104 E. RAY LANKESTER, ON THE 
undoubtedly have the power of absorbing liquid by capillary 
attraction from the external surface, as may be demonstrated 
by immersing the caudal extremity of a worm in asolution of 
carmine and ammonia, when the capillary tubes will be found 
containing carmineif viewed under the miscroscope. Compo- 
silion.—The composition of the perivisceral fluid which is thus 
situated in the worm’s body now remains to be considered. 
Chemically, it appears to resemble dilute serum, and to have 
much the same constitution as the blood of higher animals, 
being, however, poorer, or containing a larger amount of 
water. Portions of it coagulate, and it becomes turbid when 
submitted to the action of strong spirits of wine; it has, 
moreover, a slightly saline taste, and an alkaline reaction 
with turmeric paper. When examined with the microscope 
it is seen to consist of a plasma and corpuscles, the latter 
varying in number, size and form. ‘The general form of the 
corpuscles is a flattened ene cell, containing granules 
and a nucleus, and about the +,!,,th of an inch in ‘diameter ; - 
sometimes they exhibit amoeboid movements, but generally 
are inert. A great variety of particles of other forms are to 
be found in this perivisceral fluid, particularly at the posterior 
portion of the body. Among these are young forms of the 
Monocystis Lumbrici, one of the Gregarinide,* encysted 
individuals of this species, its pseudo- navicula, parasitic 
nematodes, and their eggs (fig 6). The colourless fluid 
presents, therefore, a marked contrast to the vascular fluid 
with regard to its intimate structure; its function may be 
briefly considered when the disposition and nature of the 
vascular fluid has been described. 
Vascular, Non-corpusculated, or Coloured Fluid.—The vas- 
cular fluid of the earthworm is contained in a very extensive 
series of vessels, which have three principal trunks and 
various ramifications. The vascular system in Annelida is 
divided, by M. Milne Edwards,+ into two parts—the euta- 
neous and the visceral. In the ideal representativeyAnnelida, 
the cutaneous system is considered as being composed of two 
longitudinal lateral trunks, which communicate with one 
another by their cutaneous and terminal capillaries, and also 
(as in the higher forms of Annelida) by direct transverse 
vessels, called by M. Milne Edwards the “ inferior commis- 
sural vessels.” This forms the cutaneous system; the two 
lateral trunks may be united into one and form a single 
ventral vessel, when, of course, there are no inferior commis- 
* See the author’s paper in this Journal, April, 1863. 
t Loc. cit., vol. iii, p. 252. 
