144 AGRICULTURAL RESEARCH AND THE FARMER : 



None of the life histories of the adult tape-worms affecting" 

 grass-eating animals are known. The Institute is now attempting: 

 to find out the life history of a tape-worm affecting horses, and 

 at the same time is studying a tape-worm of sheep, known a& 

 the lamb tape-worm, Moniezia expansa. This parasite has 

 recently been causing serious losses amongst lambs and sheep,, 

 particularly in North Wales. 



A study of the lamb tape-worm common around Aberystwyth 

 is also being made by the University College of Wales, A herystwyth^ 

 with the aid of a special grant. 



One of the best known and most dreaded flat worms is, of 

 course, the fluke worm, which causes liver rot in sheep. As 

 is well known, this worm spends a part of its life history in a 

 small water-snail, Limnea truncahila, one of a number of species 

 of somewhat similar snails which are common on wet lands 

 throughout Great Britain. The Advisory Officer in Zoology 

 attached to the University College of North Wales, Bangor, has 

 devoted much time to the study of this worm during the past 

 few 5/ears, and in particular has in^'estigated closely the life histor}?- 

 of the snail, which had hitherto not been accurately known. He 

 found, amongst other things, that the eggs of the snail can 

 apparently survive very considerable drought, hatching out in 

 the autumn when all adults have perished and the land is appar- 

 ently free from snails, or only dead snails can be seen. Thus the 

 impression amongst many farmers that land which is apparently 

 free of snails in the autumn will not produce liver rot, may not 

 be correct. Such knowledge is now proving very useful to him 

 in dealing with the outbreak of liver rot in North Wales. 

 The disease lately spread in this district to an alarming extent,, 

 and owing to the Advisory Officer's special knowledge of the 

 subject, much of his time has been taken up in dealing with 

 requests for advice from farmers who feared attack. During last 

 summer he carried out a series of spraying experiments with, 

 copper sulphate in an attempt to eradicate snails from the pasture 

 land. The results so far are very promising, and are being 

 continued. 



University of London [Helniinthology Department of the London 

 School of Tropical Medicine). 

 An important line of work which has been going on since 1919 

 and is still in progress consists in the preparation of a guide to- 

 the diagnosis of worms affecting domestic animals by means of 

 the eggs found in their faeces. As a result of the prehrninary work 

 the important fact was observed that the eggs of parasites could 

 be grouped according to the classification of the adult worms. 



