ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 641 



This coincidence between the disappearance of the globule and the 

 lessened activity leads to the belief that the globule constitutes a 

 reserve of material for the organism. 



To determine the animal or vegetable nature of the organism, the 

 author employed various reagents. By distilled water they were 

 slowly, and. by glycerine, alcohol, and acetic acid instantaneously 

 killed, the red colour disappearing slowly with glycerine, but rapidly 

 in the case of the alcohol and the acid. A 1 per cent, solution of 

 iodine is also a violent poison, causing the rapid disappearance of the 

 pigment, and colouring the organism slightly yellow. Chloriodide of 

 zinc acts in the same way, but tbe colour is a brownish yellow. 

 Iodine and sulphuric acid used simultaneously also give a brown 

 colour if they are not too dilute. Picric acid gives a green colour 

 and carmine red, but if they are used successively (the carmine last), 

 the protoplasm is coloured green and the granulations red, the centre 

 of each remaining clear. The periphery of the body is not differen- 

 tiated from the central protoplasm. Finally, an alcoholic solution of 

 hematoxylin gives no colour. 



After the action of these reagents no nucleus could be discovered, 

 whatever was the stage of the life of the microbion, either in the diffe- 

 rent stages of transverse segmentation or during the increase of the 

 body in length, a fact which deserves attention, as it affords an 

 instance of the division of protoplasm into two individualities without 

 it having been possible to observe any previous differentiation of its 

 constituent parts. 



There is also clearly no cellulose ternary vegetable envelope at 

 the periphery of the body, as all the reagents which colour the proto- 

 plasm colour the external portion, and vice versa. With fuchsin the 

 colouring is general, as with carmine ; it is of an equally intense red 

 in the different regions, whether internal or peripheral. In the same 

 way with Paris violet, it is impossible to distinguish the external 

 membrane from the subjacent protoplasm. This membrane is, there- 

 fore, simply a protoplasmic envelope, like that of the Infusoria, and 

 cannot be compared to the cellular membrane of the Bacteria. 



The use of reagents leads us, moreover, to recognize the existence 

 of organs very different from those which have been described among 

 the Bacteria. In treating the organisms with a concentrated solution 

 of Paris violet, we see at one of the two extremities, seldom at both, 

 a filament, about 2 or 2i times as long as the body. It is very slender, 

 and does not resemble the caudal prolongations which Koch has de- 

 scribed as cilia among the Bacilli. It takes the same colour as the 

 rest of the body. The existence and position of this filament leave no 

 room for doubt, in the author's opinion, that Bacterium rubescens is 

 Monas OTcenii. Ehrenberg and Cohn's descriptions of the latter also 

 agree in all points with that of B. rubescens. The filaments of Monas 

 differ also from those of the Bacteria by their greater length and 

 by the fact that they are cylindrical from their base to the free 

 extremity. 



Van Tieghem considers the caudal filaments of the Bacteria to be 

 prolongations of the cellular membrane, and not protoplasmic cilia 



