REPORT OF LIVERPOOL EXPEDITION TO NIGERIA 
Part II 
I. FILARIASIS 
Introduction 
THE Nemathelminthes, the order to which the genus Filaria belongs, have the 
following characteristics : — they are worm-like in form, but non-segmented ; 
that is, their bodies are not divided into segments, each resembling more or 
less exactly in outward appearance and internal structure the preceding and following 
segment. Many bear bristles or hooks, and exceptionally suckers. The body is 
elongated, thread-like, enclosed in a more or less thick cuticle. They have no closed 
vascular system nor special respiratory organs. They are almost all dioecious — the 
male and female reproductive organs being in different individuals. The young some- 
what resemble the adults, but have no sexual organs ; the immature stages, termed 
larvae, are often free while the adults are parasitic or vice versa, or inhabit a different 
host from the adult. Some of these Nemathelminthes spend their life within the 
bodies of their hosts, or are only parasitic during a portion ; a few have a free life in 
water or damp earth. 
The Nemathelminthes comprise three sub-orders : — 
1 . — The Nematoda 
2. — The Nematomorpha (Gordiidae) 
3. — The Acanthocephala 
The Nematoda have a complete digestive tube ; in the Nematomorpha it is 
atrophied in the adult, while in the adults of Acanthocephala it is absent altogether. 
In the sub-order Nematomorpha (Gordiidae) are two genera, Gordius and Nectonema ; 
the latter has only a single species, Nectonema agile, which is marine. The genus 
Gordius, which is entirely fresh water, has a large number of species. Worms of this 
genus pass through three stages, two larval and parasitic, the third, sexually mature, 
living in water. The first larval stage has been found in the larvae of Stalls lutaria 
Ephemera, Tanypus, Corethra, Chironomus ; the second is parasitic in the bodies of 
Carabus hortensis, Procerus (Carabus), Coriaceus, Calatbus fuscipes, Molops elatus, 
several species of Pterosticbus, and other beetles. 
According to Railliet' cases have been recorded in which the adult forms of 
some species of this genus have been evacuated after the administration of an 
anthelmintic — in some of the cases troublesome symptoms occurred. The actual 
I. Railliet, Traite de Zoologie Medicate ct Agricole. Paris, 1895. P. 563. 
