490 HANDT-BOOK OF HUSBANDRY. 



" Influenced by these latter considerations, and by the strong 

 " counter-testimony of such really able veterinarians as Messrs. 

 " Clark and Youatt, and the silence on the subject of Mr. 

 " Spooner and some other modern writers, I was formerly led 

 " to doubt whether the larvae of the CEstrus ovis ever did 

 " more in the sheep's head than effect a degree of temporary 

 " irritation of the lining membranes, which might produce serious 

 " inconvenience when acting in concert with the inflammation 

 " already established by catarrhal or other cerebral affections, but 

 " which never caused death. Again reminding the reader that I 

 " speak from a very limited personal knowledge of the disease, I 

 " feel it due to frankness to say that my opinions have undergone 

 " some change. The testimony of intelligent men has satisfied 

 " me that the irritation and ultimate inflammation of the mucous 

 *' lining of the head, produced by the tentacula of the worm and 

 " by its constant feeding on the secretions, if not even on the 

 " substance of the membrane itself, in certain stages of the dis- 

 "ease, are sufficient in some cases to cause death. I should not 

 " expect a sheep in high condition and apparent health to die sud- 

 " denly from this cause without previous symptoms of disease, and 

 " under circumstances resembling those of apoplexy. I should 

 *' not expect the powerful nervous disturbances of epilepsy. But 

 " if the sheep began to fall off rapidly in condition a little before 

 " the opening of spring, without any other traceable cause — if it 

 " wandered round with irregular movements, twisting about its 

 " head occasionally as if it was suffering pain — and especially if 

 " the mucus discharged from the nose was tinged with blood — I 

 *' should suspect 'grub-in-the-head,' and administer remedies or 

 " antidotes on that hypothesis. And, after the death of patients, 

 " I should, as carefully as practicable, examine not only the 

 " sinuses of the head, but also the entire nasal cavities, to ascer- 

 " tain whether there were any traces of the supposed destructive 

 " action of the larvae. 



" S9me farmers protect their sheep measurably from the attacks 

 " of the (Estrus ovis^ by plowing a furrow or two in different por- 

 " tions of their pastures. The sheep thrust their noses into this 



