DEVELOPMENT OF ALGM. 77 



whole matter, is that all of these forms are precisely similar to 

 creatures which have been ranked by Ehrenberg and others 

 in the animal kingdom, under different names, but most 

 commonly that of Eugleyia. To make the resemblance to the 

 Euglenas still more marked, as soon as the circlet of cilia has 

 disappeared, and the mass elongates, a bright red spot 

 appears near the clear end, and usually also, one or more clear 

 seeming vacuoles are seen to arise within the green mass. 

 The red spot has been called an eye, and the vacuoles 

 stomachs ; and in this Avay Ehrenberg was enabled to classify 

 these forms as ' Polygastric Animalcules.' The spirally 

 twisted forms have been placed in a separate genus and in 

 fact I have seen, in the way mentioned, developed from the 

 cell-contents of a filament of ffidogonium forms identical with 

 several genera of ' Polygastric Animalcules/ After a little 

 longer time the cell-contents have again changed in appear- 

 ance so as to be coarsely granular, each granule being so 

 large and distinct that it can readily be distinguished, and 

 now the active motion of the mass ceases, and it takes on the 

 static condition. This it does by increasing in size, elongat- 

 ing and losing its cilium and red " eye " spot, while the clear 

 portion elongates, sub-divides, and branches out and becomes 

 fixed either to a full-grown filament of ffidogonium or some 

 other submerged substance that may serve it as a support. 

 Now the cell-contents become finely granular again, and 

 arrange themselves against the cell-wall Avhicli is thickened 

 considerably. Soon a bending in of an inner membrane, or 

 * Primordial Utricle ' is seen to take place and cell-division 

 after the well-known method occurs, until a filament is 

 formed exactly like that from which the original green sphere 

 was projected." 



The points to which the author wishes to drawn special 

 attention are the finding of the means by which the active 

 spherical form is. converted into the still state previous to 

 growth into a filament ; and, further, the identification of this 

 phase with certain forms hitherto classed, sometimes in the 

 vegetable, sometimes in the animal kingdom. 



Boohs received. 



' Jenaische Zeitschrift,' Bd. vi. Heft 4. 

 ' The Microscopic Dictionary,' ord edition. Parts 1 and %. 

 ' Ueber die Nesselkapseln einiger Polypen und Quallen. 

 Von Dr. Karl Mobius. 



' Medizinische Jahrbiicher,' red. von Strieker, Heft 3. 



