506 Mv. C. R. Narayana Rao on the Anatomy of 



few corpuscles. The cells of the external covering are 

 irregular in outline, and the cytoplasm is only sparsely 

 granular, but mostly clear. This outer epithelium becomes 

 membranous when the cell-layers are numerous, and a few 

 connective - tissue fibres become incorporated into the 

 structure. The ducts also were empty in all the species, and 

 the epithelium of these tubes is composed of a lining of 

 non-ciliated cubical cells, with granular cytoplasm and a 

 centrally situated nucleus. The shimmer often noticeable 

 in the ducts is due to the muscle-fibres, which are circularly 

 disposed, rarely a few longitudinal filjres being present, and 

 held together between the internal lining and the excessively 

 thin external membrane (PI. XVII. fig. 10a). 



In the teased preparations of the atrium and the atrial 

 pouches of these species (PI. XVIII. figs. 10 A, 10 i), I could 

 discover nothing, except in one individual out of four [D. so- 

 mavarpatana subjected for examination), in which well- 

 developed sperms were found in a mucilaginous base which 

 clogged both the pouches. Dr. Michaelsen found, in his 

 preparations of the ampulla and the atrial appendices of 

 MonUi(jastei\ fibrous and granular masses which he iden- 

 tified respectively as sperms and glandular secretions. He 

 next proceeds to establish the functional differences between 

 the ampulla and the copulator}'^ vesicles of the two families 

 Megascolecidse and Moniligastridse. From the observation 

 I have recorded above, i. <?., that the copulatory ai)})en- 

 dices were full of sperms in one individual of D. somavar- 

 patana and from histological considerations of the ampulla 

 and the diverticula, it is quite possi!)le to reach the 

 opposite conclusion. In D. ghatensis the cavity of the 

 atrial pouch is a trigonal chamber; in D. somavarpatana 

 it is irregularly divided up into very minute recesses ; in 

 D. elegans it is a wide chamljer, disposed in a spiral ; in 

 D. brunnea its surface bears a number of annular ridges; 

 in D. chlurina the cavity is flask-shaped, and it is simi)ly 

 wide in D. pellucidaj D. modest a, D. scandens, and D. 

 paradoA-a. In all these species the epithelial lining near 

 the ectal ends of the pouches is composed of short cubical 

 cells full of granular cytoplasm and a large nucleus, while 

 in the ental end the cells tend to become syncytial and 

 the cytoplasm is present only very poorly (PI. XVII I. 

 figs. 10/, 10^). The cell-walls have a strong tendency to 

 become cornified and look like those of the epidermal layer. 

 The muscle-fibres are circularly disposed in a thick layer, and 

 the outer tunic in D. somavarpatana is distinctly a thin 

 cuticular layer with little cellular structure. The main fact 



