I902. FriKnd. — Studies in Irish Enchytrmds. 1 1 1 



distinguished by the microscopist who is not a specialist in 

 worms, is the number and arrangement of the setae. As in 

 other oligochsets, there is an entire absence of setae, or 

 bristles, on the first segment ; while on the twelfth, which 

 bears the girdle or clitellum and the male pores, the ventral 

 bundles are missing. All the other segments, of which there 

 are about thirty in an adult worm, bear four bundles of setae, 

 of which two bundles are lateral and two ventral. In the 

 first eighteen segments, or thereabouts, there are three setae 

 in each ventral bundle and two in each lateral ; but in the 

 last ten or twelve segments each bundle, ventral and lateral 

 alike, has three setae. Thus the bundles are all either 

 couples or triplets, and the order and arrangement are 

 definite, not irregular or promiscuous. There is a large 

 head-pore between the prostomium and the first ring — /.<?., 

 the one without setae, and when a little pressure rests upon 

 the worm's body the fluid and particles contained within the 

 coelomic cavity and head are poured out of this aperture, 

 thus relieving the pressure. The brain is somewhat pear- 

 shaped, rounded off", or convex at the hinder margin, and 

 there is a slight tendency on the ^^art of the ventral nerve- 

 cord to broaden between the third and fourth segments. 

 The blood-vessels and other parts are of the usual type; 

 the girdle is slightly papillose, and accompanying the pores 

 on the twelfth segment are somewhat large, vase-shaped 

 glands." 



The Irish material has not been sufficient to afford me any 

 new features. The worm comes very near to, if it be not 

 identical with, Dr. Michaelsen's E. argent tiis, which he found 

 on the shores of the Elbe in Germany. For the present we 

 will allow them to be regarded as distinct. 



I have now to point out a curious fact. In the winter of 

 1897-8, after I had described the Aster Worm^ and recorded 

 it for many different parts of the countr}', besides obtaining 

 it under circumstances which clearly showed it was an in- 

 digenous British vSpecies, I found it had attacked my celery. 

 During the early stages of the celery sickness only 

 Enchy trc^K s parvulus w2iS noi^^. As the sickness progressed 

 however, a new form made its appearance. Presently the 

 two forms were equal in number, but eventually, in March, 



