291 AfclC 





ON THE DISC-LIKE TERMINATION OF THE 

 FLAGELLUM OF SOME EUGLENAE. 



By James Burton. 



(Bead November 25th, 19130 



About two years ago, one of our members Mr. Ellis was 

 exhibiting here living Euglena viridis. During the evening the 

 creatures, presumably affected by the light, heat and confine- 

 ment of the life-slide, threw off their flagella ; it was perhaps a 

 preparatory step to encystment, or even to their death, under 

 the unnatural conditions of their environment. In the field of 

 the microscope there were numbers of these organs floating 

 free, and in the case of many of them, if not quite the ma- 

 jority, they were terminated by what appeared to be a small 

 disc or bulb. We were greatly interested in the phenomenon, 

 and decided to investigate it. Mr. Ellis soon after wrote a 

 letter to The English Mechanic, describing what he had seen, and 

 inquiring if any one else had had a similar experience. There 

 were no very definite answers, no one claiming to have noticed 

 this occurrence before. In his letter he says : 



" On turning on the one-sixth, something quite out of the 

 ordinary at least, to me was seen in the shape of minute 

 transparent discs, each with a long, thick, but motionless fla- 

 gellum, and apparently associated with the resting Euglenae, 

 around which they appeared most plentiful. For some time I 

 was puzzled to account for these objects, until, noting the 

 obvious similarity in length and thickness between their flagella 

 and those of the motile Euglenae, I became convinced they were 

 one and the same, they having been thrown off* bodily by the 

 exhausted Euglenae, and not retracted as is usual, I under- 

 stand." . . . " Now here comes the difficulty : What is the little 

 disc to which the flagellum is attached ? Is it the ' knob-like 

 inflated distal extremity ' of a flagellum belonging to 'an interest- 

 ing local variety of E. vi?'idis' described by a writer in Science 

 Gossip for October 1879, and referred to by Saville-Kent on 

 p. 382 of his ' Manual of the Infusoria,' and illustrated on 



Jourx. Q. M. C, Series II. No. ~. 21 



