DENDEOCOMETES PARADOXUS. 337 



the view that there is a micron ucleus in the body of the 

 Acinetarian. 



In the recently published monograph of the Acinetaria, 

 however, Sand (23) denies the existence of true micronuclei. 

 He believes, however, in the existence of a body lying close 

 to the meganucleus, which he calls the " centrosome." 



" Un corps un pen plus colorable que le noyau, creusee 

 expres pour le recevoir. . . . Quand ce corps est vu au 

 centre du noyau, il parait entoure d'une petite zone claire 

 formee par le cytoplasma qui le separe dii noyau/' . He 

 further states that no Acinetarian ever contains two of these 

 bodies, and that it is absolutely homogeneous, both in a state 

 of rest and of division. He has proved the existence of this 

 body in sixteen species. I have very little doubt that the 

 " controsome " of Sand is not a " pseudo-micronucleus," but 

 a true mici'onucleus. Maupas (20) says that his series of 

 stages of the micronuclei of Podophrya fixa is incomplete, 

 and he would probably himself admit that the figures he has 

 published of them are not satisfactory. To account for his 

 unsatisfactory results in the Acinetaria, Maupas ventures 

 upon the statement that the micronuclei of these Infusoria 

 are smaller than they are in the Ciliata, and stain very 

 lightly. He adds that the study of the nuclear phenomena 

 of the Acinetaria is beset with so many difficulties that he 

 considers it to be " une des recherches les plus penibles 

 qu'un micrographe puisse entreprendre." 



In Dendrocometes, however, these excuses cannot be put 

 forward, as the micronuclei are even larger than they are in 

 many Ciliata, and their affinities for certain stains are ex- 

 ceedingly powerful. 



The presence of micronuclei in this genus has, neverthe- 

 less, been denied. 



Plate (21) described a number of small bodies in the cyto- 

 plasm which, on account of their affinities for safranin, he 

 called the " Tinktiukornchen," but he denied the existence of 

 " Nebenkerne." Maupas replied to Plate's paper by stating 

 emphatically that micronuclei do occur in Dendrocometes 



