ETE-SPOT A.'NB ELAGELLUM Ilf EUGLENA VIRIDTS. 467 



It is theuseeu that the external opening of the depression at 

 the anterior end of the cell is slightly funnel-shaped, that it 

 leads into the gullet, a narrow tube-like passage, which is curved 

 towards the dorsal side of the animal, and opens at its distal 

 end into the so-called principal vacuole or excretory reservoir 

 (PI. 32. figs. 2-8). 



The cavity of the excretory reservoir is thus in communication 

 with the exterior ; and this affords a more satisfactory explanation 

 of the discharge of the liquid poured into it by the pulsating 

 vacuole than that given by previous observers. 



Tbis connection between the excretory reservoir and the 

 gullet does not appear to have been recognized by previous 

 observers ; although Stein (I. c.) figures wbat appears to me to 

 be a distinct connection between them in Euglena deses, Ehrbg., 

 JiJ. Sj)iroffi/ra and Colacium calvium, Stein. 



As to the function of this anterior cavity we know very little. 

 The flagellum arises in it, and it is often stated that the ingestion 

 of solid food material can take place through it, small particles 

 of solid matter being forced down into the protoplasm at the 

 base of the opening by the continual movement of the flagellum, 

 where they become digested in the same way as in Aynceha*. 



But it is doubtful whether this can be definitely proved, and 

 the evidence at present brought forward in favour of it is not 

 altogether satisfactory. I have constantly repeated the experi- 

 ment, which is commonly taken as a demonstration that Euglena 

 possesses the power of absorbing solid food-material, of putting 

 finely powdered carmine in water containing Euglena-ceWs in 

 active movement; and have observed that the motion of the 

 flagellum causes a rapid and violent movement of the carmine 

 grains, often sweeping them up to and past the mouth-cipening 

 in large numbers ; but I have never been able to satisfy myself 

 that any of them ever get into the gullet. Dangeard t states 

 that the nutrition in the whole group is distinctly vegetal in 

 character; and that no solid particles penetrate the interior of 

 the body. The gullet, according to him, certainly does not serve 

 for the introduction of solid matter. 



Khawkine (Z. c.) suggests that liquid nutriment may be 



* See, for example, Parker's ' Elements of Biology,' p. 40. 

 t "Kecherches sur les Oryptomonadinae et les Euglente." Le Botanisfce, i. 

 1889, p. 1. 



