CHAPTER VIII 
EELWORM GALLS (NEMATODA) 
T HE eelworms are comprised in the family Anguillulidae, 
belonging to the order Nematoda, or threadworms. 
It would promote the happiness of the human race if these 
creatures were non-existent, for amongst them are some of 
the most dreaded of human parasites. Those with which 
we are concerned live a parasitic life in plants, causing 
remarkable nodosities and tumours. 
Eelworms are very minute, and cannot be seen well with¬ 
out the aid of a microscope, the adult in many cases being 
only i mm. long. The shape is that of an eel. The mouth 
has a sharply pointed spine, which is used for boring into 
plants. The ova are hatched within the body of the female; 
with growth they distend the skin until it becomes a mere 
sac. Eventually the parent dies, and the young are liber¬ 
ated by the rupture of the sac. They attain maturity, on 
an average, in thirty days. In the case of Tylenchus devasta- 
trix, the larvae bore into the rootlets and become stationary. 
The adult female emerges from the plant, and is joined 
by the larger male, which bores its way out later. After 
fertilization the female degenerates, and at last is nothing 
more than a broad pouch containing ova and larvae; the 
majority of the ova hatch out within the body of the parent. 
There are six or seven generations in one year. 
There are ten species of eelworms in this country, belong¬ 
ing to three genera: 
Aphelenchus fragariae Ritz. Bos, on cultivated Straw¬ 
berries. 
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