446 PARASITES OF ANIMALS 



tables which the grass plot of the menagerie afforded, recovered 

 the others in a very short time/' 



Fourthly. The plan I employed in my experiment. This is 

 only desirable in advanced cases, where suffocation is impend- 

 ing. It will afford instant relief, as the trachea may be cleared 

 of all parasitic obstructions. 



Lastly. The essential point to be observed is the total de- 

 struction of the worms. This will help to put a stop to future 

 epizootics. If the parasites are merely killed and thrown 

 away carelessly, the eggs will sustain no injury. Decomposi- 

 tion having set in, the young embryos will sooner or later 

 escape their shells, migrate in the soil or elsewhere, and ulti- 

 mately find their way into the air-passages of birds in the same 

 manner as their parents did before them. 



In this place I must not omit to mention the remarkable cir- 

 cumstance, quoted in my pamphlet on the grouse disease, that 

 Prof. Wyman, of Boston, found Eustrongyli surrounding the 

 cerebellum in seventeen out of nineteen snake-birds or water- 

 turkeys that had been shot in Florida. These viviparous 

 nematodes apparently occasion their avian bearers no inconveni- 

 ence. No doubt, as Wyman observes, their presence must be 

 regarded as a normal state of things : but should they occur in 

 excessive numbers, then we can hardly doubt the result. 



As regards acanthocephalous parasites, although not so nume- 

 rous as the nematodes, it is extremely probable that they 

 play a similar role. Parasites which prove fatal to swine are 

 scarcely likely to be harmless in birds. On the 18th of 

 February, 1875, I received from Sir Joseph Hooker eleven 

 worms for identification. Mr Charles P. Hooker, his son, 

 subsequently informed me by letter that he had found them in 

 a Redwing (Turdus iliacus) which he dissected in January, 1875. 

 The worms (Echinorhynchus transversus) occupied the large 

 intestine, probably to the number of one hundred in all. 

 Hitherto this parasite has been found abundantly in the black- 

 bird, thrush, and in most of the Turdida ; but not in the red- 

 wing. It has also been obtained from the starling and red- 

 breast. The presence of so many of these armed parasites in 

 one small host could hardly fail to inflict severe injury on the 

 bearer. 



In concluding this section of my work I can only find space 

 to make a few acknowledgments. Most of the rare, new, or 

 interesting avian entozoa which I have examined and described 



