ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 903 



off processes in all directions ; in other cases the nuclear fragments are 

 very numerous, and have the form of homogeneous granular rods or 

 spheres. From these observations it may be concluded that the 

 nucleus of B. elegans exhibits some peculiar characters ; in the living 

 state it is not a fixed and immobile element, but it is endowed with 

 amoebiform powers, in virtue of which it gives off processes, and 

 divides into fragments which take on a spherical form, and can no 

 doubt fuse again to form a single body. The only mode of repro- 

 duction observed was that by transverse fission ; a transverse groove 

 separates without detaching a fragment of the hinder part of the 

 body ; this, which is not small, divides into two ; each of these halves 

 again divides, and the resulting pieces again dividing give rise to 

 eight, which for a time remain attached to the hinder extremity of 

 their parent ; the segments appear to detach themselves separately, 

 the hindermost doing so first. The author believes that the nuclei 

 divide into fragments before the appearance of the process of seg- 

 mentation, but exact observations on this point are stiU wanting. 



B. coronata is distinguished by the marked development of the 

 cilia at the anterior region, where they form a true crown ; the nuclei 

 vary greatly in form, but are not so large as in B. elegans. Here 

 again there is segmentation. The author thinks that Benedenia is 

 one of the family OpaUnida. 



In the liver of Sepiola rondeletii, M. Foettinger found an ovoid 

 Infusorian without mouth or digestive tube, which he proposes to call 

 Opalinopsis sepiolce. In size about O'l mm., they exhibit a holo- 

 trichous arrangement of their cilia, and present, below their delicate 

 cuticle, the same appearance of muscular fibrillae as that which has 

 been already noted in B. elegans. The author insists on the muscular 

 character of these structures, basing his views on the facts that the 

 fibrils diminish in thickness towards either pole of the animal, and 

 that their dotted appearance calls to mind the muscular fibrils dis- 

 covered by E. van Beneden in the Gregarinidte ; moreover, the 

 appearance, the refrangibility, and the dimensions of these fibrils are 

 brought forward as supporting this view. The nuclei may be either 

 small granular spheres, scattered through the protoplasm, or they may 

 fuse ; at other times they are spherical or rod-shaped, and occupy in 

 numbers the central part of the Infusorian. Sometimes they give rise 

 to a still more interesting plexiform arrangement. The amoebiform 

 character of the nucleus is here again noted, as is also the phenomenon 

 of transverse division ; conjugation also was sometimes observed. 



Opalinopsis octopi is a very similar form which was found in the 

 liver of Octopus tetracirrhus. 



Flagellata.* — J. Kiinstler claims to have established some new 

 points in regard to the very minute anatomy of Flagellata. In Cryp- 

 tomonas ovafa there is in the superior portion a narrow cavity which 

 extends from the dorsal to the ventral face and forms a kind of vesti- 

 bule for the digestive tube. The two flagella are inserted at the 

 centre of this cavity, at the base of a tube which projects from its 



* Comptes Eendus, xciii. (1881) pp. 602-.5. 



