CONTRIBUTIONS TO THE ANATOMY OF BARTHWORMS. 457 
V. On Certain Points in the Anatomy of Pericheta, with 
Description of a New Species. 
(1) Blood-glands. 
Tue observations of Kikenthal (28) have gone some way 
towards showing that the peritoneal cells in Annelids play an 
important part in excretion. The so-called “ chloragogen 
cells” of the intestine—which were regarded by earlier writers 
as representing a liver, and were on that account termed 
hepatic cells—are not, according to Kiikenthal, an integral part 
of the intestine, but arise from the lymph; these cells attach 
themselves to the intestinal and other blood-vessels ; the cells 
are at first clear but afterwards become loaded with yellow 
brown granules; the cells in this condition give a very dis- 
tinctive appearance to the intestine in the Oligocheta. Later 
on these celis become again detached, and float freely for a 
time in the celom; finally they break down and the secreted 
granules liberated by this process are evacuated by the 
nephridia. The nephridia therefore in Annelids play to a 
certain extent a secondary part in the elimination of waste 
matter ; in this capacity they serve merely as the conduits 
through which this waste matter, drawn from the blood by the 
chloragogen cells, reaches the exterior. It would appear 
therefore that the chloragogen cells do not, as they are com- 
monly stated to do, form a layer covering the intestine, but 
their relation is to the blood-plexus or sinus which surrounds 
the intestine. The fact that these cells are generally pear- 
shaped, attached to the surface of the gut by a slender stalk 
devoid of granules, has probably given rise to the idea that 
they were unicellular secreting glands, pouring their secretion 
into the lumen of the gut. As to the connection between the 
chloragogen cells and the blood system, this was originally 
pointed out by Claparéde (15, p. 227), who remarks, ‘‘ The 
general opinion is that the pigmented cells form a hepatic 
layer on the intestines. M.d’Udekem describes them as uni- 
cellular glands of two kinds opening directly into the intes- 
