AMONG SIMPLE SAECOBE OEGANISMS. 413 



filiform, &c.) which had already existed in the earlier forms, and 

 which they thus derive by inheritance from their non-nucleated 

 progenitors. Finally, throagh the branch of the Heliozoa we are 

 conducted to the ultimate twigs formed by the families of the 

 Badiolaria, in which we find not only nuclei, but a " central cap- 

 sule," indicating the highest grade of differentiation attained by 

 any members of the group. 



In 1863 Cienkowski published the results of a series of careful 

 observations on the development of the Myocomycetce*, a group of 

 very low organisms which had been unhesitatingly assigned to 

 the fungi, until De Bary had a few years previously called atten- 

 tion to their real nature, and in a very important memoir f pointed 

 out the predominance in them of characters which had been 

 generally regarded as the proper attribute of animals. De Bary 

 believed that the facts which he had demonstrated in the struc- 

 ture and life-history of the Myxomycetce would render necessary 

 their removal from the vegetable and their relegation to the 

 animal kingdom. 



Shortly after the appearance of De Bary's memoir, some 

 further important observations on the Myxomycetce had been made 

 by CurreyiJ:, who fully confirmed the production by them of free 

 locomotive bodies resembling the zoospores of an Alga. 



The researches of De Bary, of Currey, and of Cienkowski have 

 now made us well acquainted with the structure and development 

 of these extraordinary organisms. A typical Myxomycete (fig. 9) 

 consists of a network of ramifying and anastomosing threads of a 

 slimy or creamy consistence, which spreads over the surface of 

 decayed leaves and stems (A). 



From various parts of this slimy network there arise oval 

 vesicles (sporangia) (B) with membranous walls, within which the 

 reproductive bodies or spores are developed. 



De Bary was the first to show that the basal network is com- 

 posed of a substance possessing all the characters of animal sar- 

 code, and his observations have been fully confirmed and further 

 extended by subsequent observers, more especially by Cienkowski. 

 Under the microscope the threads composing the network ex- 

 hibit active spontaneous movements, which in the larger branches 

 are visible under an ordinary lens or even by the naked eye. A 



* " Zur Entwickelungsgeschichte der Myxomyceten," Prings. Jahrb. 1863. 

 t " Die Mycetozoen," Zeitsehr. f. w. Zool. 1860, vol. x. 

 % Natural History Eeview, No. viii., Oct. 1862. 



