158 DR. EBKRHARD^ ON SEXUAL REPRODUCTION. 



form of progeny, whilst the author, relying upon numerous 

 observations, asserts it with equal pdsitiveness. 



3. The contractile vesicle which, according to Stein, is 

 situated in the hinder part of the embryo, is placed by the 

 author in the anterior; and the latter was also unable to per- 

 ceive any trace of a suctorial acetabulum. 



Such decided contradictions are probably to be explained 

 by some diversity in the modes of propagation, which still 

 demand closer investigation. 



