ANATOMY OF THE EARTHWORM. 103 
The means whereby the aqueous constituent of the peri- 
visceral fluid appears to me to be chiefly replenished is to be 
found in the remarkable minute tegumentary canals, de- 
scribed and figured in my last paper, and resembling somewhat 
in their appearance “ dentinal tubules.”” These minute canals 
and 9th rings, and was thence continued, apparently without interruption, 
to the caudal extremity. 
The fluid expressed from these pores was of a dirty grayish colour, thin 
and opaque. Examined under the microscope it contained numerous spherical 
particles and pyriform granular bodies, besides irregular organic parti- 
cles. The only other openings observable on the dorsal aspect, as far as 
to the 32nd ring, where the clitellus commenced, were minute rounded 
pores of smaller size than the median dorsal, and situated, not in the 
intervals between the rings, but on the sides of the rings themselves, at a 
greater or less distance from the dorsal median line; they occurred in the 
following rings, viz. (see Fig. 1, p. 102). 
There being none on the Ist, 2nd, 3rd, 8th, 12th, 16th, 25th, 30th. 
From these puncta could be expressed a clear fluid, containing only 
minute nucleolar particles, and it was probably derived from the subcutaneous 
glandular tissue, constituting the lubricating fluid of the surface. 
In a second specimen, prepared in the same way, and at the same time, 
and apparently in the same condition as to development, the arrangement of 
the pores and puncta was as follows. 
No. 2.—Median dorsal pores commenced between 8th and 9th rings, and 
they afforded a fluid precisely like that of the former case. The puncta 
were situated in the following rings: 
There being none perceptible on the Ist, 2nd, 3rd, 4th, 16th, and they 
were not looked for beyond the 22nd. The fluid expressed from them was 
the same as in the former case. 
In other cases, again, the median dorsal pore did not exist anterior to the 
11th segment, aid the lateral puncta appeared very variable. 
Besides these pores and puncta, in a worm which had been immersed 
in water, a general sweating or oozing from very minute pores, was observ- 
able all over the surface, especially on the dorsal aspect. 
No other kinds of permanent openings exist in any part of the body except 
the mouth andanus. The sexual openings in the 16th segment appear to be 
formed only at the time they are wanted, and of these, as well as of the 
smaller lobes on either side, no vestige whatever is perceptibie, even in very 
large worms, when not sexually mature. The same may be said of the 
clitellus, of which no indication whatever is often perceptible; one, also, 
of the two adherent discs (?) in the 27th segment, which appear to be 
formed solely for the purpose of sexual congress. They are developed on the 
situation, and, in fact, by a thickening of the integument immediately 
around the inner pair of sete in that segment. ‘This swelling is very porous, 
and a mucous fluid can be freely expressed from the pores. Another change 
in the external aspect of the worm, connected with the period of sexual 
activity, consists in the thickening and opacity of the subcutaneous tissue, 
in the ventral halves of the segments, extending from Sth or 9th to 14th or 
15th (?), and which is more observable in the inside. And in the 11th seg- 
ment, at this time, an elevation and porosity of the skin is set up around 
the inner pair of sete, which, in some cases, are themselves altered in shape 
from the rest, and when pulled out they draw out with them a long 
stringy appendage, not apparently of cetera descent. 
