Ld 
No. 419.] NOTES AND LITERATURE. 939 
the various classes of pigment granules, resulting in a selection of 
the more favored kind. In consequence of this a harmony of color 
would prevail, first locally and finally throughout the organism. 
P 
Excretion in Annelids. — The elimination of waste products from 
the bodies of annelids, particularly earthworms, has been fully studied 
by Willem and Minne.! In Lumbricus reserve products in the form 
of fat and of glycogen occur, the former in the ciliated cells of the 
intestinal epithelium, the latter in the peritoneal cells. True waste 
products are found in the same animal as guanine in the chloragogic 
cells and nephridial tubules, as uric acid in the peritoneal cells and 
similar elements found between the fibres of the body musculature, 
and as cholesterine probably in all tissues. The chloragogic cells 
produce guanine with more or less regularity. This is periodically 
discharged from these cells into the coclomic fluid, where in common 
with other particles it is engulfed by the free coelomic cells. The 
cclomic cells when charged with the products of excretion make 
their way through the intestinal epithelium and are finally discharged 
into the digestive cavity The nephridial walls excrete soluble mate- 
rials exclusively. Only a small amount of coelomic fluid passes 
through the nephridial canal. This fluid is kept in motion by the 
cilia of the canal and the waste products are thus discharged. 
Similar studies were made on Nereis, Nephelis, and Clepsine, and 
the following general conclusion drawn. In all the annelids studied 
the cells that line those parts of the caelom particularly connected 
with the circulatory system are of service in purifying the blood. 
They accumulate in their protoplasm various excretory products, in 
some annelids one, in others another. Thus far the following sub- 
Stances have been identified : uric acid, guanine, sodic urate, and a 
substance like chitine. Many annelids show a tendency toward the 
obliteration of the nephrostomes, and this is accompanied by * change 
in the way in which the solid excreta are discharged. Cast out 
freely in those worms with large nephridial funnels, these products 
in worms with restricted nephridia are accumulated and disintegrated 
in the phagocytic organs and thus prepared for discharge. P. 
! Wi inne, ches sur l'Excrétion chez quelques Anné- 
Willem, V., et Minne, A. Recher iengipmgh ges 
ech 
lides, Mém. "Acad. roy. de Belgique, tome lviii (1900), 
