TRANSLATION. 



On the Sexual Reproduction of the Infusoria. 

 By Dr. Ernst Eberhard. 



(From ' Zeitscl). f. wissenschaft. Zoologie,' vol. xviii, p. 120.) 



After a delay which must have appeared of long dura- 

 tion to all who are interested in the study of the Infusoria, 

 the second volume of F. Stein's excellent work* has made 

 its welcome appearance. The volume contains a general re- 

 view of the present state of our knowledge respecting tlie Infu- 

 soria ; and especially discusses the difficult problems that have 

 arisen concerning their sexual reproduction, connected with 

 which is the question of the value of the systematic arrange- 

 ment of the Infusoria, as proposed by Stein himself, to be based 

 upon the mode of disposition of the cilia. This part is fol- 

 lowed by a detailed exposition of the systematic arrangement 

 of the heterotrichous Infusoria, in which will be found a full 

 account of Bursaria truncatella, one of the giants of a pigmy 

 world, and whose structure and organization is, for the first 

 time, fully expounded. 



Dr. Eberhard, who has had abundant materials at his 

 command, has, in almost every essential point, arrived at the 

 same results as those of Stein; and he prDposes, in a subse- 

 quent memoir, to explain where they apj)ear to differ. On 

 the present occasion he confines himself solely to the point 

 of sexual reproduction, since his results in this subject, though 

 in some respects agreeing with those of Stein, yet in others 

 present a very marked contrast with them. 



Stein remarks that he has not unfrequently met with in- 

 dividuals of Bursaria truncatella which were filled with a 

 great number of indubitable embryos. The individuals in 

 question, he says, are distinguished from the rest by their 

 spherical form, and the almost complete closure of the peris- 



* ' Der Orgauismus der Infusiousthiere.' 

 VOL, VIII. NEW SER. N 



