QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 411 



of the polycephalism of Spongilla. He would rather regard 

 the individuals of Spongilla as forming a colony analogous 

 to that of the compound Tunicata, possessing, as in that 

 case, a common cloacal orifice. He endeavours to refute 

 Eimer's ohservations on the thread-cells in sponges, by 

 bringing forward two facts — firstly, that fragments of Coelen- 

 terata, with abundant thread-cells, are often to be found 

 attached to organisms with which they have no connection, 

 and quotes a remark from Wyville Thomson to the effect 

 that thread-cells have the power of living for some time apart 

 from the organism to which they belong ; secondly, he has 

 observed a small hydroid polyp, parasitic in, or closely in- 

 vested by, certain sponges, and he suggests tliat Eimer may 

 have got hold of something of this kind. 



The reporter is able to state that Dr. Eimer spent a por- 

 tion of the past spring (1872) again at Capri, and repeated 

 his observations on the occurrence of thread-cells in sponges, 

 and appears not to have found any facts which lead him to 

 change his already published statements. Dr. Eimer has also 

 worked out other points in the histology of siliceous sponges, 

 in which he has observed considerable cell-differentiation, 

 giving rise to connective tissue and fusiform muscular tissue. 

 The Natural History of the Vibriones. By Oscar Grimm. 

 — This paper, in the 4th part of ' Schultze's Archiv' for 1872, 

 is of some interest, for it shows that at last the Germans are 

 beginning to pay some attention to the question of the 

 origin of Bacteria, concerning which so much has been 

 written in France and England. Grimm ignores almost 

 completely the Avork of other observers, referring only to the 

 papers of Polotebnoff and Frau Joh. Liiders. He mentions 

 the action of various reagents on Bacteria or Vibriones, as 

 he prefers to call them, and states that he has failed to bring 

 the electric discharge to bear upon them. He concludes that 

 they are protoplasmic, or derivatives of protoplasm, in their 

 chemical nature. Chains of Bacteria are formed by the 

 fusion of previously separate individuals, not by division, 

 according to this author. He distinguishes the molecular 

 from the vital movements, as so many others have done 

 and recognises two kinds of movement due to the motion 

 of the members of a chain one on the other, and a third 

 kind of movement, in certain large and long Bacteria, which 

 consisted in the bending of a single individual, first to one 

 side and then to the other. Large individuals like this 

 Grimm saw divide spontaneously into smaller individuals. 

 To those who doubt that Vibriones are organisms Grimm 

 replies that they are protoplasmic, they move, they nourish 



