VETERINARY SCIENCE AND PRACTICE. 191 



worms are capable of withstanding- freezing. I^arthworms were kept 

 in earth for some months and when finally examined embryos of the 

 nematode were found that were considerably in advance of those that 

 had been kept in moist earth. Sheep were introduced into infested 

 pastures and from time to time killed and examined. 



Summarizing the results of his experiments the author concludes 

 relative to 8. filaria as follows: 



"It appears that eggs containing living embryos and embryos which have got free 

 from the eggs are expelled from the bronchial tubes of infested sheep in enormous 

 numbers. It is also established that the adult worms have only a temporary resi- 

 lience in the lungs, but whether they are expelled living or dead has not been ascer- 

 tained with certainty; nor is it known what becomes of them when they quit the 

 lung tubes. The embryos, it has been proved, live for months in wet earth; they 

 may be dried by the heat of the sun without being destroyed; nor does the frost 

 seem to do them any serious damage. In common with the other larval forms of 

 strongyles, they are swallowed by earthworms and again ejected after having gone 

 through certain changes; but, with the evidence obtained from the examination of 

 many hundreds of earthworms, it is impossible to believe that even a considerable 

 proportion of the embryos which are expelled from the sheep's lungs are disposed of 

 in this way. It is not unlikely, however, that a large number become parasitic to 

 certain plants and in that position acquire a sufficient development to lit them for 

 residence in a warm-blooded animal. Here again, however, the evidence is utterly 

 insufficient." 



The red thread worm, Strongylus rufescens, and the hairworm, Pseu- 

 dalius o vis, are critically discussed and support given to Koch's con- 

 clusion that these two worms have often been confounded. According 

 to this view, Pseudalius represents the first stage in the life cycle of 

 8. rufescens. But the author's observations do not coincide in certain 

 details with those of Koch, and he would regard "Pseudalius as the 

 last stage of 8. rufescens rather than the lirst; in short, that having 

 finished its life work' and done as much damage to the lung structures 

 as the circumstances of its organization permit, it finally retires into 

 an isolated position in various parts of the lungs, especially on the 

 surface, coils itself up, and at length becomes a mere calcareous mass." 



The effect of the presence of the worms in the lungs is passed over 

 briefly, and then the .subject of treatment discussed. Overcrowding 

 and the continued repasturing of sheep on the same ground, exposure, 

 and insufficient feeding are to be avoided as unquestionable causes. It 

 is shown that the services of the veterinary are seldom called in until the 

 worms have taken up a position from which they can not be dislodged 

 by the ordinary remedies. 



Louping ill, P. Williams (Trans. Highland and Agr. 8oc. Scotland. 

 5. ser., '.) (1*96), pp. 278-290, figs. 10). — The author reports upon his 

 researches into the causation and prevention of louping ill or trembling 

 in sheep (Lrodic toxaemia). Sheep were muzzled and pastured with 

 others in pastures infected with ticks; pastures were sown with salt, 

 which killed the old grasses; inoculation experiments were made with 

 cultures made from diseased animals — all with the general result of 

 4513— No. 2 7 



