308 ALFRED GIBBS BOURNE. 
There is very little pigment in the body-wall, which in the 
greater portion of the animal’s length is very transparent, but 
which becomes opaque at the two extremities. The opacity is 
due even here rather to the greater amount of muscle present 
than to the presence of pigment. What little pigment there is 
occurs in the connective tissue which lies below the epidermis 
and between the muscle-fibres. There is in Segments x—x111 
(the region where the clitellum develops) in all fully-grown 
worms an orange tint which is due to pigment, and the dorsal 
region of the anterior segments of a worm which has been 
killed in spirit presents a greenish appearance which must be 
due to the alteration in colour of a pigment. When the worm 
has been preserved in spirit for some time, this coloration passes 
away. 
The coloration of M. grandis depends chiefly upon the 
earth which it takes into the gut. It almost always occurs 
here in a light-coloured soil, and is consequently itself light in 
colour. 
Number and Character of the Segments. — The 
largest number of segments which I have met with is 480, the 
smallest 266, this in a worm 3% inches long. One of the most 
striking features in the external appearance of the worm is the 
great variation in size of the segments (figs. 1,2, 15,16). They 
increase in both length and circumference from before backwards 
down to Segment vit1, which is the longest in the body. Seg- 
ments 1x and x are of about the same length as one another, but 
rather shorter than Segment vi1r. Segments x1, x11, and x1Ir 
are each rather shorter than the preceding segment. From 
Segment x111 there is but very little decrease in the length of the 
segments, which are all, as compared with most worms, very 
short relatively to their circumference. The circumference of 
the body varies so much with the amount of earth in the 
alimentary canal that one must be very guarded in making any 
statement respecting it (fig. 1 gives the natural size of a big 
it: were tough, and in others as though it were brittle, and the end of the 
worm breaks off on receiving the slightest injury—like the end of a lizard’s 
tail. 
