164 WILLIAM J. DAKIN 
From the illustration it would appear as if the pigment formed 
a separate layer which acted as a kind of capsule enclosing the 
retina and bounding the eye internally. This impression is 
strengthened by the fact that the cells below the pigment are 
marked ‘ optic ganglion ’. 
The space within the structures enumerated above is 
occupied by the lens, and by a layer termed the rods. 
Text-Fia. |. 
Longitudinal section of the Eye of Peripatus capensis after 
Balfour, ‘Quart. Jour. Micr. Sc.’, vol. 23, plate 18, fig. 24. cor. = 
cornea; /.=lens; op.=optic ganglion; op.n.=optic nerve; 
pir. =pigment ; Re. =rods; s.p.=secondary papilla. 
Now let us turn to the results of the present investigation. 
The species utilized was Peripatoides occidentalis from 
Western Australia. A large number of preparations had to be 
made, including sections and maceration preparations. No 
single method can be singled out, the usual series of fixatives 
and stains must be adopted, one method giving a little informa- 
tion, another a little more (see Dakin, “ Eye of Pecten”’, 
‘Quart. Journ. Micros. Sci.’, 1909). 
The Kye of Peripatus is not stalked although the distal 
