414 QUARTERLY CIIIIONICLE OF MICROSCOPICAL SCIENCE. 



near Nowgorod. It is very similar to a true marine Radio- 

 larian, as, for instance, Cyrtidosphcera reticulata, Hkl., 

 excepting the absence of yellow cells. It has a central 

 capsule, and, but for this, and tlie great number of 

 its radiating straight pseudopodia, might be taken for 

 a Clathrulina detached from its pedicle. The shell is alto- 

 gether similar to that of this latter form. Grimm was not 

 able to study the specimen carefully, hence no details are 

 given as to this central capsule. It is figured in a single 

 drawing. When speaking of the discovery of the fresh- 

 water Radiolaria Grimm attributes all the merit to Focke 

 and Greeff. He ought to knov/ and to have studied Mr. 

 Archer's various papers published in this Journal. Mr. 

 Archer has precedence of both the German writers. 



Noctihica. — Professor Cienkowski, at the meeting of Rus- 

 sian naturalists at Kiew, gave the result of his further obser- 

 vations on the development of zoospores in this animal. We 

 noticed at some length his paper published in ' Schultze's 

 Archiv,' on the same subject, in our April number, 1871. 

 Prof. Cienkowski's recent observations have been made at 

 Odessa. He finds that the formation of the curious boss or 

 disc from which the zoospores develop is preceded by a 

 segmentation of the entire mass of the protoplasm of the 

 Noctiluca into 2, 4, 8, 16, &c., parts, and that then the boss 

 begins to grow up on the surface of the Noctiluca. He 

 has traced fully the conversion of a normal Noctiluca into 

 one of the disc-bearing saccules, which he described in his 

 last paper, and which might readily be overlooked or taken 

 for anything but Noctiluca. He was previously doubtful as 

 to how far copulation, or the fusion of two Noctiluca, was a 

 necessary antecedent to the production of zoospores. He 

 now finds that it is by no means necessary, though it does 

 frequently occur, and, as in the fusion of the zoospores of 

 Myxomycetce, and the copulation of Actinophrys, and others, 

 leads to an augmentation of the mass of the protoplasm. 

 Zoospores occur in quite small Noctilucse which certainly 

 could not be the product of the fusion of two individuals. In 

 the zoospores, in the neighbourhood of the attachment of the 

 cilium (see woodcuts in former abstract, 1871), a thin long 

 process is to be observed, which Cienkowski regards as the 

 rudimentary * whip' or ' vibraculum' of the adult, and we 

 thus have in the zoospores all the characteristic parts of the 

 mature Noctiluca. Sometimes the zoospores develop very 

 rapidly whilst still in the disc, and their protoplasm becomes 

 differentiated into nucleus and radiating threads. Cien- 

 kowski considers that the zoospores of Noctiluca decide the 



