THE BIONOMICS OF ENGLISH OLIGOCH^TA 105 



in the matter of secretion. Some exude it from the entire 

 length of the body, others from the head or tail, or from special 

 segments. Nor is the appearance and smell the same in the 

 different cases. Let us examine a few of the principal. 



In the Brandling {Eisenia fcetida Sav.) we find a very profuse 

 exudation of a yellow colour and pungent odour from almost 

 the entire length of the body. To some the smell resembles 

 garlic, to others the liquor from boiled cabbage. It leaves a 

 good deal of powdery matter behind when dry, but I am not 

 able to recall any memoir dealing with its chemical constituents. 

 Next to it, so far as volume of output goes, we may place 

 A. chlorotica Sav., often known as the green worm. It is very 

 sluggish as a rule, and one would suppose the secretion serves 

 to keep off enemies. It is similar in colour to the last, and 

 may be poured off from any part of the body. Eisenia rosea Sav. 

 and Eophila icterica Mich, also act in a similar way, but the fluid, 

 particularly in the case of the former (which was once known as 

 Alio, mucosa), leaves a white chalky sediment. D. submbicunda 

 has a yellowish tail, and it frequently happens that a large 

 quantity of gold-coloured secretion exudes therefrom. Then 

 from O. cyaneum and O. profugum a yellow exudation may be 

 obtained from the region of the sexual organs and from the 

 caudal segments. Thus, without giving further details, it is very 

 clear that much variety prevails, and it seems very desirable that 

 a careful study of the subject should be undertaken with a view 

 to determining the exact nature and composition of the various 

 kinds of fluid, and the exact purposes for which the fluid exists. 

 The slime seems to be almost purely lubricative, the white and 

 yellow fluids preservative. 



Helodrilus oculatus Hoffmeister. — As illustrating some of the 

 problems in bionomics which the study of the Oligochaets 

 raises, it may be well to take one particular species ; and I 

 select for the purpose H. oculatus. The name is well chosen. 

 Helodrilus means the worm found by low marshy ground (&V09) 

 on the sides of rivers, while oculatus refers to the presence 

 at certain periods of a couple of eye-spots. This is, I believe, 

 the only species of Lumbricidae in which eye-spots have been 

 discovered, and is of interest because such spots are not un- 

 known in Naididae on the one hand and Polychaeta on the other. 

 Helodrilus was first described by Hoffmeister in 1843. No 

 adult was known, and the description was therefore incomplete; 



