Boyal Microscopical Society. 61 



they are pseudo-lisemal sinuses, from the large number of minute 

 pseudo-haemal vessels which appear to ramify from them. These 

 are very apparent when a transverse section of the band is stained 

 with carmine fluid. The disposition of the parts of the bands are 

 represented in Figs. 4 and 5, Plate LXXVI. 



I have repeatedly observed certain oval cellular bodies, of 

 greater transparency than the bands themselves, at intervals bulging 

 out, and apparently compressing the normal structure of the bauds. 

 They are very irregular in their occurrence, and I have been unable 

 to make out their import. They are very hke the cellular bodies 

 which Meisner described as so abundant in the lateral bands of 

 Mermis. Meisner thought the lateral bands of Mermis were con- 

 nected with the alimentary canal, and called them corpora adiposa. 

 The connection between the alimentary canal of Ascaris and the 

 lateral bands is by connective tissue only, as has been already 

 stated ; and the same is even more marked in Gordius.* The spe- 

 cimens in which I observed the cellular bodies had been preserved 

 in spirit too long, but I have no doubt they are collections of 

 ganglion corpuscles, so that they may be looked upon as true 

 ganglia. The lateral bands contain a large quantity of oily matter, 

 and unless examined in a tolerably recent condition it is impossible 

 to make out their true nature. 



Cuvier seems to have rightly interpreted the nature of the lateral 

 bands. Meisner has described certain nervous cords in Mermis, 

 but I suspect he fell into the same error as Cloquet and Otto, who 

 described the dorsal and ventral bands in Ascaris as nerve-trunks. 

 Perhaps Meisner has described a portion of the water vascular 

 system as a nerve-trunk ; I do not know, as I have not examined 

 Mermis ; but I cannot help beheving that the bands, or some of 

 them, for there are three, are homologous to those in Ascaris. In 

 Gordius there is a single ventral cord, which undoubtedly represents 

 the lateral bands in Ascaris ; in this I think I agree with Schneider. 

 It is on the ventral aspect of this cord in Gordius that Meisner de- 

 scribed his ventral nerve-cord, but Grenacherf has failed to detect 

 it. The last-named author thinks that the ventral cord in Gordius 

 as well as the lateral bands in Ascaris are mere folds of the cellular 

 layer of the integument. In this I cannot agree with him ; and 

 his beautiful drawings of Gordius, in the paper already referred to, 

 are far from giving me the idea, that the ventral cord is so simple a 

 structure as he is inchned to consider it. The epithehal layer 

 covering the lateral bands may, however, be a portion of the inner 

 layer of the integument, and this leads me to say a few words on a 

 point of very considerable interest. 



* Dr. H. Grenacher, ' Zur Anatomie der Gattung Gordius.' ' Koll. Zeitschrift 

 fiir Zoologie,' band xviii., p. 322. 



j- Loc. cit. 



F 2 



