176 NOTES AND MEMORANDA. 



branched in seeking out new Euglenge. Such as have early 

 penetrated become enlarged and more and more ramified ; 

 they may even, though rarely, bore through and penetrate a 

 Euglena behind the first. At the point where they penetrate 

 a Euglena the haustoria show a slight constriction ; they may 

 become several times branched in the interior of the Euglena. 

 Sometimes if a zoospore germinate in contact with an encysted 

 Euglena it may push a haustorium into it at the place of 

 contact, so that the latterbecomes wholly immersed in the host, 

 and the parasite then appears to sit directly on the Euglena. 

 Not rarely several parasites may attack one and the same 

 Euglena. 



The Euglense so attacked gradually lose their green pro- 

 oplasm, becoming at first greenish-yellow, and then quite 

 deprived of colour, till nothing is left but brownish granular 

 remains (b, e, e) ; even the membrane at last perishes. Some 

 of the brownish remains may finally adhere to the haustoria 



The haustoria, especially in a young condition, thus in a 

 measure resemble the pseudopodia of certain Rhizopoda or 

 Acinetae, but they never alter their figure and very early 

 possess a rigid membrane, which, however, is not coloured 

 blue by iodine and sulphuric acid. Inasmuch as the haustoria 

 are prolongations of the parasite and are without septa, the 

 organism must be regarded as xmicellular. Its protoplasm 

 contains yellowish oil-drops, coloured reddish brown by 

 iodine, like that of the haustoria, which however, seldom 

 show any oil-drops. The body of the Polyphagus shows con- 

 siderable variety of shapes, resolvable roughly into two prin- 

 cipal forms — the round and the clubshaped, but it may be 

 ovate or elliptic, its variable shape influenced by its search 

 after the host Euglense. 



Its reproduction takes place both in an asexual and in a 

 sexual way. 



Asexual reproduction is by means of zoospores. — These 

 originate in zoosporangia which are produced externally to 

 the parasite-body from the whole of its extruded protoplasm, 

 hence Delpino's designation " prosporangium" is very applic- 

 able to the body itself of the parasite (e, e). The zoosporangia 

 are thus formed : The whole of the protoplasm of the Polypha- 

 gus bores through the cell-wall at a certain point and passes 

 out by a rather large circular opening, making its appear- 

 ance at first as a little protoplasmic vesicle slowly increasing in 

 volume ; when this has very slowly taken up the whole of the 

 protoplasm it forms either a sharply bounded oval or elliptic 

 body directly in front of the opening or it assumes a cylin- 

 drical elongate figure. The emerged protoplasmic substance 



