THE AMBULATORY TUBES AND OTHER FEATURES 



of the ncma 



DRACONEMA CEPHALATUM 



CONTRIBUTIONS TO A SCIENCE OF NEMATOLOGY XXII 1 

 BY N. A. COBB 



There is no adequate published description of the locomotion of 

 Draconema and its numerous marine relatives ; very few persons have 

 ever witnessed one of these nemas perambulating its natural sub- 

 stratum. 



Draconema moves much after the manner of the ordinary inchworm, 

 or measuring worm. The caterpillar called the "inchworm" has two 

 bunches of feet, a bunch near each extremity. Standing on the bunch 

 of hind feet, it stretches forward and takes hold with the front bunch. 

 Then, releasing the hind bunch, it draws the body forward into a loop 

 so that the posterior bunch may attach itself near the front one. 

 Loosening the front bunch, the caterpillar again stretches forward, 

 etc. 



It is convenient to speak of the two attachment organs of the adult 

 Draconema as "soles." The method of attachment of these soles to 

 the substratum in Draconema is very different from that of the inch- 

 worm. The sole of Draconema is armed with projecting hollow setae 

 connected with internal glands supplying a sticky and, presumably, 

 non-water-soluble secretion, and it is by the aid of this secretion 

 emerging from ends of the hollow setae that the sole is attached. 



Reprinted from the JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES, Vol. 19, 

 No. 12, June 19, 1929. 



