460 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



stripes ; so far as the body-muscles are concerned the Vortieellinse 

 agree essentially with, the Stentores and the Spirostomese. 



The only observer who has given an account of the encystation 

 of Bursaria truncatella is Cienkowski (1854) ; when encystation 

 commences the parenchyma becomes vacuolated, and the peristome 

 with all its parts becomes completely aborted ; when this organ is 

 lost, we have apparently quite another infusorian ; this is partly due 

 to the great increase in size of the layer of trichocysts, which becomes 

 double its former breadth. Encystation is completed by the gradual 

 diminution of this layer, the convorsion of the vacuolated parenchyma 

 into a granular mass, in the loss of the cilia, and the rounding off of 

 the form of the body. Two membranes become developed, the outer 

 of which — the so-called stellate membrane — may be best likened to 

 a number of parallelograms of unequal size distributed irregularly 

 over the body of a sphere ; where the diagonals cut there are depres- 

 sions; the inner membrane is homogeneous, thick and strong, and 

 slightly refractive. The contents are in the form of a dark brown mass 

 composed of coarse large granules. Encystation appears to take place 

 in December, and the first Bursaria observed to become free was seen 

 at the end of February. Few changes go on within the cyst ; the 

 rotating spores described by Cienkowski were Flagellata, which made 

 their way into some of the cysts. The author remaks that this is 

 the only infusorian known to him in which there is a retrograde 

 metamorphosis, but he thinks that similar phenomena may be seen in 

 some of the Stentors. 



Spirochona.* — M. E. Canu, after referring to the work of Stein 

 and Hertwig on >S'. gemmipara, which is found on Gammarus pulex, and 

 on >S^. tintinnahuhim, found on the skin of the tadpole of Triton, gives 

 an account of his discovery of S. crystallina n. sp., together with 

 Freya limnorim and numerous other peritrichous infusorians, on a 

 marine isopod Limnoria. The author does not agree with Entz's 

 opinions on the affinities between the Ciliata ; he regards Spirochona 

 as separated from all other infusorians by the arrangement of its 

 peristome ; and considers it as a peritrichous stage, with homogeneous 

 cilia, amongst the Hypotricha. He further regards the Oxytrichinidse, 

 Halteridse, and Tintinnidse as highly developed hypotrichous forms 

 with a ciliated peristomial area. 



Characters of the Cilio-flagellata.f — Prof. 0. Biitschli has been 

 able to study Glenodinium cinctum in the living condition, when he 

 finds that forms differ not inconsiderably from one another ; smaller 

 examples appear to be almost round when looked at ventrally or 

 dorsally, but the large are ordinarily oval ; the colour varies between 

 yellowish and greenish brown, and is generally pretty deep. All 

 those examined had a thin envelope which lies directly on the body, 

 but it is only distinctly visible when the body is contracted under the 

 influence of killing reagents, or when the flagellum has been lost and 

 the specimen has passed into a resting condition. Resting forms do 



* Bull. Sci. Dep. Nord, ix. (1886) pp. 21-31. 

 t Morphnl. Jahrb., x. (1885) pp. 529-77 (3 pis.). 



