TELESCOPIC TUBES. 461 



known. Our own telescopic rods require to be withdrawn at 

 the butt- end, and then fitted together in front. But the 

 Japanese rods are so made that, after taking off the ferrule of 

 the seeming walking-stick, a mere fling of the hand will send 

 joint after joint flying out, and fixing themselves in regular 

 succession. So admirably are these rods made, that even 

 blowing into the butt-end will have the same effect. 



One of the most perfect, if not the most perfect, example of 

 the telescopic tube is to be found in the Tripod Wheel -bearer 

 {Actinurus), one of the numerous aquatic Rotifers. 



It is not usually so small as the generality of its class, being 

 nearly one-twjntieth of an inch in length, and visible to the 



actinubtjs tail, open and closed telescope, 



(magnified). 



unassisted eye, provided that the owner of the eye in question 

 knows how to use it. 



"When placed under a miscroscope of moderate power, the 

 Actinurus is seen to be built almost wholly upon the telescopic 

 pattern. Only the centre of the body remains stationary, the 

 two ends being framed on the principle of the telescopic tube, 

 and capable of being enclosed within the central portion, just 

 as is the case with the Japanese fishing-rod. 



In the illustration the Actinurus is shown in two attitudes. 

 In the upper figure it is represented as having the fore-part 

 of the body entirely, and the tail part nearly, withdrawn within 

 the central portion. The lower figure shows the same speci- 

 men with all its telescopic tubes drawn out t© full length. 



