticed several live embryos escaping from the same, together with a 

 few pear-shaped bddies of orange color sinking to the bottom. The lat- 

 ter proved to be also embryos inclosed in a homogeneous thin egg skin. 

 The outlines of the inclosed embryos could be distinctly seen through 

 the egg skin, as well as the motions of the embryo. Such viviparous 



1 " Sitziiugsberichte der mattematisch-physicalischen Classe zu Miinchen, 1873, 

 H&ft. II." 



