AMONG SIMPLE SAECODE OEGANISMB. 435 



In a subsequent memoir*, Haeckel gives the following syste- 

 matic arrangement of all hitherto known Monera : — 



I. Genera. 



Gtmnomonbea. 

 Monera without rest 



< 



1. Protamoeba 5 species. 



2. Protogenes 1 species. 



ing state or encys- i 3. Bathybius 1 species. 



tation. 1^4. Myxodictyum 1 species. 



II, Genera. 



Lepomoneba. I 5. Protomonas 2 species. 



Monera with resting) 6. Protomyxa 1 species. 



state and encysta 

 tion. 



VampyreUa 4 species. 



Myxastrum 1 species. 



Of all these sixteen species, seven live in fresh water, the remain- 

 ing nine in the sea. 



One of the most extraordinary of all those very low organisms 

 whose recent study has been rewarded by the discovery of new 

 and significant facts is one to which Haeckelf has given the name 

 of Magosphcsra (fig. 17). 



Attached to the filaments of a species of the confervoid genus 

 Gladophora were noticed small spherical cells (A) of a pale yellow 

 colour, surrounded by a thick membrane, and showing in the 

 middle of their transparent protoplasm a large spherical nucleus 

 with a nucleolus. The structure of these bodies was thus undis- 

 tinguishable from that of a true animal egg, with its vitelline 

 membrane, vitellus, germinal vesicle, and germinal spot. 



This egg-like form constitutes the first stage of Magosphcsra. 

 In attaining the second (B), a phenomenon in all respects like that 

 of the total cleavage of the yelk sets in. The nucleus of the cell 

 breaks up by self-division into two nuclei, and the protoplasm of 

 the cell has now become divided into two segments, each envelop- 

 ing one of the nuclei. Thus are formed the first two cleavage- 

 spheres, each of which in its turn, dividing into two, exactly 

 repeats the phenomenon (C). And the process is continued (D) 

 precisely as in ordinary yelk- cleavage, until with the fifth seg- 

 mentation thirty-two cleavage-spheres or daughter cells are pro- 

 duced, and the process of segmentation is completed. 



* " Nachtrage zur Monographic der Moneren," Jena. Zeitschr. 1871. 



t Haeckel, " Die Catallacten, eine neue Protisten-G-ruppe," Jena. Zeitschr. 

 Band vi. 1871. 



