54 D. KEILIN 
bacteroid or uric acid cells and amoebocytes, similar to the 
yellow cells of the alimentary canal. 
6. SUPPLEMENTARY NOTES. 
According to Cuénot (1897) and Willem and Minne (1899) 
there are five different excretory organs im earthworms : 
(1) nephrida, (2) chloragogenous cells, which contain guanine, 
(3) cells with bacteroids or with crystals of uric acid, (4) yellow 
cells of the walls of alimentary canal, (5) amoebocytes of the 
blood. As the two latter elements are found in the pharyngeal 
bulb, we will examine them im greater detail. 
(a) Cells with bacteroids or crystals of uric acid. 
These cells are very common in earthworms, being found in 
enormous numbers on the peritoneum, the septa, between the 
muscle fibres, on the nerve ganglia, in the nephridia, &e. In 
the case of Allolobophora foetida, I found them m 
large numbers between the muscles of the pharyngeal bulb 
(cf. p. 45 of this paper). These cells, of various shapes 
and sizes, are filled with elongated crystalline bodies. In 
sections, or in stained smears, these bodies so closely resemble 
bacteria, that several authors have considered them to be such. 
Thus, according to Cuénot, Cerfontame (1890) described them 
as bacilli; he also thinks that the tubercle bacili, found in 
such numbers by Lortet and Despeignes (1892) in the bodies of 
earthworms which lived in soil mixed with the sputum of 
tuberculous patients, were also the bacteroids of these excretory 
cells, and, moreover, Cuénot believes that among the three 
kinds of commensal bacteria, found by Lim Boon Keng (1895) 
in the coelomic fluid of earthworms, there were undoubtedly 
some of the bacteroids which had become accidentally freed from 
the cells. The crystalline nature of these bacteroid bodies was 
demonstrated by Cuénot, while their chemical composition (1. e. 
that they are formed of uric acid) was proved-by Willem and 
Minne.* 
1 Tt isimportant to mention here that Willem and Minne (1899, pp. 16-19) 
have completely misunderstood Cuénot, in ascribing to him the opinion 
