238 Dr. A. de Bary on the Mycetozoa. 



it may be observed that they are most numerous at the periphery 

 of the circle. The cords vary from a few lines to an inch in 

 length, and are mostly much ramified, and often exhibit irregu- 

 larly disposed varicosities. Their thickness varies from that of 

 a bristle above half a line in diameter to that of a filament 

 invisible to the naked eye. 



On bringing these cords, with or without any of the surround- 

 ing mass, under the microscope, in a little water, their form is, 

 after one or two hours, seen to change. They generally increase 

 in breadth at the sacrifice of their length ; and their twigs either 

 change in figure, or new ones are produced. Further, the whole 

 surface becomes by degrees covered with small, obtuse, wartlike 

 prominences, which give it, to the naked eye, a granular aspect 

 (fig. 17). These prominences extend themselves progressively 

 into filiform cords, which soon overspread the surface in the 

 form of an anastomosing network ; and ere long it may be ob- 

 served that these reticulated fibres change in figure, and give off 

 new twigs, and produce new anastomoses, whilst others vanish 

 (fig. 18). In this manner the whole fragment under notice 

 changes its place; but this result is not observable until after 

 it has remained under notice from four to twelve hours. 



The organic basis of the cords is the same material as the 

 sarcode of Dujardin, or the so-called "formless contractile sub- 

 stance" of Ecker, and presents the characteristic contractility, 

 the gradual changes of form, and the flowing motions seen in 

 the bodies of Bhizopoda. The substance of these cords and 

 sarcode likewise agree precisely in chemical composition and 

 reaction, except in relation to carbonate of potash an exception 

 insufficient to establish a difference in chemical nature. 



The sarcode-matter is rendered turbid by countless granules 

 (figs. 14, 15), some having the form of minute colourless points, 

 whilst others are of larger dimensions, globular, with a dark 

 outline and refracting centre, like fat-particles, soluble in alcohol 

 and ether, and producing a yellow colour. The granules are 

 either uniformly diffused or collected in the centre, leaving a 

 clear peripheral margin. Vacuoles are often, but not always, 

 present in the interior, of various and changeable figure, filled 

 with water, and without special walls. 



The onward flowing movements and the production of pseudo- 

 podous processes are seen, in the cords of &thalium placed in 

 water, to resemble those of Rhizopoda, although the structures 

 in question are comparatively of colossal dimensions (figs. 14, 15). 



Two kinds of processes or twigs are distinguishable : one 

 visible to the naked eye, always filled with granules ; the other 

 microscopic, produced as simple or ramified tubercles on the 

 former, and variable and retractile (fig. 17). These latter corre- 



