On s g 111 e Australian Cladocera, raised from Dried Mud. 



By 



G. 0. Sars. 



With 8 Autographic Plates, coloured from Living Specimens. 



(Read at the Meeting held- 30th January 1885. — Section for Mathematics and 



Natural Science). 



ljast winter I received, thanks to the kindness of the Nor- 

 wegian traveller, Mr. Lumholtz, a considerable quantity of 

 dried mud from a fresh-water lake in the tropical part of Au- 

 stralia. When requesting Mr. Lumholtz to forward me such 

 material, it had been my intention to institute, during the spring 

 and summer of the following year, a series of experiments, with 

 a view to obtain the ova of Entomostraca, probably enclosed 

 within the mud, artificially hatched, and thus become enabled to 

 examine some of the entomostracous forms occurring in that 

 remote tract of the globe. 



As well known, a great number — perhaps all — of our indige- 

 nous freshwater Entomostraca, and more particularly the Clado- 

 cera, exhibit two essentially different modes of propagation, viz., 

 the parthenogenetical and that generally observed in Crustacea — 

 by means of fertilized ova. During the spring and fore-summer, 

 our Cladocera are invariably found to bring forth egg-like germs, 

 — the so-called summer-eggs, — which immediately, without 

 the intervention of males, develop to new individuals, these 

 propagating in like manner, and so on for numerous genera- 



Vid.-Selsk. Forn. 1885. No. 8. 1 



Introduction. 



