318 



MR. H. H. STIRRUP ON 



understood, and makes the question of the origin of the septal 

 glands much move complicated. The structure of the strands 

 connecting the sejDtal glands with the pharynx leads one to try 

 and discover whether these strands are connected in some manner 

 with the nervous system, but my own observations prove mosb 

 conclusively that they end blindly in the substance of the 

 pharyngeal bulb. 



The diagram of the septal glands (PI. XLVIII. fig. 14), recon- 

 structed from series of transverse and longitudinal sections, is 

 useful in enabling one to understand the exact shape of these 

 glands and also their relation with the gut and the solid strands 

 connecting the glands. Most existing drawings of the septal 

 glands are sketches taken from the living animal, and, although 

 these give one a rough idea of their shape, they are never very 

 satisfactory, 



(c) Presence of a thin-toalled Ovisac which coviviitnicates with 

 the Exterior hy two Pores in Segment 13. — Although in my prepara- 

 tions ova have not been actually seen in this thin-walled sac, 

 there can be little doubt but that it is an ovisac. The fact that it 

 communicates with the female pores on segment 13 proves that 

 ova must, at some time, be present in the sac in order to escape 

 to the exterior by the female pores. 



(d) The ventral clitellar Glands. — It seems likely that the 

 function of these glands is to secrete a substance which will 

 enable two copulating Enchytrjeids to be held firmly together. 

 My own observations on two copulating Enchytreeids show that 

 there is certainly something which enables the two worms to 

 adhere very closely together. 



It is difficult to account for the extraordinary muscles which 

 cover these glands and extend obliquely across to the body-wall. 



According to anatomical evidence, the " penial bulb " is simply 

 an enlarged ventral clitellar gland. It is epidermal in origin 

 like the ventral glands near it, and has a similar but slightly 

 thicker muscular coat. 



These ventral clitellar glands (although it is quite likely that 

 they are " copulation-glands ") must not be confused with the 

 masses of large cells which almost surround the nerve-cord in 

 some Enchytrasids (segments 13 and 14), and which have also 

 been called " copulation-glands." 



(e) Astomatoas Ciliate Protozoa in the Gut of EnchytrceiJjS. — 

 Altogether four different kinds of these ciliates have been found 

 in the gut of E. pellucidus. The commonest and largest of them 

 was Mesnilella ; this was also the only one which had the 

 chitinous-like rod or spicule. This ciliate has already been 

 recorded and described by Cepede in his extremely useful work 

 on the Astomatous Infusorians (3), but I have not been able to 

 find any records or descriptions of the other three ciliates, so that 

 they may be quite new. 



(f) Observations on two Copulating Enchytrceids. — These obser- 

 vations on two Enchytrfeids in copulation are interesting, as one 



