An Ac(W)unt of home IIelmintheh iojntauned 
IN 1)k. C. M. Wen yon’s Collection from the Sudan 
BY 
JioBEHT T. Leiper, M.B., F.Z.S. 
Helminthologist to the London School of Tropical Medicine 
The collection of parasitic worms made by Dr. Wenyon during his stay in the southern 
parts of the Sudan was handed to me in most excellently preserved condition for further 
investigation and description. The number of individual species obtained by him is con¬ 
siderable. Some of them are known to science only in briefest outline; others are new, and in 
some instances present highly novel characteristics. An account of the Nematodes and 
Trematodes alone is given in this paj)er, which deals with them from the systematic standpoint 
rather than from that of species anatomy, to which the material so admirably lends itself. 
These restrictions have been imposed by the limited time available for the examination of the 
matei’ial and the amount of helminthological literature involved in the identification of forms 
hut distantly related to one another. 
The hosts of the ten varieties of Nematoda were Mule, Bat, Guinea fowl. Snake, Toad, and 
Garmot fish. The Trematoda were of four kinds, and were obtained from Watcrhuck, Sheep 
and Marabou Stork. The Cestodes, contained in sixteen tubes, remain unexamined. 
P K E P A K A T o R Y METHODS 
The great bulk of the helminthological material from abroad usually reaches England in 
a very poor state of preservation, owing to the use, by collectors, of methods that are quite 
inapplicable to these particular parasites, however excellent they may have proved them¬ 
selves for general histological purposes. 
It mav not be out of place, therefore, to detail briefly the methods used, and the further 
treatment adopted, in the investigation of the helminthes that form the subject of this paper. 
The Nematoda and Trematoda react in such radically different ways to various fixing 
reagents that those adopted for one group are often quite unsuited to the other. 
Nematoda.^¥orma,\m, on account of its general use and handiness, is a very commonly 
used preservative. It should, however, never be used for roundworms, unless in tbe absence 
of other reagents. It over-distends, and in weak solution, badly macerates, the tissues. In 
10 per cent, solution specimens sometimes keep well, but it frequently happens that, during 
the process of fixation, the specimens coil considerably, and often part of the viscera is 
extruded by rupture of the integument during spasmodic contraction. The lack of trans¬ 
parency of formalin-preserved specimens renders the observation of details of structure and 
internal topography difficult, but the required details must be searched for in this fluid once 
the animals are fixed in it, as transference later to glycerin, no matter how gradual the 
process, leads to irretrievable shrinkage and distortion. For the same reason Kaiserling’s 
fluid should never be used. The preservation of colour in the Nematoda is of practically 
no importance. Mercurial solutions destroy the translucency and form deposits within the 
Methods of 
preservation 
